Details of a Researcher - HATAKENAKA Masamitsu

Papers - HATAKENAKA Masamitsu

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Diagnosis of prosthetic joint infection at the hip using the standard uptake value of three-phase 99mTc-hydroxymethylene diphosphonate SPECT/CT

Naoya Yama, Satoshi Nagoya, Shintaro Sugita, Masayuki Koyama, Masamitsu Hatakenaka

Annals of Nuclear Medicine ( Springer Science and Business Media LLC ) 2022.04

DWI-related texture analysis for prostate cancer: differences in correlation with histological aggressiveness and data repeatability between peripheral and transition zones

Chie Tsuruta, Kenji Hirata, Kohsuke Kudo, Naoya Masumori, Masamitsu Hatakenaka

European Radiology Experimental ( Springer Science and Business Media LLC ) 6 ( 1 ) 2022.03

Abnormal [18F]fluorodeoxyglucose accumulation to tori tubarius in IgG4-related disease

Ken Nagahata, Masatoshi Kanda, Ryuta Kamekura, Masanari Sugawara, Naoya Yama, Chisako Suzuki, Kenichi Takano, Masamitsu Hatakenaka, Hiroki Takahashi

Annals of Nuclear Medicine ( Springer Science and Business Media LLC ) 36 ( 2 ) 200 - 207 2022.02 [Domestic journal]

OBJECTIVES: Tubarial glands (TGs) are recently refocused gland tissues localized near the tori tubarius in the nasopharynx and their clinical relevance is not clear yet. IgG4-related disease (IgG4-RD) is a progressive fibrosing condition and salivary glands are well-affected lesions. The aim of the present study is to examine [18F]fluorodeoxyglucose ([18F]FDG) accumulation to the tori tubarius in IgG4-related disease (IgG4-RD). METHODS: 48 patients with IgG4-RD who underwent positron emission tomography (PET) scanning with [18F]FDG were included and semi-quantitative analysis of [18F]FDG accumulation to tori tubarius was performed along with the clinical features and histopathological analysis. RESULTS: Of the 48 patients, abnormal [18F]FDG accumulation (metabolic tumour volume ≥ 1) to tori tubarius was observed in 15 (31.3%), all of whom had lesions in other head and neck glands. IgG4-RD patients with abnormal [18F]FDG accumulation to tori tubarius showed swollen nasopharyngeal walls around tori tubarius and forceps biopsy of the lesion revealed acinar cells and IgG4-positive plasma cells histologically. Abnormal [18F]FDG accumulation (maximum standard uptake value, metabolic tumour volume and total lesion glycolysis) to tori tubarius correlated with higher IgG4 and lower IgA serum concentrations. CONCLUSIONS: Abnormal [18F]FDG accumulation to tori tubarius can be observed in patients with IgG4-RD and the abnormal [18F]FDG accumulation to tori tubarius can be a clue of TG involvement in IgG4-RD.

MRI-detected extramural vascular invasion potentiates the risk for pathological metastasis to the lateral lymph nodes in rectal cancer.

Atsushi Hamabe, Masayuki Ishii, Koichi Onodera, Kenji Okita, Toshihiko Nishidate, Koichi Okuya, Emi Akizuki, Ryo Miura, Takahiro Korai, Masamitsu Hatakenaka, Ichiro Takemasa

Surgery today 2021.03 [Domestic journal]

PURPOSE: Multidisciplinary treatment for locally advanced rectal cancer requires an accurate assessment of the risk of metastasis to the lateral lymph nodes (LNs). We herein aimed to stratify the risk of pathological metastasis to lateral LNs based on the preoperatively detected malignant features. METHODS: All patients with rectal cancer who underwent surgery from January 2016 to July 2020 were identified. We recorded the TNM factors; perirectal and lateral LN sizes; and MRI findings, including mesorectal fascia involvement, extramural vascular invasion (EMVI), tumor site, and tumor distance from the anal verge. RESULTS: 101 patients underwent rectal resection with lateral lymph node dissection, of whom 16 (15.8%) exhibited pathological metastases to the lateral LNs. Univariate analyses demonstrated that lateral LN metastasis was significantly correlated with mrEMVI positivity (p = 0.0023) and a baseline lateral LN short-axis length of ≥ 5 mm (p < 0.0001). These significant associations were confirmed by a multivariate analysis (p = 0.0254 and 0.0027, respectively). The lateral LN metastasis rate was as high as 44% in cases bearing both risk factors, compared to 0% in cases lacking both risk factors. CONCLUSION: The results elucidated in this study may contribute to risk stratification, which can be used when determining the indications for lateral lymph node dissection.

CT reconstruction with thick slices not only underestimates lymph node size but also reduces data reproducibility in colorectal cancer.

Yurina Onuma, Chie Tsuruta, Kenji Okita, Atsushi Hamabe, Keishi Ogura, Ichiro Takemasa, Masamitsu Hatakenaka

Acta radiologica (Stockholm, Sweden : 1987) 284185120968569 - 284185120968569 2020.10 [International journal]

BACKGROUND: Reliable size measurement of lymph node (LN) metastases is important for the evaluation of cancer treatment. However, image analyses without proper settings may result in inappropriate diagnoses and staging. PURPOSE: To investigate whether reconstruction slice thickness in computed tomography (CT) affects measurements of LN size and reproducibility. MATERIAL AND METHODS: We analyzed 48 patients with histological diagnoses of sigmoid colon and rectal cancer who underwent contrast-enhanced CT colonography as part of a surgical treatment preparation. A board-certified radiologist selected 106 LNs whose short-axis diameter was ≥5 mm on 1-mm-thick images; the short-axis diameters were measured on 1- and 5-mm-thick images by the radiologist and residents and compared using Wilcoxon matched-pairs signed rank test. Data variation and reproducibility were evaluated using the F test and Bland-Altman analysis. P<0.05 was considered significant. RESULTS: Short-axis diameters measured on 5-mm-thick images were significantly lower than those measured on 1-mm-thick images (P<0.01), even in the LNs whose short-axis diameters were over twice the slice thickness (P<0.05). Of the 106 LNs, 57 showed short-axis diameter <5 mm on 5-mm-thick images; the maximum short-axis diameter was 6.7 mm on a 1-mm thick image. Data variation was significantly larger on 5-mm thick images than 1-mm-thick images in small LNs (P<0.05) and reproducibility on 5-mm-thick images was inferior to that on 1-mm-thick images. CONCLUSION: Thick reconstruction slices in CT can result in an underestimation of LN size and reduce data reproducibility. When measuring LN size, a thin reconstruction slice would be recommended based on targeted LN size.

Lateral Position With Gantry Tilt Further Improves Computed Tomography Image Quality Reconstructed Using Single-Energy Metal Artifact Reduction Algorithm in the Oral Cavity

Maki Onodera, Kazunori Aratani, Takaharu Shonai, Keishi Ogura, Ken-ichi Kamo, Kazuhiro Ogi, Atsushi Kondo, Masamitsu Hatakenaka

Journal of Computer Assisted Tomography ( Ovid Technologies (Wolters Kluwer Health) ) 44 ( 4 ) 553 - 558 2020.07

Spatial resolution of CT

Masamitsu Hatakenaka

European Journal of Surgical Oncology ( Elsevier BV ) 45 ( 9 ) 1748 - 1748 2019.09

Optimizing T1rho and T2 Values for Intervertebral Discs Obtained from the Combined T1rho and T2 Sequence

Imamura Rui, Takashima Hiroyuki, Nakanishi Mitsuhiro, Akatsuka Yoshihiro, Nagahama Hiroshi, Okuaki Tomoyuki, Yoneyama Masami, Hatakenaka Masamitsu

APPLIED MAGNETIC RESONANCE ( SPRINGER WIEN ) 50 ( 8 ) 959 - 966 2019.08 [Refereed]

To investigate the effect of the number of spin-lock (SL) and T2 preparation pulse using T1rho and T2 values obtained from the combined T1rho and T2 sequence. We included 30 patients who underwent magnetic resonance imagingof the lumbar spine because of low back pain and leg numbness, tingling, and pain. We used 3D turbo-field echo and the adiabatic pulse as SL pulse for T1rho mapping and the block pulse as T2 preparation pulse for T2 mapping of the combined T1rho and T2 sequence. The preparation time of T1rho and T2 was set at 0, 20, 40, 60, and 80ms. We defined the T1rho and T2 values calculated from all SL and T2 preparation pulses as Dfull and decreased several number of SL and T2 preparation pulses from Dfull as other groups (D1, D2, and D3). We used the Bland-Altman analyses to estimate the systematic and proportional bias between Dfull and other groups. The 95% CI of the mean difference included zero in all groups. Therefore, systematic bias was not detected. The regression coefficients with D3 of the T1rho and T2 value were -0.34 and -0.23, respectively (p<0.01). We detected the proportional bias in the T1rho and T2 values in only D3 (0 and 80ms). An investigation of the T1rho and T2 values of IVDs using the combined T1rho and T2 sequence suggested that the accuracy of these values decreased with suitably adjusted three preparation pulses, facilitating the assessment of both T1rho and T2 values at approximately 10min.

Optimization of MR Signal Contrast of the Lumbar Cartilaginous Endplates Using Ultra-Short TE

Hiroyuki Takashima, Mika Yanagida, Rui Imamura, Mitsunori Yoshimoto, Izaya Ogon, Mitsuhiro Nakanishi, Yoshihiro Akatsuka, Tomoyuki Okuaki, Masami Yoneyama, Masamitsu Hatakenaka, Toshihiko Yamashita

APPLIED MAGNETIC RESONANCE ( SPRINGER WIEN ) 50 ( 1-3 ) 381 - 389 2019.03

The ultra-short TE (UTE) technique has been recently used to investigate lumbar cartilaginous endplates (CEPs). However, parameters of UTE have not been investigated, especially optimal second TE is unclear. The aim of this study was to investigate the use of an optimal second TE with UTE for visualizing CEPs. The subjects included 20 volunteers without LBP who did not undergo lumbar spine surgery. A UTE sequence with fat suppression was used, and TEs were set at 0.16ms as first TE, and 4.6, 9.2, 13.8, 18.2ms as second TE. Analyzed images subtracted each second TE image from first TE image. Two researchers measured contrast ratio (CR) between CEPs and vertebral bodies (VBs), intervertebral discs (IVDs). ICCs between two researchers were calculated for CRs (r=0.924, 0.939). CR between CEP and VB of 13.8 and 18.4ms was significantly higher than that of other TEs (p<0.01). CR between CEP and IVD of 9.2 and 13.8ms was significantly higher than that of other TEs (p<0.01, 0.05). CEPs were evaluated using subtraction images obtained with UTE. The first TE was 0.16ms, the optimal second TE was suggested to be 13.8ms for evaluating human CEPs.

Clinical utility of 18F-fluorodeoxyglucose/positron emission tomography in diagnosis of immunoglobulin G4–related sclerosing sialadenitis

Kenichi Takano, Ryoto Yajima, Ryuta Kamekura, Motohisa Yamamoto, Hiroki Takahashi, Naoya Yama, Masamitsu Hatakenaka, Tetsuo Himi

Laryngoscope ( John Wiley and Sons Inc. ) 128 ( 5 ) 1120 - 1125 2018.05 [Refereed]

Objectives/Hypothesis: The aim of this study was to evaluate the utility of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for accurately diagnosing immunoglobulin G4-related sclerosing sialadenitis (IgG4-SS). Study Design: Retrospective cohort study. Methods: We reviewed the records of 64 patients with IgG4-SS (35 male and 29 female patients) and 10 patients with clinically suspected IgG4-SS. Pathological diagnoses of patients clinically suspected with IgG4-SS included four cases of malignant lymphoma, one case of multicentric Castleman disease, one case of Sjögren's syndrome, and four cases of sialadenitis. All patients underwent submandibular gland (SMG) biopsies and baseline FDG-PET/CT evaluation. Clinical, serological, pathological, and PET/CT findings were analyzed. We also investigated maximum standardized uptake values (SUVmax) in the salivary glands of 15 patients with malignant disease of the salivary glands during the same period. Results: Increased FDG uptake in the SMG and parotid gland was found in 63 (98%) and 23 (35%) patients with IgG4-SS, respectively. FDG uptake of the bilateral SMG and unilateral SMG was recorded in 57 patients (89%) and six patients (9%), respectively. Mean SUVmax in patients with malignant disease of the salivary glands was significantly higher than that in patients with IgG4-SS (P =.035). We defined a positive test for IgG4-SS diagnosis as high SMG FDG uptake and serum IgG4 level ≥135 mg/dL, resulting in a sensitivity, specificity, and accuracy of 96.9%, 90.0%, and 86.4%, respectively. Conclusions: FDG-PET/CT findings in combination with serological and clinical findings may have the capacity to diagnose IgG4-SS and lead to less-invasive biopsy procedures. Level of Evidence: 4. Laryngoscope, 128:1120–1125, 2018.

Repeatability analysis of ADC histogram metrics of the uterus.

Onodera K, Hatakenaka M, Yama N, Onodera M, Saito T, Kwee TC, Takahara T

Acta Radiol. 2018.01 [Refereed]

Three cases of implantation of a SureScan(A (R)) system and MRI for investigating causes of pain

Kazunobu Takahashi, Atsushi Sawada, Soshi Iwasaki, Naoya Yama, Hiroyuki Takashima, Maki Onodera, Masamitsu Hatakenaka, Michiaki Yamakage

JOURNAL OF ANESTHESIA ( SPRINGER JAPAN KK ) 31 ( 6 ) 915 - 917 2017.12 [Refereed]

Improvement in automated quantitation of myocardial perfusion abnormality by using iterative reconstruction image in combination with resolution recovery, attenuation and scatter corrections for the detection of coronary artery disease

Taiki Chono, Masahisa Onoguchi, Takayuki Shibutani, Akiyoshi Hashimoto, Tomoaki Nakata, Naoya Yama, Kazufumi Tsuchihashi, Masamitsu Hatakenaka

ANNALS OF NUCLEAR MEDICINE ( SPRINGER ) 31 ( 2 ) 181 - 189 2017.02 [Refereed]

An iterative reconstruction method in combination with resolution recovery, attenuation and scatter corrections (IR-RASC) can improve image quality. It, however, is undetermined whether this technique can improve the detection of coronary artery disease (CAD) when automated quantitative analysis is used. This study evaluated diagnostic values of IR-RASC in combination with automated quantitative analysis in stress myocardial perfusion imaging (MPI) in the CAD detection. This study enrolled consecutive 64 patients (mean age 66.2 +/- 17.3 years, 39 males) who had undergone both Tc-99m-labeled tetrofosmin stress MPI and coronary angiography within 3 months. Stress MPI abnormalities quantified as summed stress score (SSS), summed rest score (SRS) and summed difference score (SDS) by Heart Risk View-S (HRV-S) and Quantitative Perfusion SPECT (QPS) softwares using IR-RASC images were compared with those by using conventional filtered back-projection method (FBP) images and angiographic findings. Based on expert visual assessment, SSS and SRS by HRV-S/QPS softwares with IR-RASC were significantly lower than those by HRV-S/QPS softwares with FBP at mid- and basal left ventricular segments. Receiver-operating characteristics analysis showed that areas under the curve assessed by HRV-S (0.687) and QPS (0.678) with IR-RASC were nearly identical to those (0.717-0.724) by expert assessment with FBP, and were significantly (P < 0.05) greater than those by HRV-S (0.505) and QPS (0.522) with FBP. When HRV-S was used, the specificity and diagnostic accuracy of IR-RASC in the CAD detection were significantly greater than those of FBP: 90.3 versus 51.6%, P < 0.0001 and 79.7 versus 54.7%, P = 0.0027, respectively. Likewise, when QPS was used, the specificity and diagnostic accuracy of IR-RASC in the CAD detection were significantly greater than those of FBP: 80.6 versus 41.9%, P < 0.0001, and 78.1 versus 51.6%, P = 0.0018, respectively. There, however, were no significant differences in sensitivity between IR-RASC and FBP images. IR-RASC can improve diagnostic accuracy of the CAD detection using an automated scoring system compared to FBP, by reducing false positivity due to artefactual appearance.

Influence of the Different Primary Cancers and Different Types of Bone Metastasis on the Lesion-based Artificial Neural Network Value Calculated by a Computer-aided Diagnostic System, BONENAVI, on Bone Scintigraphy Images.

Isoda T, BaBa S, Maruoka Y, Kitamura Y, Tahara K, Sasaki M, Hatakenaka M, Honda H

Asia Ocean J Nucl Med Biol. 5 ( 1 ) 49 - 55 2017 [Refereed]

Balanced MR cholangiopancreatography with motion-sensitised driven-equilibrium (MSDE) preparation: feasibility of Gd-EOB-DTPA-enhanced biliary examination

T. Nakayama, T. Yoshiura, A. Nishie, Y. Asayama, K. Ishigami, D. Kakihara, Y. Takayama, M. Hatakenaka, M. Obara, H. Honda

CLINICAL RADIOLOGY ( W B SAUNDERS CO LTD ) 71 ( 12 ) 1284 - 1288 2016.12 [Refereed]

AIM: To evaluate the effectiveness of motion-sensitised driven-equilibrium (MSDE)-prepared balanced magnetic resonance cholangiopancreatography (MRCP) in a gadolinium ethoxybenzyl diethylene triamine pentaacetic acid (Gd-EOB-DTPA)-enhanced study compared to conventional T2-weighted MRCP. MATERIALS AND METHODS: Fifteen patients (seven male and eight female patients) prospectively underwent conventional three-dimensional turbo spin-echo T2-weighted MRCP and MSDE-balanced MRCP using a 1.5 T MRI system after hepatobiliary phase image acquisition. For quantitative evaluation, the contrast-to-noise ratio (CNR) of the common hepatic duct to liver tissue was calculated. For qualitative analysis, two radiologists evaluated the depiction of the biliary system and main pancreatic duct (MPD) using a scoring system. Signal suppression of the portal vein (PV) and hepatic vein (HV) on MSDE-balanced MRCP was also scored. RESULTS: MSDE-balanced MRCP showed significantly higher CNR than T2-weighted MRCP. For all biliary structures, the mean depiction scores of MSDE-balanced MRCP were significantly higher than those of T2-weighted MRCP, whereas the mean depiction score of MPD with MSDE-balanced MRCP was significantly lower than that of T2-weighted MRCP. Signal suppression of the PV and HV was thought to be clinically sufficient. CONCLUSIONS: MSDE-balanced MRCP more clearly depicted biliary structures compared with T2-weighted MRCP in a Gd-EOB-DTPA-enhanced study. This sequence may be utilised for routine MRCP on Gd-EOB-DTPA-enhanced MRI. (C) 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

The signal intensity ratio of the optic nerve to ipsilateral frontal white matter is of value in the diagnosis of acute optic neuritis

Maki Onodera, Naoya Yama, Masato Hashimoto, Takaharu Shonai, Kazunori Aratani, Hiroyuki Takashima, Ken-ichi Kamo, Hiroshi Nagahama, Hiroshi Ohguro, Masamitsu Hatakenaka

EUROPEAN RADIOLOGY ( SPRINGER ) 26 ( 8 ) 2640 - 2645 2016.08 [Refereed]

To evaluate the usefulness of the signal intensity ratio (SIR) of the optic nerve to the white matter (WM) on short tau inversion recovery (STIR) images to diagnose acute optic neuritis (AON). The 405 consecutive patients with suspected orbital diseases underwent orbital magnetic resonance imaging (MRI) using a 3-T scanner between June 2008 and August 2011. Among them, 108 optic nerves (33 AON and 75 control) were retrospectively analysed. The averaged SIR (SIRave) and maximum SIR (SIRmax) were defined as the averaged signal intensity (SI) of the optic nerve divided by that of WM, and the maximum SI of the optic nerve divided by averaged SI of WM, respectively. These values were compared between AON and control using the Mann-Whitney U test. A P < 0.05 was considered statistically significant. SIRave and SIRmax were significantly (P < 0.001) higher in the AON compared to the control. At a cut-off SIRave value of 1.119, the sensitivity, specificity and accuracy were 0.939, 0.840, and 0.870; and at a cut-off SIRmax value of 1.281, these were 1.000, 0.720 and 0.806, respectively. The SIR of the optic nerve to WM on STIR images is of value in diagnosing AON. aEuro cent We propose a method of diagnosing acute optic neuritis using 3-T MRI. aEuro cent Our method is simple and objective and requires no novel imaging techniques. aEuro cent Our method shows high diagnostic accuracy.

Trials of vaccines for pancreatic ductal adenocarcinoma: Is there any hope of an improved prognosis?

Toru Mizuguchi, Toshihiko Torigoe, Fukino Satomi, Hiroaki Shima, Goro Kutomi, Shigenori Ota, Masayuki Ishii, Hiroshi Hayashi, Sumiyo Asakura, Yoshihiko Hirohashi, Makoto Meguro, Yasutoshi Kimura, Toshihiko Nishidate, Kenji Okita, Masaho Ishino, Atsushi Miyamoto, Masamitsu Hatakenaka, Noriyuki Sato, Koichi Hirata

SURGERY TODAY ( SPRINGER ) 46 ( 2 ) 139 - 148 2016.02 [Refereed]

Pancreatic tumors are chemoresistant and malignant, and there are very few therapeutic options for pancreatic cancer, as the disease is normally diagnosed at an advanced stage. Although attempts have been made to develop vaccine therapies for pancreatic cancer for a couple of decades, none of the resultant protocols or regimens have succeeded in improving the clinical outcomes of patients. We herein review vaccines tested within the past few years, including peptide, biological and multiple vaccines, and describe the three sets of criteria used to evaluate the therapeutic activity of vaccines in solid tumors.

Risk of node metastasis of sentinel lymph nodes detected in level II/III of the axilla by single-photon emission computed tomography/computed tomography

Hiroaki Shima, Goro Kutomi, Fukino Satomi, Hideki Maeda, Tomoko Takamaru, Hidekazu Kameshima, Tosei Omura, Mitsuru Mori, Masamitsu Hatakenaka, Tadashi Hasegawa, Koichi Hirata

EXPERIMENTAL AND THERAPEUTIC MEDICINE ( SPANDIDOS PUBL LTD ) 8 ( 5 ) 1447 - 1452 2014.11 [Refereed]

In breast cancer, single-photon emission computed tomography/computed tomography (SPECT/CT) shows the exact anatomical location of sentinel nodes (SN). SPECT/CT mainly exposes axilla and partly exposes atypical sites of extra-axillary lymphatic drainage. The mechanism of how the atypical hot nodes are involved in lymphatic metastasis was retrospectively investigated in the present study, particularly at the level II/III region. SPECT/CT was performed in 92 clinical stage 0-IIA breast cancer patients. Sentinel lymph nodes are depicted as hot nodes in SPECT/CT: Patients were divided into two groups: With or without hot node in level II/III on SPEC/CT. The existence of metastasis in level II/III was investigated and the risk factors were identified. A total of 12 patients were sentinel lymph node biopsy metastasis positive and axillary lymph node dissection (ALND) was performed. These patients were divided into two groups: With and without SN in level and nodes in level II/III were pathologically proven. In 11 of the 92 patients, hot nodes were detected in level There was a significant difference in node metastasis depending on whether there were hot nodes in level II/III (P=0.0319). Multivariate analysis indicated that the hot nodes in level II/III and lymphatic invasion were independent factors associated with node metastasis. There were 12 SN-positive patients followed by ALND. In four of the 12 patients, hot nodes were observed in level Two of the four patients with hot nodes depicted by SPECT/CT and metastatic nodes were pathologically evident in the same lesion. Therefore, the present study indicated that the hot node in level II/III as depicted by SPECT/CT may be a risk of SN metastasis, including deeper nodes.

Many Methods of Mediastinal Division

Satoru Yoshida, Masamitsu Hatakenaka

RADIOLOGY ( RADIOLOGICAL SOC NORTH AMERICA ) 272 ( 1 ) 302 - 303 2014.07 [Refereed]

Quantitative Analysis of 1.5-T Whole-Heart Coronary MR Angiograms Obtained with 32-Channel Cardiac Coils: A Comparison with Conventional Quantitative Coronary Angiography

Masato Yonezawa, Motonori Nagata, Kakuya Kitagawa, Shingo Kato, Yeonyee Yoon, Hiroshi Nakajima, Shiro Nakamori, Hajime Sakuma, Masamitsu Hatakenaka, Hiroshi Honda

RADIOLOGY ( RADIOLOGICAL SOC NORTH AMERICA ) 271 ( 2 ) 356 - 364 2014.05 [Refereed]

Purpose: To develop a method to determine significant stenosis at whole-heart coronary magnetic resonance (MR) angiography and to evaluate the accuracy and reproducibility of this approach.Materials and Methods: The institutional review board approved the study, and all participants provided written informed consent. Sixty-two patients who were suspected of having coronary artery disease (CAD) and were scheduled for conventional coronary angiography were included. Coronary MR angiography was performed by using a 1.5-T imager with 32-channel coils. Luminal narrowing was evaluated with quantitative analysis (QA) of coronary MR angiograms on the basis of the signal intensity profile along the vessel. Percentage stenosis with QA of coronary MR angiograms was calculated as [1 - (SImin/SIref)] Chi 100, where SImin is minimal signal intensity and SIref is corresponding reference signal intensity. Diagnostic performance of QA of coronary MR angiograms for predicting at least a 50% reduction in diameter was evaluated by using quantitative coronary angiography (QCA), with conventional angiography findings serving as the reference standard. Receiver operating characteristic (ROC) analysis, Spearman rank correlation, Bland-Altman analysis, and Cohen k analysis were used.Results: The areas under the ROC curve in a segment-based analysis for detecting significant CAD were 0.96 (95% confidence interval [CI]: 0.94, 0.98) with QA of coronary MR angiograms and 0.93 (95% CI: 0.88, 0.98) with visual assessment. The correlation coefficients between percentage stenosis with QA of coronary MR angiograms and percentage stenosis with QCA were 0.84 (P < .001), 0.80 (P < .001), and 0.66 (P < .001) in the patient-, vessel-, and segment-based analyses, respectively.Conclusion: QA of coronary MR angiograms with use of a signal intensity profile along the vessel permits detection of CAD. This method had a diagnostic performance approximately equal to that of visual analysis of coronary MR angiograms with high inter-and intraobserver reliability, allowing for more objective interpretation of coronary MR angiography findings. (C) RSNA, 2013

Apparent diffusion coefficient is a prognostic factor of head and neck squamous cell carcinoma treated with radiotherapy

Masamitsu Hatakenaka, Katsumasa Nakamura, Hidetake Yabuuchi, Yoshiyuki Shioyama, Yoshio Matsuo, Takeshi Kamitani, Masato Yonezawa, Takashi Yoshiura, Torahiko Nakashima, Mitsuru Mori, Hiroshi Honda

JAPANESE JOURNAL OF RADIOLOGY ( SPRINGER ) 32 ( 2 ) 80 - 89 2014.02 [Refereed]

To evaluate the correlation between apparent diffusion coefficient (ADC) and prognosis in head and neck squamous cell carcinoma (HNSCC) treated with radiotherapy. We retrospectively studied 41 patients (38 male and 3 female, ages 37-85 years) diagnosed with HNSCC (14 oropharynx, 22 hypopharynx, 4 larynx, 1 oral cavity) and treated with radiotherapy, with radiation dose to gross tumor volume over 60 Gy. The association between age, gender, performance status, tumor location, T stage, N stage, stage, dose, overall treatment time, treatment method, adjuvant therapy, or ADC and prognosis was analyzed using a Cox proportional hazard test. ADC calculated with b-values of 300, 500, 750, and 1,000 s/mm(2) (ADC 300-1,000) alone showed a significant correlation with all of the analyses (p = 0.022 for local control, p = 0.0109 for regional control, p = 0.0041 for disease-free survival, and p = 0.0014 for overall survival). ADC calculated with b-values of 0, 100, and 200 s/mm(2) (ADC 0-200) showed a significant correlation with overall survival (p = 0.0012). N stage showed a significant correlation with regional control (p = 0.0241). Performance status showed significant association with local control (p = 0.0459), disease-free survival (p = 0.023), and overall survival (p = 0.0151), respectively. ADC is an independent predictor of prognosis in HNSCC treated with radiotherapy.

PARP阻害剤オラパリブの放射線増感効果のメカニズム

染谷正則, 三浦勝利, 坂田耕一, 中田健生, 堀正和, 畠中正光

Japanese Journal of Radiology ( (公社)日本医学放射線学会 ) 32 ( Suppl. ) 5 - 5 2014.02

Feasibility of low-radiation-dose CT for abdominal examinations with hybrid iterative reconstruction algorithm: Low-contrast phantom study

Masatoshi Kondo, Masamitsu Hatakenaka, Ko Higuchi, Taisuke Fujioka, Takashi Shirasaka, Yasuhiko Nakamura, Katsumasa Nakamura, Takashi Yoshiura, Hiroshi Honda

Radiological Physics and Technology ( 2 ) 6 ( 2 ) 287 - 292 2013.07 [Refereed]

Our purpose in this study was to evaluate the image quality of low-radiation-dose CT using hybrid iterative reconstruction (HIR), and to compare the results with those of filtered back projection (FBP) at routine doses. We measured the mean values and standard deviation of the CT numbers within and outside a 15-mm low-contrast object cylinder at 1.0 % contrast level. The noise reduction levels of the HIR were 1 (weak) to 7 (strong). Visual inspection of the low-contrast detectability was done by six radiologic technologists. The low-contrast detectability of the cylinder at the 1.0 % contrast level with HIR at all mAs levels was equal to that obtained with FBP, and thus the use of HIR did not result in any improvement of low-contrast detectability. © 2013 Japanese Society of Radiological Technology and Japan Society of Medical Physics.

[Optimized magnetic resonance sequences and parameters with operative assisted images for radical prostatectomy at 3 tesla-magnetic resonance image].

Shirase R, Sakurai Y, Nagahama H, Harada K, Takashima H, Nakanishi M, Harada K, Shishido H, Imamura R, Sakata M, Hatakenaka M

Nihon Hoshasen Gijutsu Gakkai zasshi ( 5 ) 69 ( 5 ) 529 - 534 2013.05 [Refereed] [Domestic journal]

The objective of our study was to optimize magnetic resonance image (MRI) sequences and parameters using operative assisted images (three-dimensional images) for radical prostatectomy at 3 tesla (T) MRI. Five healthy volunteers underwent MRI on the 3.0 T scanner. Various sequences and parameters [Cube (TE/TR = 18, 50, 90 ms/2000 ms), FIESTA (TE/TR/FA = 2.4 ms/5 ms/40 degrees, 90 degrees), fSPGR (TE/TR/FA = 2.3 ms/11.2 ms/20 degrees), slice thickness = 1.2 mm, matrix = 192 x 160] were respectively compared. Several structures of the pelvis (the central zones and transition zones of the prostate, the peripheral zones of the prostate, seminal vesicles, rectum wall, bladder, muscle and fat) were determined. The signal intensities of these structures were measured on reformatted axial images and compared against several structures of the pelvis. Correlation with various sequences and parameters was based on the signal-to-noise ratio (SNR), the contrast ratio (CR) and the presence of artifacts. Student's t-test was used for statistical analysis. With Cube (TE/TR = 50 ms/2000 ms), the average value of visual evaluation with artifacts was high, and SNR and CR were higher than for other sequence and parameters. Optimized MRI sequences and parameters were Cube (TE/TR = 50 ms/2000 ms) which provides improved SNR and CR and the presence of artifacts with operative assisted images for radical prostatectomy. These operative assisted images obtained from Cube (TE/TR = 50 ms/2000 ms) are likely to be useful for surgery.

3T-MR装置を用いた根治的前立腺全摘除術における手術支援用3D画像作成のための適切なMR撮像シーケンスと撮像条件の検討

白勢竜二, 櫻井佑樹, 長濱宏史, 原田邦明, 高島弘幸, 中西光広, 原田耕平, 宍戸博紀, 今村塁, 坂田元道, 畠中正光

日本放射線技術学会雑誌 ( (公社)日本放射線技術学会 ) 69 ( 5 ) 529 - 534 2013.05 [Refereed]

3T-MR装置を用い、根治的前立腺全摘除術に対する支援画像(3D画像)に適した撮像方法について検討した。シーケンスはfast spin-echo sequence-Cube、three-dimensional fast imaging employing steady state acquisition(FIESTA)、three-dimensional fast spoiled gradient recalled acquisition in the steady state(fSPGR)を用い、Cubeではeco time(TE)を変化させて3通り、FIESTAではflip angle(FA)を変えて2通りの計6通りの撮像条件とし、健常者5名(平均48.4歳)を対象に10ヶ所の領域でアーチファクト、signal-to-noise ratio(SNR)、コントラスト比を評価した。その結果、アーチファクトのスコアはFIESTA群が1.8以上、CubeおよびfSPGRは0〜0.8であった。SNRが最も高値を示したのはFIEST(FA 40°)であったが、アーチファクトのスコアは2.0であった。最終結果として、最も適切な撮像方法はCube(TE 50ms/TR 2000ms)であった。

Differences in Tibiotalar Joint Alignment During Non-loaded and Axial Loaded Condition in Intact Male Feet

Nozaki Shuhei, Taniguchi Keigo, Takashima Hiroyuki, Watanabe Kota, Hatakenaka Masamitsu, Katayose Masaki

MEDICINE AND SCIENCE IN SPORTS AND EXERCISE ( LIPPINCOTT WILLIAMS & WILKINS ) 45 ( 5 ) 55 - 56 2013.05 [Refereed]

T1 rho is superior to T2 mapping for the evaluation of articular cartilage denaturalization with osteoarthritis: Radiological-pathological correlation after total knee arthroplasty

Yukihisa Takayama, Masamitsu Hatakenaka, Hidetoshi Tsushima, Ken Okazaki, Takashi Yoshiura, Masato Yonezawa, Kei Nishikawa, Yukihide Iwamoto, Hiroshi Honda

EUROPEAN JOURNAL OF RADIOLOGY ( ELSEVIER IRELAND LTD ) 82 ( 4 ) E192 - E198 2013.04 [Refereed]

Purpose: We compared the diagnostic performance of T1 rho and T2 mappings in the evaluation of denatured articular cartilage with osteoarthritis of the knee. Materials and methods: 2D-Sagittal T1 rho and T2 mappings of the knee were obtained from 16 patients before total knee arthroplasty. After surgery, specimens of the femur and tibia were regionally segmented according to a 5-point scale of the severity of denaturalization. The T1 rho and T2 values in the full thickness of the articular cartilage in each region were measured by two observers. The two mappings were compared for their ability to differentiate between normal and denatured articular cartilage and also for their usefulness in grading the severity of the denaturalization using the area under receiver operating characteristic curves (Az). A p < 0.05 was considered significant for each analysis. Results: The T1 rho mapping showed a significantly higher Az value than the T2 mapping for the differentiation between normal and denatured articular cartilage (p < 0.05). Regarding the assessment of the severity of denaturalization, T1 rho mapping could differentiate between normal and mild denaturalization (p < 0.05), but T2 mapping could not. However, there were no significant differences between the two mappings in the discrimination of mild versus moderate denaturalization or of moderate versus severe denaturalization. The two observers showed good agreement in the results (intraclass correlation coefficient = 0.81 for T1 rho and 0.92 for T2). Conclusion: T1 rho mapping is superior to T2 mapping for the evaluation of denatured articular cartilage with osteoarthritis of the knee. (C) 2012 Elsevier Ireland Ltd. All rights reserved.

Diffusion-weighted imaging (b value = 1500 s/mm2) is useful to decrease false-positive breast cancer cases due to fibrocystic changes

Miho Ochi, Toshiro Kuroiwa, Shunya Sunami, Junji Murakami, Shinichiro Miyahara, Takashi Nagaie, Masafumi Oya, Hidetake Yabuuchi, Masamitsu Hatakenaka

Breast Cancer ( 2 ) 20 ( 2 ) 137 - 144 2013.04 [Refereed]

Background: We aimed to evaluate the application of apparent diffusion coefficient (ADC) values calculated from diffusion-weighted imaging (DWI) (b value = 1500 s/mm2) in the breast imaging reporting and data system (BI-RADS). Methods: For 104 cases of breast lesions with definitive histology diagnosis (45 benign cases, 59 malignant cases) in which breast magnetic resonance imaging was performed, ADC values were compared between benign and malignant cases, between ductal carcinoma in situ (DCIS) and fibrocystic changes, and between DCIS and ductal hyperplasia (one type of fibrocystic change). Diagnostic accuracy was compared for a total of 101 images and for 34 images including only nine DCIS and 25 fibrocystic changes between BI-RADS alone (with categories 4a, 4b, and 5 defined as malignancies) and BI-RADS plus ADC. Results: There were significant differences in mean ADC values between malignant and benign cases (p < 0.0001) and between DCIS and fibrocystic changes (p < 0.002), but not between DCIS and ductal hyperplasia. Positive predictive values were significantly greater for BI-RADS plus ADC than for BI-RADS alone in all cases (70.5% for BI-RADS alone, 81.3% for BI-RADS plus ADC) and in cases of DCIS versus fibrocystic changes (40.9% for BI-RADS alone, 64.3% for BI-RADS plus ADC), resulting in a significant improvement in diagnostic accuracy with the addition of ADC. Conclusion: Adding ADC values calculated from DWI (b value = 1500 s/mm2) to BI-RADS is a useful way to improve differential diagnostic accuracy for malignant tumors and benign lesions, especially for DCIS versus fibrocystic changes, except in cases of ductal hyperplasia. © 2011 The Japanese Breast Cancer Society.

Detection of axillary node metastasis using diffusion-weighted MRI in breast cancer

Takeshi Kamitani, Masamitsu Hatakenaka, Hidetake Yabuuchi, Yoshio Matsuo, Nobuhiro Fujita, Mikako Jinnouchi, Michinobu Nagao, Kengo Shirahane, Eriko Tokunaga, Hiroshi Honda

Clinical Imaging ( 1 ) 37 ( 1 ) 56 - 61 2013.01 [Refereed]

Breast magnetic resonance imagings (MRIs) including diffusion-weighted MRI (DWI) of 110 breast cancers (26 with pathologically proven axillary node metastasis and 84 without metastasis) were retrospectively studied. Axillary nodes were detected as high-signal-intensity areas on DWI in 71 cancers (24 with metastasis and 47 without) and not detected in 39 cancers (2 with metastasis and 37 without). The ADC of metastatic nodes was significantly greater than that of the benign ones (1.08±0.18×10-3 mm2/s vs. 0.92±0.22×10-3 mm2/s, P=004). When detectability of axillary nodes on DWI and ADC over 1.05×10-3 mm2/s was applied as a threshold, 53.8% sensitivity, 86.9% specificity, and 79.1% accuracy were provided. © 2013 Elsevier Inc.

Vascular measurement changes observed using postmortem computed tomography

Hideki Hyodoh, Taishi Sato, Maki Onodera, Hirokazu Washio, Tadashi Hasegawa, Masamitsu Hatakenaka

JAPANESE JOURNAL OF RADIOLOGY ( SPRINGER ) 30 ( 10 ) 840 - 845 2012.12 [Refereed]

Postmortem vascular changes were quantitatively analyzed in the aorta and vena cava and compared with antemortem findings as a basis for distinguishing between normal postmortem changes and pathological changes. Whole-body computed tomography (CT) was performed on 12 individuals before and after death. The scans, performed at seven levels (five for the aorta, two for the vena cava) within the vasculature, allowed various measurements to be made on the same individual before and after death. Postmortem long-axis diameter, short-axis diameter, and the square of the radius of the aorta were 79.2-85.0 % (mean 81.3 %), 55.6-80.0 % (68.0 %), and 48.5-71.4 % (60.8 %) of the antemortem measurements, respectively. The ante- and postmortem measurements of the long and short axes and the caliber of the aorta were statistically different (p < 0.05). The superior vena cava (SVC) was increased in size: the short-axis diameter and the square of the radius were both statistically different after death. None of the measured parameters of the inferior vena cava (IVC) changed significantly following death. In postmortem images, the aortic diameter decreased and changes in the size and shape of the SVC were noted. The IVC did not exhibit significant postmortem changes.

Evaluation of cartilage degradation in arthritis using T1 rho magnetic resonance imaging mapping

Hidetoshi Tsushima, Ken Okazaki, Yukihisa Takayama, Masamitsu Hatakenaka, Hiroshi Honda, Toshiaki Izawa, Yasuharu Nakashima, Hisakata Yamada, Yukihide Iwamoto

RHEUMATOLOGY INTERNATIONAL ( SPRINGER HEIDELBERG ) 32 ( 9 ) 2867 - 2875 2012.09 [Refereed]

T1 rho magnetic resonance imaging (MRI) can be used to map proteoglycan (PG) loss in cartilage. Here, we used T1 rho MRI to map cartilage degradation in osteoarthritis (OA) and rheumatoid arthritis (RA). Tissue samples were obtained from five RA patients and 14 OA patients following total knee arthroplasty (TKA). Three parameters were measured: First, macroscopic grading of cartilage sample tissues was performed on a 5-grade scale (G0: normal, G1: swelling, G2: superficial fibrillation, G3: deep fibrillation, G4: subchondral bone exposure). Second, semi-quantitative values of PG were assessed by measuring the optical density of Safranin-O-stained paraffin sections that had been digitally photographed. Third, cartilage was divided into superficial and deep layers and the T1 rho values were quantified. T1 rho values of OA and RA in the superficial layers showed significant differences between groups (G0/1 and G0/2 for OA; G0/2 and G1/2 for RA). In the deep layers, T1 rho values of OA and RA also differed significantly between groups. In both the superficial and deep layers, there was a significant correlation between the mean T1 rho values and macroscopic grading (P < 0.01 for OA, P < 0.001 for RA). We found a negative correlation between the score of Safranin-O staining and T1 rho values (r = -0.61 for OA, r = -0.79 for RA). In addition, RA subjects had significantly higher T1 rho values than OA subjects of similar morphologic grade. In conclusion, T1 rho MRI is able to detect and map the early stages of cartilage degradation in OA and RA. This method is reliable and useful for the evaluation of macromolecular changes in arthritic cartilage.

Pharmacokinetic analysis based on dynamic contrast-enhanced MRI for evaluating tumor response to preoperative therapy for oral cancer

Toru Chikui, Erina Kitamoto, Shintaro Kawano, Tsuyoshi Sugiura, Makoto Obara, Arjan W. Simonetti, Masamitsu Hatakenaka, Yoshio Matsuo, Shoichi Koga, Masahiro Ohga, Katsumasa Nakamura, Kazunori Yoshiura

JOURNAL OF MAGNETIC RESONANCE IMAGING ( WILEY-BLACKWELL ) 36 ( 3 ) 589 - 597 2012.09 [Refereed]

Purpose: To evaluate whether a pharmacokinetic analysis is useful for monitoring the response of oral cancer to chemoradiotherapy (CRT). Materials and Methods: Twenty-nine patients were included. They underwent dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) before and after CRT. The DCE-MRI data were analyzed using a Tofts and Kermode (TK) model. The histological evaluation of the effects of CRT was performed according to Ohboshi and Shimosato's classification. Results: None of the pre-CRT parameters were significantly different between the responders and nonresponders. The post-CRT volume of the extravascular extracellular space (EES) per unit volume of tissue (ve) of responders (0.397 +/- 0.080) was higher than that of nonresponders (0.281 +/- 0.076) (P = 0.01). The change of the ve between the pre- and post-CRT of the responders (0.154 +/- 0.093) was larger than that of the nonresponders (0.033 +/- 0.073) (P = 0.001). Therefore, the increase in the ve strongly suggested a good tumor response to CRT, which reflected an increase of the EES secondary to the destruction of the cancer nest. The changes in the volume transfer constant (Ktrans) were significantly different between the responders and nonresponders (P = 0.018). Conclusion: Both the increase of the ve and the elevation of permeability (Ktrans) were indicative of a good tumor response to CRT. The pharmacokinetic analysis had potential for monitoring the histopathological response to CRT. J. Magn. Reson. Imaging 2012;36:589597. (C) 2012 Wiley Periodicals, Inc.

Acute Cardiac Impairment Associated With Concurrent Chemoradiotherapy for Esophageal Cancer: Magnetic Resonance Evaluation

Masamitsu Hatakenaka, Masato Yonezawa, Takeshi Nonoshita, Katsumasa Nakamura, Hidetake Yabuuchi, Yoshiyuki Shioyama, Michinobu Nagao, Yoshio Matsuo, Takeshi Kamitani, Taiki Higo, Kei Nishikawa, Taro Setoguchi, Hiroshi Honda

INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS ( ELSEVIER SCIENCE INC ) 83 ( 1 ) E67 - E73 2012.05 [Refereed]

Purpose: To evaluate acute cardiac effects of concurrent chemoradiotherapy (CCRT) for esophageal cancer. Methods and Materials: This prospective study was approved by the institutional review board, and written informed consent was obtained from all participants. The left ventricular function (LVF) of 31 patients with esophageal cancer who received cisplatin and 5-fluorouracil-based CCRT was evaluated using cardiac cine magnetic resonance imaging. The patients were classified into two groups according to mean LV dose. The parameters related to LVF were compared between before and during (40 Gy) or between before and after CCRT using a Wilcoxon matched-pairs single rank test, and parameter ratios (during/before CCRT, after/before CCRT) were also compared between the groups with a t test. Data were expressed as mean +/- SE. Results: In the low LV-dose group (n = 10; mean LV dose <0.6 Gy), LV ejection fraction decreased significantly (before vs. during vs. after CCRT; 62.7% +/- 2.98% vs. 59.8% +/- 2.56% vs. 60.6% +/- 3.89%; p < 0.05). In the high LV-dose group (n = 21; mean LV dose of 3.6-41.2 Gy), LV end-diastolic volume index (before vs. after CCRT; 69.1 +/- 2.93 vs. 57.0 +/- 3.23 mL/m(2)), LV stroke volume index (38.6 +/- 1.56 vs. 29.9 +/- 1.60 mL/m(2)), and LV ejection fraction (56.9% +/- 1.79% vs. 52.8% +/- 1.15%) decreased significantly (p < 0.05) after CCRT. Heart rate increased significantly (before vs. during vs. after CCRT; 66.8 +/- 3.05 vs. 72.4 +/- 4.04 vs. 85.4 +/- 3.75 beats per minute, p < 0.01). Left ventricle wall motion decreased significantly (p < 0.05) in segments 8 (before vs. during vs. after CCRT; 6.64 +/- 0.54 vs. 4.78 +/- 0.43 vs. 4.79 +/- 0.50 mm), 9 (6.88 +/- 0.45 vs. 5.04 +/- 0.38 vs. 5.27 +/- 0.47 mm), and 10 (9.22 +/- 0.48 vs. 8.08 +/- 0.34 vs. 8.19 +/- 0.56 mm). The parameter ratios of LV end-diastolic volume index, stroke volume index, wall motion in segment 9, and heart rate showed significant difference (p < 0.05) after CCRT between the groups. Conclusions: Concurrent chemoradiotherapy for esophageal cancer impairs LVF from an early treatment stage. This impairment is prominent in patients with high LV dose. (C) 2012 Elsevier Inc.

Subendocardial contractile impairment in chronic ischemic myocardium: assessment by strain analysis of 3T tagged CMR

Michinobu Nagao, Masamitsu Hatakenaka, Yoshio Matsuo, Takeshi Kamitani, Ko Higuchi, Fumiaki Shikata, Mitsugi Nagashima, Teruhito Mochizuki, Hiroshi Honda

JOURNAL OF CARDIOVASCULAR MAGNETIC RESONANCE ( BIOMED CENTRAL LTD ) 14 14 2012.02 [Refereed]

Background: The purpose of this study was to quantify myocardial strain on the subendocardial and epicardial layers of the left ventricle (LV) using tagged cardiovascular magnetic resonance (CMR) and to investigate the transmural degree of contractile impairment in the chronic ischemic myocardium. Methods: 3T tagged CMR was performed at rest in 12 patients with severe coronary artery disease who had been scheduled for coronary artery bypass grafting. Circumferential strain (C-strain) at end-systole on subendocardial and epicardial layers was measured using the short-axis tagged images of the LV and available software (Intag; Osirix). The myocardial segment was divided into stenotic and non-stenotic segments by invasive coronary angiography, and ischemic and non-ischemic segments by stress myocardial perfusion scintigraphy. The difference in C-strain between the two groups was analyzed using the Mann-Whitney U-test. The diagnostic capability of C-strain was analyzed using receiver operating characteristics analysis. Results: The absolute subendocardial C-strain was significantly lower for stenotic (-7.5 +/- 12.6%) than non-stenotic segment (-18.8 +/- 10.2%, p < 0.0001). There was no difference in epicardial C-strain between the two groups. Use of cutoff thresholds for subendocardial C-strain differentiated stenotic segments from non-stenotic segments with a sensitivity of 77%, a specificity of 70%, and areas under the curve (AUC) of 0.76. The absolute subendocardial C-strain was significantly lower for ischemic (-6.7 +/- 13.1%) than non-ischemic segments (-21.6 +/- 7.0%, p < 0.0001). The absolute epicardial C-strain was also significantly lower for ischemic (-5.1 +/- 7.8%) than non-ischemic segments (-9.6 +/- 9.1%, p < 0.05). Use of cutoff thresholds for subendocardial C-strain differentiated ischemic segments from non-ischemic segments with sensitivities of 86%, specificities of 84%, and AUC of 0.86. Conclusions: Analysis of tagged CMR can non-invasively demonstrate predominant impairment of subendocardial strain in the chronic ischemic myocardium at rest.

Exogenous Lipoid Pneumonia Induced by Aspiration of Insecticide

Keisuke Ishimatsu, Takeshi Kamitani, Yoshio Matsuo, Masamitsu Hatakenaka, Shunya Sunami, Mikako Jinnouchi, Michinobu Nagao, Hidetake Yabuuchi, Hiroshi Honda

JOURNAL OF THORACIC IMAGING ( LIPPINCOTT WILLIAMS & WILKINS ) 27 ( 1 ) W18 - W20 2012.01 [Refereed]

Exogenous lipoid pneumonia is a rare disorder caused by inhalation and/or aspiration of oil-based substances. The confirmed diagnosis of exogenous lipoid pneumonia is difficult, especially in cases for which it is impossible to ascertain a history of inhalation or aspiration. We present a case of exogenous lipoid pneumonia due to aspiration of insecticide, for which the computed tomography findings of fat attenuation within the lesion were helpful in reaching a correct diagnosis.

Reduction of the unnecessary dose from the over-range area with a spiral dynamic z-collimator: Comparison of beam pitch and detector coverage with 128-detector row CT

Takashi Shirasaka, Yoshinori Funama, Mutsukazu Hayashi, Shinichi Awamoto, Masatoshi Kondo, Yasuhiko Nakamura, Masamitsu Hatakenaka, Hiroshi Honda

Radiological Physics and Technology ( 1 ) 5 ( 1 ) 53 - 58 2012.01 [Refereed]

Our purpose in this study was to assess the radiation dose reduction and the actual exposed scan length of over-range areas using a spiral dynamic z-collimator at different beam pitches and detector coverage. Using glass rod dosimeters, we measured the unilateral over-range scan dose between the beginning of the planned scan range and the beginning of the actual exposed scan range. Scanning was performed at detector coverage of 80.0 and 40.0 mm, with and without the spiral dynamic z-collimator. The dose-saving ratio was calculated as the ratio of the unnecessary over-range dose, with and without the spiral dynamic z-collimator. In 80.0 mm detector coverage without the spiral dynamic z-collimator, the actual exposed scan length for the over-range area was 108, 120, and 126 mm, corresponding to a beam pitch of 0.60, 0.80, and 0.99, respectively. With the spiral dynamic z-collimator, the actual exposed scan length for the over-range area was 48, 66, and 84 mm with a beam pitch of 0.60, 0.80, and 0.99, respectively. The dose-saving ratios with and without the spiral dynamic z-collimator for a beam pitch of 0.60, 0.80, and 0.99 were 35.07, 24.76, and 13.51%, respectively. With 40.0 mm detector coverage, the dose-saving ratios with and without the spiral dynamic z-collimator had the highest value of 27.23% with a low beam pitch of 0.60. The spiral dynamic z-collimator is important for a reduction in the unnecessary over-range dose and makes it possible to reduce the unnecessary dose by means of a lower beam pitch. © Japanese Society of Radiological Technology and Japan Society of Medical Physics 2011.

Angiomyolipomas of the Mediastinum and the Lung

Koichiro Morita, Yoshitaka Shida, Kenji Shinozaki, Satoru Uehara, Takashi Seto, Kenji Sugio, Yukito Ichinose, Kenichi Nishiyama, Yoshio Matsuo, Masamitsu Hatakenaka, Hiroshi Honda

JOURNAL OF THORACIC IMAGING ( LIPPINCOTT WILLIAMS & WILKINS ) 27 ( 1 ) W21 - W23 2012.01 [Refereed]

Ytterbium-based PARACEST Agent: Feasibility of CEST Imaging on a Clinical MR Scanner

Yukihisa Takayama, Takashi Yoshiura, Akihiro Nishie, Tomohiro Nakayama, Masamitsu Hatakenaka, Naoki Kato, Satoshi Yoshise, Jochen Keupp, Dirk Burdinski, Hiroshi Honda

MAGNETIC RESONANCE IN MEDICAL SCIENCES ( JPN SOC MAGNETIC RESONANCE IN MEDICINE ) 11 ( 1 ) 35 - 41 2012 [Refereed]

Purpose: We investigated the feasibility of performing chemical exchange saturation transfer (CEST) imaging using ytterbium-based paramagnetic CEST (PARACEST) agents on a clinical magnetic resonance (MR) scanner. Materials and Methods: We prepared solutions of 3 different ytterbium-based PARACEST agents at concentrations of 5, 10, 20, and 50 mM at a pH of 7.4 and at a concentration of 50 mM at pHs of 3.0, 5.0, 7.4, and 9.5. We acquired images with a turbo spin echo technique using a quadrature head coil and a clinical 3.0-tesla MR system in accordance with the safety limits of the specific absorption rate (SAR). We acquired CEST images with presaturation offset frequencies from -5,000 Hz (-39.1 ppm) to 5,000 Hz (39.1 ppm) with an interval of 500 Hz (3.9 ppm) for each condition. We repeated each scan 3 times and then calculated the mean and standard deviations of the magnitude of the CEST effect at different concentrations and pH values for each agent. We used one-way analysis of variance and Tukey's honestly significant difference post hoc test to compare mean values of the magnitude of the CEST effect obtained at different concentrations and pH values. P < 0.05 was considered significant. Results: PARACEST agents showed a strong CEST effect at their specific presaturation offset frequencies. For each agent, the CEST effect showed significant concentration dependency (P < 0.05), increasing with agent concentration, and significant pH dependency (P < 0.05), with strong effect near physiological pH. Conclusion: CEST imaging using ytterbium-based PARACEST agents might be feasible on a clinical MR scanner with further modifications, such as adjustments of the presaturation radiofrequency pulse and imaging protocols.

Non-Small Cell Lung Cancer: Detection of Early Response to Chemotherapy by Using Contrast-enhanced Dynamic and Diffusion-weighted MR Imaging

Hidetake Yabuuchi, Masamitsu Hatakenaka, Koichi Takayama, Yoshio Matsuo, Shunya Sunami, Takeshi Kamitani, Mikako Jinnouchi, Shuji Sakai, Yoichi Nakanishi, Hiroshi Honda

RADIOLOGY ( RADIOLOGICAL SOC NORTH AMERICA ) 261 ( 2 ) 598 - 604 2011.11 [Refereed]

Purpose: To evaluate the ability of dynamic contrast material-enhanced and diffusion-weighted (DW) magnetic resonance (MR) imaging to help detect early response to chemotherapy in patients with non-small cell lung cancer (NSCLC). Materials and Methods: This study was approved by the institutional review board, and written informed consent was obtained from all subjects. Twenty-eight patients with stage IIIB or IV NSCLC (17 women, 11 men; mean age, 64.8 years) who underwent chemotherapy were enrolled. All patients underwent MR imaging before and after the first course of chemotherapy. The time to peak enhancement, maximum enhancement ratio, and washout ratio were determined from the time-signal intensity curves of dynamic contrast-enhanced MR images. The apparent diffusion coefficient (ADC) of each lung carcinoma was calculated from DW MR images. The responses of these parameters to the first course of chemotherapy and the pretreatment ADC itself were compared with final tumor size reduction by using the Pearson correlation coefficient. Kaplan-Meier curves of progression-free survival and overall survival were generated, and comparisons between the group with a good response of the significant parameter (upper 50th percentile) and that with a poor response of the significant parameter (lower 50th percentile) were performed by using a two-sided log-rank test. Results: Significant correlation was found only between early ADC change and final tumor size reduction rate (r(2) = 0.41, P = .00025). The median progression-free survival for the group with a good increase in ADC was 12.1 months, and that for the group with a stable or decreased ADC was 6.67 months (P = .021), while median overall survival was 22.4 and 12.3 months, respectively (P = .048). Conclusion: ADC seems to be a promising tool for monitoring the early response to or predicting prognosis after chemotherapy of NSCLC. (C) RSNA, 2011

Apparent Diffusion Coefficient Calculated with Relatively High b-Values Correlates with Local Failure of Head and Neck Squamous Cell Carcinoma Treated with Radiotherapy

M. Hatakenaka, Y. Shioyama, K. Nakamura, H. Yabuuchi, Y. Matsuo, S. Sunami, T. Kamitani, T. Yoshiura, T. Nakashima, K. Nishikawa, H. Honda

AMERICAN JOURNAL OF NEURORADIOLOGY ( AMER SOC NEURORADIOLOGY ) 32 ( 10 ) 1904 - 1910 2011.11 [Refereed]

BACKGROUND AND PURPOSE: Few studies have investigated the relationship between ADC and clinical outcome in HNSCC. Our hypothesis has that relatively high pretreatment ADC would correlate with local failure of HNSCC treated with radiation therapy. MATERIALS AND METHODS: This includes prospective and validation studies. Seventeen patients treated with radiation therapy for primary HNSCC completed the prospective study. Variables considered to affect local failure including MR imaging-related parameters such as ADC and its change ratio were compared between patients with local failure and controls, and those showing difference or association with local failure were further tested by survival analysis. Furthermore, variables were analyzed in 40 patients enrolled in the validation study. RESULTS: Relatively high ADC calculated with b-values 1300, 500, 750, and 1000 s/mm(2)) before treatment, high ADC increase ratio, and treatment method (chemoradiotherapy versus radiation therapy alone) revealed significant difference between patients with local failure and controls or association with local failure. In Cox proportional hazard testing, high ADC before treatment alone showed significant association with local failure (P = .0186). In the validation study, tumor volume before treatment, high ADC before treatment, T stage (112 versus 134), and treatment method showed significance. Tumor volume before treatment (P = .0217) and high ADC before treatment (P = .0001) revealed significant association with local failure in Cox proportional hazard testing. High ADC before treatment was superior to tumor volume before treatment regarding association with local failure. CONCLUSIONS: These results suggest pretreatment ADC obtained at high b-values as well as tumor volume correlate with local failure of HNSCC treated with radiation therapy.

PRETREATMENT APPARENT DIFFUSION COEFFICIENT OF THE PRIMARY LESION CORRELATES WITH LOCAL FAILURE IN HEAD-AND-NECK CANCER TREATED WITH CHEMORADIOTHERAPY OR RADIOTHERAPY

Masamitsu Hatakenaka, Katsumasa Nakamura, Hidetake Yabuuchi, Yoshiyuki Shioyama, Yoshio Matsuo, Kayoko Ohnishi, Shunya Sunami, Takeshi Kamitani, Taro Setoguchi, Takashi Yoshiura, Torahiko Nakashima, Kei Nishikawa, Hiroshi Honda

INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS ( ELSEVIER SCIENCE INC ) 81 ( 2 ) 339 - 345 2011.10 [Refereed]

Purpose: This study was performed to evaluate whether the apparent diffusion coefficient (ADC) of a primary lesion correlates with local failure in primary head-and-neck squamous cell carcinoma (HNSCC) treated with chemoradiotherapy or radiotherapy. Methods and Materials: We retrospectively studied 38 patients with primary HNSCC (12 oropharynx, 20 hypopharynx, 4 larynx, 2 oral cavity) treated with chemoradiotherapy or radiotherapy with radiation dose to gross tumor volume equal to or over 60 Gy and who underwent pretreatment magnetic resonance imaging, including diffusion-weighted imaging. Ten patients developed local failure during follow-up periods of 2.0 to 9.3 months, and the remaining 28 showed local control during follow-up periods of 10.5 to 31.7 months. The variables that could affect local failure (age, tumor volume, ADC, T stage, N stage, dose, treatment method, tumor location, and overall treatment time) were analyzed using logistic regression analyses for all 38 patients and for 17 patients with Stage T3 or T4 disease. Results: In univariate logistic analysis for all 38 cases, tumor volume, ADC, T stage, and treatment method showed significant (p < 0.05) associations with local failure. In multivariate analysis, ADC and T stage revealed significance (p < 0.01). In univariate logistic analysis for the 17 patients with Stage T3 or T4 disease, ADC and dose showed significant (p < 0.01) associations with local failure. In multivariate analysis, ADC alone showed significance (p < 0.05). Conclusions: The results suggest that pretreatment ADC, along with T stage, is a potential indicator of local failure in HNSCC treated with chemoradiotherapy or radiotherapy. (C) 2011 Elsevier Inc.

Diagnostic performance in differentiation of breast lesion on digital mammograms: comparison among hard-copy film, 3-megapixel LCD monitor, and 5-megapixel LCD monitor

Takeshi Kamitani, Hidetake Yabuuchi, Yoshio Matsuo, Taro Setoguchi, Shuji Sakai, Takashi Okafuji, Shunya Sunami, Masamitsu Hatakenaka, Nobuhide Ishii, Makoto Kubo, Eriko Tokunaga, Hidetaka Yamamoto, Hiroshi Honda

CLINICAL IMAGING ( ELSEVIER SCIENCE INC ) 35 ( 5 ) 341 - 345 2011.09 [Refereed]

We compared observer performance of digital mammography among hard-copy readings and soft-copy readings using 3-megapixel (3M) and 5-megapixel (5M) liquid crystal display (LCD) monitors. Five experienced radiologists assessed 80 mammograms of 40 cancers and 40 benign lesions. There were no significant differences among the average A(z) of three modalities and among the kappa values for intra- and interobserver agreement. The soft-copy reading using the 3M LCD monitor took a slightly longer time, although there were no significant differences. (C) 2011 Elsevier Inc. All rights reserved.

Prediction and monitoring of the response to chemoradiotherapy in oral squamous cell carcinomas using a pharmacokinetic analysis based on the dynamic contrast-enhanced MR imaging findings

Toru Chikui, Shintaro Kawano, Toshiyuki Kawazu, Masamitsu Hatakenaka, Syouzou Koga, Masahiro Ohga, Yoshio Matsuo, Syunya Sunami, Tsuyoshi Sugiura, Yoshiyuki Shioyama, Makoto Obara, Kazunori Yoshiura

EUROPEAN RADIOLOGY ( SPRINGER ) 21 ( 8 ) 1699 - 1708 2011.08 [Refereed]

To evaluate whether a pharmacokinetic analysis is useful for both predicting and monitoring the response to chemoradiotherapy (CRT) in oral cancer. Patients with oral squamous cell carcinoma treated with preoperative CRT and surgery were enrolled. They underwent dynamic contrast-enhanced MRI before (n = 23), and after CRT (n = 20). We estimated four parameters: arrival time of contrast medium (TA), exchange rate constant from the extracellular extravascular space (EES) to plasma (k(ep)), elimination of contrast medium from the central compartment (k(el)) and an amplitude scaling constant (AH) using the Brix model. The histological evaluation of the effects of CRT was performed according to Ohboshi and Shimosato's classification. We analysed the correlation between the parameters and the histological evaluation. The pre-CRT AH between the responders and non-responders was significantly different (P = 0.046), however, the three parameters (TA, K-ep, K-el) were not significantly different among the groups (P = 0.76, P = 0.60, P = 0.09). As AH decreased, the tumour response improved. The change in the AH between the pre- and post-CRT of responders was significantly higher than that of non-responders (P = 0.043). The AH, which is affected by the ratio of the EES, was an important parameter for predicting and monitoring the tumour response to CRT.

Correlation between pretreatment or follow-up CT findings and therapeutic effect of autologous peripheral blood stem cell transplantation for interstitial pneumonia associated with systemic sclerosis

Hidetake Yabuuchi, Yoshio Matsuo, Hiroshi Tsukamoto, Shunya Sunami, Takeshi Kamitani, Shuji Sakai, Masamitsu Hatakenaka, Koji Nagafuji, Takahiko Horiuchi, Mine Harada, Koichi Akashi, Hiroshi Honda

EUROPEAN JOURNAL OF RADIOLOGY ( ELSEVIER IRELAND LTD ) 79 ( 2 ) E74 - E79 2011.08 [Refereed]

Purpose: To evaluate what is useful among various parameters including CT findings, laboratory parameters (%VC, %DLco, KL-6), patients related data (age, sex, duration of disease) to discriminate between responder and non-responder in patients who received autologous peripheral blood stem cell transplantation (auto-PBSCT) for interstitial pneumonia (IP) with systemic sclerosis (SSc). Method: Auto-PBSCT and follow-up of at least one year by chest CT, serum KL-6, %VC, and %DLco were performed in 15 patients for IP with SSc. Analyzed CT findings included extent of ground-glass opacity (GGO), intralobular reticular opacity, number of segments that showed traction bronchiectasis, and presence of honeycombing. We regarded the therapeutic response of patients as responders when TLC or VC increase over 10% or DLco increase more than 15%, otherwise we have classified as non-responder. We applied univariate and multivariate analyses to find the significant indicators to discriminate responders from non-responders. P < 0.05 was considered statistically significant. Results: Univariate and multivariate analyses showed that the significant parameter to discriminate responders from non-responders were pretreatment KL-6, presence of honeycombing, extent of GGO, and early change in extent of GGO. Among them, extent of GGO and early change in extent of GGO were the strongest discriminators between responders and non-responders (P = 0.001, 0.001, respectively). Conclusion: Several CT findings and pretreatment KL-6 may be useful to discriminate between responder and non-responder in patients who received auto-PBSCT for IP with SSc. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

Prediction of Local Failures with a Combination of Pretreatment Tumor Volume and Apparent Diffusion Coefficient in Patients Treated with Definitive Radiotherapy for Hypopharyngeal or Oropharyngeal Squamous Cell Carcinoma

Kayoko Ohnishi, Yoshiyuki Shioyama, Masamitsu Hatakenaka, Katsumasa Nakamura, Koichiro Abe, Takashi Yoshiura, Saiji Ohga, Takeshi Nonoshita, Tadamasa Yoshitake, Torahiko Nakashima, Hiroshi Honda

JOURNAL OF RADIATION RESEARCH ( JAPAN RADIATION RESEARCH SOC ) 52 ( 4 ) 522 - 530 2011.07 [Refereed]

Purpose: The purpose of this study was to investigate the clinical factors for predicting local failure after definitive radiotherapy in oropharyngeal or hypopharyngeal squamous cell carcinoma. Materials and Methods: Between July 2006 and December 2008, 64 consecutive patients with squamous cell carcinoma of the hypopharynx or the oropharynx treated with definitive radiotherapy were included in this study. Clinical factors, such as pretreatment hemoglobin (Hb) level, T-stage, gross tumor volume of primary tumors (pGTV), and maximum standardized uptake value (SUV(max)) on FDG-PET, were evaluated for the correlation with local failure. A subset analysis of 32 patients with MR images including diffusion-weighted images (DWI) as a pretreatment evaluation was also performed. The Kaplan-Meier curves, the log-rank test, and the Cox proportional hazards model were used to evaluate these clinical factors. Results: Eleven of 64 patients experienced local recurrence, with a median follow-up time of 15 months. In the univariate analysis, Hb level (p = 0.0261), T-stage (p = 0.012), pGTV (p = 0.0025), and SUV(max) (p = 0.024) were significantly associated with local failure. In the multivariate analysis, pGTV (p = 0.0070) remained an adverse factor for local control. In the subset analysis of 32 patients with DWI, the median apparent diffusion coefficient (ADC) value of primary tumors on DWI was 0.79 x 10(-3) mm(2)/s (range, 0.40-1.60 x 10(-3) mm(2)/s). Patients with a high ADC value (> 0.79 x 10(-3) mm(2)/s) had a significantly lower local control rate than patients with a low ADC value (100% vs. 44%, p = 0.0019). The rate of local failure among patients with a large pGTV and a high ADC value was 55% (6/11), whereas no local failures occurred (0%, 0/21) among patients with a small pGTV or a low ADC. Conclusions: These results suggest that a combination of a large tumor volume and a high ADC value could be predictive of local recurrence after definitive radiotherapy in hypopharyngeal or oropharyngeal squamous cell carcinoma.

A case of localized amyloidosis in the mediastinum, CT, MRI, and 18F-FDG-PET/CT findings

Mikako Jinnouchi, Masamitsu Hatakenaka, Hidetake Yabuuchi, Yoshio Matsuo, Shunya Sunami, Takeshi Kamitani, Masahiro Komori, Yuko Kitajima, Nobuhiro Fujita, Hiroshi Honda

European Journal of Radiology Extra 77 ( 2 ) e39 - e42 2011.02 [Refereed]

Amyloidosis is a heterogeneous group of diseases characterized by the presence of extracellular deposition of amyloid. We present a case of localized amyloidosis of the middle mediastinum, that was diagnosed by trans-esophageal endoscopic ultrasound (EUS)-guided biopsy, focusing on imaging features of contrast-enhanced CT, MRI including dynamic contrast-enhanced study and DWI, and integrated fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/CT. © 2010 Elsevier Ireland Ltd.

Volumetric Asymmetry and Differential Aging Effect of the Human Caudate Nucleus in Normal Individuals: A Prospective MR Imaging Study

Koji Yamashita, Takashi Yoshiura, Akio Hiwatashi, Tomoyuki Noguchi, Osamu Togao, Yukihisa Takayama, Eiki Nagao, Hironori Kamano, Masamitsu Hatakenaka, Hiroshi Honda

JOURNAL OF NEUROIMAGING ( WILEY-BLACKWELL PUBLISHING, INC ) 21 ( 1 ) 34 - 37 2011.01 [Refereed]

PURPOSE The purpose of this study was to examine interhemispheric asymmetry in volume of the caudate nucleus and its age dependency. METHODS High-resolution T1-weighted brain magnetic resonance (MR) images were obtained for each subject using a 3-dimensional fast field-echo pulse sequence. The volumes of the bilateral caudate nuclei on MR images were measured using an automated method. Right-to-left comparison was made using paired t-test. Age-related change of right-to-left volume ratio (R/L ratio) was examined using Pearson's correlation coefficient. RESULTS Fifty healthy right-handed Japanese male subjects (age 12 to 67 years, mean 39.6 years) were involved in this study. The volume of right caudate nucleus was larger than the left in 48 of 50 subjects (P < .001). R/L ratio increased with age (r = .420, P < .01). CONCLUSIONS Our results confirmed the rightward volumetric asymmetry of caudate nucleus in right-handed individuals, and revealed that this asymmetry becomes notable with age.

Detection of non-palpable breast cancer in asymptomatic women by using unenhanced diffusion-weighted and T2-weighted MR imaging: comparison with mammography and dynamic contrast-enhanced MR imaging

Hidetake Yabuuchi, Yoshio Matsuo, Shunya Sunami, Takeshi Kamitani, Satoshi Kawanami, Taro Setoguchi, Shuji Sakai, Masamitsu Hatakenaka, Makoto Kubo, Eriko Tokunaga, Hidetaka Yamamoto, Hiroshi Honda

EUROPEAN RADIOLOGY ( SPRINGER ) 21 ( 1 ) 11 - 17 2011.01 [Refereed]

To compare the detectability of non-palpable breast cancer in asymptomatic women by using mammography (MMG), dynamic contrast-enhanced MR imaging (DCE-MRI) and unenhanced MR imaging with combined diffusion-weighted and T2-weighted images (DWI + T2WI). Forty-two lesions in 42 patients with non-palpable breast cancer in asymptomatic women were enrolled. For the reading test, we prepared a control including 13 normal and 8 benign cases. Each imaging set included biplane MMG, DCE-MRI and DWI + T2WI. Five readers were asked to rate the images on a scale of 0 to 100 for the likelihood of the presence of cancer and the BI-RADS category. Confidence level results were used to construct receiver operating characteristic analysis. Sensitivity and specificity were calculated for each technique. DWI + T2WI showed higher observer performances (area under the curve, AUC, 0.73) and sensitivity (50%) for the detection of non-palpable breast cancer than MMG alone (AUC 0.64; sensitivity 40%) but lower than those of DCE-MRI (AUC 0.93; sensitivity 86%). A combination of MMG and DWI + T2WI exhibited higher sensitivity (69%) compared with that of MMG alone (40%). DWI + T2WI could be useful in screening breast cancer for patients who cannot receive contrast medium and could be used as a new screening technique for breast cancer.

Assessment of the sequential change of the masseter muscle by clenching: A quantitative analysis of T-1, T-2, and the signal intensity of the balanced steady-state free precession

Toru Chikui, Tomoko Shiraishi, Kenji Tokumori, Daisuke Inatomi, Masamitsu Hatakenaka, Kenji Yuasa, Kazunori Yoshiura

ACTA RADIOLOGICA ( ROYAL SOC MEDICINE PRESS LTD ) 51 ( 6 ) 669 - 678 2010.07 [Refereed]

Background: The persistent muscle contractions during clenching are thought to cause some temporomandibular disorders. However, no report has so far evaluated the effect of clenching on the masticatory muscles by magnetic resonance imaging (MRI). Purpose: To investigate the effect of clenching with maximum voluntary contraction on the T-1, T-2, and signal intensity (SI) of the balanced fast field-echo (b FFE) of the masseter muscle. Material and Methods: A total of 11 volunteers participated. Multi-echo spin-echo echo-planar imaging was used for T-2 measurements, and multi-shot Look-Locker sequence for T-1 measurements. The Look-Locker sequence has been used for fast T-1 mapping and this method has been applied for the imaging of various tissues. In addition, the b FFE was used due to the high temporal resolution. These three sequences lasted for 10 min and the participants were instructed to clench from 60 s to 80 s after the start of the data acquisition. T-2, T-1, and SI were normalized compared to pre-clenching values. Results: T-2 decreased by clenching, which reflected a decrease of tissue perfusion due to the mechanical pressure. It increased rapidly after the clenching (peak value, 1.11 +/- 0.03; peak time, 16.8 +/- 7.6 s after the clenching), which corresponded to the reactive hyperemia and later, it gradually returned to the initial values (half period, 2.22 +/- 0.84 min). The change in the SI of the b FFE was triphasic and similar to that of T-2 clenching. T-1 increased after the cessation of the clenching and later gradually decreased during the recovery periods. However, the change of T-1 was quite different from that of T-2, with a lower peak value (1.04 +/- 0.02), a later peak time (36.0 +/- 28.0 s), and a longer half period (4.76 +/- 3.40 min) (P < 0.0001, 0.0066, 0.02, respectively). Conclusion: The change in T-2 was triphasic and we considered that it predominantly reflected the tissue perfusion.

Non-mass-like enhancement on contrast-enhanced breast MR imaging: Lesion characterization using combination of dynamic contrast-enhanced and diffusion-weighted MR images

Hidetake Yabuuchi, Yoshio Matsuo, Takeshi Kamitani, Taro Setoguchi, Takashi Okafuji, Hiroyasu Soeda, Shuji Sakai, Masamitsu Hatakenaka, Makoto Kubo, Eriko Tokunaga, Hidetaka Yamamoto, Hiroshi Honda

EUROPEAN JOURNAL OF RADIOLOGY ( ELSEVIER IRELAND LTD ) 75 ( 1 ) E126 - E132 2010.07 [Refereed]

Purpose: To evaluate the diagnostic accuracy of a combination of dynamic contrast-enhanced MR imaging (DCE-MRI) and diffusion-weighted MR imaging (DWI) in characterization of lesions showing non-mass-like enhancement on breast MR imaging and to find the strongest discriminators between carcinoma and benignancy. Materials and methods: We analyzed consecutive MR images in 45 lesions showing non-mass like enhancement in 41 patients. We analyzed lesion size, distribution, internal enhancement, kinetic curve pattern, and apparent diffusion coefficient (ADC) values. We applied univariate and multivariate analyses to find the strongest indicators for malignancy. In a validation study, 22 non-mass-like enhancement lesions in 21 patients were examined. We calculated diagnostic accuracy when we presume category 4b, 4c, and 5 lesions as malignant or high to moderate suspicion for malignancy, and category 4a and 3 as low suspicion for malignancy or benign. Results: Segmental distribution (P = 0.018), clumped internal enhancement (P = 0.005), and ADC less than 1.3 x 10(-3) mm(2)/s (P = 0.047) were the strongest MR indicators of malignancy. In a validation study, sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 87% (13/15), 86% (6/7), 93% (13/14), 75% (6/8) and 86% (19/22), respectively. Conclusion: The combination of DCE-MRI and DWI showed high diagnostic accuracy in characterization of non-mass-like enhancement lesions on breast MR images. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

[Future of diagnostic radiology: prediction of treatment outcome using MRI].

Hatakenaka M, Yoshiura T, Shioyama Y, Honda H

Fukuoka igaku zasshi = Hukuoka acta medica ( 3 ) 101 41 - 45 2010.03 [Refereed]

Detection of Hepatocellular Carcinoma (HCC) Using Super Paramagnetic Iron Oxide (SPIO)-Enhanced MRI: Added Value of Diffusion-Weighted Imaging (DWI)

Akihiro Nishie, Tsuyoshi Tajima, Kousei Ishigami, Yasuhiro Ushijima, Daisuke Okamoto, Masakazu Hirakawa, Yunosuke Nishihara, Akinobu Taketomi, Masamitsu Hatakenaka, Hiroyuki Irie, Kengo Yoshimitsu, Hiroshi Honda

JOURNAL OF MAGNETIC RESONANCE IMAGING ( JOHN WILEY & SONS INC ) 31 ( 2 ) 373 - 382 2010.02 [Refereed]

Purpose: To evaluate whether diffusion-weighted imaging (DWI) improves the detection of hepatocellular carcinoma (HCC) on super paramagnetic iron oxide (SPIO)-enhanced MRI. Materials and Methods: This retrospective study group consisted of 30 patients with 50 HCC nodules who underwent MRI at 1.5 Tesla. Two combined MR sequence sets were compared for detecting HCC: SPIO-enhanced MRI (axial T2-weighted fast spin-echo (FSE) and T1-/T2*-weighted fast field echo (FFE) scanned before and after administration of ferucarbotran) and SPIO-enhanced MRI + DWI (SPIO-enhanced MRI With axial DWI scanned before and after administration of ferucarbotran). Three blinded readers independently reviewed for the presence of HCC on a segment-by-segment basis using a four-point confidence scale. The performance of the two combined MR sequence sets was evaluated using receiver operating characteristic (ROC) analysis. Results: The average area under the ROC curve (Az) of the three readers for the SPIO-enhanced MRI + DWI set (0.870 +/- 0.046) was significantly higher that that for the SPIO-enhanced MRI set (0.820 +/- 0.055) (P = .025). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for detection of HCC were 66.0%, 98.0%, 90.0%, and 91.4%, respectively, for the SPIO-enhanced MRI set, and 70.0%, 98.6%, 92.9%, and 92.4%, respectively, for the SPIO-enhanced MRI + DWI set. Conclusion: The SPIO-enhanced MRI + DWI set outperformed the SPIO-enhanced MRI set for depicting HCC.

Detection of breast cancer by soft-copy reading of digital mammograms: Comparison between a routine image-processing parameter and high-contrast parameters

Takeshi Kamitani, Hidetake Yabuuchi, Hiroyasu Soeda, Yoshio Matsuo, Takashi Okafuji, Shuji Sakai, Taro Setoguchi, Masamitsu Hatakenaka, Nobuhide Ishii, Hiroshi Honda

ACTA RADIOLOGICA ( TAYLOR & FRANCIS LTD ) 51 ( 1 ) 15 - 20 2010.02 [Refereed]

Background: Recent studies have reported the clinical usefulness of the soft-copy reading of mammograms. However, image-processing parameters for soft-copy reading of digital mammograms have not been established. Purpose: To compare observer performance in detecting breast cancer by soft-copy reading of digital mammograms using a routine image-processing parameter versus each of several high-contrast parameters. Material and Methods: The mammograms of 154 breasts, including 48 abnormal breasts with breast cancer and 106 normal breasts, were examined. Cancers were classified into 34 mass-dominant cancers, 11 microcalcification-dominant cancers, two cancers showing only architectural distortion, and one cancer without abnormal findings. All mammograms were performed using a computed radiography (CR) system. Each image was processed using GA (1.2), which was the contrast parameter recommended by the manufacturer for hard-copy film, GA (1.4), GA (1.6), and GA (1.8). These images were displayed on 5-megapixel (M) liquid-crystal display monitors. Five experienced radiologists classified them into BI-RADS category 1-2 or 3-5, and were also asked to rate the images on a scale of 0 to 100 for the likelihood of the presence of masses and microcalcifications in each breast. Results: In mass-dominant cancers of dense breast tissue, the mean sensitivities of GA (1.2), GA (1.4), GA (1.6), and GA (1.8) were 32.7, 38.2, 36.4, and 40.0, and the A(Z) values were 0.67, 0.73, 0.71, and 0.73, respectively; in microcalcification-dominant cancers, the mean sensitivities were 80.0, 74.5, 80.0, and 78.2, respectively; however, there were no significant differences among them. Conclusion: High-contrast parameters tended to show relatively high sensitivity and A(Z) values in the detection of masses in dense breast tissue, but relatively low sensitivity for microcalcifications.

Can calcification predict I-131 accumulation on metastatic lymph nodes in papillary thyroid carcinoma patients receiving I-131 therapy? Comparison of CT, I-131 WBS and F-18-FDG PET/CT

Koichiro Kaneko, Koichiro Abe, Shingo Baba, Yoshitaka Tanabe, Hidetake Yabuuchi, Masamitsu Hatakenaka, Masayuki Sasaki, Hiroshi Honda

EUROPEAN RADIOLOGY ( SPRINGER ) 20 ( 2 ) 477 - 483 2010.02 [Refereed]

The aim of this study was to clarify the predictive significance of nodal calcification in terms of the therapeutic option of I-131 therapy in papillary thyroid carcinoma (PTC) patients. We reviewed 19 computed tomography (CT) examinations of PTC patients on receiving I-131 therapy for the presence of nodal calcification, and compared the I-131 whole-body scintigraphy and F-18-2-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET)/CT findings. The metastatic lymph nodes (mLNs) were divided into three groups: A, those with calcification; B, those without calcification but belonging to patients who had calcified mLNs; C, those without calcification and belonging to patients who had no calcified mLNs. The incidences of I-131 accumulation and maximum standardised uptake values (SUV max) in the three groups were compared. A total of 70 mLNs were evaluated. Twelve mLNs belonged to group A, 13 to group B and 45 to group C. The incidences of I-131 accumulation were significantly higher in groups A (100%) and B (100%) than in group C (11.1%) (p < 0.0001 for both). The SUVmax was significantly lower in groups A (4.1 +/- 1.9) and B (3.9 +/- 1.4) than in group C (7.1 +/- 4.4) (p = 0.01, p = 0.002, respectively). Our results indicated that calcification in mLNs related to the ability of I-131 accumulation and less dedifferentiation.

Joint Position Affects Muscle Proton Diffusion: Evaluation With a 3-T MR System

Masamitsu Hatakenaka, Hidetake Yabuuchi, Shunya Sunami, Takeshi Kamitani, Yukihisa Takayama, Kei Nishikawa, Hiroshi Honda

AMERICAN JOURNAL OF ROENTGENOLOGY ( AMER ROENTGEN RAY SOC ) 194 ( 2 ) W208 - W211 2010.02 [Refereed]

OBJECTIVE. To determine whether joint position affects muscle proton diffusion, fractional anisotropy and primary (lambda(1)), secondary (lambda(2)), and tertiary (lambda(3)) eigenvalues of calf muscles were compared among ankle positions of plantar flexion, intermediate, and dorsiflexion. CONCLUSION. In tibialis anterior, fractional anisotropy and lambda(1) decreased, but lambda(2) and lambda(3) increased (p < 0.01) as the joint angle increased. Opposite results were obtained for the gastrocnemius and soleus (p < 0.05). These results indicate that joint position affects muscle proton diffusion.

Effect of clenching on T-2 and diffusion parameters of the masseter muscle

Toru Chikui, Tomoko Shiraishi, Takahiro Ichihara, Toshiyuki Kawazu, Masamitsu Hatakenaka, Yukiko Kami, Kenji Yuasa, Kazunori Yoshiura

ACTA RADIOLOGICA ( ROYAL SOC MEDICINE PRESS LTD ) 51 ( 1 ) 58 - 63 2010.02 [Refereed]

Background: Persistent muscle contractions during clenching are considered to be one reason for temporomandibular disorders. However, no report has evaluated the effect of clenching on the masticatory muscles, as measured by magnetic resonance imaging (MRI). Purpose: To investigate whether clenching has an effect on either T-2 or the coefficients for diffusion of the masseter muscles (MM), and to evaluate the effect of the distribution of bite force on such indices. Material and Methods: Twenty-three subjects were examined. Bite force was measured by a pressure-sensitive sheet, and the force of the right and the left sides was calculated. MRI was used to evaluate T-2, the apparent diffusion coefficient (ADC), and the primary (lambda 1), secondary (lambda 2),and tertiary eigenvalues (lambda 3). These indices on the stronger side of the bite force were compared to those on the weaker side. Thereafter, the indices were compared between at rest and during clenching. Results: There was no significant difference in any of the indices (T-2, ADC, lambda 1, lambda 2, and lambda 3) between the side of stronger bite force and the side with weaker. T-2 increased by clenching, and the difference was significant in the side with stronger bite force (P = 0.006). ADC, lambda 1, lambda 2, and lambda 3 increased significantly by clenching (P < 0.01, P < 0.01, P < 0.01, and P < 0.01, respectively) on both sides. The percentage of change of lambda 2 by clenching was 26.2 +/- 15.7% on the stronger side and 26.9 +/- 18.6% on the weaker side, which was significantly greater than either that of lambda 1 or lambda 3. Conclusion: The coefficients for diffusion of the MM were sensitive to change by clenching, and lambda 2 was the most sensitive. Moreover, the relative distribution of the bite forces had no effect on any of the indices.

Detection of Residual Lymph Node Metastases in High-Risk Papillary Thyroid Cancer Patients Receiving Adjuvant I-131 Therapy The Usefulness of F-18 FDG PET/CT

Koichiro Kaneko, Koichiro Abe, Shingo Baba, Takuro Isoda, Hidetake Yabuuchi, Masayuki Sasaki, Masamitsu Hatakenaka, Hiroshi Honda

CLINICAL NUCLEAR MEDICINE ( LIPPINCOTT WILLIAMS & WILKINS ) 35 ( 1 ) 6 - 11 2010.01 [Refereed]

Objective: The aims of this retrospective study were to evaluate the incidence of residual lymph node (LN) metastases in high-risk papillary thyroid cancer (PTC) patients receiving adjuvant I-131 therapy, especially in those without I-131 accumulation, and to evaluate the clinical usefulness of F-18 FDG PET/CT to detect those lesions. Methods: The 37 PTC patients receiving adjuvant I-131 therapy were retrospectively evaluated. We examined the incidence of residual LN metastasis and compared the accumulation of F-18 FDG and I-131 in those lesions, and compared the serum thyroglobulin (Tg) levels between patients with and without residual LN metastases. Result: A total of 33 lesions were diagnosed as residual LN metastases in 9 patients. FDG accumulated in all of the lesions, but 19 lesions (57.6%) of them had no I-131 accumulation. The SUVmax was significantly higher in lesions without I-131 accumulation than in lesions with I-131 accumulation (6.6 +/- 2.8 vs. 4.2 +/- 1.8; P = 0.007). The serum Tg levels were significantly higher in patients with residual LN metastases than in patients without it (709.9 +/- 1470.8 vs. 25.6 +/- 37.1 ng/mL; P = 0.005). The incidence of residual LN metastasis was significantly higher in patients with a detectable serum Tg level than in patients without it (35.0% vs. 0%, P = 0.03). Conclusion: These results indicate that the residual LN metastasis was relatively common in high-risk PTC patients receiving adjuvant I-131 therapy whose serum Tg levels remained detectable, and those lesions often had no I-131 accumulation, FDG-PET/CT would be recommended for PTC patients with detectable serum Tg levels to detect residual LN metastases.

A Simplified Method of T-1 rho Mapping in Clinical Assessment of Knee Joint

Yukihisa Takayama, Masamitsu Hatakenaka, Takashi Yoshiura, Ken Okazaki, Kei Nishikawa, Tomoyuki Okuaki, Ivan Zimine, Hiroshi Honda

MAGNETIC RESONANCE IN MEDICAL SCIENCES ( JPN SOC MAGNETIC RESONANCE IN MEDICINE ) 9 ( 4 ) 209 - 215 2010 [Refereed]

Purpose: We assessed the clinical utility of our proposed simplified method for T-1 rho mapping calculations. Materials and Methods: Ten healthy subjects underwent scanning on a 3-tesla magnetic resonance system using an 8-channel phased-array coil. For each subject, we obtained sagittal T-1 rho-prepared images using 5 different time of spin-lock pulses (TSL = 1, 20, 40, 60, and 80 ms), produced conventional T-1 rho maps (cT(1)rho maps) using all TSLs, and recomputed our proposed simplified T-1 rho maps (sT(1)rho maps) using a decreasing number of TSLs (from 4 to 2). We then investigated the differences and correlations in T-1 rho values of the tissues obtained using different numbers of spin-lock times. Results: There was a strong positive correlation (single measure intraclass correlation coefficient = 0.948; 95% confidence interval = 0.911 to 0.970) in T-1 rho values of tissues between the cT(1)rho and sT(1)rho [1, 80] maps. The 2 maps were comparable, though there was a small difference in T-1 rho value between the two. The total scan time to acquire the data from 5 spin-lock times was 16 min 15 s. Similarity of the T-1 rho [1, 80] map with the conventional approach reduced scan time by 60%, to 6 min 30 s. Conclusion: The clinical relevance of our proposed simplified method is potentially similar to that of the conventional method, and our method requires a shorter examination time and generally preserves the reliability of the T-1 rho relaxation time of the tissues.

A fast Look-Locker method for T (1) mapping of the head and neck region

Toru Chikui, Kenji Tokumori, Ryosuke Zeze, Tomoko Shiraishi, Takahiro Ichihara, Masamitsu Hatakenaka, Kazunori Yoshiura

ORAL RADIOLOGY ( SPRINGER ) 25 ( 1 ) 22 - 29 2009.06 [Refereed]

A sequence for T (1) relaxation time measurements that allows a high-resolution image to be obtained within a short acquisition time is described. Its application to the orofacial region is investigated. The sequence is based on the Look-Locker (LL) method and employs a magnetization-preparation pulse prior to data acquisition, with either a turbo-field echo (TFE) or turbo-field echo echo-planar imaging (TFEPI) sequence. We applied the multiple LL sequence by synchronizing the data acquisition with the virtual electrocardiogram. T (1) results from the LL sequence were compared with those from the inversion recovery (IR) sequence. In an in vitro study, we evaluated the T (1) maps of contrast medium at different concentrations. In an in vivo study, we evaluated the T (1) maps in seven volunteers. In the in vitro study, the correlation between the T (1) values obtained from the LL sequence and those from the IR sequence was high, with an R (2) of more than 0.99. For T (1) values between 200 and 1,500 ms, the difference between the two methods was less than 7%. In the in vivo study, a high correlation was observed between the T (1) values from the IR sequence and those from the LL sequence. The scan duration for the LL sequence was less than 3 min. Our method, based on the LL sequence, was found to be clinically useful for producing a T (1) map.

Nonspecific Interstitial Pneumonia After Peripheral Blood Stem Cell Transplantation in an 11-year-old boy

Keiji Matsumoto, Hidetake Yabuuchi, Yoshio Matsuo, Takeshi Kamitani, Taro Setoguchi, Shuji Sakai, Masamitsu Hatakenaka, Aiko Suminoe, Ichiro Yoshino, Masazumi Tsuneyoshi, Hiroshi Honda

JOURNAL OF THORACIC IMAGING ( LIPPINCOTT WILLIAMS & WILKINS ) 24 ( 1 ) 59 - 61 2009.02 [Refereed]

Late-onset pulmonary complications after peripheral blood stem cell transplantation include various conditions such as opportunistic infection, and interstitial pneumonias. It is Sometimes difficult to diagnose interstitial pneumonia, because there is substantial overlap in their computed tomography appearances. We present a case of an 11-year-old boy who consecutively developed pulmonary infection and cellular nonspecific interstitial pneumonia 9 months after peripheral blood stem cell transplantation for recurrent acute lymphocytic leukemia.

Computed tomographic and magnetic resonance features of inflammatory myofibroblastic tumor of the lung in children

Yukihisa Takayama, Hidetake Yabuuchi, Yoshio Matsuo, Hiroyasu Soeda, Takashi Okafuji, Takeshi Kamitani, Yoshiaki Kinoshita, Naoya Kubokura, Shuji Sakai, Yoshinao Oda, Masamitsu Hatakenaka, Hiroshi Honda

Radiation Medicine - Medical Imaging and Radiation Oncology ( 10 ) 26 ( 10 ) 613 - 617 2008.12 [Refereed]

We report two cases of inflammatory myofibroblastic tumor (IMT) of the lung in a 4-year-old boy and a 7-year-old girl. We performed dynamic contrastenhancement computed tomography in both of our cases and dynamic contrast enhancement magnetic resonance imaging (MRI) in one case. These dynamic studies showed a demarcated mass with delayed enhancement in both cases. A T1-weighted MR image shows a mass with homogeneous low signal intensity, and a T2- weighted image shows a mass with slightly high signal intensity. A post-contrast-enhanced T1-weighted image demonstrates homogeneous enhancement. We speculate that the delayed enhancement could be attributed to the abundant fibrous tissue, which was the main structural material of the tumor. This same finding has been described in previous reports of IMT in other organs. © 2008 Japan Radiological Society.

Parotid Gland Tumors: Can Addition of Diffusion-weighted MR Imaging to Dynamic Contrast-enhanced MR Imaging Improve Diagnostic Accuracy in Characterization?

Hidetake Yabuuchi, Yoshio Matsuo, Takeshi Kamitani, Taro Setoguchi, Takashi Okafuji, Hiroyasu Soeda, Shuji Sakai, Masamitsu Hatakenaka, Torahiko Nakashima, Yoshinao Oda, Hiroshi Honda

RADIOLOGY ( RADIOLOGICAL SOC NORTH AMERICA ) 249 ( 3 ) 909 - 916 2008.12 [Refereed]

Purpose: To determine the value of adding diffusion-weighted (DW) magnetic resonance (MR) imaging to dynamic contrast material-enhanced MR imaging when distinguishing between benign and malignant parotid tumors. Materials and Methods: This retrospective study was approved by the institutional review board, and the informed consent requirement was waived. The authors analyzed MR images of 50 lesions ( 36 benign, 14 malignant) in 47 patients. DW MR imaging and dynamic contrast-enhanced MR imaging were performed in all patients. Time-intensity curve ( TIC) patterns were categorized as follows: type A, time to peak was more than 120 seconds; type B, time to peak was 120 seconds or less with high washout ratio (>= 30%); type C, time to peak was 120 seconds or less with low washout ratio (< 30%); and type D, flat. The apparent diffusion coefficient ( ADC) values were measured on DW MR images. Sensitivity, specificity, accuracy, and positive and negative predictive values were calculated for type A, B, and D tumors regarded as benign and for type C tumors regarded as malignant. On the basis of DW MR imaging results, ADC threshold values between pleomorphic adenomas and carcinomas and between Warthin tumors and carcinomas were selected. Diagnostic accuracy was compared before and after modification diagnosis referring to the ADC value obtained with the McNemar test. P < .05 was considered to indicate a significant difference. Results: ADC threshold values were 1.4 x 10(-3) mm(2)/sec between pleomorphic adenomas and carcinomas and 1.0 x 10(-3) mm2/sec between Warthin tumors and carcinomas. Accuracy (82% vs 94%) and positive predictive value (67% vs 92%) significantly improved with the addition of ADC values in the evaluation of patients with type B or C tumors. Conclusion: A persistent or flat TIC pattern on dynamic contrast-enhanced MR images indicates benign disease, but there is added value from including the ADC value in the evaluation of tumors that show a plateau or washout TIC pattern. (C) RSNA, 2008

Computed tomographic and magnetic resonance features of inflammatory myofibroblastic tumor of the lung in children

Yukihisa Takayama, Hidetake Yabuuchi, Yoshio Matsuo, Hiroyasu Soeda, Takashi Okafuji, Takeshi Kamitani, Yoshiaki Kinoshita, Naoya Kubokura, Shuji Sakai, Yoshinao Oda, Masamitsu Hatakenaka, Hiroshi Honda

RADIATION MEDICINE ( SPRINGER ) 26 ( 10 ) 613 - 617 2008.12 [Refereed]

We report two cases of inflammatory myofibroblastic tumor (IMT) of the lung in a 4-year-old boy and a 7-year-old girl. We performed dynamic contrastenhancement computed tomography in both of our cases and dynamic contrast enhancement magnetic resonance imaging (MRI) in one case. These dynamic studies showed a demarcated mass with delayed enhancement in both cases. A T1-weighted MR image shows a mass with homogeneous low signal intensity, and a T2- weighted image shows a mass with slightly high signal intensity. A post-contrast-enhanced T1-weighted image demonstrates homogeneous enhancement. We speculate that the delayed enhancement could be attributed to the abundant fibrous tissue, which was the main structural material of the tumor. This same finding has been described in previous reports of IMT in other organs.

Enhanced Mass on Contrast-Enhanced Breast MR Imaging: Lesion Characterization Using Combination of Dynamic Contrast-Enhanced and Diffusion-Weighted MR Images

Hidetake Yabuuchi, Yoshio Matsuo, Takashi Okafuji, Takeshi Kamitani, Hiroyasu Soeda, Taro Setoguchi, Shuji Sakai, Masamitsu Hatakenaka, Makoto Kubo, Noriaki Sadanaga, Hidetaka Yamamoto, Hiroshi Honda

JOURNAL OF MAGNETIC RESONANCE IMAGING ( JOHN WILEY & SONS INC ) 28 ( 5 ) 1157 - 1165 2008.11 [Refereed]

Purpose: To evaluate the diagnostic accuracy of a combination of dynamic contrast-enhanced MR imaging (DCE-MRI) and diffusion-weighted MR imaging (DWI) in characterization of enhanced mass on breast MR imaging and to find the strongest discriminators between carcinoma and benignancy. Materials and Methods: We analyzed consecutive breast MR images in 270 patients; however, 13 lesions in 93 patients were excluded based on our criteria. We analyzed tumor size, shape, margin, internal mass enhancement, kinetic curve pattern, and apparent diffusion coefficient (ADC) values. We applied univariate and multivariate analyses to find the strongest indicators of malignancy and calculate a predictive probability for malignancy. We added the corresponding categories to these prediction probabilities for malignancy and calculated diagnostic accuracy when we consider category 4b, 4c, and 5 lesions as malignant and category 4a. 3. and 2 lesions as benign. In a validation study, 75 enhancing lesions In 71 patients were examined consecutively. Results: Irregular margin, heterogeneous internal enhancement, rim enhancement, plateau time-intensity curve (TIC) pattern, and washout TIC pattern were the strongest indicators of malignancy as well as past studies, and ADC values less than 1.1 X 10(-3) mm(2)/S were also the strongest indicators of malignancy. In a validation study, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 92% (56/61), 86% (12/14), 97% (56/58), 71% (12/17), and 91% (68/75), respectively. Conclusion: The combination of DWI and DCE-MRI could produce high diagnostic accuracy in the characterization of enhanced mass on breast MR Imaging.

Optimal gradation processing parameter for soft-copy reading of digital mammogram: Comparison between the parameter recommended for hard-copy and other parameters

Takeshi Kamitani, Hidetake Yabuuchi, Hiroyasu Soeda, Yoshio Matsuo, Takashi Okafuji, Taro Setoguchi, Shuji Sakai, Masamitsu Hatakenaka, Nobuhide Ishii, Hiroshi Honda

EUROPEAN JOURNAL OF RADIOLOGY ( ELSEVIER IRELAND LTD ) 66 ( 2 ) 309 - 312 2008.05 [Refereed]

Purpose: To investigate optimal gradation processing parameter for soft-copy reading comparing the parameter recommended for hard-copy with other parameters. Materials and methods: Digital mammograms using a Computed Radiography system were evaluated. The gradation processing parameter recommended by the manufacturer was GA (1.2). We prepared seven parameters that changed the degree of contrast: GA (0.6, 0.8, 1.0, 1.2, 1.4, 1.6, and 1.8). Images of an anthropomorphic breast phantom were displayed on a 5-megapixel liquid crystal display monitor using each parameter. Three readers independently assessed each image, and scored for the following items: intramammary contrast, extramammary contrast, sharpness, and graininess. Total score was calculated in each parameter. We also displayed normal mammograms of nine cases: three with a scattered fibroglandular density, three with a heterogeneously dense breast, and three with an extremely dense breast. These were displayed using GA (1.2) or using parameters with a higher total score than GA (1.2) in the phantom test. Three readers assessed each mammogram as in the phantom test. Results: In phantom test, GA (1.4), GA (1.6), and GA (1.8) obtained higher scores than GA (1.2). In normal cases tested using these parameters, GA (1.4) obtained the highest score. This was significantly higher than that of GA (1.2) (P = 0.004). The score obtained for GA (1.4) was the highest in cases with extremely dense and heterogeneously dense breast tissue, though there was no statistically significant difference. Conclusion: Soft-copy image quality was improved by gradient processing using higher contrast parameter than that routinely used in hard-copy, especially in dense breast cases. (C) 2007 Etsevier Ireland Ltd. All rights reserved.

Alteration of proton diffusivity associated with passive muscle extension and contraction

Masamitsu Hatakenaka, Yoshio Matsuo, Taro Setoguchi, Hidetake Yabuuchi, Takashi Okafuji, Takeshi Karnitani, Kei Nishikawa, Hiroshi Honda

JOURNAL OF MAGNETIC RESONANCE IMAGING ( JOHN WILEY & SONS INC ) 27 ( 4 ) 932 - 937 2008.04 [Refereed]

Purpose: To determine whether passive muscle extension and contraction affect the proton diffusivity of the muscle. Materials and Methods: Five male subjects were examined. The fractional anisotropy (FA), and primary (lambda(1)), secondary (lambda(2)), and tertiary eigenvalues (lambda(3)) of the right tibialis anterior and medial gastrocnemius muscles were compared between conditions of passive plantar flexion and passive dorsiflexion of the ankle joint. Results: In the tibialis anterior, FA, and lambda(1) at dorsiflexion decreased significantly (P < 0.01 and P < 0.01, respectively) compared to those at plantar flexion, but lambda(3) at dorsiflexion increased significantly (P = 0.02). In the gastrocnemius, FA and lambda(1) at dorsiflexion increased significantly (P < 0.0 1 and P < 0.0 1, respectively) compared to those at plantar flexion, but lambda(3) at dorsiflexion decreased significantly (P < 0.01). The lambda(2) value showed no significant change in either the tibialis anterior or medial gastrocnemius. Conclusion: The results indicate that passive muscle extension and contraction associated with passive joint movement would affect the proton diffusivity of the muscle. This alteration of proton diffusivity is probably associated with microscopic structural changes of the muscle.

Apparent diffusion coefficients of breast tumors: Clinical application

Masamitsu Hatakenaka, Hiroyasu Soeda, Hidetake Yabuuchi, Yoshio Matsuo, Takeshi Kamitani, Yoshinao Oda, Masazumi Tsuneyoshi, Hiroshi Honda

Magnetic Resonance in Medical Sciences ( 1 ) 7 ( 1 ) 23 - 29 2008 [Refereed]

Purpose: To evaluate the usefulness of apparent diffiusion coefficient (ADC) for the differential diagnosis of breast tumors and to determine the relation between ADC and tumor cellularity. Materials and Methods: One hundred and thirty-six female patients (age range, 17-83 years average age, 51.7 years) with 140 histologically proven breast tumors underwent diffusion-weighted magnetic resonance (MR) imaging (DWI) using the spin-echo echo-planar technique, and the ADCs of the tumors were calculated using 3 different b values, 0, 500, and 1000 s/mm2. The diagnoses consisted of fibroadenoma (FA, n=16), invasive ductal carcinoma, not otherwise specified (IDC, n=117), medullary carcinoma (ME, n=3) and mucinous carcinoma (MU, n=4). Tumor cellularity was calculated from surgical specimens. The ADCs of breast tumors and cellularity were compared between different histological types by analysis of variance and Scheffe's post hoc test. The correlation between tumor cellularity and ADC was analyzed by Pearson correlation test. Results: Significant differences were observed in ADCs between FA and all types of cancers (P< 0.05) and between MU and other types of cancers (P< 0.01) and in cellularity between FA and cancers except MU (P< 0.01) and between MU and other types of cancers (P< 0.01). There was an inverse correlation between ADC and tumor cellularity (P< 0.01, r2=0.451). Conclusions: The ADC may potentially help in differentiating benign and malignant breast tumors. Tumor ADC correlates inversely with tumor cellularity.

Circumscribed mass lesions on mammography: Dynamic contrast-enhanced MR imaging to differentiate malignancy and benignancy

Takashi Okafuji, Hidetake Yabuuchi, Hiroyasu Soeda, Yoshio Matsuo, Takeshi Kamitani, Shuji Sakai, Masamitsu Hatakenaka, Syoji Kuroki, Eriko Tokunaga, Hidetaka Yamamoto, Hiroshi Honda

Magnetic Resonance in Medical Sciences ( 4 ) 7 ( 4 ) 195 - 204 2008 [Refereed]

Purpose: We evaluated the magnetic resonance (MR) features of breast lesions showing circumscribed mass on mammography to understand the characteristics that differentiate malignancy and benignancy. Materials and Methods: Our institutional review board approved the study, and informed consent was waived. Using logistic regression analysis, we examined morphologic and kinetic MR imaging data of 90 breast lesions (43 malignant, 47 benign) that showed circumscribed mass on mammography. Results: Features identified as having high odds for malignancy included: rim enhancement (odds ratio, 70.894 95% confidence interval (CI), 7.525-667.938) heterogeneous enhancement (odds ratio, 10.839 95z CI, 1.032-113.856) and washout dynamic pattern (odds ratio, 46.262 95z CI, 3.716-575.901). Combinations of washout dynamic pattern and either rim or heterogeneous enhancement reflected excessively high prediction probability for malignancy (> 0.95), whereas combinations lacking washout dynamic pattern and with either homogeneous enhancement or dark internal septation revealed excessively low prediction probability for malignancy (< 0.05). Conclusion: Breast cancers with circumscribed mass on mammography could be differentiated from benign masses using internal enhancement and the kinetic pattern of contrast-enhanced breast MR imaging.

Effect of passive muscle length change on apparent diffusion coefficient: Detection with clinical MR imaging

Masamitsu Hatakenaka, Hidetake Yabuuchi, Yoshio Matsuo, Takashi Okafuji, Takeshi Kamitani, Taro Setoguchi, Kei Nishikawa, Hiroshi Honda

Magnetic Resonance in Medical Sciences ( 2 ) 7 ( 2 ) 59 - 63 2008 [Refereed]

Purpose: We investigated whether change in muscle microstructure associated with passive extension and contraction affects proton diffusivity. Material and Methods: In 6 male subjects, we compared apparent diffusion coefficients (ADC) along the posterior-to-anterior (ADC-PA), right-to-left (ADC-RL) and superior-to-inferior (ADC-SI) directions of the right tibialis anterior muscle with the ankle joint in passive plantar flexion and passive dorsiflexion. Results: Compared to the respective ADCs at plantar flexion, the ADC-PA (P=0.002) and ADC-RL (P=0.008) were significantly greater, but ADC-SI (P=0.008) significantly lower at dorsiflexion. Conclusion: Our results indicate that change in muscle microstructure associated with passive extension and contraction would affect proton diffusivity, and this alteration of proton diffusivity could be detected by measuring ADC with a clinical magnetic resonance scanner.

In vitro imaging of human monocytic cellular activity using superparamagnetic iron oxide

Akihiro Nishie, Kengo Yoshimitsu, Tomohiro Nakayama, Masamitsu Hatakenaka, Hiroyuki Irie, Yoshiyuki Shioyama, Shuji Matsuura, Yunosuke Nishihara, Koji Kobayashi, Hiroshi Honda

COMPUTERIZED MEDICAL IMAGING AND GRAPHICS ( PERGAMON-ELSEVIER SCIENCE LTD ) 31 ( 8 ) 638 - 642 2007.12 [Refereed]

The aim is to evaluate if a difference in activity of monocytic cells can be described on superparamagnetic iron oxide (SPIO)-magnetic resonance imaging (MRI) in vitro when a low concentration of SPIO is administered. Human monocytic cells were stimulated with phorbol 12-myristate 13-acetate (PMA) or left non-stimulated for 24 It and then treated with SPIO with a final concentration of 7.2 mu g Fe/ml for 48 h. They were collected, and an MRI phantom was prepared by suspending them in 4% gelatin and scanned using gradient-echo T2*-weighted and spin-echo T2-weighted imaging with two different echo times. The signal intensity and T2*/T2 relaxation times of each layer were also assessed. The number and degree of intracellular filling of cells positively stained with Berlin blue were evaluated microscopically. In addition, the heme oxygenase-1 expression in non-stimulated monocytic cells or monocytic cells stimulated with PMA was evaluated using semiquantitative reverse transcription and polymerase chain reaction. The signal reduction of cells stimulated with PMA was 3.9- to 5.0-fold and 2.7- to 3.1-fold greater than that of non-stimulated cells on the T2* and T2-weighted images, respectively. These signal reductions were also visually confirmed. Estimated T2*/T2 relaxation times of cells stimulated with PMA and non-stimulated cells were 31.3/137.8 and 122.8/182.6 ms, respectively. Cells positively stained with Berlin blue were observed in 4.5% and 25.3% of non-stimulated cells and those stimulated with PMA, respectively (p < 0.05). The intracellular filling in cells stimulated with PMA was significantly larger than that in non-stimulated cells (p < 0.05). The expression of the heme oxygenase-1 gene in monocytic cells stimulated with PMA was 2.9-fold greater than that in non-stimulated monocytic cells. SPIO-MRI can visually describe a difference in activity of monocytic cells in vitro when a low concentration of SPIO is administered. (c) 2007 Elsevier Ltd. All rights reserved.

Detection of masses and microcalcifications of breast cancer on digital mammograms: comparison among hard-copy film, 3-megapixel liquid crystal display (LCD) monitors and 5-megapixel LCD monitors: an observer performance study

Takeshi Kamitani, Hidetake Yabuuchi, Hiroyasu Soeda, Yoshio Matsuo, Takashi Okafuji, Shuji Sakai, Akio Furuya, Masamitsu Hatakenaka, Nobuhide Ishii, Hiroshi Honda

EUROPEAN RADIOLOGY ( SPRINGER ) 17 ( 5 ) 1365 - 1371 2007.05 [Refereed]

The purpose of the study was to compare observer performance in the detection of masses and microcalcifications of breast cancer among hard-copy reading and soft-copy readings using 3-megapixel (3M) and 5-megapixel (5M) liquid crystal display (LCD) monitors. For the microcalcification detection test, we prepared 100 mammograms: 40 surgically verified cancer cases and 60 normal cases. For the mass detection test, we prepared 100 mammograms: 50 cancer cases and 50 normal cases. After six readers assessed both microcalcifications and masses set for each modality, receiver operating characteristic (ROC) analysis was performed. The average A(z)s for mass detection using a hard copy and 3M and 5M LCD monitors were 0.923, 0.927 and 0.920, respectively; there were no significant differences. The average A(z) for microcalcification detection using hard copy, 3M and 5M LCD monitors was 0.977, 0.954 and 0.972, respectively. There were no significant differences, but the P-values between the hard copy and 3M LCD monitor and that between the 3M and 5M LCD monitor were 0.08 and 0.09, respectively. In conclusion, the observer performances for detecting masses of breast cancers were comparable among the hard copy and two LCD monitors; however, soft-copy reading with a 3M LCD monitor showed slightly lower observer performance for detecting microcalcifications of breast cancers than hard-copy or 5M LCD monitor reading.

Familial turner mosaicism 46XX/45XO with brain calcification [5]

Toyoki Maeda, Masahiro Sugano, Jing-Zhi Guan, Jun-Ichi Oyama, Yoshihiro Higuchi, Naoki Makino, Masamitsu Hatakenaka, Hiromi Muta, Masaharu Nakayama, Yukoh Nakazaki, Ryo Kurita, Takashi Hiroyama, Tomokazu Suzuki, Kenzaburo Tani

Journal of Neuropsychiatry and Clinical Neurosciences ( American Psychiatric Publishing Inc. ) 19 ( 3 ) 342 - 343 2007 [Refereed]

MR imaging features of pure mucinous carcinoma of the breast

Takashi Okafuji, Hidetake Yabuuchi, Shuji Sakai, Hiroyasu Soeda, Yoshio Matsuo, Takahiro Inoue, Masamitsu Hatakenaka, Naoki Takahashi, Syoji Kuroki, Eriko Tokunaga, Hiroshi Honda

EUROPEAN JOURNAL OF RADIOLOGY ( ELSEVIER IRELAND LTD ) 60 ( 3 ) 405 - 413 2006.12 [Refereed]

Objective: To characterize MR imaging features of pure mucinous carcinoma of the breast. Materials and methods: MR images obtained from 16 women (age range, 29-81; mean age, 57 years) with pure mucinous carcinoma of the breast determined at surgery were reviewed. The MR findings used were shape, margin, internal mass enhancement, kinetic curve pattern on dynamic study, signal intensity on short time inversion recovery (STIR) T2-weighted images, and non-mass-like enhancement around the main tumor. Non-mass-like enhancement was compared with the presence of extensive intraductal component (EIC) on histopathological findings. Results: Eleven tumors (69%) had lobular contour, and nine tumors (56%) had smooth margin. Eight tumors (50%) showed rim enhancement and six tumors (38%) showed heterogeneous enhancement. Fourteen tumors (88%) showed a persistent enhancing pattern on kinetic curve. Fifteen tumors exhibited homogenous strongly high signal intensity on STIR T2-weighted images. In six cases with EIC, five cases had non-mass-like enhancement around the main mass. Conclusions: MR findings such as lobular shape, rim or heterogeneous enhancement, persistent pattern on kinetic curve, and homogeneous strongly high signal intensity on STIR T2-weighted images may be useful in diagnosing pure mucinous carcinoma. Moreover, linear-ductal enhancement around main mass may indicate presence of EIC. (C) 2006 Elsevier Ireland Ltd. All rights reserved.

Phyllodes tumor of the breast: Correlation between MR findings and histologic grade

Hidelake Yabuuchi, Hiroyasu Soeda, Yoshio Matsuo, Takashi Okafuji, Takashi Eguchi, Shuji Sakai, Syoji Kuroki, Eriko Tokunaga, Shinji Ohno, Kenichi Nishiyama, Masamitsu Hatakenaka, Hiroshi Honda

RADIOLOGY ( RADIOLOGICAL SOC NORTH AMERICA ) 241 ( 3 ) 702 - 709 2006.12 [Refereed]

Purpose: To retrospectively evaluate the magnetic resonance (MR) aging findings of phyllodes tumor of the breast and to Uro, compare these findings with the histologic grade. Materials and Methods: Institutional review board approval and informed consent were obtained. The authors reviewed the MR findings in 30 female patients aged 16-73 years (mean, 40.2 years) with surgically confirmed phyllodes tumors. Analyzed MR findings included tumor, shape, margin, internal enhancement, and size; signal intensity (SI) of tumor higher than that of normal breast tissue on T1-weighted images; SI of tumor lower than or equal to that of normal tissue on T2-weighted images; cyst wall appearance; kinetic curve assessment; and apparent diffusion coefficient (ADC). The MR findings and histologic, grade were statistically analyzed to determine whether any correlations existed. Significant MR findings were compared with histopathologic findings. Results: Nineteen benign, six intermediate (characterized by five to nine cell reproductions at 10 high-power fields, pushing or infiltrative margins, moderate stromal cellularity, and atypia and overgrowth), and five malignant phyllodes tumors were assessed. Irregular cyst wall (P = .003), tumor SI lower than or equal to normal tissue SI on T2-weighted images (P = .005), and low ADC (P = .001) correlated significantly with histologic grade. Tumor SI higher than normal tissue SI on T1-weighted images was more frequent in the malignant (in three of five tumors) and inter mediate (in three of six tumors) groups than in the benign group (in two of 19 tumors); however, it was not a significant finding (P = .024). Tumor SI higher than normal tissue SI on T1-weighted images and irregular cyst wall corresponded histopathologically to hemorrhagic infarction and necrosis, respectively. Tumor SI lower than or equal to normal tissue SI on T2-weighted images and low ADC corresponded histopathologically to stromal hyper- cellularity. Other findings were not significant. Conclusion: Several MR findings can be used to help determine the histologic grade of phyllodes breast tumors.

Pulmonary lesions associated with visceral larva migrans due to Ascaris suum or Toxocara canis: Imaging of six cases

S Sakai, Y Shida, N Takahashi, H Yabuuchi, H Soeda, T Okafuji, M Hatakenaka, H Honda

AMERICAN JOURNAL OF ROENTGENOLOGY ( AMER ROENTGEN RAY SOC ) 186 ( 6 ) 1697 - 1702 2006.06 [Refereed]

OBJECTIVE. The objective of our study was to evaluate chest radiographic and CT findings of patients with pulmonary lesions associated with visceral larva migrans due to Ascaris suum or Toxocara canis. CT investigation was focused on the location, size, contour, and internal features of the lesions; migration of lesions; mediastinal lymphadenopathy; and pleural effusion. CONCLUSION. Pulmonary visceral larva migrans appears on CT as multifocal subpleural nodules with halo or ground-glass opacities and ill-defined margins.

A case of lymphangioleiomyomatosis affecting the supraclavicular lymph nodes

T Kamitani, H Yabuuchi, H Soeda, Y Matsuo, T Okafuji, S Sakai, M Hatakenaka, T Minami, H Inoue, A Tanaka, H Kohno, M Tanaka, Y Nakashima, H Honda

JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY ( LIPPINCOTT WILLIAMS & WILKINS ) 30 ( 2 ) 279 - 282 2006.03 [Refereed]

The case of a 46-year-old woman with lymphangioleiomyomatosis (LAM) involving the supraclavicular, mediastinal, and pelvic lymph nodes in addition to the lungs is reported. Computed tomography incidentally revealed multiple thin-walled pulmonary cysts and low-attenuating masses in the supraclavicular, mediastinal, and retroperitoneal lymph nodes. A biopsy of the supraclavicular mass was performed and diagnosed as LAM histopathologically. The common sites of extrapulmonary LAM include retroperitoneal and mediastinal lymph nodes; however, supraclavicular lymph node involvement is extremely rare.

Steroid myopathy: Evaluation of fiber atrophy with T2 relaxation time - Rabbit and human study

M Hatakenaka, H Soeda, T Okafuji, H Yabuuchi, S Shiokawa, J Nishimura, H Honda

RADIOLOGY ( RADIOLOGICAL SOC NORTH AMERICA ) 238 ( 2 ) 650 - 657 2006.02 [Refereed]

Purpose: To determine whether muscle fiber atrophy associated with steroid myopathy can be detected with T2 relaxation time. Materials and Methods: Animal and human studies were approved by the ethics committee. Informed consent was obtained. Twelve rabbits were divided into a group that received 3 mg/kg of triamcinolone subcutaneously each day for 10 consecutive days (n = 6) and a control group that received saline (n = 6). Magnetic resonance (MR) imaging was performed before and after treatment. T2 and fat deposition ratio (FDR) of soleus and gastrocnemius muscles before and after treatment and between control rabbits and rabbits treated with steroids were compared by using two-way repeated analysis of variance and Bonferroni post hoc test to evaluate effects of steroid treatment. After imaging, rabbits were sacrificed. Extracellular space ratio (ECSR) and fiber diameter were examined. Correlation among T2, ECSR, and diameter of type 2 muscle fibers was analyzed with a Pearson correlation test with Bonferroni correction in gastrocnemius to determine factors affecting T2. In humans, T2 relaxation time and FDR of both muscles were compared between volunteers not treated with steroids and patients treated with steroids by using an unpaired t test to evaluate the effects of steroids. Results: In rabbits, T2 of gastrocnemius muscle was significantly (P < .01) longer after steroid treatment than before steroid treatment and was also significantly (P < .01) longer than after saline administration. T2 of the gastrocnemius showed no significant difference in control rabbits before or after saline administration or in control rabbits and rabbits before steroid administration. T2 of the soleus muscle or FDR of either muscle showed no significant difference. There was a significant correlation (P < .01) among T2, ECSR, and diameter of type 2 muscle fibers in the gastrocnemius. In humans, T2 of the gastrocnemius was significantly (P < .01) longer in patients than in volunteers. T2 of the soleus or FDR of either muscle showed no significant difference. Conclusion: Muscle fiber atrophy associated with steroid myopathy is detectable as prolongation of T2 relaxation time in the gastrocnemius muscle; the authors believe prolongation of T2 relaxation time is mainly due to increased ECSR reflecting type 2 muscle fiber atrophy. (c) RSNA, 2005.

Gorham's disease of the chest wall - CT and MR characteristics

T Okafuji, H Yabuuchi, H Soeda, N Takahashi, M Hatakenaka, S Sakai, Y Nishihara, N Noda, Inoshima, I, H Honda

JOURNAL OF THORACIC IMAGING ( LIPPINCOTT WILLIAMS & WILKINS ) 20 ( 4 ) 284 - 287 2005.11 [Refereed]

We report a case of Gorham's disease of the chest wall in a 29-year-old man. A chest radiograph showed osteolysis of the left first, second, and third ribs. CT and MR images revealed a soft tissue mass around the affected ribs. The mass presented as having heterogeneous high signal intensity on T2-weighted MR images, and it showed minimal enhancement on contrast-enhanced MR images. A histologic specimen obtained by incisional. biopsy from the left third rib revealed proliferation of lymphangiomatous tissue in the bone marrow. A diagnosis of Gorham's disease was made based on these clinical, radiologic, and histologic findings.

Clinically mild, atypical, and aged craniofacial syndrome is diagnosed as Crouzon syndrome by identification of a point mutation in the fibroblast growth factor receptor 2 gene (FGFR2)

T Maeda, M Hatakenaka, H Muta, M Nakayama, Y Nakazaki, T Hiroyama, T Suzuki, K Tani

INTERNAL MEDICINE ( JAPAN SOC INTERNAL MEDICINE ) 43 ( 5 ) 432 - 435 2004.05 [Refereed]

A 53-year-old Japanese woman presented with mild mental retardation, short stature, hypertelorism, saddle nose, vertebral fusion, and hydrocephalus, implying an underlying bone growth impairment mainly of the head and neck. A point mutation in fibroblast growth factor receptor 2 (FGFR2) was identified that had previously been seen only in sporadic cases of Crouzon syndrome. This patient did not exhibit any of the typical features of Crouzon syndrome primarily seen in affected infants, such as a severely deformed skull, an apical shaped skull, or severe mental retardation. The patient was diagnosed with a mild form of Crouzon syndrome. The patient's symptoms very early in life may have been ameliorated and modified through growth and aging. The age-related phenotype modifications in Crouzon syndrome are discussed.

Transient uterine myometrial contraction associated with moles

M Hatakenaka, K Yoshimitsu, T Adachi, T Matsuda, N Wake, H Honda

JOURNAL OF MAGNETIC RESONANCE IMAGING ( JOHN WILEY & SONS INC ) 19 ( 2 ) 182 - 187 2004.02 [Refereed]

Purpose: To examine the incidence of transient distortion of uterine central tissue and myometrial hypointense areas observed on MR images in women with clinically suspicious moles. Materials and Methods: The study population consisted of six women aged 15-47 years with clinically suspicious moles (hydatidiform mole in four, invasive mole in one, and microscopic mole in one). The control study population was 105 reproductive-age women (18-52 years) without uterine malignancy, gestational trophoblastic disease, or pregnancy. MR images were analyzed to check for discrepancies of the uterine central tissue configuration. If a discrepancy was observed, the myometrial hypointense area, its diameter, and changes in its shape and location were analyzed. Results: Differences in uterine central tissue configuration and hypointense areas were observed in all six patients. In the control study, only seven cases showed uterine endometrial distortion, and five exhibited hypointense areas. These areas disappeared, changed in shape, or other hypointense areas appeared on subsequent MR images. Significant differences (P<0.01) in the incidence of uterine central tissue distortion and hypointense areas, and in their maximum diameter between the study and the control groups were observed. Conclusion: Uterine myometrial hypointense areas with central tissue distortion, most likely due to transient myometrial contraction, are frequently seen in women with clinically suspicious moles.

Xanthogranulomatous cholecystitis: importance of chemical-shift gradient-echo MR imaging

M Hatakenaka, T Adachi, A Matsuyama, M Mori, Y Yoshikawa

EUROPEAN RADIOLOGY ( SPRINGER-VERLAG ) 13 ( 9 ) 2233 - 2235 2003.09 [Refereed]

Gallium-67 scintigraphy in the diagnosis and the management of chronic sarcoid myopathy

S. Suehiro, Sahasu Shiokawa, S. Taniguchi, Y. Sakai, H. Goda, M. Shiratsuchi, T. Sugimura, M. Hatakenaka, Y. Yoshikawa, S. Ikuyama, J. Nishimura

Clinical Rheumatology 22 ( 2 ) 146 - 148 2003.05 [Refereed]

The authors describe a patient with chronic sarcoid myopathy. Except for the presence of left posterior synechia, no other organ involvement was observed. Gallium-67 (67Ga) scintigraphy showed many intense nodular uptake areas in both the upper and lower extremities. Treatment with oral prednisolone 30 mg/day resulted in a marked improvement on 67Ga scintigraphy. This case suggests that 67Ga scintigraphy is useful for the differential diagnosis of systemic myopathies and also for monitoring the effect of glucocorticoid treatment.

Effect of muscular contraction on magnetization transfer detected at 1.5T

Masamitsu Hatakenaka

Magnetic Resonance in Medical Sciences ( 3 ) 2 ( 3 ) 151 - 154 2003 [Refereed]

The effect of rigor (formation of actomyosin complexes) on magnetization transfer was observed with a 1.5T clinical magnetic resonance (MR) imaging system. The magnetization transfer ratio of chemically skinned (calcium-sensitive) muscle fiber preparations increased much more in a rigor state than in a relaxed state, while that of calcium-insensitive fiber preparations and solutions showed no difference. These results suggest that the formation of actomyosin complexes increased the magnetization transfer ratio. A clinical MR system is not only effective for medical imaging, but also has the potential to demonstrate physiological characteristics.

Expression of the c-myc end c-fos genes as a potential indicator of late radiation damage to the kidney

M Otsuka, M Hatakenaka, K Ishigami, K Masuda

INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS ( ELSEVIER SCIENCE INC ) 49 ( 1 ) 169 - 173 2001.01 [Refereed]

Purpose: To evaluate proliferative response according to c-myc and c-fos gene expression as an early indicator of late radiation damage to the kidney. Methods and Materials: c-myc and c-fos gene expression was measured in the irradiated kidney of C3H/HeSlc mice using reverse transcriptase-polymerase chain reaction (RT-PCR) 24 h after 9, 12, and 15 Gy as well as 2 and 7 days after 15 Gy, In a second experiment, 12 Gy was administered to the right kidney plus the lower half of left kidney. The mice underwent left nephrectomy 24 h after, and the correlation between increased gene expression and elevation of the blood urea nitrogen (BUN) level representing late functional damage was investigated. Results: c-myc and c-fos expression increased in 1 of 10 controls and in 8 of 10 and 7 of 10 mice that received 15 Gy, respectively. Expression increased dose-dependently from 9 to 15 Gy, In mice having an increased BUN level, 7 of 10 and 8 of 10 were positive for c-myc and c-fos, respectively, All 6 mice having an unchanged BUN level were negative for e-fos, while 5 were negative for c-myc. Conclusion: Measurement of c-myc and c-fos gene expression is potentially an early indicator of late radiation damage to the kidney. (C) 2001 Elsevier Science Inc.

MR imaging findings of uterine endometrial stromal sarcoma: differentiation from endometrial carcinoma

M Ueda, M Otsuka, M Hatakenaka, S Sakai, M Ono, K Yoshimitsu, H Honda, Y Torii

EUROPEAN RADIOLOGY ( SPRINGER-VERLAG ) 11 ( 1 ) 28 - 33 2001 [Refereed]

Endometrial stromal sarcoma (ESS) is a rare malignant neoplasm of the uterus. We retrospectively analyzed pelvic MR imaging in 8 cases of ESS to determine the characteristic MR findings of ESS. Magnetic resonance images of 8 cases of ESS were evaluated for findings including the size, margin of the tumor, nodular lesions at the tumor margin, intramyometrial wormlike nodular extension, multiple nodular mass formation, hemorrhage, and necrosis in the tumor. The degree of contrast enhancement was also analyzed. The MR imaging findings of 21 consecutive cases of endometrial carcinoma (EC) were also evaluated and compared with those of ESS. The mean and the standard deviation of the maximum diameter of ESS and EC were 8.80 +/- 4.99 and 3.93 +/- 2.47 cm, respectively. Increased enhancement in at least a part of the tumor was observed in five of the six analyzed ESS cases and in 2 of 12 analyzed EC cases. The irregular margin, nodular lesions at the margin, intramyometriar nodular extension, and multiple nodular mass formation were more frequently seen in cases of ESS than in cases of EC. Magnetic resonance imaging can play a role in both diagnosing ESS as well as in differentiating ESS from EC.

Gene and protein expression of epidermal growth factor measured on the kidney 24 hours after irradiation correlates to late radiation damage

Makoto Otsuka, Masamitsu Hatakenaka

Journal of JASTRO 13 ( 4 ) 197 - 201 2001 [Refereed]

Purpose: This study was designed to evaluate the proliferative response of epidermal growth factor (EOF) gene expression as an early indicator of late renal radiation damage. Materials and Methods: EGF gene expression was measured in the irradiated left kidney of C3H/HeSlc mice using RT-PCR 24 hours after radiation doses of 9, 12, or 15 Gy. In a second experiment, the same radiation doses were administered to the right kidney plus the lower half of the left kidney. The partly irradiated left kidneys were harvested and EGF gene expression was measured. The irradiated whole right kidneys were subjected to immunohistochemical staining for EGF protein. In a third experiment, 12 Gy was administered to the right kidney plus the lower half of the left kidney. The mice underwent left nephrectomy 24 hours after radiation, and the EGF gene expression in the kidney was correlated with the blood urea nitrogen (BUN) level representing late renal functional damage. Results: EGF expression increased in 1 of 10 control mice and in 9 of 10 mice that received 15 Gy. The extent of increase of EGF was dependent on radiation dose. In mice having an increased BUN level after irradiation, 7 of 10 had EGF positive irradiated kidneys. All six mice whose BUN levels were unchanged had EGF-negative irradiated kidneys. EGF protein staining was observed in tubule cells only, not in glomerular cells. The amount of EGF protein staining correlated with radiation dose to some extent. Conclusions: EGF gene expression seems to be a very early indicator of late radiation damage to the kidney. © 2001, Japanese Society for Therapeutic Radiology and Oncology. All rights reserved.

Uterine endometrial stromal sarcoma located in uterine myometrium: MRI appearance

M Ueda, M Otsuka, M Hatakenaka, Y Torii

EUROPEAN RADIOLOGY ( SPRINGER VERLAG ) 10 ( 5 ) 780 - 782 2000 [Refereed]

Penetrating atherosclerotic ulcer at the proximal aorta complicated with cardiac tamponade and aortic valve regurgitation

K. I. Yano, N. Makino, H. Hirayama, M. Hatakenaka, H. Matsui, T. Soeda, T. Hadama

Japanese Circulation Journal 63 ( 3 ) 228 - 230 1999 [Refereed]

Effect of caffeine on the mental calculation

N. Suenaga, T. Inamitsu, M. Hatakenaka, F. Yanaga, F. Shiraishi

Fukuoka Acta Medica 88 ( 2 ) 27 - 29 1997 [Refereed]

Phosphatidic acid induces the release of β-glucuronidase but not lactoferrin from electropermeabilized human neutrophils

Wahid Zaman, Takashi Mitsuyama, Masamitsu Hatakenaka, Dongchon Kang, Shigeki Minakami, Koichiro Takeshige

Journal of Biochemistry ( Oxford University Press ) 115 ( 2 ) 238 - 244 1994 [Refereed]

We studied the degranulation reaction of electropermeabilized human neutrophils induced by 1,2-didecanoyl-3-sn-phosphatidic acid (PA10). PA10 dose-dependently induced the release of β-glucuronidase, an enzyme of azurophil granules, but did not induce the release of lactoferrin, a protein of specific granules. The enzyme release by PA10 absolutely required Ca2+, ATP, and Mg2+ and the concentrations for the half-maximal response were 2.5 μM, 60 μM, and 0.25 mM, respectively. Although Ca2+ alone at concentrations higher than 10 μM induced the release of both β-glucuronidase and lactoferrin, the extents of the release were far less than that of the β-glucuronidase release by PA10. Phorbol myristate acetate (PMA) and 1-oleoyl-2-acetyl-sn-glycerol induced the release of lactoferrin alone at concentrations of Ca2+ below 0.5 μM while they induced the release of both β-glucuronidase and lactoferrin at higher Ca2+ concentrations, indicating that the degranulation induced by PA10 is not mediated by diacylglycerol which might be formed from PA. The degranulation reactions induced by PA10 and PMA were dose-dependently inhibited by staurosporine and calphostin C, protein kinase C inhibitors, although no direct activation of protein kinase C by PA10 was observed. The extent of the β-glucuronidase release by PA10 was not enhanced by the addition of PMA. Propranolol, which inhibits protein kinase C as well as phosphatidic acid phosphohydrolase, strongly inhibited the degranulation reactions induced by PA10 and PMA. Ethanol, a metabolic modulator of phospholipase D, and cyclic AMP did not affect the degranulation reactions by PMA and PA10. These observations suggest that selective enzyme release from azurophil granules of the permeabilized neutrophils might be induced through the activation of protein kinase C or some other protein kinase sensitive to the protein kinase C inhibitors and that phospholipase D may not be involved in the PMA-induced release. © 1994 BY THE JOURNAL OF BIOCHEMISTRY.

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