Faculty Profiles - NAGANAWA, Shinji

Papers - NAGANAWA, Shinji

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Effects of endolymphatic hydrops on acoustic energy absorbance. Reviewed International journal

Masumi Kobayashi, Tadao Yoshida, Satofumi Sugimoto, Mariko Shimono, Masaaki Teranishi, Shinji Naganawa, Michihiko Sone

Acta oto-laryngologica Vol. 140 ( 8 ) page： 626 - 631 2020.7

Language：English Publishing type：Research paper (scientific journal)

Background: The presence of endolymphatic hydrops (EH) may cause hearing loss and affect the transmission of acoustic energy to the inner ear.Objectives: Acoustic energy absorbance on wideband acoustic immittance (WAI) was evaluated, focusing especially on EH in the vestibule.Material and methods: A total of 32 ears from 16 patients who underwent 3-T magnetic resonance imaging (MRI) to evaluate the presence of EH were examined, retrospectively. The degree of EH in the vestibule was classified into three grades (no, mild, and significant), and pure tone audiometry (PTA) and WAI were measured before and after a glycerol drip.Results: Ears with significant EH showed significantly higher hearing levels and air-bone gaps (ABG), and higher absorbance values on WAI at low frequencies (560-600 Hz) than ears with mild or no EH. Changes in absorbance values were observed in some ears without threshold change on PTA.Conclusions and Significance: This study showed significantly higher absorbance values of acoustic energy with significant vestibular EH at low frequencies. Considering ABGs observed in ears with significant EH, the presence of EH in the vestibule might cause an obstacle to the transmission of acoustic energy to the inner ear.

DOI： 10.1080/00016489.2020.1754460

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A phase I/II trial of intraoperative breast radiotherapy in an Asian population: 10-year results with critical evaluation. Reviewed International journal

Mariko Kawamura, Yoshiyuki Itoh, Takeshi Kamomae, Masataka Sawaki, Toyone Kikumori, Nobuyuki Tsunoda, Junji Ito, Yoshie Shimoyama, Hiroko Satake, Shinji Naganawa

Journal of radiation research Vol. 61 ( 4 ) page： 602 - 607 2020.7

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

Although phase III trials have been published comparing whole breast irradiation (WBI) with accelerated partial breast irradiation (APBI) using intraoperative radiotherapy (IORT), long-term follow-up results are lacking. We report the 10-year follow-up results of a prospective phase I/II clinical trial of IORT. The inclusion criteria were as follows: (i) tumor size <2.5 cm, (ii) desire for breast-conserving surgery, (iii) age >50 years, (iv) negative margins after resection and (v) sentinel lymph node-negative disease. A single dose of IORT (19-21 Gy) was delivered to the tumor bed in the operation room just after wide local excision of the primary breast cancer using a 6-12 MeV electron beam. Local recurrence was defined as recurrence or new disease within the treated breast and was evaluated annually using mammography and ultrasonography. A total of 32 patients were eligible for evaluation. The median patient age was 65 years and the median follow-up time was 10 years. Two patients experienced local recurrence just under the nipple, out of the irradiated field, after 8 years of follow-up. Three patients had contralateral breast cancer and one patient experienced bone metastasis after 10 years of follow-up. No patient experienced in-field recurrence nor breast cancer death. Eight patients had hypertrophic scarring at the last follow-up. There were no lung or heart adverse effects. This is the first report of 10-year follow-up results of IORT as APBI. The findings suggest that breast cancer with extended intraductal components should be treated with great caution.

DOI： 10.1093/jrr/rraa029

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Evaluation of segment 4 portal vein embolization added to right portal vein for right hepatic trisectionectomy: a retrospective propensity score-matched study. Reviewed

Jun Ito, Tomohiro Komada, Kojiro Suzuki, Masaya Matsushima, Masahiro Nakatochi, Yumiko Kobayashi, Tomoki Ebata, Shinji Naganawa, Masato Nagino

Journal of hepato-biliary-pancreatic sciences Vol. 27 ( 6 ) page： 299 - 306 2020.6

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Adding segment 4 (S4) portal vein embolization (PVE) to right PVE before right hepatic trisectionectomy is controversial. We retrospectively examined the effect of S4 PVE on segments 2 and 3 (S2+3) hypertrophy. METHODS: We reviewed patients with biliary carcinoma who underwent right PVE with (R3PVE) or without (R2PVE) S4 PVE using gelatin sponge particles and coils (2010-2019). Propensity score matching balanced the cohort for baseline characteristics, including total liver volume and S2+3 volume before PVE. We compared the groups regarding the S2+3 volume changes after PVE. RESULTS: Of 178 enrolled patients, 38 underwent R3PVE for right hepatic trisectionectomy and 140 underwent R2PVE for right hepatectomy. Twenty-eight patients from each group were respectively matched. The median absolute volume increase in (146 cm3 vs 70 cm3 ), hypertrophy rate of (52.4% vs 32.3%), and kinetic growth rate of (3.1 %/week vs 2.0 %/week) S2+3 were significantly higher in the R3PVE group than in the R2PVE group. In the pre-matched cohort, the rate of posthepatectomy liver failure and postoperative hospital stay did not significantly differ between the patients who underwent right hepatic trisectionectomy and right hepatectomy. CONCLUSION: R3PVE increased the S2+3 volume more effectively than R2PVE in patients with biliary carcinoma.

DOI： 10.1002/jhbp.723

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Unexpected radioactive iodine accumulation on whole-body scan after I-131 ablation therapy for differentiated thyroid cancer. Reviewed

Shingo Iwano, Shinji Ito, Shinichiro Kamiya, Rintaro Ito, Katsuhiko Kato, Shinji Naganawa

Nagoya journal of medical science Vol. 82 ( 2 ) page： 205 - 215 2020.5

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

We retrospectively evaluated the frequency of unexpected accumulation of radioactive iodine on the post-therapy whole-body scan (Rx-WBS) after radioactive iodine (RAI) ablation therapy in patients with differentiated thyroid cancer (DTC). We searched our institutional database for Rx-WBSs of DTC patients who underwent RAI ablation or adjuvant therapy between 2012 and 2019. Patients with distant metastasis diagnosed by CT or PET/CT before therapy, and those had previously received RAI therapy were excluded. In total, 293 patients (201 female and 92 male, median age 54 years) were selected. Two nuclear medicine physicians interpreted the Rx-WBS images by determining the visual intensity of radioiodine uptake by the thyroid bed, cervical and mediastinal lymph nodes, lungs, and bone. Clinical features of the patients with and without the metastatic accumulation were compared by chi-square test and median test. Logistic regression analyses were performed to compare the association between the presence of metastatic accumulation and these clinical factors. Eighty-four of 293 patients (28.7%) showed metastatic accumulation. Patients with metastatic RAI accumulation showed a significantly higher frequency of pathological N1 (pN1) and serum thyroglobulin (Tg) > 1.5 ng/ml under TSH stimulation (p = 0.035 and p = 0.031, respectively). Logistic regression analysis indicated that a serum Tg > 1.5 ng/ml was significantly correlated with the presence of metastatic accumulation (odds ratio = 1.985; p = 0.033). In conclusion, Patients with Tg > 1.5 ng/ml were more likely to show metastatic accumulation. In addition, the presence of lymph node metastasis at the initial thyroid surgery was also associated with this unexpected metastatic accumulation.

DOI： 10.18999/nagjms.82.2.205

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特集　基礎から学ぶ肺癌診断　　肺癌の3次元CT・PET/CT診断―原発巣の診断と悪性度― Reviewed

岩野信吾、伊藤信嗣、伊藤倫太郎、神谷晋一朗、加藤克彦、長縄慎二

画像診断 Vol. 40 ( 5 ) page： 439 - 446 2020.5

150周年記念記事　高次医用科学　創基150周年に寄せて Reviewed

長縄慎二

名大医学部学友時報 Vol. 843 ( - ) page： 10 - 10 2020.4

Evaluation of newly implemented dose calculation algorithms for multileaf collimator-based CyberKnife tumor-tracking radiotherapy. Reviewed International journal

Kohei Kawata, Takeshi Kamomae, Hiroshi Oguchi, Fumitaka Kawabata, Kuniyasu Okudaira, Mariko Kawamura, Kazuhiro Ohtakara, Yoshiyuki Itoh, Shinji Naganawa

Medical physics Vol. 47 ( 3 ) page： 1391 - 1403 2020.3

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: In the previous treatment planning system (TPS) for CyberKnife (CK), multileaf collimator (MLC)-based treatment plans could be created only by using the finite-size pencil beam (FSPB) algorithm. Recently, a new TPS, including the FSPB with lateral scaling option (FSPB+) and Monte Carlo (MC) algorithms, was developed. In this study, we performed basic and clinical end-to-end evaluations for MLC-based CK tumor-tracking radiotherapy using the MC, FSPB+, and FSPB. METHODS: Water- and lung-equivalent slab phantoms were combined to obtain the percentage depth dose (PDD) and off-center ratio (OCR). The CK M6 system and Precision TPS were employed, and PDDs and OCRs calculated by the MC, FSPB+, and FSPB were compared with the measured doses obtained for 30.8 × 30.8 mm2 and 60.0 × 61.6 mm2 fields. A lung motion phantom was used for clinical evaluation and MLC-based treatment plans were created using the MC. The doses were subsequently recalculated using the FSPB+ and FSPB, while maintaining the irradiation parameters. The calculated doses were compared with the doses measured using a microchamber (for target doses) or a radiochromic film (for dose profiles). The dose volume histogram (DVH) indices were compared for all plans. RESULTS: In homogeneous and inhomogeneous phantom geometries, the PDDs calculated by the MC and FSPB+ agreed with the measurements within ±2.0% for the region between the surface and a depth of 250 mm, whereas the doses calculated by the FSPB in the lung-equivalent phantom region were noticeably higher than the measurements, and the maximum dose differences were 6.1% and 4.4% for the 30.8 × 30.8 mm2 and 60.0 × 61.6 mm2 fields, respectively. The maximum distance to agreement values of the MC, FSPB+, and FSPB at the penumbra regions of OCRs were 1.0, 0.6, and 1.1 mm, respectively, but the best agreement was obtained between the MC-calculated curve and measurements at the boundary of the water- and lung-equivalent slabs, compared with those of the FSPB+ and FSPB. For clinical evaluations using the lung motion phantom, under the static motion condition, the dose errors measured by the microchamber were -1.0%, -1.9%, and 8.8% for MC, FSPB+, and FSPB, respectively; their gamma pass rates for the 3%/2 mm criterion comparing to film measurement were 98.4%, 87.6%, and 31.4% respectively. Under respiratory motion conditions, there was no noticeable decline in the gamma pass rates. In the DVH indices, for most of the gross tumor volume and planning target volume, significant differences were observed between the MC and FSPB, and between the FSPB+ and FSPB. Furthermore, significant differences were observed for lung Dmean , V15 Gy , and V20 Gy between the MC, FSPB+, and FSPB. CONCLUSIONS: The results indicate that the doses calculated using the MC and FSPB+ differed remarkably in inhomogeneous regions, compared with the FSPB. Because the MC was the most consistent with the measurements, it is recommended for final dose calculations in inhomogeneous regions such as the lung. Furthermore, the sufficient accuracy of dose delivery using MLC-based tumor-tracking radiotherapy by CK was demonstrated for clinical implementation.

DOI： 10.1002/mp.14013

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Pharmacologic and non-pharmacologic interventions to prevent hypersensitivity reactions of non-ionic iodinated contrast media: a systematic review protocol Reviewed

Hiroyasu Umakoshi, Takashi Nihashi, Hironori Shimamoto, Takehiro Yamada, Hiroaki Ishiguchi, Akira Takada, Naoki Hirasawa, Shunichi Ishihara, Yasuo Takehara, Shinji Naganawa, Matthew Davenport, Teruhiko Terasawa

BMJ OPEN Vol. 10 ( 3 ) page： e033023 2020.3

Language：English Publishing type：Research paper (scientific journal) Publisher：BMJ PUBLISHING GROUP

Introduction Iodinated contrast media are commonly used in medical imaging and can cause hypersensitivity reactions, including rare but severe life-threatening reactions. Although several prophylactic approaches have been proposed for severe reactions, their effects remain unclear. Therefore, we aim to review systematically the preventive effects of pharmacologic and non-pharmacologic interventions and predictors of acute, hypersensitivity reactions.Methods and analysis We will search the PubMed, EMBASE and Cochrane Central Register of Controlled Trials databases from 1 January 1990 through 31 December 2019 and will examine the bibliographies of eligible studies, pertinent review articles and clinical practice guidelines. We will include prospective and retrospective studies of any design that evaluated the effects of pharmacological and non-pharmacological preventive interventions for adverse reactions of non-ionic iodinated contrast media. Two assessors will independently extract the characteristics of the study and intervention and the quantitative results. Two independent reviewers will assess the risk of bias using standard design-specific validity assessment tools. The primary outcome will be reduction in acute contrast media-induced hypersensitivity reactions. The secondary outcomes will include characteristics associated with the development of contrast media-induced acute hypersensitivity reactions, and adverse events associated with specific preventive interventions. Unique premedication regimens (eg, dose, drug and duration) and non-pharmacological strategies will be analysed separately. Average-risk and high-risk patients will be considered separately. A meta-analysis will be performed if appropriate.Ethics and dissemination Ethics approval is not applicable, as this will be a secondary analysis of publicly available data. The results of the analysis will be submitted for publication in a peer reviewed journal.

DOI： 10.1136/bmjopen-2019-033023

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磁気共鳴画像によるNeurofluids動態の解明 Reviewed

長縄慎二、田岡俊昭、川井　恒

脳とこころの研究センター脳疾患克服に向けた次世代創薬開発のためのコホート・コンソーシアム型研究拠点形成令和元年度活動報告書 Vol. - ( - ) page： 30 - 30 2020.3

脳動脈瘤破裂リスク評価のための磁気共鳴流体解析と計算流体解析による形態ならびに血流動態バイオマーカーの検討 Reviewed

MAJUWANA GAMAGE,　礒田治夫、泉　孝嗣、若林俊彦、長縄慎二

脳とこころの研究センター脳疾患克服に向けた次世代創薬開発のためのコホート・コンソーシアム型研究拠点形成令和元年度活動報告書 Vol. - ( - ) page： 27 - 27 2020.3

【基礎から学ぶ肺癌診断】肺癌の3次元CT・PET/CT診断原発巣の診断と悪性度 Reviewed

岩野信吾, 伊藤信嗣, 伊藤倫太郎, 神谷晋一朗, 加藤克彦, 長縄慎二

画像診断 Vol. 40 ( 5 ) page： 439 - 446 2020.3

Authorship：Last author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：(株)Gakken

＜文献概要＞肺癌の臨床病期分類(TNM分類)は主に画像診断に基づいて行われる.2017年に改訂されたTNM分類では,T因子(サイズ)の診断が複雑になった.病理学的浸潤径に相当する充実成分径の計測はthinsection CTで行うのが基本であるが,3次元CTやPET/CTを利用することで精度の向上が期待できる.

Other Link： https://search-tp.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2020&ichushi_jid=J00235&link_issn=&doc_id=20200408090014&doc_link_id=10.15105%2FGZ.0000001656&url=https%3A%2F%2Fdoi.org%2F10.15105%2FGZ.0000001656&type=%88%E3%8F%91.jp_%83I%81%5B%83%8B%83A%83N%83Z%83X&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00024_2.gif

White matter microstructural changes in tuberous sclerosis: Evaluation by neurite orientation dispersion and density imaging (NODDI) and diffusion tensor images. Reviewed International journal

Toshiaki Taoka, Noriko Aida, Yuta Fujii, Kazushi Ichikawa, Hisashi Kawai, Toshiki Nakane, Rintaro Ito, Shinji Naganawa

Scientific reports Vol. 10 ( 1 ) page： 436 - 436 2020.1

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

Neurite orientation dispersion and density imaging (NODDI) is a novel diffusion method for evaluating tissue microstructure, and may provide additional information over conventional diffusion tensor imaging (DTI). We evaluated NODDI and DTI parameters in cases of tuberous sclerosis (TS) to assess microstructural changes in the white matter. Eleven cases of tuberous sclerosis and eight age-matched controls underwent NODDI and DTI. We performed qualitative analysis and tract-based spatial statistics (TBSS) analysis of the NODDI parameters (Ficv: intracellular volume fraction, Fiso: isotropic fraction, ODI: orientation dispersion index) as well as DTI parameters (MD: mean diffusivity, FA: fractional anisotropy). We also performed a correlation analysis between clinical symptoms and parameters. The qualitative analysis indicated that the Ficv had a lower value in TS cases particularly in the tubers adjacent to the white matter. The TBSS analysis showed that the TS cases had decreased Ficv in a greater area compared to the other parameters including MD. In particular, the Ficv was decreased in deep white matter, such as the superior longitudinal fascicles (SLF). The application of NODDI to TS cases revealed tissue microstructural changes, and particularly the Ficv could detect more widespread abnormalities in white matter structure compared to DTI parameters.

DOI： 10.1038/s41598-019-57306-w

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Glymphatic imaging using MRI. Reviewed International journal

Toshiaki Taoka, Shinji Naganawa

Journal of magnetic resonance imaging : JMRI Vol. 51 ( 1 ) page： 11 - 24 2020.1

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

In recent years, the existence of a mass transport system in the brain via cerebrospinal fluid (CSF) or interstitial fluid (ISF) has been suggested by many studies. The glymphatic system is hypothesized to be a waste clearance system of the CSF through the perivascular and interstitial spaces in the brain. Tracer studies have primarily been used to visualize or evaluate the waste clearance system in the brain, and evidence for this system has accumulated. The initial study that identified the glymphatic system was an in vivo tracer study in mice. In that study, fluorescent tracers were injected into the cisterna magna and visualized by two-photon microscopy. MRI has also been used to evaluate glymphatic function primarily with gadolinium-based contrast agents (GBCAs) as tracers. A number of GBCA studies evaluating glymphatic function have been conducted using either intrathecal or intravenous injections. Stable isotopes, such as 17 O-labeled water, may also be used as tracers since they can be detected by MRI. In addition to tracer studies, several other approaches have been used to evaluate ISF dynamics within the brain, including diffusion imaging. Phase contrast evaluation is a powerful method for visualizing flow within the CSF space. In order to evaluate the movement of water within tissue, diffusion-weighted MRI represents another promising technique, and several studies have utilized diffusion techniques for the evaluation of the glymphatic system. This review will discuss the findings of these diffusion studies. Level of Evidence: 5 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019. J. Magn. Reson. Imaging 2020;51:11-24.

DOI： 10.1002/jmri.26892

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Celebrating the beginning of international journal collaboration. Reviewed

Shinji Naganawa, Yukunori Korogi

Japanese journal of radiology Vol. 38 ( 1 ) page： 1 - 2 2020.1

中枢神経系原発anaplastic lymphoma kinase陽性未分化大細胞リンパ腫の1例 Reviewed

佐々木裕太郎, 中道玲瑛, 伊藤信嗣, 川井恒, 岩野信吾, 田岡俊昭, 加藤克彦, 川島直美, 下山芳江, 長縄慎二

映像情報Medical Vol. 52 ( 1 ) page： 82 - 83 2020.1

Quantification of Endolymphatic Space Volume after Intravenous Administration of a Single Dose of Gadolinium-based Contrast Agent: 3D-real Inversion Recovery versus HYDROPS-Mi2. Reviewed

Toshio Ohashi, Shinji Naganawa, Ai Takeuchi, Toshio Katagiri, Kayao Kuno

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 19 ( 2 ) page： 119 - 124 2020

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: Recently, the use of 3D real inversion recovery (3D-real IR) imaging has been proposed for the evaluation of endolymphatic hydrops (EH). This method shows similar contrast between the endolymphatic and perilymphatic spaces and surrounding bone compared with the hybrid of reversed image of positive endolymph signal and native image of perilymph signal multiplied with heavily T2-weighted MR cisternography (HYDROPS-Mi2) image. We measured the volume of the endolymphatic space using 3D-real IR and HYDROPS-Mi2 images, and compared the measurements obtained with both techniques. METHODS: HYDROPS-Mi2 and 3D-real IR images were obtained for 30 ears from 15 patients with clinical suspicion of EH; imaging was performed 4 h after intravenous administration of a single dose of gadolinium-based contrast agent. We measured the volume of the endolymphatic space in the cochlea and vestibule by manually drawing the regions of interest. The correlation between endolymphatic volume determined from HYDROPS-Mi2 images and 3D-real IR images was calculated. RESULTS: There was a strong positive linear correlation between the cochlear and vestibular endolymphatic volume determined from HYDROPS-Mi2 and 3D-real IR images. The Spearman's rank correlation coefficient (ρ) between the measurements obtained with both images was 0.805 (P < 0.001) for the cochlea and 0.826 (P < 0.001) for the vestibule. CONCLUSION: The endolymphatic volume measured using 3D-real IR images strongly correlated with that measured using HYDROPS-Mi2 images. Thus, 3D-real IR imaging might be a suitable method for the measurement of endolymphatic volume.

DOI： 10.2463/mrms.mp.2019-0013

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The Space between the Pial Sheath and the Cortical Venous Wall May Connect to the Meningeal Lymphatics. Reviewed

Shinji Naganawa, Rintaro Ito, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 19 ( 1 ) page： 1 - 4 2020

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

We currently obtain pre- and post-contrast enhanced whole brain 3D-real inversion recovery images for the evaluation of endolymphatic hydrops. We noticed that the space between the pial sheath surrounding the cortical veins and the cortical venous wall is enhanced and this enhancement seems to connect to the meningeal lymphatics along superior sagittal sinus. This new anatomical concept regarding the outflow from the glymphatic system might be important for the future research in neuroscience.

DOI： 10.2463/mrms.bc.2019-0099

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Optimal Plane Selection for Measuring Post-prandial Blood Flow Increase within the Superior Mesenteric Artery: Analysis Using 4D Flow and Computational Fluid Dynamics. Reviewed

Masataka Sugiyama, Yasuo Takehara, Masanori Kawate, Naoki Ooishi, Masaki Terada, Haruo Isoda, Harumi Sakahara, Shinji Naganawa, Kevin M Johnson, Oliver Wieben, Tetsuya Wakayama, Atsushi Nozaki, Hiroyuki Kabasawa

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 19 ( 4 ) page： 366 - 374 2020

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: 2D cine phase contrast (PC)-MRI is a standard velocimetry for the superior mesenteric artery (SMA); however, the optimal localization of the measurement plane has never been fully discussed previously. The purpose of this Institutional Review Board approved prospective and single arm study is to test whether flow velocimetry of the SMA with combined use of 2D cine PC-MRI and meal challenge is dependent on the localizations of the measurement planes and to seek optimal section for velocimetry. METHODS: Seven healthy volunteers underwent cardiac phase resolved ECG gated 2D cine PC-MRI pre- and 30 min post-meal challenge at three measurement planes: proximal, curved mid section and distal straight section of the SMA at 3T. 4D Flow using 3D cine PC-MRI with vastly undersampled isotropic projection imaging (PC VIPR) was also performed right after 2D cine PC-MRI to delineate the flow dynamics within the SMA using streamline analysis. Two radiologists measured flow velocities, and rated the appearances of the abnormal flow in the SMA on streamlines derived from the 4D Flow and the computational fluid dynamics (CFD). RESULTS: 2D cine PC-MRI measured increased temporally averaged flow velocity (mm/s) after the meal challenge only in the proximal (129.3 vs. 97.8, P = 0.0313) and distal section (166.9 vs. 96.2, P = 0.0313), not in the curved mid section (113.1 vs. 85.5, P = 0.0625). The average velocities were highest and their standard errors (8.5-26.5) were smallest at the distal straight section both before and after the meal challenge as compared with other sections. The streamline analysis depicted more frequent appearances of vertical or helical flow in the curved mid section both on 4D Flow and CFD (κ: 0.27-0.68). CONCLUSION: SMA velocimetry with 2D cine PC-MRI was dependent on the localization of the measurement planes. Distal straight section, not in the curved mid section is recommended for MR velocimetry.

DOI： 10.2463/mrms.mp.2019-0089

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Detection of IV-gadolinium Leakage from the Cortical Veins into the CSF Using MR Fingerprinting. Reviewed

Shinji Naganawa, Toshiki Nakane, Hisashi Kawai, Toshiaki Taoka, Hirokazu Kawaguchi, Katsuya Maruyama, Katsutoshi Murata, Gregor Körzdörfer, Josef Pfeuffer, Mathias Nittka, Michihiko Sone

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 19 ( 2 ) page： 141 - 146 2020

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: It has been reported that leakage of intravenously administered gadolinium-based contrast agents (IV-GBCAs) into the cerebrospinal fluid (CSF) from the cortical veins even in healthy subjects can be detected using a highly sensitive pulse sequence such as heavily T2-weighted 3D fluid-attenuated inversion recovery and 3D-real inversion recovery (IR). The purpose of this study was to evaluate the feasibility of MR fingerprinting to detect GBCA leakage from the cortical veins after IV-GBCA. MATERIALS: Fourteen patients with suspected endolymphatic hydrops (EH) who received a single dose of IV-GBCA (39-79 years old) were included. The real IR images as well as MR fingerprinting images were obtained at 4 h after IV-GBCA. T1 and T2 values were obtained using MR fingerprinting and analyzed in ROIs covering intense GBCA leakage, and non-leakage areas of the CSF as determined on real IR images. The scan time for real IR imaging was 10 min and that for MR fingerprinting was 41 s. RESULTS: The mean T1 value of the ROI in the area of GBCA leakage was 2422 ± 261 ms and that in the non-leakage area was 3851 ± 235 ms (P < 0.01). There was no overlap between the T1 values in the area of GBCA leakage and those in the non-leakage area.The mean T2 value in the area of GBCA leakage was 319 ± 90 ms and that in the non-leakage area was 670 ± 166 ms (P < 0.01). There was some overlap between the T2 values in the area of GBCA leakage and those in the non-leakage area. CONCLUSION: Leaked GBCA from the cortical veins into the surrounding CSF can be detected using MR fingerprinting obtained in <1 min.

DOI： 10.2463/mrms.mp.2019-0048

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Confirmation of Age-dependence in the Leakage of Contrast Medium around the Cortical Veins into Cerebrospinal Fluid after Intravenous Administration of Gadolinium-based Contrast Agent. Reviewed

Shinji Naganawa, Rintaro Ito, Hisashi Kawai, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 19 ( 4 ) page： 375 - 381 2020

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: It has been reported previously that intravenously administered gadolinium-based contrast agent (GBCA) leaks into the subarachnoid space around the cortical veins at 4 h after injection in all old people over 37 years, but not in younger people up to 37 years of age in 3D-real IR images. The purpose of this study was to investigate whether there was a strict threshold of 37 years of age for the leakage of the GBCA into the subarachnoid space. METHODS: The subjects included 190 patients, that were scanned for 3D-real IR images at 4 hours after intravenous injection of GBCA as a diagnostic test for endolymphatic hydrops. The patient's age ranged from 14 to 81 years. Two experienced neuroradiologists evaluated the images to determine whether the GBCA leakage around the cortical veins was positive or negative. Any discrepancies between the two observers were discussed and a consensus was obtained.A Mann-Whitney U test and receiver operating characteristic (ROC) curve analysis were used to compare the positive and the negative group and to set the age cut-off value for the prediction of GBCA leakage. RESULTS: The GBCA leakage around the cortical veins was negative in 35 patients and positive in 155 patients. The average age was 33 ± 11 years in the negative group, and 55 ± 12 years in the positive group (P < 0.01). In the ROC analysis for the age and leakage of the GBCA, an area under the curve was 0.905 and the cut-off age was 37.317 years (sensitivity of 0.942 and specificity of 0.771). CONCLUSION: Intravenously administered GBCA leaks into the subarachnoid space around the cortical veins in most patients over 37 years of age. However, it should be noted that it can be found occasionally in patients under 37 years of age.

DOI： 10.2463/mrms.mp.2019-0182

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Papers - NAGANAWA, Shinji