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HIWATASHI Akio

    Graduate School of Medical Sciences Department of Radiology　Professor
Last Updated :2024/06/27

Researcher Information

Research funding number

  • 30444855

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J-Global ID

Published Papers

MISC

Research Grants & Projects

  • 日本学術振興会：科学研究費助成事業
    Date (from‐to) : 2023/04 -2026/03 
    Author : 橋爪 卓也; 杉浦 真由美; 樋渡 昭雄; 下平 政史
  • 日本学術振興会：科学研究費助成事業
    Date (from‐to) : 2021/04 -2024/03 
    Author : 樋渡 昭雄; 栂尾 理; 菊地 一史; 石神 康生
     
    脳転移は成人で最多の頭蓋内腫瘍であるが、微小な病変や多発病変が多い。診断には一般に造影後3DT1WIが用いられるが、増強された血管と微小転移の区別が困難な場合があり、正確な診断には時間を要し、見逃される病変が多い。VISIBLE (Volume Isotropic Simultaneous Interleaved Bright- and bLack-blood Examination)法は血管信号抑制画像と非抑制画像を同時取得し、高感度、低偽陽性率で脳転移を診断可能であるが、従来法では撮像に5分程度必要である。そこで近年臨床応用されつつある圧縮センシング法やハーフスキャンなども活用し、撮像時間の短縮、すなわち患者負担の軽減を試みている。また、VISIBLE法でさえも血管信号の不十分な抑制などで脳転移と偽病変を鑑別することは困難である。そのために、本研究では経過観察し、臨床的に確実に脳転移と診断された病変を教師画像に用いることで、偽病変を鑑別することでより精度の高い脳転移のsegmentationを目的としており、継続的に症例を蓄積中である。さらにAIシステムを応用し、脳転移を自動検出することで、診断効率のさらなる向上が期待される。現在ファントム、正常被験者を用いた至適撮像条件の確立、最適化されたVISIBLE法を用いた脳転移疑い患者の撮像、および患者データベース構築、データベースからの脳転移segmentation及びその深層学習、AIシステムを応用した脳転移の自動検出診断支援システム確立、脳転移の大きさ、部位、個数及び全身状態を加味した自動治療法選択を目標として取り組んでいる。
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2021/04 -2024/03 
    Author : 中尾 智博; 村山 桂太郎; 樋渡 昭雄; 豊見山 泰史
     
    今年度までにためこみ症25名の臨床データを収集し、頭部MRIの撮像を行った。ためこみ症25名と健常対象者36名について全能の主要な白質路の異常を調査するため、拡散テンソル画像に対してTract-based spatial statistics（TBSS）を用いた解析を行った。また、臨床的特徴との相関関係を調査するために関心領域の事後解析を実施した。TBSSではためこみ症患者において、拡散異方性比率（Fractional anisotropy：FA）の増加と放射拡散係数（Radial diffusivity：RD）の増加を示し、前頭皮質視床回路、前頭頭頂ネットワーク、前頭辺縁系経路などの前頭白質路に広範な変化を認めた。また、関心領域の事後解析ではためこみ症状の重症度と左内包前脚のFAは負の相関を示し、更にためこみ症状の重症度と右前視床放線のRDは正の相関を示した。ためこみ症はこれまで視覚情報処理、注意、ワーキングメモリ、反応抑制などの認知機能障害が指摘されているが、今回異常を認めた前頭白質路はそれらの認知機能を担う皮質領域を接続している。そのため、ためこみ症状の重症度と前頭白質路の異常に相関があることは、ためこみ症の生物学的基盤に新たな知見をもたらす可能性がある。 今後もためこみ症患者のリクルートを続けながら、安静時機能画像を用いた機能画像解析、およびFreeSurferを用いた構造画像解析を行う予定である。
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2020/04 -2023/03 
    Author : 秦 暢宏; 溝口 昌弘; 空閑 太亮; 波多江 龍亮; 三月田 祐平; 樋渡 昭雄; 栂尾 理
     
    脳脊髄液には神経膠腫由来のct-DNAが存在することが知られていたが、従来はそのような微量な核酸では、正確な解析を行うことは困難であった。我々はdigital PCRシステムを用いた解析法を開発して、グリオーマで重要とされるドライバー変異：IDHR132H,TERT promoter mutation,H3K27M mutationに対して、digital PCRのプローブを設計して、各々の変異を高感度で検出することに成功した。以上の研究内容を”Molecular diagnosis of diffuse glioma using a chip-based digital PCR system to analyze IDH, TERT, and H3 mutations in the cerebrospinal fluid”として、論文化した（J Neurooncol. 2021 Mar;152(1):47-54. doi: 10.1007/s11060-020-03682-7.) 以上の研究を踏まえて、実際の臨床で採取した髄液を用いて、術前診断に繋げる試みを導入しており、一部の患者では臨床に役立つ知見を得られるようになってきている。
  • 日本学術振興会：科学研究費助成事業
    Date (from‐to) : 2020/04 -2023/03 
    Author : 栂尾 理; 菊地 一史; 樋渡 昭雄
     
    閉塞性脳血管障害や脳動静脈短絡疾患の診断および治療においては脳血管構造や血行動態の可視化および灌流の把握が重要である。本研究の目的は新たなarterial spin labeling (ASL)アプローチを用いた頭部MR angiography (MRA)および脳灌流画像の開発とその臨床応用を行うことであり、具体的に以下の３点である。 1) Acceleration selective ASL (AccASL)を用いた灌流画像の開発 2) Pseudo-continuous ASL (pCASL)を用いた4D-MRAの臨床応用 3) Superselective pCASLを用いた血管超選択的 4D-MRAの開発 本年度はsuperselective pCASLを用いた血管選択的4D-MRAの開発に主眼を起き、ボランティアでの最適な撮像パラメータの検討をまず行い、内頚動脈および椎骨・脳底動脈のラベルの最適位置およびラベルの最適な傾斜モーメントを決定した。その結果内頚動脈はcervical portionの上部、椎骨動脈はC2レベルが最適と考えられた。gradient momentは0.75が最適であった。その撮像条件を用いて、頭蓋内硬膜動静脈瘻の患者において血管選択的4D-MRAの撮像を行った。血管非選択的な4D-MRAに比べて、本手法では硬膜動静脈瘻の流入動脈の描出に優れていた。また流出静脈の描出、皮質静脈の逆流についてはほぼ同等であった。本手法は血管造影検査の代替検査となりうる非侵襲的な手法であると考えられた。
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2019/04 -2022/03 
    Author : Murayama Keitaro
     
    The aim of this study was to investigate whether patients with obsessive-compulsive disorder in childhood and adolescence and their relatives have abnormalities in similar intrinsic brain networks. However, the recruitment of child and adolescent patients and their relatives did not proceed, and the number of the subjects required for imaging and neuropsychological test analysis was not reached. Therefore, we investigated whether there were abnormalities in the intrinsic brain network and neuropsychological functions in adult patients with OCD and their relatives. The results revealed that not only OCD patients but also their relatives had common abnormalities in their intrinsic brain networks. In addition, we found that cognitive dysfunction in OCD patients is related to abnormalities in the large intrinsic brain networks.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2018/04 -2021/03 
    Author : Nakao Tomohiro
     
    From April 2018 to March 2021, we performed head MRI examinations on 25 patients with hoarding disorder and 31 healthy control participants, and compared them by resting-state functional MRI, supported by KAKENHI. The results showed that the right dorsolateral prefrontal cortex（DLPFC） and hippocampus were more functionally connected in the hoarding group than in the healthy control group, during resting state. DLPFC plays a key role in working memory and works cooperatively with the hippocampus which is involved in memory formation, to select information necessary for task execution. Previous studies have suggested that hoarding disorder is associated with impairments in executive functions including working memory. These results of the present study provide new insights into hoarding disorder. We plan to conduct further analyses with larger samples in the future.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2017/04 -2020/03 
    Author : TOGAO OSAMU
     
    In the present study, we first developed the clinical amide proton transfer (APT) imaging sequence and optimized its parameters. We then evaluated its clinical usefulness in glioma patients. We employed Dixon method for B0 inhomogeneity correction in the 3D fast spin-echo sequence. The APT-weighted signals of tumor measured with the 3D-Dixon sequence was almost identical to those with single slice 2D sequence. With this condition, it was able to monitor the temporal progression of glioma, evaluate therapeutic response to anti-cancer drugs such as temozolomide and bevasizumab, and differentiate radiation induced necrosis from tumor progression. APT imaging can be a non-ivasive clinical tool to assess and monitor temporal changes in gliomas.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2017/04 -2020/03 
    Author : Hiwatashi Akio
     
    This study included 13 patients with CIDP and five healthy subjects who underwent simultaneous apparent T2 mapping and neurography with SHINKEI. The T2 relaxation times of the ganglia and roots were longer in patients with CIDP (119.31msec and 111.15msec) than in healthy subjects (101.42msec and 85.29msec). The sizes of the ganglia and the roots were larger in patients with CIDP (6.25mm and 4.37mm) than in healthy subjects (5.59mm and 3.50mm). ROC analysis revealed that T2 relaxation time of the roots was best at distinguishing CIDP patients from healthy subjects.
  • 日本学術振興会：科学研究費助成事業
    Date (from‐to) : 2017/04 -2019/03 
    Author : 山下 孝二; 栂尾 理; 樋渡 昭雄; 空閑 太亮; 吉本 幸司; 本田 浩; 平田 秀成
     
    まず、後方視的に評価可能な画像データ収集および検討可能な画像パラメータの抽出を行った。MRI装置は九州大学放射線部の臨床用1.5Tもしくは3T MRI装置を使用した症例とした。当院における倫理審査委員会にて承認を得た後に収集を開始し、2003年までの解析にて膠芽腫症例は118例、悪性リンパ腫は52例の画像データが使用可能であった。共通して使用可能なシーケンスは造影前後のT1強調画像および一部の症例にて拡散強調像から得られるみかけの拡散係数（ADC）値が使用可能であった。摘出された腫瘍標本より得られた遺伝子データに関しては後ろ向きにはIDH1やTERT遺伝子データが取得されていたため、TERT遺伝子変異の有無について画像所見の特徴を解析し、ASNR 55th Annual Meeting & NER Foundation Symposiumにて報告した。論文作成は終了し、現在投稿中である。 同時にMRI撮像パルスシーケンスの開発および最適化を行った。複数の遺伝子変異有無を予測するためにはより多くのパラメータを用いる事が望ましいが、単に撮像シーケンスを増やすだけでは撮像時間の延長につながるため、臨床現場で用いる際には撮像時間を減らす、つまりある程度撮像条件を限定することが求められる。ただし、発生部位や増強効果、細胞密度、腫瘍血流量や分子学的特性の情報が正確に得られるように、また、得られたデータより多くの特徴量が抽出できるように撮像シーケンス数、スライス枚数・スライス厚などを考慮し、撮像条件を設定した。また、臨床データとして年齢・性別、既往歴、血液データを記録する。倫理審査委員会承認後に脳腫瘍患者撮像を行い、前向きにデータ取得を行う予定であったが、今回研究代表者は海外留学のため、廃止申請を行った。
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2016/04 -2019/03 
    Author : Murayama Keitaro
     
    The aim of this study was to identify the biological indicator by the endophenotype of obsessive-compulsive disorder(OCD). We planed to investigate the differences of the brain activity and neuropsychological function between OCD, their first degree siblings and healthy controls(HC). However, we could not complete this study because we could not recruit enough number of the first degree siblings of the OCD patients. We, however, explored the difference between OCD and HC groups in the functional brain network related to impaired cognitive flexibility by using a seed-based approach from dorsal striatal regions of interest. Significant differences between the OCD and HC groups were identified in the resting state functional network from the dorsal caudate. Increased functional connectivity from the dorsal caudate to the dorsal anterior cingulate cortex and anterior insula was associated with poorer cognitive flexibility in the OCD group.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2015/04 -2019/03 
    Author : Gondo Motoharu; Moriguchi Yoshiya
     
    One of the hypotheses about the psychopathology in anorexia nervosa (AN) patients is their inappropriate self-referential processing, such as worry about their own bodily images. We hypothesized that the default mode network (DMN) might be altered in AN patients, and the treatment on them could normalize their neural activity. We measured resting state functional magnetic resonance images. These data were collected from 18 AN and 18 healthy control(HC) subjects. After a series of integrated hospital treatment, AN subjects were measured again. The functional connectivity of retrosplenial cortex (RC) to DMN were decreased in comparison with HC. Comparison of the pre- and post-treatment images from AN patients showed increase in functional connectivity to DMN in the RC in post-treatment. Individual DMN functional connectivity increase with the treatment in the RC region of interest was significantly negatively correlated with drive for thinness and perfectionism after the treatment.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2015/04 -2018/03 
    Author : WATANABE YUJI
     
    The assessment of vulnerability of carotid plaque is very important to determine treatment plan for preventing future cardiovascular events. The key factors are inflammatory activity within the plaque as well as the condition of the fibrous cap and plaque components. Magnetic resonance (MR) imaging can provide information of carotid wall morphology and plaque composition. FDG-PET imaging can allow for the detection of inflammatory activity of atherosclerotic plaque. Recent advances in PET/MR hybrid imaging have permitted simultaneous acquisition of metabolic and anatomic information, which could increase accuracy of risk assessment of carotid plaque. We tried to obtain high-resolution PET-images and also to analyze carotid wall strain by using cine MR imaging. However, the 2mm3-voxel was not able to differentiate carotid wall from the lumen, and the pulsatile movement of carotid wall was not so large that wall strain could be measured by using the voxel-wise tracking software.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2015/04 -2018/03 
    Author : Nakao Tomohiro
     
    Seventeen patients who met the DSM-5 criteria for HD(Hoarding disorder), 17 obsessive-compulsive disorder (OCD) patients, and 17 healthy controls (HCs) participated in this study. All participants underwent MRI scanning of the brain by a 3.0-Tesla MRI scanner. In a voxel-based morphometric procedure, preprocessed GM structural images were used to compare the three groups. The average age of the 3 groups was HD: 43.9±11.5, OCD: 39.9±9.0, HCs: 42.4±10.4 respectively. In the results of VBM analyses, all three groups (HD, OCD, and HCs) exhibited the presence of significant regional GM volume differences in the right prefrontal regions. As with OCD, HD is considered to have cognitive dysfunction as its basis. This result is convincing after considering the clinical features of HD and suggested that structural abnormalities in the prefrontal regions might relate to the pathophysiology of HD.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2014/04 -2017/03 
    Author : Yamashita Koji
     
    IVIM MR imaging allows the simultaneous extraction of perfusion and diffusion parameters. In our study, IVIM MR imaging non-invasively provides useful quantitative information in distinguishing between PCNSL and GBM. We also reported that IVIM MR imaging is useful for differentiating between high- and low-grade gliomas.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2014/04 -2017/03 
    Author : TOGAO Osamu
     
    Toward the clinical application of amide proton transfer (APT) imaging of brain tumors, we developed and optimized APT MR imaging sequences on a clinical MR scanner. We developed the parallel transmission based APT imaging and 3D fast spin echo Dixon method. With this sequence, we evaluated the effect of saturation pulse length on the APT contrast of brain tumors and found that APT contrast of glioma was increased with the length of saturation pulse. APT signal was increased with WHO grade of glioma. APT imaging showed better diagnostic performance in differentiating high-grade from low-grade gliomas compared to contrast enhanced imaging, diffusion-weighted imaging, and perfusion weighted imaging. APT imaging could be a non-invasive clinical tool for assessing brain tumors.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2014/04 -2017/03 
    Author : Hiwatahi Akio
     
    This retrospective study included 23 adult patients with pituitary adenomas. Among them, 6 each were prolactin-producing adenomas and growth hormone producing adenomas (GH) and the remaining 11 were non-functioning adenomas (NON). The apparent diffusion coefficients (ADCs) were measured in the pituitary adenoma and in the unaffected pituitary gland using coronal reformatted plane. All pituitary adenomas were clearly visualized on DSDE-TFE and ADC maps without obvious geometrical distortion. There were no statistically significant differences in ADC of the all pituitary adenoma (1.50±0.61×10-3mm2/s) and the unaffected anterior lobe of the pituitary gland (1.49 ±0.3×10-3mm2/s,p=0.99). The ADC in prolactin-producing adenomas (2.04±0.76×10-3mm2/s) was significantly higher than that in GH (1.26±0.47×10-3mm2/s, p<0.05) and NON (1.33±0.42×10-3mm2/s, p=0.04). There was no statistically significant difference between GH and NON (p50.97).
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2014/04 -2017/03 
    Author : Yoshiura Takashi; KEUPP Jochen
     
    We developed and optimized pH weighted magnetic resonance (MR) imaging, which is based on amide proton transfer (APT) through in vitro phantom experiments and imaging of clinical patients with acute brain infarction. Optimal strength and duration of the saturation pulse were determined, and a 3D APT imaging covering the whole brain method was implemented. We investigated a new method of image analysis that can acquire APT-related signal more efficiently. We analyzed images of clinical patients with acute brain infarction by comparing findings from conventional MR images, and found that the APT signal as measured with magnetization transfer ration (MTR) asymmetry at 3.5 ppm was reduced from 0.26% (normal region) to -0.48% (infarction) on average, and that this APT signal reduction was clearly visible in 37% of the included cases. Our study revealed that ph-weighted MR imaging based on APT is feasible in detection of anaerobic metabolism due to acute bran infarction in clinical patients.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2014/04 -2016/03 
    Author : YOSHIURA Takashi; HIWATASHI Akio; TOGAO Osamu; YAMASHITA Koji; BABA Shingo; ISODA Takuro; OHYAGI Yasumasa; KUMAZAWA Seiji; HONDA Hiroshi
     
    We performed an in-vitro phantom experiment and revealed that beta-amyloid can be detected by means of chemical exchange saturation transfer (CEST) imaging. We evaluated the effect of skull in PET/MRI measurement of PIB accumulation. As a results, we found that presence of skull led to significant underestimate of SUV in the cortex and the cerebellum, in comparison with those by PET/CT. This finding suggested a need for customized standard of SUV and SUVr for PET/MRI detection of amyloid. We developed a more objective and reproducible method for amyloid detection in PIB-PET/MRI takin advantage of MRI morphological information.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2013/04 -2016/03 
    Author : Kawasaki Hiroaki; NAKAO TOMOHIRO; MITUYASU HIROSHI; SANEMATSU HIROKUNI; HIWATASHI AKIO; YOSHIURA TAKASHI; KANBA SHIGENOBU; NAKAGAWA AKIKO
     
    95 obsessive and compulsive disorder (OCD) patients and 93 healthy controls (HCS) were genotyped with L- and s- types polymorphisms of 5HTT-LPR, 5HTT-VNTR, DAT-VNTR, D4-120、D4-48. As a result, any genetic polymorphisms were observed no significant difference between OCD patients and HCs. Magnetic resonance imaging examinations of 40 OCD patients and 40 HCs were carried out. As of genotype-diagnosis interaction, though no voxels survived multiple comparison, we observed a tendency that 5-HTTLPR polymorphism with OCD patients had stronger effects on the right frontal pole than those in HCs. Moreover, we investigated the differences in terms of DNA methylation profile of HTR2A gene and COMT gene between 48 OCD patients and 48 HCs. We found a significant difference between the OCD patients and HCs in the percent methylation of the COMT gene.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2012/04 -2015/03 
    Author : CHIKUI Toru; TOKUMORI Kenji; KAWAZU Toshiyuki; YOSHIURA Takashi; HIWATASHI Akio; KAMI Yukiko; KAWANO Shintarou; YOSHIURA Kazunori
     
    We performed compartment model analysis on the basis of the DCE-MRI. The arterial input function was estimated using phase images. We obtained the influx forward volume transfer constant (Ktrans), the fractional volume of extravascular extracellular space (ve) and the fractional volume of plasma (vp).The pleomorphic adenoma had lower Ktrans than malignant tumors. The ve was characteristic parameters among the tumors. Pleomorphic adenoma has a characteristic large ve value, while malignant lymphoma has characteristically small ve. In the oral squamous cell carcinoma, a decrease in the Ktrans at the primary site was found in advanced N stage cases, which might indicate that the hypoxic status cause a high possibility of the metastasis. For the evaluation of arterial spin labeling, we estimated the relative blood flow (r BF). There was significant correlation between r BF and Ktrans and between r BF and Ktrans. However, some lesions could not identified on r BF map.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2012/04 -2015/03 
    Author : NAKAO TOMOHIRO; SANEMSTSU Hirokuni; YOSHIURA Takashi; HIWARASHI Akio
     
    Until the end of May 2015, 25 participants were conducted a structured interview. Of those participants, 17 cases met the diagnostic criteria of Hoarding Disorder(HD). The average age of HD patients were 43.6±13.5（21～73）. We assessed the severity of hoarding symptoms using CIRS. To investigate the correlation between gray matter volume and hoarding severity, we conducted one way analysis of variance using voxel-based morphometry among three groups(4 HD patients, 22 OCD patients, 10 healthy controls). We, however, could not find any significant differences among the three groups. In the correlation analysis using the hoarding scores of OCD patients, several candidate (visual association area, supramarginal gyrus, etc) sites have been found.In the present study, we cooud not find significant results by image analysis due to the small sample size of the hoarding patients. Reanalysis shoud be needed with larger hoarding samples.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2012/04 -2014/03 
    Author : TOGAO Osamu; YAMATO Mayumi; HIWATASHI Akio; YOSHIURA Takashi; HONDA Hiroshi; ICHIKAWA Kazuhiro
     
    Recent study suggested that impared cognitive function observed in Alzheimer disease (AD) is related to microglia activations evoked by amyloid deposition in the brain. In this study, we have develop the novel MR molecular imaging method to detect microglia accumulation in the brain tissue by using Ultrasmall super paramagnetic iron oxide (USPIO) contrast agent. We confirmed in the animal model of AD that this technique could sensitively detect the USPIO phagocytized by microglia in the brain. In the future, this method can be a useful and sensitive method for early diagnosis and monitoring of AD in the clinical settings.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2010 -2012 
    Author : HIWATASHI Akio
     
    OBJECTIVE: To investigate risk factors for subsequent fractures after prophylactic percutaneous vertebroplasty.MATERIALS AND METHODS: This study included 116 patients with osteoporotic compression fractures who underwent prophylactic percutaneous vertebroplasty. We analyzed the following multiple covariates to determine whether they were associated with recurrence: age, sex, steroid use, and the preoperative number of unhealed or chronic compression fractures.RESULTS: The incidence of subsequent fractures was significantly higher in patient s with three or more fractures than in those with one fracture (p < 0.05). There were no statistically significant differences for the other factors.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2010 -2012 
    Author : YOSHIURA Takashi; HONDA Hiroshi; HIWATASHI Akio; YAMASHITA Koji; TOGAO Osamu; OHYAGI Yasumasa; MONJI Akira; OHARA Noriyuki; ARIMURA Hidetaka; KUMAZAWA Seiji
     
    We revealed early morphological changes in gray and white matter in mild cognitiveimpairment using voxel-based morphometry (VBM). We developed a novel multi-parametric method by combining VBM and ASL, and showed that our method is superior to each method alone in diagnosing AD. In addition, we developed a high-resolution diffusion tensor imaging method to detect early AD pathology in the hippocampus.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2007 -2009 
    Author : HIWATASHI Akio
     
    BACKGROUND AND PURPOSE : Subsequent fracture is often seen after percutaneous vertebroplasty. The purpose of this prospective study was to evaluate preoperative multi-detector row computed tomography (MDCT) for predicting subsequent fractures after vertebroplasty. MATERIALS AND METHODS : This study included 26 consecutive patients (18 women and 8 men) with osteoporotic compression fractures (58 vertebrae). Sixty-four-slice MDCT with multiplanar reformation was obtained within a day before the procedure. Repeat magnetic resonance (MR) imaging was used to evaluate new fractures at least three months after treatment on a routine basis or if there was recurrent pain. We used logistic regression analysis with MDCT findings and clinical data for statistical evaluation according to the location of new fractures. RESULTS : Subsequent fractures were noted at 14 adjacent vertebrae (12.1%) in 13 patients and at 14 remote vertebrae in 6 patients (23.1%). Subsequent fractures in adjacent vertebrae tended to occur in small vertebrae before treatment (P < .05). Steroid medication and low CT value in nonfractured vertebrae were associated with subsequent fractures in remote vertebrae (P < .05). Further collapse of the treated vertebral bodies was noted in 10 patients (11 vertebrae, 19.0 %) without specific findings (P > .05). CONCLUSION: The small size of the treated vertebrae may relate to subsequent fracturesin adjacent vertebrae. Steroid use and low CT value of nonfractured vertebrae on preoperative MDCT can be associated with subsequent fractures in remote vertebrae.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2006 -2009 
    Author : YOSHIURA Takashi; MIHARA Futoshi; KUMAZAWA Seiji; NOGUCHI Tomoyuki; HONDA Hiroshi; ARIMURA Hidetaka; KOGA Hiroshi; HIWATASHI Akio; TANAKA Kazuhiro; MONJI Akira
     
    We have developed a new method based on diffusion tensor MR imaging to quantitatively visualize brain network consisting of cerebral cortices interconnected by the white matter pathways. Using our method, we evaluated regional variations and age-related changes in cerebral microstructure. Moreover, we evaluated damages in the brain network due to Alzheimer's disease, and revealed that our method is useful in diagnosing Alzheimer's disease.

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