Details of a Researcher - Jinzaki, Masahiro

Papers - Jinzaki, Masahiro

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Detection of bladder tumors with dynamic contrast-enhanced MDCT

Jinzaki Masahiro, Tanimoto Akihiro, Shinmoto Hiroshi, Horiguchi Yutaka, Sato Kozo, Kuribayashi Sachio, Silverman Stuart G.

American Journal of Roentgenology 188 ( 4 ) 913 - 918 2007.04

Research paper (scientific journal), Joint Work, ISSN 0361-803X

OBJECTIVE. In a small pilot study, we assessed whether early-phase dynamic contrast-enhanced MDCT can be used to detect bladder tumors and whether thin reconstruction improves the detection rate. SUBJECTS AND METHODS. Thirty-six patients (30 with 59 cystoscopy-proven bladder cancers and six with normal bladders) underwent dynamic contrast-enhanced MDCT of the pelvis and abdomen. Images were obtained from the symphysis pubis to the diaphragm 70 seconds after injection of 100 mL of contrast medium. McNemar test was used to compare sensitivity per patient, segment, and tumor and specificity per patient and segment for each of three reconstruction methods: 5-mm sections with no overlap (i.e., 5-mm axial images), 2.5-mm sections with 1.25-mm overlap (i.e., thin-section axial images), and 2.5-mm sections with 1.25-mm overlap and multiplanar reformation (MPR) (i.e., thin-section axial images with MPR). RESULTS. MDCT with a combination of thin, overlapped sections and MPR depicted all but one of 47 bladder tumors larger than 5 mm but only five of 12 tumors 5 mm or smaller. There were no false-positive findings. Per-tumor sensitivity was significantly better with thin-section images with MPR (90%) and thin-section images alone (86%) than with 5-mm axial images (80%) (p < 0.05). Per-segment sensitivity was significantly better with thin-section images with MPR (95%) and thin-section axial images alone (87%) than with 5-mm axial images (79%) (p < 0.05). Per-patient sensitivity and per-patient and per-segment specificity did not differ with the three methods. CONCLUSION. Dynamic contrast-enhanced MDCT of the pelvis shows promise for the detection of bladder tumors. Use of thin-section images with MPR and thin-section axial images alone had a significantly better rate of detection of bladder tumors than use of 5-mm axial images. © American Roentgen Ray Society.

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今月の主題血管超音波検査話題他の検査法からみた超音波検査の使いかた-CT,MRIとの比較,超音波が有利なのはどのような点か

篠原真木子, 陣崎雅弘, 大熊潔, 栗林幸夫

臨床検査 (株式会社医学書院) 51 ( 3 ) 325 - 332 2007.03

ISSN 0485-1420

HEART's Original [Editorial Comment] 安田論文に対するEditorial Comment

陣崎雅弘

Shinzo (Japan Heart Foundation) 39 ( 4 ) 371 - 371 2007

ISSN 0586-4488

Imaging findings of solitary fibrous tumor of the prostate

Oguro Sota, Tanimoto Akihiro, Jinzaki Masahiro, Akita Hirotaka, Yashiro Hideki, Okuda Shigeo, Kuribayashi Sachio, Kameyama Kaori, Mukai Makio

Magnetic Resonance Imaging 24 ( 5 ) 673 - 675 2006.06

Research paper (scientific journal), Joint Work, ISSN 0730-725X

The imaging findings of a solitary fibrous tumor of the prostate are presented. A 35-year-old male presented with urinary retention and was found on transrectal ultrasonography to have a hypoechoic tumor of the prostate, measuring 5.5 cm in size. Magnetic resonance imaging on, the tumor showed low signal intensity on T1-weighted images and heterogeneous mixed signal intensity on T2-weighted images. Gadolinium-enhanced dynamic study showed gradual enhancement from the periphery to the center, and the enhancement is sustained. On immunohistochemistry, the spindle cells of the tumor showed positive staining for CD34 and bcl-2. Although the tumor was labeled as a low-grade malignancy on account of a low mitotic index (MIB-1 index) of about 5%, the patient developed local recurrence of the tumor with bladder wall invasion 12 months later. © 2006 Elsevier Inc. All rights reserved.

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Coronary CT angiography; 16 slice CT vs 64 slice CT

Jinzaki Masahiro, Sato K., Tanami M., Kuribayashi Y., Yamada Y.

Japanese Journal of Clinical Radiology 51 ( 1 ) 41 - 44 2006

Research paper (scientific journal), Joint Work, ISSN 0009-9252

64-slice CT enabled the improved image quality of patients with high heart rate, the stabilization of heart rate during scan, volume reduction of contrast media, and wider coverage of ECG-gated scan compared with 16-slice CT. These advantages reduce the motion artifact, increase the percentage of assessable segments, and widen its clinical application. However, evaluation of lesions with severe calcification is still the limitation, that needs to be overcome with further technical advancement.

Novel method of displaying coronary CT angiography - Angiographic view

Jinzaki Masahiro, Sato Kozo, Tanami Yutaka, Yamada Minoru, Kuribayashi Sachio, Anzai Toshihisa, Asakura Yasushi, Ogawa Satoshi

Circulation Journal (The Japanese Circulation Society) 70 ( 12 ) 1661 - 1662 2006

Research paper (scientific journal), Joint Work, ISSN 1346-9843

Background: A method of displaying coronary computed tomography (CT) angiography, which enables evaluation of coronary artery disease (CAD) with fewer images and is understandable to the third person, is preferable. Methods and Results: A maximum intensity projection image was created in which contrast media in the ventricles is eliminated, enabling an overview of CAD in a single 3-dimensional (D) image that can be rotated to be viewed at various angles and is easily understood by a third person. Conclusions: A novel method of displaying coronary CT angiography in a single 3-D image has been developed and we believe it should become available for many workstations.

Evaluation of coronary artery lumen diameter with 16-slice multidetector-row computed tomography

Yamada Minoru, Jinzaki Masahiro, Kuribayashi Sachio, Sato Kozo, Tanami Yutaka, Yun Shen, Sasaki Kosuke

Circulation Journal (The Japanese Circulation Society) 69 ( 10 ) 1230 - 1232 2005.09

Research paper (scientific journal), Joint Work, ISSN 1346-9843

Background: When using 16-slice multidetector-row computed tomography (MDCT) to detect coronary artery stenosis, coronary arteries measuring 1.5 mm or larger in lumen diameter are usually evaluated. The purpose of this study was to investigate the frequency of the visualized lumen in each coronary artery segment measuring more than 1.5 mm in diameter. Methods and Results: Electrocardiographic-gated 16-slice MDCT was used to scan 20 patients after administration of nitroglycerin. The luminal diameter of each coronary artery segment was measured on cross-sectional images using a caliper method. The frequency of the visualized lumen of each coronary artery segment measuring larger than 1.5 mm in diameter was as follows: #1: 100%, #2: 100%, #3: 100%, #4PD:85%, #4AV:80%, #5: 100%, #6: 100%, #7: 100%, #8: 90%, #9: 85%, #10: 40%, #11: 100%, #12: 65%, #13: 100%, #14: 80%. Averaged lumen diameter± standard deviation (mm) larger than 1.5 mm in all patients was calculated as follows: #1: 3.8±0.70, #2: 3.5±0.69, #3: 3.2±0.82, #5: 4.2±1.04, #6: 3.4±0.79, #7: 2.9±0.62, #11: 2.9±0.69, #13: 2.6±0.57. Conclusion: Luminal diameter larger than 1.5 mm of each coronary artery segment can be assessed in most cases by 16-slice MDCT.

Design and development of a new pulsating cardiac coronary phantom for ECG-gated CT and its experimental characteristics

Shen Yun, Sato Munekuni, Kimura Fumiko, Jinzaki Masahiro, Horiguchi Jun, Ito Katsuhide, Kuribayashi Sachio

Nippon Acta Radiologica 65 ( 3 ) 224 - 232 2005.07

Research paper (scientific journal), Joint Work, ISSN 0048-0428

The optimal pulsating cardiac phantom is an important tool for the evaluation of cardiac images and cardiac applications on ECG-gated MDCT. The purpose of this study was to demonstrate the design and fabrication of the pulsating cardiac coronary phantom. The newly developed pulsating cardiac coronary phantom has the following five key advantages: 1 )a driver component that uses only one servomotor to move the phantom in three dimensions (X, Y, and Z directions) with 16 presets of different heart types (heartbeat: 0-120 bpm; ejection fraction: 0-90%): 2)versatile pumping and filling phases to simulate a real heart in a cardiac cycle can be incorporated into the driver sequence including shift of patient heartbeat or irregular pulse (maximum: 200 different heart waves in one scan): 3)a cardiac coronary component constituted of an acrylic/silicon/rubber tube(2-6 mm inner diameter)with stent/in-stent restenosis/steriosis/soft plaque/ calcification parts and maximum 16 coronary arteries that can be attached to the phantom in the same scan: 4)the complete phantom can be submerged in a tank to simulate the heart and its surrounding tissues: 5)ECG gating can be from interior trigger and exterior trigger. It has been confirmed that the developed pulsating cardiac phantom is very useful to quantitatively assess imaging of the heart and coronary arteries during phantom experiments.

Correlation of effective temporal resolution and accuracy of volume ejection fraction on the ECG-gated cardiac MDCT

Shen Yun, Jinzaki Masahiro, Sato Kozo, Kuribayashi Sachio

Nippon Acta Radiologica 65 ( 3 ) 233 - 239 2005.07

Research paper (scientific journal), Joint Work, ISSN 0048-0428

Purpose: ECG-gated cardiac MDCT offers many cardiac clinical applications. The goals of this report are 1) to introduce a new concept of effective reliability (ER) from effective temporal resolution for the evaluation of ejection fraction (EF) and evaluation of image quality (IQ)of coronary arteries, and 2)to show the correlation of ER and the accuracy of EF with different cardiac reconstruction algorithms and different rotation speeds. Methods and Materials: To assess the accuracy of EF, helical scanning was performed with a gated cardiac MDCT(GE LightSpeed, 8/16 slice)on pulsating cardiac coronary phantoms(0.5 and 0.6 sec rotation speed for each 50-110 bpm, 5-bpm step). We define effective reliability(ER)from effective temporal resolution(%)as follows: ER=(1-TR/HC)x100: TR: Effective temporal resolution, HC: time of heart cycle in each bprn. Results: From the results of the EF measurement and calculated ER, high accuracy was obtained by using optimal scan conditions (optimal rotation speed and cardiac reconstruction algorithm)in a wide range of heart rates (heart rate<90: EF & ER>81%; heart rate<110 bpm: EF & ER>73%). Results showed that the calculated ER is closely correlated with the measurement results of EF based on the phantom experiment (R ²=0.901±0. 075; Max: 0.994, Min: 0.738). Optimal reconstruction thickness can reduce total image number for the evaluation of EF. Conclusion: We concluded that the ER is useful to evaluate EF accuracy and the IQ of images of coronary arteries.

Quantitative evaluation of coronary arterial stenosis using 16-slice multidetector-row computed tomography

Yamada Minoru, Jinzaki Masahiro, Kuribayashi Sachio, Sato Kozo, Tanami Yutaka, Yun Shen, Sasaki Kosuke, Okano Yoshiyuki, Sugisawa Koichi

Journal of Computer Assisted Tomography 29 ( 3 ) 382 - 386 2005.05

Research paper (scientific journal), Joint Work, ISSN 0363-8715

Objective: The purpose of this study is to consider the possibility of quantitative evaluation of coronary arterial stenosis by using 16-slice multidetector-row computed tomography (MDCT). Methods: Simulated coronary arteries were prepared, which consist of 5-mm-diameter acryl tubes with contrast media (270 HU). Simulated stenoses of known density (-33 HU) were created in each coronary artery (25%, 50%, and 75%). Cardiac pulsating with 0, 50, 65, 85, and 105 beats per minute (bpm) was performed. Multiplanar reformation images for each coronary artery were created. Percent stenosis was calculated using the width middle value of boundary part of the arteries. Results: The stenoses were depicted in all heart rates. Average percent stenosis ± standard deviation was 27.4 ± 3.6%, 45.8 ± 2.6%, and 69.4 ± 2.7%, respectively. For each percent stenosis, there was a significant difference (P < 0.05). Conclusion: Sixteen-slice MDCT has a potential for noninvasive quantitative evaluation of stenosis in coronary arteries. Copyright © 2005 by Lippincott Williams & Wilkins.

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Angiomyolipomas that do not contain fat attenuation at unenhanced CT [2] (multiple letters)

Jinzaki Masahiro, Silverman Stuart G., Tanimoto Akihiro, Shinmoto Hiroshi, Kuribayashi Sachio, Kim Jeong Kon, Cho Kyoung Sik

Radiology 234 ( 1 ) 311 - 312 2005.01

Research paper (scientific journal), Joint Work, ISSN 0033-8419

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Improving coronary artery imaging quality in the high heart rate region and on MDCT using a pulsating cardiac phantom

Shen Yun, Sasaki Kosuke, Okano Yoshiyuki, Jinzaki Masahiro, Shinya Masae, Sugisawa Koichi, Yamada Minoru, Nagasawa Kiyoshi, Kuribayashi Sachio

Nippon Hoshasen Gijutsu Gakkai zasshi (Japanese Society of Radiological Technology) 61 ( 4 ) 506 - 513 2005

Research paper (scientific journal), Joint Work, ISSN 0369-4305

The multi-sector reconstruction (MSR) algorithm and cardiac half-reconstruction (CHR) algorithm are the main algorithms used in cardiac reconstruction. Analysis of effective temporal resolution (TR) confirmed that optimal rotation speed depends on different heart rates when using MSR. During visualization (3D/MPR image) and quantitative (EF: ejection fraction) evaluations, it was found that image quality and measurement accuracy are well correlated with effective temporal resolution (TR) by the different algorithms. The CHR algorithm resulted in less desirable image quality at TR 250 ms than that from MSR at high heart rates (>75 bpm) in the phantom experiment. We determined that the combination of the MSR algorithm and the optimal selection of gantry rotation speed is important for obtaining high-quality cardiac imaging in the high heart rate region.

Evaluation of small (≤ 3 cm) renal masses with MDCT

Jinzaki Masahiro, McTavish Jeffrey D., Zou Kelly H., Judy Philip F., Silverman Stuart G.

American Journal of Roentgenology 183 ( 1 ) 223 - 228 2004.07

Research paper (scientific journal), Joint Work, ISSN 0361-803X

OBJECTIVE. Our purpose was to determine whether thin overlapping reconstructions using MDCT improve the detection and characterization of small renal masses. MATERIALS AND METHODS. Thirty-seven patients were scanned with MDCT using 2.5-mm collimation. Nephrographic phase data were reconstructed in two ways: a standard protocol (5-mm section thickness, no overlap) and an experimental protocol (3-mm section thickness, 50% overlap). Masses were detected and classified into three groups: group 1, measuring less than 20 H on both protocols (classified as cysts on both); group 2, measuring 20 H or greater on standard protocol and less than 20 H on experimental protocol (classified as cysts using experimental protocol only); and group 3, measuring 20 H or greater on both protocols (not classified as cysts using either protocol). Masses 10 mm or larger in group 3 were evaluated further for enhancement. Statistically significant differences between protocols were assessed using an analysis of counts and proportions. RESULTS. Of 175 detected lesions, 29 (17%) were detected only with the experimental protocol; all but one were smaller than 5 mm. Using the experimental protocol, of 45 masses between 5 and 10 mm, the number of masses that could be characterized as cysts increased from 13 (29%) to 38 (84%). The overall number of indeterminate lesions was reduced from 101 (69%) of 146 lesions detected with the standard protocol to 86 (53%) of 161 lesions detected with the experimental protocol. CONCLUSION. Using MDCT and thin overlapping reconstructions, renal cysts as small as 5 mm can be diagnosed with more confidence than is possible with standard reconstructions, and the overall number of indeterminate renal masses is reduced.

Non-invasive imaging of coronary artery and plaque with multi-slice CT

Kuribayashi Sachio, Jinzaki Masahiro, Sato Kozo, Tanami Yutaka, Yamada Minoru

Respiration and Circulation (株式会社医学書院) 52 ( 7 ) 667 - 675 2004.07

Research paper (scientific journal), Joint Work, ISSN 0452-3458

今月の主題血栓症の予防と治療血栓症を診断する血栓症を画像で診断する-CT・MR

松本一宏, 陣崎雅弘, 栗林幸夫

medicina (株式会社医学書院) 41 ( 6 ) 942 - 944 2004.06

ISSN 0025-7699

マルチスライスCTによる冠動脈プラークの診断

'JINZAKI MASAHIRO, Kuribayashi Sachio'

Clinician 51 ( 528 ) 309-313 2004.03

Research paper (scientific journal), Joint Work

１６スライスCTによる冠動脈プラークの診断

'JINZAKI MASAHIRO, Sato Kozo, Tanami Yutaka, Kuribayashi Sachio'

A Monthly Journal of Medical Imaging and Information 36 ( 2 ) 22-25 2004.01

Research paper (scientific journal), Joint Work

The usefulness of multidetector-row CT urography - Comparison with intravenous urography

Jinzaki Masahiro, Tanimoto Akihiro, Sato Kozo, Kuribayashi Sachio

Nishinihon Journal of Urology 66 ( 5 ) 350 - 354 2004

Research paper (scientific journal), Joint Work, ISSN 0029-0726

We compared multidetector-row CT urography and intravenous urography (IVU) for the detection of pelvic tumors. CT images (axial image, MIP image and MPR image) and IVU images of three cases were evaluated with the consensus of two radiologists. The usefulness of CTU was as follows. 1) The MIP image is very similar to the IVU image. 2) The images of CTU are free from the overlying bowel gas, whereas IVU images are obscured by it. 3) Although the spatial resolution of CT is lower than that of IVU, pelvic tumors sized 10 mm can be demonstrated on CTU, but not on IVU.

CP4-3 CT urography and MR urography(総合企画4「泌尿器科画像診断 : 新旧交替はあるのか」)

陣崎雅弘

The Japanese Journal of Urology (THE JAPANESE UROLOGICAL ASSOCIATION) 95 ( 2 ) 141 2004

ISSN 0021-5287

Impression and Discussion on RSNA'03 (Round Table Discussion)

石垣武男, 煎本正博, 高原太郎, 今岡いずみ, 早川克己, 大野良治, 陣崎雅弘, 小寺吉衞

Japanese Journal of Radiological Technology (Japanese Society of Radiological Technology) 60 ( 2 ) 233 - 244 2004

ISSN 0369-4305

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