Jinzaki, Masahiro



School of Medicine, Department of Radiology (Diagnostic Radiology) (Shinanomachi)



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Career 【 Display / hide

  • 1987.04

    慶應義塾大学医学部, 放射線診断科, 研修医

  • 1990.04

    日本鋼管病院, 放射線科, 医員

  • 1994.07

    慶應義塾大学医学部, 放射線診断科, 助手

  • 1997.05

    慶應義塾大学医学部, がんセンター, 医員

  • 1999.02

    Harvard 大学付属Brigham and Women’s Hospital, 放射線科, 研究員

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Academic Background 【 Display / hide

  • 1981.04

    Keio University, 医学部

    University, Graduated

Academic Degrees 【 Display / hide

  • 医学博士, Keio University, Dissertation, 1999.03

    Small solid renal lesions: Usefulness of power Doppler US


Research Areas 【 Display / hide

  • Radiation science

Research Keywords 【 Display / hide

  • Computed Tomography

  • Magnetic Resonance Imaging

  • 循環器疾患

  • 泌尿器腫瘍

  • 画像診断

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Research Themes 【 Display / hide

  • 画像診断への人工知能の活用, 


  • PETのアミロイドイメージング研究, 


  • 全身立位CTの開発と臨床応用, 


  • 4次元画像診断の脈管疾患及び整形疾患における活用, 


  • 2重エネルギーCTの臨床応用, 


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Books 【 Display / hide

  • Coronary CT angiography.

    Lehmkuhl L, Martuscelli E, JINZAKI MASAHIRO, Springer, 2014

    Scope: General Electric LightSpeed VCT, Optima CT660 and Discovery CT750 HD

  • Computed Tomography Imaging.

    JINZAKI MASAHIRO, Akita H, Kikuchi E., Taylor and Francis, 2013

    Scope: Urinary bladder.

  • Computed Tomography Imaging.

    JINZAKI MASAHIRO, Yamada Y, Kuribayashi S., Taylor and Francis, 2013

    Scope: Computed Tomography Multispectral Imaging.

  • Advances in the Diagnosis of Coronary Atherosclerosis.

    JINZAKI MASAHIRO, Yamada M, Kuribayashi S., InTech, 2011

    Scope: Image post-processing and interpretation.

  • Multislice CT 2003 BOOK

    JINZAKI MASAHIRO, 産業開発機構株式会社, 2003.05

    Scope: GE社製16スライスCT LightSpeed Ultra16の使用経験

Papers 【 Display / hide

  • Traction Bronchiectasis/Bronchiolectasis is Associated with Interstitial Lung Abnormality Mortality

    Hida T., Nishino M., Hino T., Lu J., Putman R.K., Gudmundsson E.F., Araki T., Valtchinov V.I., Honda O., Yanagawa M., Yamada Y., Hata A., Jinzaki M., Tomiyama N., Honda H., Estepar R.S.J., Washko G.R., Johkoh T., Christiani D.C., Lynch D.A., Gudnason V., Gudmundsson G., Hunninghake G.M., Hatabu H.

    European Journal of Radiology (European Journal of Radiology)  129 2020.08

    ISSN  0720048X

     View Summary

    © 2020 Elsevier B.V. Purpose: To investigate if the presence and severity of traction bronchiectasis/bronchiolectasis are associated with poorer survival in subjects with ILA. Method: The study included 3,594 subjects (378 subjects with ILA and 3,216 subjects without ILA) in AGES-Reykjavik Study. Chest CT scans of 378 subjects with ILA were evaluated for traction bronchiectasis/bronchiolectasis, defined as dilatation of bronchi/bronchioles within areas demonstrating ILA. Traction bronchiectasis/bronchiolectasis Index (TBI) was assigned as: TBI = 0, ILA without traction bronchiectasis/bronchiolectasis: TBI = 1, ILA with bronchiolectasis but without bronchiectasis or architectural distortion: TBI = 2, ILA with mild to moderate traction bronchiectasis: TBI = 3, ILA and severe traction bronchiectasis and/or honeycombing. Overall survival (OS) was compared among the subjects in different TBI groups and those without ILA. Results: The median OS was 12.93 years (95%CI; 12.67 – 13.43) in the subjects without ILA; 11.95 years (10.03 – not reached) in TBI-0 group; 8.52 years (7.57 – 9.30) in TBI-1 group; 7.63 years (6.09 – 9.10) in TBI-2 group; 5.40 years (1.85 – 5.98) in TBI-3 group. The multivariable Cox models demonstrated significantly shorter OS of TBI-1, TBI-2, and TBI-3 groups compared to subjects without ILA (P < 0.0001), whereas TBI-0 group had no significant OS difference compared to subjects without ILA, after adjusting for age, sex, and smoking status. Conclusions: The presence and severity of traction bronchiectasis/bronchiolectasis are associated with shorter survival. The traction bronchiectasis/bronchiolectasis is an important contributor to increased mortality among subjects with ILA.

  • A case of pancreatic hamartoma with characteristic radiological findings: radiological-pathological correlation

    Toyama K., Matsusaka Y., Okuda S., Miura E., Kubota N., Masugi Y., Kitago M., Hori S., Yokose T., Shinoda M., Sakamoto M., Jinzaki M.

    Abdominal Radiology (Abdominal Radiology)  45 ( 7 ) 2244 - 2248 2020.07

    ISSN  2366004X

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    © 2020, Springer Science+Business Media, LLC, part of Springer Nature. Pancreatic hamartoma is a rare benign tumor. Its preoperative diagnosis is challenging. We present a case of pancreatic hamartoma whose radiological-pathological correlation was evaluated in detail. A 53-year-old man was referred to our institution for diagnosis and treatment. Contrast-enhanced computed tomography (CT) and magnetic resonance image revealed a 3.5 cm long tumor arising from the head of the pancreas with cystic and solid components, the latter of which was gradually and inhomogeneously enhanced in the delayed phase. Fluorodeoxyglucose (FDG) positron emission tomography/CT revealed slight FDG uptake in the solid component. Histologically, a number of pancreatic lobule-like structures, which were mainly composed of aggregates of small ducts embedded in concentric fibrous stroma with no apparent islets or peripheral nerves, were observed in the solid component, whereas multiple dilated ducts were seen in the cystic region. The solid component also contained a narrow area of edematous fibrous stroma with low vessel density, which corresponded with the unenhanced part in the inhomogeneously enhanced solid component. There was no remarkable cytological atypia throughout the mass. A pathological diagnosis of pancreatic hamartoma was made. The radiological findings agree well with the pathological findings. When a pancreatic tumor is of the solid type, preoperatively diagnosing it as pancreatic hamartoma is not possible. However, when a pancreatic tumor with cystic and solid components is inhomogeneously enhanced in contrast-enhanced studies, a diagnosis of pancreatic hamartoma can be considered.

  • Egested Feces Revealed Massive Protein Loss in <sup>99m</sup>Tc-HSA-D Scintigraphy

    Matsusaka Y., Nakahara T., Iwabuchi Y., Owaki Y., Narimatsu H., Jinzaki M.

    Clinical Nuclear Medicine (Clinical Nuclear Medicine)  45 ( 7 ) e329 - e330 2020.07

    ISSN  03639762

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    © 2020 Wolters Kluwer Health, Inc. All rights reserved. A 66-year-old man with severe diarrhea and severe hypoproteinemia was referred for 99mTc-DTPA-human serum albumin (HSA-D) scintigraphy. The scintigraphy at 24 hours postinjection showed strong accumulation of 99mTc-HSA-D in not only the colon but also all his diapers containing his egested feces. The ratio of the diapers counts to the total counts was 17.0%, and a considerable amount of protein loss was confirmed. 99mTc-HSA-D scintigraphy has an important role in diagnosing protein-losing enteropathy, but the abdomen is the only routinely scanned area. Additional scanning of egested radiotracer and the whole body can be useful for evaluating the disease severity.

  • Usefulness of <sup>18</sup>F-fluorodeoxyglucose positron emission tomography/computed tomography for predicting the prognosis and treatment response of neoadjuvant therapy for pancreatic ductal adenocarcinoma

    Yokose T., Kitago M., Matsusaka Y., Masugi Y., Shinoda M., Yagi H., Abe Y., Oshima G., Hori S., Endo Y., Toyama K., Iwabuchi Y., Takemura R., Ishii R., Nakahara T., Okuda S., Jinzaki M., Kitagawa Y.

    Cancer Medicine (Cancer Medicine)  9 ( 12 ) 4059 - 4068 2020.06

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    © 2020 The Authors. Cancer Medicine published by John Wiley & Sons Ltd. Background: The Response Evaluation Criteria in Solid Tumors (RECIST) for computed tomography (CT) is preoperatively used to evaluate therapeutic effects. However, it does not reflect the pathological treatment response (PTR) of pancreatic ductal adenocarcinoma (PDAC). The Positron Emission Tomography Response Criteria in Solid Tumors (PERCIST) for positron emission tomography (PET)/CT is effective in other cancers. This study aimed to confirm the usefulness of PERCIST and the prognostic utility of PET/CT for PDAC. Methods: Forty-two consecutive patients with PDAC who underwent neoadjuvant therapy (NAT) and pancreatectomy at our institution between 2014 and 2018 were retrospectively analyzed. We evaluated the treatment response and prognostic significance of PET/CT parameters and other clinicopathological factors. Results: Twenty-two patients who underwent PET/CT both before and after NAT with the same protocol were included. RECIST revealed stable disease and partial response in 20 and 2 cases, respectively. PERCIST revealed stable metabolic disease, partial metabolic response, and complete metabolic response in 8, 9, and 5 cases, respectively. The PTR was G3, G2, and G1 in 8, 12, and 2 cases, respectively. For comparing the concordance rates between PTR and each parameter, PERCIST (72.7% [16/22]) was significantly superior to RECIST (36.4% [8/22]) (P =.017). The area under the curve survival values of PET/CT parameters were 0.777 for metabolic tumor volume (MTV), 0.500 for maximum standardized uptake value, 0.554 for peak standardized uptake value corrected for lean body mass, and 0.634 for total lesion glycolysis. A 50% cut-off value for the MTV reduction rate yielded the largest difference in survival between responders and nonresponders. On multivariate analysis, MTV reduction rates < 50% were independent predictors for relapse-free survival (hazard ratio [HR], 3.92; P =.044) and overall survival (HR, 14.08; P =.023). Conclusions: PERCIST was more accurate in determining NAT’s therapeutic effects for PDAC than RECIST. MTV reduction rates were independent prognostic factors for PDAC.

  • Spatial resolution compensation by adjusting the reconstruction kernels for iterative reconstruction images of computed tomography

    Sugisawa K., Ichikawa K., Urikura A., Minamishima K., Masuda S., Hoshino T., Nakahara A., Yamada Y., Jinzaki M.

    Physica Medica (Physica Medica)  74   47 - 55 2020.06

    ISSN  11201797

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    © 2020 Associazione Italiana di Fisica Medica Purpose: Hybrid iterative reconstruction (IR) is useful to reduce noise in computed tomography (CT) images. However, it often decreases the spatial resolution. The ability of high spatial resolution kernels (harder kernels) to compensate for the decrease in the spatial resolution of hybrid IRs was investigated. Methods: An elliptic cylindrical phantom simulating an adult abdomen was used. Two types of rod-shaped objects with ~330 and ~130 HU were inserted to simulate contrasts of arteries in CT angiography. Two multi-slice CT systems were used to scan the phantoms with 120 kVp and scan doses of 20 and 10 mGy. The task transfer functions (TTFs) were measured from the circular edges of the rod images. The noise power spectrum (NPS) was measured from the images of the water-only section. The CT images were reconstructed using a filtered back projection (FBP) with baseline kernels and two levels of hybrid IRs with harder kernels. The profiles of the clinical images across the aortic dissection flaps were measured to evaluate actual spatial resolutions. Results: The TTF degradation of each hybrid IR was recovered by the harder kernels, whereas the noise reduction effect was retained, for both the 20 and 10 mGy. The profiles of the dissection flaps for the FBP were maintained by using the harder kernels. Even with the best combination of hybrid IR and harder kernel, the noise level at 10 mGy was not reduced to the level of FBP at 20 mGy, suggesting no capability of a 50% dose reduction while maintaining noise.

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Papers, etc., Registered in KOARA 【 Display / hide

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Reviews, Commentaries, etc. 【 Display / hide

Presentations 【 Display / hide

  • 心臓・冠動脈CTの現状


    第68回日本循環器学会総会・学術集会 (東京) , 2004.03, Other

  • Imaging of renal masses for diagnosis and management


    2004 STANFORD RADIOLOGY POSTGRADUATE COURSES (Maui, Hawaii) , 2004.03, Oral Presentation(guest/special)

  • マルチスライスCTの臨床応用


    河田町放射線学術講演会 (東京) , 2004.02, Other

  • 泌尿器領域の画像診断


    第23回日本画像医学会 (東京) , 2004.02, Other

  • マルチスライスCTによる冠動脈プラークの診断


    第4回動脈硬化教育フォーラム (東京) , 2004.02, Other

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Research Projects of Competitive Funds, etc. 【 Display / hide

  • Quantitative evaluation of anatomical structures of the whole body using CT in a standing or sitting position: comp arison with CT in a supine position


    MEXT,JSPS, Grant-in-Aid for Scientific Research, 陣崎 雅弘, Grant-in-Aid for Scientific Research (B), Principal Investigator

  • Basic and clinical study of functional evaluation using 4-dimensional CT


    MEXT,JSPS, Grant-in-Aid for Scientific Research, 陣崎 雅弘, Grant-in-Aid for Scientific Research (C), Principal Investigator

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    For fundamental analysis, we took 4D-CT to measure the flow velocity of vascular phantom. The measurements had a linear correlation to those taken by Doppler US, which helped to indicate potential use of 4D-CT in measuring flow velocity.
    In regards to clinical application, we evaluated the usefulness of 4D-CT in four clinical fields. In otolaryngology, 4D-CT provided quantitative data of the regurgitated area, which will enable the replacement of conventional X-ray and invasive laryngoscopy. In cardiology, 4D-CT data showed higher diagnostic accuracy compared to conventional CT for the evaluation of endoleak after vascular stentgraft, which will help to decrease the use of invasive angiography. In urology, 4D-CT scans taken during the bladder voiding process allows visualization and clarification of the cause of obstruction in patients with dysuria. In orthopedics, with 4D-CT we could achieve quantitative analysis of joint movement, which has been difficult using X-ray.

Awards 【 Display / hide

  • 慶應医学三四会北島賞

    2013.06, 泌尿器画像診断アルゴリズムの構築

  • 第72回日本医学放射線学会 教育展示優秀賞

    2013.06, 腎血管筋脂肪腫の新しい分類

  • 第72回日本医学放射線学会 Cypos Gold Medal

    2013.04, 高分解能 CT による冠動脈の狭窄度診断精度の向上

  • 第25回日本腹部放射線学会 打田賞 

    2012.06, 腎転座型腎癌の画像所見

  • 日獨医報 Best Paper Award

    2009.04, CT・MRI時代における非血管特殊造影検査の意義:泌尿器・生殖器 -経静脈性尿路造影-

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Courses Taught 【 Display / hide











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Courses Previously Taught 【 Display / hide

  • 放射線医学臨床実習 X線、CT,MR

    Keio University, 2015, Full academic year, Major subject, Seminar, Within own faculty, 8people

  • 循環器診断学 X線

    Keio University, 2015, Autumn Semester, Major subject, Lecture

  • 放射線医学基礎講義 画像総論

    Keio University, 2015, Autumn Semester, Major subject, Lecture

Educational Activities and Special Notes 【 Display / hide

  • MDCTの基本 パワーテキスト


    , Development of Textbook and Teaching Material

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