藤原 広和 (フジワラ ヒロカズ)

Fujiwara, Hirokazu

写真a

所属(所属キャンパス)

医学部 放射線科学教室(診断) (信濃町)

職名

専任講師

外部リンク

 

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  • 放射線科学

研究キーワード 【 表示 / 非表示

  • 神経画像診断

 

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  • Ten-year Longitudinal Follow-up MRI Study of Age-related Changes in Thoracic Intervertebral Discs in Asymptomatic Subjects

    Okada E., Daimon K., Fujiwara H., Nishiwaki Y., Nojiri K., Watanabe M., Katoh H., Ishihama H., Fujita N., Tsuji T., Nakamura M., Matsumoto M., Watanabe K.

    Spine (Spine)  44 ( 22 ) E1317 - E1324 2019年11月

     概要を見る

    STUDY DESIGN: Prospective longitudinal study. OBJECTIVE: The aim of this study was to evaluate long-term degenerative changes in intervertebral discs in the thoracic spine in healthy asymptomatic subjects. SUMMARY OF BACKGROUND DATA: Longitudinal magnetic resonance imaging (MRI) studies of intervertebral disc degeneration have been reported for the cervical and lumbar but not the thoracic spine. METHODS: In this longitudinal study (average follow-up 10.0 ± 0.6 years), we assessed degenerative changes in the thoracic spine of 103 volunteers (58 men) of 223 healthy volunteers in the initial MRI study of the thoracic spine (follow-up rate 46.2%). The mean age at the initial study was 45.0 ± 11.5 years (24-77 years). Initial and follow-up thoracic-spine MRIs were graded for the following 4 factors of degenerative changes: decrease in signal intensity of intervertebral disc (DSI), posterior disc protrusion (PDP), anterior compression of dura and spinal cord (AC), and disc-space narrowing (DSN) from T1-2 to T12-L1. We assessed associations between changes in MRI grade and demographical factors such as age, sex, body mass index, smoking habits, sports activities, and disc degeneration in the cervical spine. RESULTS: MRIs revealed that 63.1% of the subjects had degenerative changes in the thoracic intervertebral discs that had progressed at least one grade during the follow-up period. DSI progressed in 44.7% of subjects, PDP in 21.4%, and AC in 18.4% during the 10-year period. No DSN progression was seen. DSI was frequently observed in the upper thoracic spine (T1-2 to T4-5). Disc degeneration was relatively scarce in the lower thoracic spine (T9-10 to T12-L1). PDP was frequently observed in the middle thoracic spine (T5-6 toT8-9). We found significant associations between DSI and cervical-spine degeneration (P = .004) and between AC and smoking (P = .04). CONCLUSION: Progressive thoracic disc degeneration, observed in 63.1% of subjects; was significantly associated with smoking and with cervical-spine degeneration.2.

  • A Novel Flow Dynamics Study of the Intracranial Veins Using Whole Brain Four-Dimensional Computed Tomography Angiography

    Mizutani K., Arai N., Toda M., Akiyama T., Fujiwara H., Jinzaki M., Yoshida K.

    World Neurosurgery (World Neurosurgery)  131   e176 - e185 2019年11月

    ISSN  18788750

     概要を見る

    © 2019 Elsevier Inc. Background: The flow dynamics of the intracranial venous channels are fundamentally important for understanding intracranial physiology and pathophysiology. However, the method clinically applicable to the evaluation of the flow dynamics of the intracranial venous system has not been well described in the reported data. We have developed a new method to evaluate intracranial venous flow direction and velocity using 4-dimensional (4D) computed tomography angiography (CTA). The aim of the present study was to verify the accuracy and validity of 4D-CTA in a clinical setting. Methods: We retrospectively analyzed 97 veins from 26 patients (16 cases of arteriovenous shunt disease, 9 intracranial tumor cases, and 1 cerebral aneurysm case) who had undergone both 4D-CTA and conventional digital subtraction angiography (DSA). Using 4D-CTA, we analyzed the time-density curve with gamma distribution extrapolation and obtained the direction of the flow and flow velocity of each vein. The direction of the flow in 4D-CTA was also collated with that obtained using conventional DSA to verify the experimental method. Results: The direction of the flow determined by 4D-CTA was consistent with that of conventional DSA in 94.8% of cases. The average venous flow velocity was 64.3 mm/second and 81.8 mm/second, respectively, in the antegrade and retrograde channels affected by arteriovenous shunts. Conclusions: The present flow analysis using 4D-CTA enabled us to evaluate the direction and velocity of intracranial venous flow. Other than some limitations, the presented method is reliable and its potential for application in clinical settings is promising.

  • Review of synthetic MRI in pediatric brains: Basic principle of MR quantification, its features, clinical applications, and limitations

    Andica C., Hagiwara A., Hori M., Kamagata K., Koshino S., Maekawa T., Suzuki M., Fujiwara H., Ikeno M., Shimizu T., Suzuki H., Sugano H., Arai H., Aoki S.

    Journal of Neuroradiology (Journal of Neuroradiology)  46 ( 4 ) 268 - 275 2019年07月

    ISSN  01509861

     概要を見る

    © 2019 Elsevier Masson SAS Quantitative magnetic resonance imaging (MRI)with multislice, multi-echo, and multi-delay acquisition enables simultaneous quantification of R1 and R2 relaxation rates, proton density, and the B1 field in a single acquisition, and requires only about 6 minutes for full-head coverage. Using dedicated SyMRI software, radiologists can generate any contrast-weighted image by manipulating the acquisition parameters, including repetition time, echo time, and inversion time. Moreover, automatic brain tissue segmentation, volumetry, and myelin measurement can also be performed. Using the SyMRI approach, a shorter scan time, an objective examination, and personalized MR imaging parameters can be obtained in daily clinical pediatric imaging. Here we summarize and review the use of SyMRI in imaging of the pediatric brain, including the basic principles of MR quantification along with its features, clinical applications, and limitations.

  • Modic changes in the cervical spine: Prospective 20-year follow-up study in asymptomatic subjects

    Tsuji T., Fujiwara H., Nishiwaki Y., Daimon K., Okada E., Nojiri K., Watanabe M., Katoh H., Shimizu K., Ishihama H., Fujita N., Nakamura M., Matsumoto M., Watanabe K.

    Journal of Orthopaedic Science (Journal of Orthopaedic Science)  24 ( 4 ) 612 - 617 2019年07月

    ISSN  09492658

     概要を見る

    © 2019 The Japanese Orthopaedic Association Background: Few studies have characterized the development of Modic changes in the cervical spine over time. We evaluated Modic changes of the cervical spine that developed over a 20-year period in a healthy cohort, and sought to clarify the relationship between Modic changes and the development of clinical symptoms. Methods: For this multicenter prospective cohort study, we recruited 193 subjects from an original cohort of asymptomatic volunteers who underwent MRI of the cervical spine between 1993 and 1996. Each cervical level from C2/3 to C7/T1 (total n = 1158 intervertebral levels) was assessed on current MRIs as normal or showing type 1, 2, or 3 Modic change, and we asked about symptoms related to the cervical spine. Relationships between the presence of Modic changes and patient characteristics, pre-existing disc degenerations or clinical symptoms were evaluated by logistic regression analysis. Results: After 20-year follow-up, Modic changes affected 31 subjects (16.1%) at 47 intervertebral disc levels. Of these 47 intervertebral disc levels, type 2, found at 30 levels (63.8%), was the most frequent, followed by type 1 at 15 levels (31.9%) and type 3 at two levels (4.3%). The most frequent changes were observed at the C5/6 segment with type 2 Modic changes. The presence of Modic changes correlated with pre-existing posterior disc protrusion (odds ratio 3.31, 95% confidence interval 1.21–9.05) and neck pain (odds ratio 2.71, 95% confidence interval 1.08–6.80). Conclusions: In the cervical spine over a 20-year period, type 2 Modic changes were most frequent at the C5/6 segment. The Modic changes were associated with pre-existing disc degeneration and neck pain but not with age, BMI, smoking, shoulder stiffness, arm pain or numbness.

  • A 20-year prospective longitudinal MRI study on cervical spine after whiplash injury: Follow-up of a cross-sectional study

    Daimon K., Fujiwara H., Nishiwaki Y., Okada E., Nojiri K., Shimizu K., Ishihama H., Fujita N., Ichihara D., Tsuji T., Nakamura M., Matsumoto M., Watanabe K.

    Journal of Orthopaedic Science (Journal of Orthopaedic Science)  24 ( 4 ) 579 - 583 2019年07月

    ISSN  09492658

     概要を見る

    © 2018 Background: Some patients suffer from long-lasting symptoms after whiplash injury. However, there are few reports on the long-term changes in the cervical spine after whiplash injury using imaging tests. The purpose of this longitudinal study was to determine the changes on MRI of the cervical spine 20 years after whiplash injury, and to examine the relationships between changes in the cervical spine on MRI and changes in related clinical symptoms. Methods: Eighty-one subjects finally participated in this study (follow-up rate 16%). The mean follow-up duration was 21.7 years. All subjects filled out a questionnaire about their clinical symptoms. The MRI findings were assessed using numerical grading system applied in the original study. Statistic analyses were used to investigate whether the progression of each MRI finding was associated with the severity of neck pain, stiff shoulders, dizziness and tinnitus. Results: All subjects had complained of some clinical symptoms in the original study: 71 had neck pain, 53 stiff shoulders, and others. In the present study, 66 subjects (81.5%) complained of some clinical symptoms: 57 had stiff shoulders, 20 neck pain, and others. The progression of degeneration on MRI was observed in 95% of the subjects, with C4/5 and 5/6 being the most frequently involved levels. Changes in the severity of neck pain, stiff shoulders, dizziness and tinnitus over 20 years were not significantly associated with the progression of degenerative changes in the cervical spine on MRI. Conclusions: Twenty years after whiplash injury, 95% of the subjects showed a progression of degeneration in the cervical spine. The progression of the intervertebral disc degeneration in the cervical spine on MRI after whiplash injury was not significantly associated with changes in the severity of related clinical symptoms, indicating that the degenerative changes on MRI may reflect the physiological aging process rather than post-traumatic sequelae.

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研究発表 【 表示 / 非表示

  • 頭部MRI上のアーチファクトと病変との鑑別 適切な診断と治療のために

    藤原広和

    第40回2007カンファレンス (川崎) , 2019年07月, 口頭(招待・特別)

  • 胸椎後方伸筋群の横断面積のMRIによる10年間の縦断的研究

    梅澤 仁, 大門 憲史, 藤原 広和, 岡田 英次朗, 野尻 賢哉, 加藤 裕幸, 清水 健太郎, 石濱 寛子, 藤田 順之, 辻 崇, 中村 雅也, 松本 守雄, 渡辺 航太

    第48回日本脊椎脊髄病学会, 2019年04月, 口頭(一般)

  • 頸椎Modic変化の縦断的研究 無症候性健常者の20年フォローアップ

    辻 崇, 藤原 広和, 西脇 祐司, 大門 憲史, 岡田 英次朗, 野尻 賢哉, 渡辺 雅彦, 加藤 裕幸, 清水 健太郎, 石濱 寛子, 藤田 順之, 中村 雅也, 松本 守雄, 渡辺 航太

    第48回日本脊椎脊髄病学会 (横浜) , 2019年04月, 口頭(一般)

  • MRIによる健常者頸椎後方伸筋の変化に関する20年間の縦断的研究

    泉田 浩之, 大門 憲史, 藤原 広和, 岡田 英次朗, 野尻 賢哉, 渡辺 雅彦, 加藤 裕幸, 清水 健太郎, 石濱 寛子, 藤田 順之, 辻 崇, 中村 雅也, 松本 守雄, 渡辺 航太

    第48回日本脊椎脊髄病学会 (横浜) , 2019年04月, 口頭(一般)

  • 健常者胸椎椎間板変性のMRIを用いた10年間の縦断的研究

    岡田 英次朗, 大門 憲史, 藤原 広和, 西脇 祐司, 野尻 賢哉, 渡辺 雅彦, 加藤 裕幸, 清水 健太郎, 石濱 寛子, 藤田 順之, 辻 崇, 中村 雅也, 松本 守雄, 渡辺 航太

    第48回日本脊椎脊髄病学会 (横浜) , 2019年04月, 口頭(一般)

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担当授業科目 【 表示 / 非表示

  • 放射線医学講義

    2019年度

  • 内科学(神経)講義

    2019年度

  • 診断学実習

    2019年度

担当経験のある授業科目 【 表示 / 非表示

  • 神経画像診断実習

    慶應義塾, 2018年度, 演習

  • 神経内科系統講義 画像診断

    慶應義塾, 2018年度, 専門科目, 講義

  • 放射線診断学

    慶應義塾, 2018年度, 通年, 専門科目, 講義, 専任, 100人

  • 放射線診断学系統講義

    慶應義塾, 2017年度, 通年, 専門科目, 講義, 100人

  • 放射線診断学

    慶應義塾, 2017年度, 通年, 専門科目, 講義, 専任, 100人

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