文献一覧: Tadao Yoshida (著者)

3 0 0 0 OA Peripheral Retinal Leakage after Intravenous Administration of a Gadolinium-based Contrast Agent: Age Dependence, Temporal and Inferior Predominance and Potential Implications for Eye Homeostasis

著者: Shinji Naganawa Rintaro Ito Mariko Kawamura Toshiaki Taoka Tadao Yoshida Michihiko Sone
出版者: Japanese Society for Magnetic Resonance in Medicine
雑誌: Magnetic Resonance in Medical Sciences (ISSN:13473182)
巻号頁・発行日: pp.mp.2021-0100, (Released:2021-10-16)
参考文献数: 18
被引用文献数: 5

Purpose: Peripheral retinal leakage (PRL) of contrast medium from the ora serrata (i.e., the peripheral part of the retina) was recently reported in normal eyes using ultra-widefield fluorescein angiography. We occasionally see PRL of gadolinium-based contrast agents (GBCAs) in the vitreous from the temporal and inferior sides of the ora serrata on MR images of subjects without ophthalmic disease. In this study, we retrospectively evaluated these MR images to determine if PRL was associated with aging. We also evaluated whether the initial leakage appeared in the temporal and inferior sides, and whether there was uniform distribution within the vitreous after 24 hours.Methods: In 127 subjects (9 volunteers, 85 patients with sudden deafness, and 33 patients with a suspicion of endolymphatic hydrops), pre- and post-contrast-enhanced heavily T2-weighted 3D-fluid attenuated inversion recovery (FLAIR) images were obtained. The presence or absence of PRL was subjectively evaluated. For patients with a suspicion of endolymphatic hydrops, 3D-real inversion recovery (IR) images were also obtained at pre-, 10 mins, 4 hours, and 24 hours after intravenous administration (IV) of GBCA. Four circular ROIs were placed in the vitreous humor and the signal intensity was measured.Results: In the cases with PRL (n = 88) and without PRL (n = 47), the median age was 59 and 47 years, respectively (P = 0.001). At 4 hours after IV-GBCA, the mean signal increase in the inferior temporal ROI was greater than all the other ROIs. At 24 hours after IV-GBCA, no significant difference in signal intensity was observed for the four ROIs.Conclusion: PRL of GBCA is age-dependent and occurs mainly from the inferior temporal side of the ora serrata. The contrast effect was uniformly distributed at 24 hours after IV-GBCA. Future observations in a variety of diseases will determine the clinical significance of these findings.

2021-10-18 20:40:31
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2 0 0 0 OA Parasagittal Cystic Lesions May Arise from the Pial Sheath around the Cortical Venous Wall

著者: Shinji Naganawa Rintaro Ito Toshiaki Taoka Tadao Yoshida Michihiko Sone
出版者: Japanese Society for Magnetic Resonance in Medicine
雑誌: Magnetic Resonance in Medical Sciences (ISSN:13473182)
巻号頁・発行日: pp.bc.2021-0141, (Released:2021-12-25)
参考文献数: 16
被引用文献数: 1

It has been reported that perivenous cystic structures near the parasagittal dura are associated with the leakage of gadolinium-based contrast agents at 4 hours after intravenous administration. The origin of such cystic structures remains unknown. While reading many cases of MR cisternography, we noticed that some of the cystic structures appeared to connect to the perivenous subpial space. This new imaging finding might facilitate future research of the waste clearance system for the central nervous system.

2021-12-27 10:58:30
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2 0 0 0 OA The Space between the Pial Sheath and the Cortical Venous Wall May Connect to the Meningeal Lymphatics

著者: Shinji Naganawa Rintaro Ito Toshiaki Taoka Tadao Yoshida Michihiko Sone
出版者: Japanese Society for Magnetic Resonance in Medicine
雑誌: Magnetic Resonance in Medical Sciences (ISSN:13473182)
巻号頁・発行日: pp.bc.2019-0099, (Released:2019-10-15)
参考文献数: 11
被引用文献数: 35

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.

2019-10-20 00:00:30
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1 0 0 0 OA Pitfalls of Using T2-contrast Enhancement Techniques in 3D-FLAIR to Detect Endolymphatic Hydrops

著者: Yutaka Kato Shinji Naganawa Toshiaki Taoka Tadao Yoshida Michihiko Sone
出版者: Japanese Society for Magnetic Resonance in Medicine
雑誌: Magnetic Resonance in Medical Sciences (ISSN:13473182)
巻号頁・発行日: pp.mp.2022-0017, (Released:2022-05-10)
参考文献数: 16
被引用文献数: 1 3

Purpose: To determine whether T2-contrast enhancement techniques can be used to diagnose endolymphatic hydrops, we compared fluid signal artifacts with and without T2-contrast enhancement techniques in 3D fluid-attenuated inversion recovery (3D-FLAIR).Methods: We prepared a custom-made phantom consisting of eight tubes half-filled with saline. Images were obtained using four 3D-FLAIR: without T2-contrast enhancement (Normal), with non-selective T2-inversion recovery (T2-IR), and two with non-selective T2 preparation IR (T2-prep). Scans were performed with and without rice covering the phantom to simulate minimal and severe B0-inhomogeneity conditions. The average signal intensity (SI) values of eight saline tubes were compared between the four sequences and between each other. Comparisons were performed for all measurement slices and the central 10 slices. The images using T2-contrast enhancement technique were obtained from a volunteer and a patient suspected of Meniere’s disease.Results: The Normal sequence SI for all slices was significantly lower than that for the other sequences, with smaller standard deviation (SD) and no outliers. Several outliers were detected in the other sequences. The SDs and outliers were larger without rice than with rice. When the central 10 slices with rice, the T2-IR had a significantly higher SI with more outliers compared with the Normal sequence. The T2-prep had no outliers and SIs that were comparable to those of the Normal sequence. However, without rice, the T2-IR and T2-prep sequences had significantly higher SIs with outliers and larger SDs compared to the Normal sequence. In the corresponding images, the Normal sequence achieved excellent fluid suppression, whereas the T2-IR and T2-prep sequences showed high-signal artifacts. Imperfect fluid suppressions were observed in the volunteer image and the endolymphatic hydrops on the post-gadolinium image differed in size and shape in the non-injected T2-IR in the patient image.Conclusion: T2-contrast enhancement techniques should be used with caution in 3D-FLAIR for diagnosing endolymphatic hydrops.

2023-12-05 20:31:42
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1 0 0 0 OA Peripheral Retinal Leakage after Intravenous Administration of a Gadolinium-based Contrast Agent: Age Dependence, Temporal and Inferior Predominance and Potential Implications for Eye Homeostasis

著者: Shinji Naganawa Rintaro Ito Mariko Kawamura Toshiaki Taoka Tadao Yoshida Michihiko Sone
出版者: Japanese Society for Magnetic Resonance in Medicine
雑誌: Magnetic Resonance in Medical Sciences (ISSN:13473182)
巻号頁・発行日: vol.22, no.1, pp.45-55, 2023 (Released:2023-01-01)
参考文献数: 18
被引用文献数: 2 5

2023-08-25 19:33:47
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1 0 0 0 OA Cross-sectional Area of the Superior Petrosal Sinus is Reduced in Patients with Significant Endolymphatic Hydrops

著者: Shinji Naganawa Rintaro Ito Hisashi Kawai Mariko Kawamura Toshiaki Taoka Tadao Yoshida Michihiko Sone
出版者: Japanese Society for Magnetic Resonance in Medicine
雑誌: Magnetic Resonance in Medical Sciences (ISSN:13473182)
巻号頁・発行日: pp.mp.2021-0010, (Released:2021-04-24)
参考文献数: 36
被引用文献数: 1

Purpose: To evaluate the relationship between the size of the venous structures related to the inner ear and the degree of endolymphatic hydrops (EH).Methods: Thirty-four patients with a suspicion of EH underwent whole brain MR imaging including the inner ear. Images were obtained pre- and post-administration, and at 4 and 24 hours after the intravenous administration of a gadolinium-based contrast agent (IV-GBCA). The cross-sectional areas (CSA) of the internal jugular vein (IJV), superior petrosal sinus (SPS), and inferior petrosal sinus (IPS) were measured on the magnetization prepared rapid acquisition of gradient echo (MPRAGE) images obtained immediately after the IV-GBCA. The grade of EH was determined on the hybrid of reversed image of positive endolymph signal and native image of positive perilymph signal (HYDROPS) images obtained at 4 hours after IV-GBCA as no, mild, and significant EH according to the previously proposed grading system for the cochlea and vestibule, respectively. The ipsilateral CSA was compared between groups with each level of EH grade. P < 0.05 was considered statistically significant.Results: There were no statistically significant differences between EH grades for the CSA of the IJV or that of the IPS in either the cochlea or the vestibule. The CSA of the SPS in the groups with significant EH was significantly smaller than that in the group with no EH, for both the cochlea (P < 0.01) and the vestibule (P < 0.05). In an ROC analysis to predict significant EH, the cut-off CSA value in the SPS was 3.905 mm2 for the cochlea (AUC: 0.8762, 95% confidence interval [CI]: 0.7952‒0.9572) and 3.805 mm2 for the vestibule (AUC: 0.7727, 95% CI: 0.6539‒0.8916).Conclusion: In the ears with significant EH in the cochlea or vestibule, the CSA of the ipsilateral SPS was smaller than in the ears without EH.

2021-04-26 19:30:35
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1 0 0 0 OA MR Imaging of Endolymphatic Hydrops in Five Minutes

著者: Shinji Naganawa Rintaro Ito Hisashi Kawai Mariko Kawamura Toshiaki Taoka Mayuko Sakai Kazushige Ichikawa Tadao Yoshida Michihiko Sone
出版者: Japanese Society for Magnetic Resonance in Medicine
雑誌: Magnetic Resonance in Medical Sciences (ISSN:13473182)
巻号頁・発行日: pp.ici.2021-0022, (Released:2021-04-24)
参考文献数: 12
被引用文献数: 7

In this study, we present images acquired by a fast-imaging method for the evaluation of endolymphatic hydrops after intravenous administration of a single dose of gadolinium-based contrast agent. We utilized the hybrid of reversed image of MR cisternography and a positive perilymph signal by heavily T2- weighted 3D-fluid attenuated inversion recovery-multiplied by T2 (HYDROPS2-Mi2) method combined with deep learning reconstruction denoising. The scan time for the fast protocol was approximately 5 mins, which is far shorter than previously reported scan times. The fast acquisition provides similar image quality and less motion artifacts compared to the longer method.

2021-04-26 19:29:06
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1 0 0 0 OA Autoxidation of Polyunsatulated Fatty Acid Initiated by Cigarette Smoke

著者: Youichi OHKUBO Chieko KADOSIMA Takashi KANEKO Junichi CHUCHIYA Yosiaki AKUTSU Masamitu TAMURA Tadao YOSHIDA
出版者: Japan Society for Atmospheric Environment
雑誌: Journal of Japan Society of Air Pollution (ISSN:03867064)
巻号頁・発行日: vol.25, no.3, pp.212-220, 1990-05-10 (Released:2011-11-08)
参考文献数: 17
被引用文献数: 2

シガレヅトスモーク中には高反応性で見かけ上長寿命の気相ラジラルが存在することが見いだされている。このラジカルの生体への有害性に関する基礎的な知見を得るため, シガレットスモークおよびスモーク中の気相ラジカル生成をモデル化したオレフィン/NO/空気系反応ガスが生体膜の主要構成脂質である高度不飽和脂酸 (PUFA) の自動酸化を開始することを共役ジエン生成法および酸素吸収法を用いて検討した。その結果, シガレットスモークは主としてその気相ラジカルによりPUFAの自動酸化を開始し, 生体に有害な過酸化物を生成することを見いだした。

2017-12-12 07:26:22
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