Jinzaki, Masahiro

写真a

Affiliation

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

Position

Professor

External Links

Career 【 Display / hide

  • 1987.04
    -
    1991.03

    慶應義塾大学医学部, 放射線診断科, 研修医

  • 1990.04
    -
    1994.06

    日本鋼管病院, 放射線科, 医員

  • 1994.07
    -
    1997.04

    慶應義塾大学医学部, 放射線診断科, 助手

  • 1997.05
    -
    1999.01

    慶應義塾大学医学部, がんセンター, 医員

  • 1999.02
    -
    2000.04

    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
    -
    1987.03

    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

  • Life Science / Radiological sciences

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, 

    2017
    -
    Present

  • PETのアミロイドイメージング研究, 

    2016
    -
    Present

  • 全身立位CTの開発と臨床応用, 

    2014
    -
    Present

  • 4次元画像診断の脈管疾患及び整形疾患における活用, 

    2010
    -
    Present

  • 2重エネルギーCTの臨床応用, 

    2006
    -
    Present

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Books 【 Display / hide

  • Imaging features of renal cell carcinoma differential diagnosis, staging, and posttreatment evaluation

    Jinzaki M., Akita H., Oya M., Renal Cell Carcinoma: Molecular Features and Treatment Updates, 2017.01

     View Summary

    With the widespread use of ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI), there has been an increase in the detection of various subtypes of renal cell carcinomas (RCCs) and benign renal tumors. The differentiation of RCCs from benign tumors such as fat-poor angiomyolipoma and oncocytoma is very important to prevent unnecessary surgery. In addition, the recent progress of therapies to treat RCCs, including nephronsparing surgery, percutaneous ablative procedures, and targeted antiangiogenic therapies, has increased the need for the accurate determination of subtypes and staging. With the development of imaging modalities, there have been significant improvements in correlating preoperative imaging with pathologic characteristics. Many studies performed within the last two decades have helped to clarify diagnostic imaging clues for both cystic and solid renal tumors. In this chapter, we discuss the current status of US, CT, and MRI for the detection and differential diagnosis of renal tumors as well as staging, postprocedural imaging, and imaging for the targeted antiangiogenic treatment of RCC.

  • General electric lightspeed vct, optima ct660 and discovery ct750 hd

    Lehmkuhl L., Martuscelli E., Jinzaki M., Cardiac CT, Second Edition, 2014.01

     View Summary

    This chapter describes how cardiac CT is performed on General Electric scanners.

  • 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.

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Papers 【 Display / hide

  • Impact of noise reduction on radiation dose reduction potential of virtual monochromatic spectral images: Comparison of phantom images with conventional 120 kVp images using deep learning image reconstruction and hybrid iterative reconstruction

    Masuda S., Yamada Y., Minamishima K., Owaki Y., Yamazaki A., Jinzaki M.

    European Journal of Radiology (European Journal of Radiology)  149 2022.04

    ISSN  0720048X

     View Summary

    Purpose: To assess the effects of deep learning image reconstruction (DLIR) and hybrid iterative reconstruction (HIR) on the image quality of virtual monochromatic spectral (VMS) images and to investigate the dose reduction potential of the VMS and conventional 120 kVp images. Methods: A cylindrical phantom simulating an adult abdomen was used. The contrast was set to 60 (medium) and 300 (high) Hounsfield units. CT acquisitions were performed at three dose levels: 12, 9, and 6 mGy. Images were reconstructed via filtered back projection (FBP), DLIR, and HIR. The noise power spectrum (NPS) and task transfer function (TTF) were measured, and the system performance (SP) function was calculated (TTF2/NPS). Results: The noise magnitudes at low spatial frequencies with DLIR and HIR were lower than that with FBP by 45.6% and 24.4%, respectively. Compared to the FBP results, the TTF values at 50% with DLIR at medium and high contrast changed by –13.2% and +25.3% with the VMS images and –2.0% and +9.3% with the 120 kVp images, respectively. In the VMS and 120 kVp images, compared to the SP values of 12 mGy FBP images, SP values of 6 mGy DLIR images decreased at medium contrast and increased at high contrast. Conclusions: DLIR achieved better noise reduction than HIR. The spatial resolution of VMS-DLIR varied significantly depending on the contrast. The image quality of VMS-DLIR and 120 kVp-DLIR potentially decrease in medium contrast tasks and increase in high contrast tasks with 50% dose reduction.

  • Does neoadjuvant chemotherapy have therapeutic benefit for node-positive upper tract urothelial carcinoma? Results of a multi-center cohort study

    Shigeta K., Matsumoto K., Ogihara K., Murakami T., Anno T., Umeda K., Izawa M., Baba Y., Sanjo T., Shojo K., Tanaka N., Takeda T., Morita S., Kosaka T., Mizuno R., Arita Y., Akita H., Jinzaki M., Kikuchi E., Oya M.

    Urologic Oncology: Seminars and Original Investigations (Urologic Oncology: Seminars and Original Investigations)  40 ( 3 ) 105.e19 - 105.e26 2022.03

    ISSN  10781439

     View Summary

    Objective: The indications of neoadjuvant chemotherapy (NAC) for lymph node-positive upper tract urothelial carcinoma (UTUC) have not been investigated regarding improved survival outcomes. Our specific aim was to compare the clinical outcomes of clinically node-positive UTUC patients who were treated by NAC followed by radical nephroureterectomy (RNU) or upfront RNU followed by adjuvant chemotherapy (AC). Materials and methods: Among 966 UTUC patients, we identified 89 with clinical nodal involvement who received either NAC before RNU nor AC after upfront RNU. Cox proportional hazard models were employed to evaluate the impact of chemotherapy modality on the oncological outcomes. Results: Of the patient cohort, 36 (40.4%) received NAC followed by RNU, whereas 53 (59.6%) underwent RNU followed by AC. Multivariate analysis revealed that tumor size ≥3 cm, clinical T4, and gemcitabine and cisplatin regimen were independent risk factors for disease recurrence, whereas NAC followed by RNU was an independent factor for favorable RFS. Furthermore, regarding cancer-specific survival (CSS), NAC followed by RNU remained an independent factor for favorable CSS. According to Kaplan-Meier analysis, the 1-year and 2-year RFS were 67.9% and 47.0%, respectively, in the NAC+RNU group, which were significantly higher than those in the RNU+AC group (43.9% and 24.6%, respectively, P = 0.006). Moreover, the 1-year and 2-year CSS were 80.5% and 64.2%, respectively, in the NAC+RNU group, which were higher than those in the RNU+AC group (68.6% and 48.2%, respectively, P = 0.016). Conclusion: For node-positive UTUC patients, NAC followed by RNU was more clinically beneficial than RNU followed by AC.

  • Photoacoustic lymphangiography exhibits advantages over near-infrared fluorescence lymphangiography as a diagnostic tool in patients with lymphedema

    Suzuki Y., Kajita H., Oh A., Urano M., Watanabe S., Sakuma H., Imanishi N., Tsuji T., Jinzaki M., Kishi K.

    Journal of Vascular Surgery: Venous and Lymphatic Disorders (Journal of Vascular Surgery: Venous and Lymphatic Disorders)  10 ( 2 ) 454 - 462.e1 2022.03

    ISSN  2213333X

     View Summary

    Objective: Photoacoustic imaging is a new technique that can evaluate the vascular system using photoacoustic effects. The present study compared the ability of the new photoacoustic lymphangiography (PAL) method and more standard near-infrared fluorescence (NIRF) to image the lymphatic system in patients with secondary lymphedema after gynecological cancer surgery. Methods: Patients with secondary lymphedema in the lower extremities after gynecologic cancer surgery, who were assessed using PAL between May 2018 and January 2019, were recruited. NIRF was performed first using 5.0 mg/mL of indocyanine green injected using a 0.2-cc 30-gauge needle. Correlations between NIRF and PAL findings on patient images were subsequently examined. Results: Seventeen patients with secondary lymphedema were enrolled. The mean age of the patients was 61 ± 11 years. The imaging sites were the medial lower leg in 15 patients, the posterior lower leg in 9 patients, the lateral lower leg in 7 patients, the medial knee in 4 patients, and other areas in 3 patients. A total of 38 pictures were obtained. Five distinct lymphatic patterns were observed over the entire sample using PAL: straight, winding, spiderweb, nebulous, and black-out pattern. Eighteen of the 24 limbs (75%) that exhibited a linear pattern in NIRF exhibited a straight pattern in PAL, and 19 of the 20 limbs (95%) that exhibited a splash pattern in NIRF exhibited a winding or spiderweb pattern in PAL. Eight limbs exhibiting diffuse patterns without linear or splash patterns with NIRF were all nebulous or black-out patterns in PAL. This suggests that more severe lymphatic degeneration was associated with poorer visualization in PAL. Conclusions: NIRF plays an important role in lymphedema treatment. In the present study, various PAL patterns were compared with those observed using NIRF. PAL provided clearer images including transectional views, which were not available using NIRF, and may promote further understanding of the changes in the lymphatic structure and function in patients with secondary lymphedema.

  • Lower limb lymphedema staging based on magnetic resonance lymphangiography

    Soga S., Onishi F., Mikoshi A., Okuda S., Jinzaki M., Shinmoto H.

    Journal of Vascular Surgery: Venous and Lymphatic Disorders (Journal of Vascular Surgery: Venous and Lymphatic Disorders)  10 ( 2 ) 445 - 453.e3 2022.03

    ISSN  2213333X

     View Summary

    Objective: Dermal backflow (DBF) and reduced lymphatic visualization are common findings of lymphedema on various imaging modalities. However, there is a lack of knowledge about how these findings vary with the anatomic location and severity of lymphedema, and previous reports using indocyanine green lymphography or lymphoscintigraphy show variable results. Magnetic resonance lymphangiography (MRL) is expected to clarify this clinical question due to its superior ability for lymphatic visualization. This retrospective study aimed to investigate the following: (1) Are there any characteristic patterns for DBF and lymphatics' visualization, depending on the anatomic location within lower limbs and severity of lymphedema? (2) Is it possible to classify the severity of lymphedema based on MRL findings? Methods: Two radiologists performed consensus readings of MRL of 56 patients (112 limbs) with lower-limb lymphedema. The frequency of visualized DBF and lymphatics was analyzed in six regions in each lower limb. The results were compared with the International Society of Lymphology clinical stages and etiology of lymphedema. Characteristic findings were categorized and compared with the clinical stage and duration of lymphedema. Results: DBF and lymphatics were observed more frequently in the distal regions than the proximal regions of lower limbs. DBF appeared more frequently as the clinical stage increased, reaching statistical significance (P < 10−3) between stages 0 or I and II. DBF above the knee joint was rarely observed (0.48%) in early stages (0 and I) but appeared more frequently (13.5%, P < 10−5) in stage II. Lymphatics appeared less frequently as the stage progressed, with significant differences (P <.05) between stages I and II and between II and III. The frequency of lymphatics above the knee joint decreased significantly (P <.05) between stages I and II and between II and III as the stage progressed, reaching 0% in stage III. An MRL staging was proposed and showed significant positive correlations with the clinical stage (r = 0.79, P <.01) and the duration of lymphedema (r = 0.57, P <.01). Conclusions: MRL-specific patterns of DBF and lymphatics that depended on the site within the lower limb and clinical stage were shown. The DBF pattern differed from those observed in previous studies with other imaging techniques. The proposed MRL staging based on these characteristic findings allows new stratification of patients with lymphedema. Combined with its excellent ability to visualize lymphatic anatomy, MRL could enable a more detailed understanding of individual patient's pathology, useful for determining the most appropriate treatment.

  • Three-Dimensional Innate Mobility of the Human Foot on Coronally-Wedged Surfaces Using a Biplane X-Ray Fluoroscopy

    Negishi T., Nozaki S., Ito K., Seki H., Hosoda K., Nagura T., Imanishi N., Jinzaki M., Ogihara N.

    Frontiers in Bioengineering and Biotechnology (Frontiers in Bioengineering and Biotechnology)  10 2022.02

     View Summary

    Improving our understanding on how the foot and ankle joints kinematically adapt to coronally wedged surfaces is important for clarifying the pathogenetic mechanism and possible interventions for the treatment and prevention of foot and lower leg injuries. It is also crucial to interpret the basic biomechanics and functions of the human foot that evolved as an adaptation to obligatory bipedal locomotion. Therefore, we investigated the three-dimensional (3D) bone kinematics of human cadaver feet on level (0°, LS), medially wedged (−10°, MWS), and laterally wedged (+10°, LWS) surfaces under axial loading using a biplanar X-ray fluoroscopy system. Five healthy cadaver feet were axially loaded up to 60 kg (588N) and biplanar fluoroscopic images of the foot and ankle were acquired during axial loading. For the 3D visualization and quantification of detailed foot bony movements, a model-based registration method was employed. The results indicated that the human foot was more largely deformed from the natural posture when the foot was placed on the MWS than on the LWS. During the process of human evolution, the human foot may have retained the ability to more flexibly invert as in African apes to better conform to MWS, possibly because this ability was more adaptive even for terrestrial locomotion on uneven terrains. Moreover, the talus and tibia were externally rotated when the foot was placed on the MWS due to the inversion of the calcaneus, and they were internally rotated when the foot was placed on the LWS due to the eversion of the calcaneus, owing to the structurally embedded mobility of the human talocalcaneal joint. Deformation of the foot during axial loading was relatively smaller on the MWS due to restricted eversion of the calcaneus. The present study provided new insights about kinematic adaptation of the human foot to coronally wedged surfaces that is inherently embedded and prescribed in its anatomical structure. Such detailed descriptions may increase our understanding of the pathogenetic mechanism and possible interventions for the treatment and prevention of foot and lower leg injuries, as well as the evolution of the human foot.

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

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Reviews, Commentaries, etc. 【 Display / hide

  • 【後期研修医がおさえておきたい泌尿器疾患TOP30 2021】エッセンシャルアイテム Computed Tomography(CT)

    陣崎 雅弘, 秋田 大宇

    泌尿器外科 (医学図書出版(株))  34 ( 特別号 ) 17 - 24 2021.12

    ISSN  0914-6180

  • 拡散強調MRIのradiomics解析による脂肪成分の少ない腎血管筋脂肪腫と淡明細胞型腎細胞癌の鑑別

    吉田 宗一郎, 松本 俊弥, 有田 祐起, 木村 浩一郎, 山田 一郎, 田中 一, 横山 みなと, 松岡 陽, 水野 隆一, 立石 宇貴秀, 大家 基嗣, 陣崎 雅弘, 藤井 靖久

    日本泌尿器科学会総会 ((一社)日本泌尿器科学会総会事務局)  109回   AOP04 - 01 2021.12

  • 泌尿器がんの最新画像診断

    陣崎 雅弘

    日本泌尿器科学会総会 ((一社)日本泌尿器科学会総会事務局)  109回   EL1 - EL1 2021.12

  • 最新基礎科学 知っておきたい 立位CTによる下肢関節機能評価

    名倉 武雄, 金田 和也, 山田 祥岳, 陣崎 雅弘

    臨床整形外科 ((株)医学書院)  56 ( 12 ) 1498 - 1500 2021.12

    ISSN  0557-0433

     View Summary

    <文献概要>はじめに 運動器疾患の診断には単純X線撮影が,依然gold standardとして用いられている.とりわけ整形外科において取り扱う運動器疾患においては,臥位ではなく立位での撮影により,病態や診断がより明確となるものが多い.これは立位または荷重位にすることで,脊椎・関節がより生理的な位置となり,症状・病態を反映するためである.そのため立位CT検査が可能となれば,有用性は極めて高く,従来のX線に取り替わる画期的な診断装置となり得る.このような背景をもとに,われわれは2013年より東芝メディカル(現・キヤノンメディカルシステムズ)と全身用立位CTの開発に着手した.既存の320列CT(Aquilion ONE)を改良することで動態撮影も可能なプロトタイプを開発し,2017年5月より慶應義塾大学病院に導入した.本稿では全身用立位CTの紹介,および関節機能評価の例として下肢アライメント評価について述べる.

  • ALSに対するロピニロール塩酸塩に関するランダム化臨床試験の結果(ROPALS)(Results Of A Randomized Clinical Trial of Ropinirole Hydrochloride For ALS(ROPALS))

    高橋 愼一, 森本 悟, 伊東 大介, 伊達 悠岳, 岡田 健佑, Chai Muh Chyi, 西山 亜由美, 鈴木 直輝, 平井 美和, 加部 泰明, 末松 誠, 陣崎 雅弘, 青木 正志, 佐藤 泰憲, 中原 仁, 鈴木 則宏, 岡野 栄之

    脳循環代謝 ((一社)日本脳循環代謝学会)  33 ( 1 ) 129 - 129 2021.11

    ISSN  0915-9401

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Presentations 【 Display / hide

  • 心臓・冠動脈CTの現状

    JINZAKI MASAHIRO

    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

    JINZAKI MASAHIRO

    2004 STANFORD RADIOLOGY POSTGRADUATE COURSES (Maui, Hawaii) , 

    2004.03

    Oral presentation (invited, special)

  • マルチスライスCTの臨床応用

    JINZAKI MASAHIRO

    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

    JINZAKI MASAHIRO

    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

    JINZAKI MASAHIRO

    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

  • Elucidation of human body function using upright CT ~Looking at the era of healthy longevity~

    2021.04
    -
    2024.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), Principal investigator

  • 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

    2017.04
    -
    2020.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), Principal investigator

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

    2014.04
    -
    2017.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Principal investigator

     View Summary

    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

  • RADIOLOGY: SEMINAR

    2022

  • RADIOLOGY: PRACTICE

    2022

  • RADIOLOGY

    2022

  • LECTURE SERIES, RADIOLOGY

    2022

  • ADVANCED RADIOLOGY

    2022

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Courses Previously Taught 【 Display / hide

  • 放射線医学臨床実習 X線、CT,MR

    Keio University

    2015.04
    -
    2016.03

    Full academic year, Seminar, Within own faculty, 8people

  • 循環器診断学 X線

    Keio University

    2015.04
    -
    2016.03

    Autumn Semester, Lecture

  • 放射線医学基礎講義 画像総論

    Keio University

    2015.04
    -
    2016.03

    Autumn Semester, Lecture

Educational Activities and Special Notes 【 Display / hide

  • MDCTの基本 パワーテキスト

    2010

    , Development of Textbook and Teaching Material

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    メディカルサイエンスインターナショナル2010