Search Results 1-20 of 5203

  • T1-weighted and T2-weighted MRI image synthesis with convolutional generative adversarial networks

    Kawahara Daisuke , Nagata Yasushi

    … Background: The objective of this study was to propose an optimal input image quality for a conditional generative adversarial network (GAN) in T1-weighted and T2-weighted magnetic resonance imaging (MRI) images.Materials and methods: A total of 2,024 images scanned from 2017 to 2018 in 104 patients were used. … Two image sizes (512 × 512 and 256 × 256) and two grayscale level conversion method (simple and adaptive) were used for the input images. …

    Reports of Practical Oncology and Radiotherapy 26(1), 35-42, 2021-01-22



    隠岐 雄太 , 佐藤 元孝 , 堀谷 弘 , 上田 倫央 , 中山 治郎 , 三宅 修

    … An abdominal plain magnetic resonance imaging T2-weighted image revealed a heterogeneous high signal mass in the right adrenal gland. …

    泌尿器科紀要 = Acta urologica Japonica 67(1), 7-10, 2021-01

    IR  DOI 

  • Comparison of Metal Artifacts of Titanium and Titanium-Zirconium Alloy Dental Implants on MRI  [in Japanese]

    Komatsu Tomohiro , Ito Kotaro , Muraoka Hirotaka , Hirahara Naohisa , Okada Shunya , Ichiki Shungo , Itakura Go , Kaneda Takashi

    … On magnetic resonance imaging(MRI), metal artifacts of dental implants often make diagnosis difficult in clinical situations. … The full width at half maximum (FWHM) of metal artifact in each phase-encoding direction and frequency-encoding was measured on Image J. …

    Shika Hoshasen 60(2), 42-47, 2021


  • Fusing of Preoperative Magnetic Resonance and Intraoperative O-arm Images in Deep Brain Stimulation Enhance Intuitive Surgical Planning and Increase Accuracy of Lead Placement

    ATSUMI Hideki , MATSUMAE Mitsunori

    … Recent advances in magnetic resonance imaging (MRI) have enabled information on the location of the basal ganglia, as the target of DBS, to be obtained preoperatively. … With our method, we first fuse preoperative MRI and pre-frame fixed computed tomography (CT) images, then fuse the CT images exactly after mounting the frame, using this fusion image as a <i>platform image</i>. …

    Neurologia medico-chirurgica, 2021


  • Hemangioma Mimicking Left Atrial Mass in the Posterior Mediastinum:A Case Report with Literature Review

    Xu Min , Xiong Feng , Zhang Lijuan , Wang Shuzhen

    … Herein, we summarize the age, gender, symptoms, diagnostic methods, image diagnosis, size, treatments, histologic features, outcomes, and follow-up of 17 cases. … Diagnostic methods mainly included chest X-ray, computed tomography (CT), and magnetic resonance imaging (MRI). …

    International Heart Journal 62(2), 453-457, 2021


  • Spontaneous intracranial hypotension complicated by atlantoaxial subluxation: a case report  [in Japanese]

    M.D. Yamazaki Naoya , M.D. Ryosuke Doijiri , M.D. Yamaguchi Eriko , M.D. Takahashi Ken , Ph.D. Takahashi Hiroaki , Ph.D. Kikuchi Takahiko

    <p>症例は54歳の女性,立位で増強し臥位で改善する頭痛と後頸部痛を主訴に来院した.33歳時より関節リウマチと診断され加療中だった.頸椎MRIとMRミエログラフィーより脳脊髄液漏出症と診断した.また,頸部X線で環椎の前方突出所見を認め環軸椎亜脱臼と診断した.環軸椎亜脱臼の部位に一致して画像上脳脊髄液の漏出を認め,物理的圧迫により硬膜が破綻し脳脊髄液漏出症を惹起したと考えた.症状は補液に …

    Rinsho Shinkeigaku 61(3), 172-176, 2021


  • Diagnostic Imaging and artificial intelligence imaging for cerebral aneurysm  [in Japanese]

    IKAWA Fusao , HIDAKA Toshikazu , KUWABARA Masashi , MATSUDA Shingo , OZONO Iori , CHIKU Masaaki , KITAMURA Naoyuki , CHOPPIN Antoine , SHIMAHARA Yuki

    日本は人口比MRI保有台数が世界一であり,日本人の未破裂脳動脈瘤は欧米人の2.8倍 破裂しやすいため,脳ドックが発展している.近年人工知能による未破裂脳動脈瘤診断もされるよ うになったため,未破裂脳動脈瘤のMRI画像診断,人工知能による画像診断について報告する.

    Medical Journal of Shimane Prefectural Central Hospital 45(0), 3-12, 2021


  • Texture Analysis in Brain Tumor MR Imaging

    Kunimatsu Akira , Yasaka Koichiro , Akai Hiroyuki , Sugawara Haruto , Kunimatsu Natsuko , Abe Osamu

    … <p>Texture analysis, as well as its broader category radiomics, describes a variety of techniques for image analysis that quantify the variation in surface intensity or patterns, including some that are imperceptible to the human visual system. … Multiple MRTA studies in gliomas have repeatedly shown high performance of entropy, a measure of the randomness in image intensity values, of either histogram- or gray-level co-occurrence matrix parameters. …

    Magnetic Resonance in Medical Sciences, 2021


  • Using MRI to Evaluate Femoral Bone Tunnel Position and Diameter afte ACL Reconstruction Surgery  [in Japanese]

    TSUNEYOSHI Katsuya , KAN Hiroyuki , UESHIMA Keiichirou , HINO Manabu , KOMAKI Shintarou , SHIMOMURA Seiji , YOSHIKAWA Tomoharu

    … Therefore, the purpose of this study was to use MRI to verify whether surface renderings created using the image processing software installed in the MRI system were useful for evaluating femoral bone tunnels without using workstation software.</p><p>Method</p><p> …

    Japanese Journal of Magnetic Resonance in Medicine, 2021


  • T<sub>2</sub>-FLAIR Mismatch Sign Is Caused by Long T<sub>1</sub> and T<sub>2</sub> of <i>IDH</i>-mutant, 1p19q Non-codeleted Astrocytoma

    Kinoshita Manabu , Uchikoshi Masato , Sakai Mio , Kanemura Yonehiro , Kishima Haruhiko , Nakanishi Katsuyuki

    … <p>T<sub>2</sub>-fluid-attenuated inversion recovery images (FLAIR) mismatch sign is now known to be a specific yet insensitive image feature for <i>IDH</i>-mutant, 1p19q non-codeleted astrocytoma. … These different relaxation time characteristics seemed to render T<sub>2</sub>-FLAIR mismatch sign of becoming such a unique and specific image feature for <i>IDH</i>-mutant, 1p19q non-codeleted astrocytoma.</p> …

    Magnetic Resonance in Medical Sciences 20(1), 119-123, 2021


  • Quick MR Neuromelanin Imaging Using a Chemical Shift Selective Pulse

    Kusama Midori , Sato Noriko , Kimura Yukio , Miyagi Kenji

    … The TSE with CHESS image was the most useful for the diagnosis of neuromelanin within the limited time.</p> …

    Magnetic Resonance in Medical Sciences 20(1), 106-111, 2021


  • Visualization of Cerebrospinal Fluid Motion in the Whole Brain Using Three-dimensional Dynamic Improved Motion-sensitized Driven-equilibrium Steady-state Free Precession

    Horie Tomohiko , Kajihara Nao , Saito Haruo , Shibukawa Shuhei , Obara Makoto , Ogino Tetsuo , Niwa Tetsu , Kuroda Kagayaki , Matsumae Mitsunori

    <p>The feasibility of the 3D dynamic improved motion-sensitized driven-equilibrium steady-state free precession (3D dynamic iMSDE SSFP) was evaluated for visualizing CSF motion and the appropria …

    Magnetic Resonance in Medical Sciences 20(1), 112-118, 2021


  • Robustness of a Combined Modified Dixon and PROPELLER Sequence with Two Interleaved Echoes in Clinical Head and Neck MRI

    Shigenaga Yutaka , Takenaka Daisuke , Hashimoto Tomohisa , Ishida Takayuki

    … <p>Purpose: The combination of modified Dixon (mDixon) and periodically rotated overlapping parallel lines with enhanced reconstruction sequence with two interleaved echoes, which promotes uniform fat-suppression and motion insensitivity, has recently become available for commercial magnetic resonance imaging (MRI) scanners. … The significantly decreased motion artifacts in the combination sequence significantly improved image quality overall.</p> …

    Magnetic Resonance in Medical Sciences 20(1), 76-82, 2021


  • Turbo Spin-echo Diffusion-weighted Imaging Compared with Single-shot Echo-planar Diffusion-weighted Imaging: Image Quality and Diagnostic Performance When Differentiating between Ductal Carcinoma <i>in situ</i> and Invasive Ductal Carcinoma

    Mori Naoko , Mugikura Shunji , Miyashita Minoru , Mori Yu , Maekawa Yui , Nagasaka Tatsuo , Takase Kei

    … <p>Purpose: To compare the image quality between turbo spin-echo (TSE)-diffusion weighted imaging (DWI) and single-shot echo-planar imaging (EPI)-DWI, and to verify the diagnostic performance of the apparent diffusion coefficient (ADC) parameters of the two techniques by using histogram analysis in terms of differentiation between ductal carcinoma <i>in situ</i> …

    Magnetic Resonance in Medical Sciences 20(1), 60-68, 2021


  • Intracranial Distribution of Intravenously Administered Gadolinium-based Contrast Agent over a Period of 24 Hours: Evaluation with 3D-real IR Imaging and MR Fingerprinting

    Naganawa Shinji , Pfeuffer Josef , Nittka Mathias , Sone Michihiko , Ito Rintaro , Kato Yutaka , Kawai Hisashi , Taoka Toshiaki , Yoshida Tadao , Maruyama Katsuya , Murata Katsutoshi , Körzdörfer Gregor

    … The signal intensity on the 3D-real IR image of the cerebrospinal fluid (CSF) in the cerebellopontine angle cistern (CPA), Sylvian fissure (Syl), lateral ventricle (LV), and cochlear perilymph (CPL) was measured. … Each averaged value at the various time points was compared using an analysis of variance.</p><p>Results: The signal intensity on the 3D-real IR image in each CSF region peaked at 4 h, and was decreased significantly by 24 h (<i>P</i>< …

    Magnetic Resonance in Medical Sciences 20(1), 91-98, 2021


  • Accelerated Acquisition of High-resolution Diffusion-weighted Imaging of the Brain with a Multi-shot Echo-planar Sequence: Deep-learning-based Denoising

    Kawamura Motohide , Tamada Daiki , Funayama Satoshi , Kromrey Marie-Luise , Ichikawa Shintaro , Onishi Hiroshi , Motosugi Utaroh

    … Denoising convolutional neural networks can reduce amplified noise without requiring extensive averaging, enabling shorter scan times and high image quality. …

    Magnetic Resonance in Medical Sciences 20(1), 99-105, 2021


  • Susceptibility-weighted Imaging for Renal Iron Overload Assessment: A Pilot Study

    Sun Jun , Sha Yuanyuan , Geng Weiwei , Chen Jie , Xing Wei

    … Angle radian value (ARV) calculated with phase image was taken as the quantitative value for cortical and medullary iron deposition. …

    Magnetic Resonance in Medical Sciences, 2021


  • Introducing Swish and Parallelized Blind Removal Improves the Performance of a Convolutional Neural Network in Denoising MR Images

    Sugai Taro , Takano Kohei , Ouchi Shohei , Ito Satoshi

    … <p>Purpose: To improve the performance of a denoising convolutional neural network (DnCNN) and to make it applicable to images with inhomogeneous noise, a refinement involving an activation function (AF) and an application of the refined method for inhomogeneous-noise images was examined in combination with parallelized image denoising.</p><p>Methods: Improvements in the DnCNN were performed by three approaches. …

    Magnetic Resonance in Medical Sciences, 2021


  • Investigating the Image Quality and Utility of Synthetic MRI in the Breast

    Fujioka Tomoyuki , Oda Goshi , Nakagawa Tsuyoshi , Tateishi Ukihide , Mori Mio , Oyama Jun , Kubota Kazunori , Yamaga Emi , Yashima Yuka , Katsuta Leona , Nomura Kyoko , Nara Miyako

    … In the present study, we aimed to compare the image quality and utility of synthetic MRI with that of conventional MRI in the breast.</p><p>Methods: We retrospectively collected the imaging data of 37 women (mean age: 55.1 years; … Two independent breast radiologists evaluated the overall image quality, anatomical sharpness, contrast between tissues, image homogeneity, and presence of artifacts of synthetic and conventional MRI on a 5-point scale (5 = <i>very good</i> …

    Magnetic Resonance in Medical Sciences, 2021


  • Effectiveness of Levodopa in Patients with Multiple System Atrophy and Associated Clinicopathological Features

    Ishida Chiho , Takahashi Kazuya , Kato-Motozaki Yuko , Tagami Atsuro , Komai Kiyonobu

    … We therefore aimed to investigate the effectiveness of levodopa and DA in autopsy cases of MSA without PD and thereby clarify the clinical course, magnetic resonance imaging (MRI) findings, and pathological features of levodopa-responsive MSA cases. …

    Internal Medicine 60(3), 367-372, 2021


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