Akio Hiwatashi

Prof. Dr. Akio Hiwatashi

orcid

Research Focus & Metrics

Academic Career Length

24Years (2003-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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24 September 2015 in American Journal of Neuroradiology
Verified
Journal Article
Open access
PDF file
KYK. Yamashita
K. Yamashita
AHAkio Hiwatashi
Akio Hiwatashi
OTO. Togao
O. Togao
KKK. Kikuchi
K. Kikuchi
RHR. Hatae
R. Hatae
HHH. Honda
H. Honda
BACKGROUND AND PURPOSE: Glioblastoma multiforme is highly aggressive and the most common type of primary malignant brain tumor in adults. Imaging biomarkers may provide prognostic information for patients with this condition. Patients with glioma with isocitrate dehydrogenase 1 (IDH1) mutations have a better clinical outcome than those without such mutations. Our purpose was to investigate whether the IDH1 mutation status in glioblastoma multiforme can be predicted by using MR imaging. MATERIALS AND METHODS: We retrospectively studied 55 patients with glioblastoma multiforme with wild type IDH1 and 11 patients with mutant IDH1. Absolute tumor blood flow and relative tumor blood flow within the enhancing portion of each tumor were measured by using arterial spin-labeling data. In addition, the maximum necrosis area, the percentage of cross-sectional necrosis area inside the enhancing lesions, and the minimum and mean apparent diffusion coefficients were obtained from contrast-enhanced T1-weighted images and diffusion-weighted imaging data. Each of the 6 parameters was compared between patients with wild type IDH1 and mutant IDH1 by using the Mann-Whitney U test. The performance in discriminating between the 2 entities was evaluated by using receiver operating characteristic analysis. RESULTS: Absolute tumor blood flow, relative tumor blood flow, necrosis area, and percentage of cross-sectional necrosis area inside the enhancing lesion were significantly higher in patients with wild type IDH1 than in those with mutant IDH1 (P < .05 each). In contrast, no significant difference was found in the ADCminimum and ADCmean. The area under the curve for absolute tumor blood flow, relative tumor blood flow, percentage of cross-sectional necrosis area inside the enhancing lesion, and necrosis area were 0.850, 0.873, 0.739, and 0.772, respectively. CONCLUSIONS: Tumor blood flow and necrosis area calculated from MR imaging are useful for predicting the IDH1 mutation status.

22 March 2016 in European Radiology
Verified
Journal Article
Closed access
PDF file
OTOsamu Togao
Osamu Togao
AHAkio Hiwatashi
Akio Hiwatashi
KYKoji Yamashita
Koji Yamashita
KKKazufumi Kikuchi
Kazufumi Kikuchi
JKJochen Keupp
Jochen Keupp
HHHiroshi Honda
Hiroshi Honda

8 January 2009 in American Journal of Neuroradiology
Verified
Journal Article
Open access
PDF file
AHAkio Hiwatashi
Akio Hiwatashi
PWP.-L.A. Westesson
P.-L.A. Westesson
TYT. Yoshiura
T. Yoshiura
TNT. Noguchi
T. Noguchi
OTO. Togao
O. Togao
HHH. Honda
H. Honda
BACKGROUND AND PURPOSE: There are few comparative studies regarding morphologic changes after kyphoplasty and vertebroplasty. The purpose of this study was to compare restoration of vertebral body height and wedge angle and cement leakage with kyphoplasty and vertebroplasty in osteoporotic compression fractures. MATERIALS AND METHODS: Forty patients (57 vertebrae) were treated with kyphoplasty, and 66 patients (124 vertebrae) were treated with vertebroplasty. Cement leakage into the disk space and paravertebral soft tissues or veins was analyzed on immediate postoperative CT scans. The height and wedge angle were measured before and after treatment and analyzed with the Mann-Whitney U test and χ2 test. RESULTS: Kyphoplasty and vertebroplasty both improved vertebral body height and the wedge angles (P < .05). However, these differences were not statistically significant when the 2 techniques were compared (P > .05). There were 18% of the kyphoplasty group and 49% of the vertebroplasty group that showed cement leakage into the paravertebral soft tissues or veins (P < .01). Cement leakage into the disk space occurred in 12% of the kyphoplasty group and in 25% of the vertebroplasty group (P < .01). However, no complications related to cement leakage were noted. CONCLUSIONS: Both kyphoplasty and vertebroplasty achieved the same degree of height restoration and improvement of the wedge angle. Kyphoplasty resulted in less cement leakage into the disk space and paravertebral soft tissues or veins than vertebroplasty.

24 April 2017 in Journal of Neuroinflammation
Verified
Journal Article
Open access
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Ryo YamasakiRyo Yamasaki
Ryo Yamasaki
HYHiroo Yamaguchi
Hiroo Yamaguchi
TMTakuya Matsushita
Takuya Matsushita
TFTakayuki Fujii
Takayuki Fujii
AHAkio Hiwatashi
Akio Hiwatashi
JKJun-ichi Kira
Jun-ichi Kira
The pathology of multiple system atrophy cerebellar-type (MSA-C) includes glial inflammation; however, cerebrospinal fluid (CSF) inflammatory cytokine profiles have not been investigated. In this study, we determined CSF cytokine/chemokine/growth factor profiles in MSA-C and compared them with those in hereditary spinocerebellar ataxia (SCA). We collected clinical data and CSF from 20 MSA-C patients, 12 hereditary SCA patients, and 15 patients with other non-inflammatory neurological diseases (OND), and measured 27 cytokines/chemokines/growth factors using a multiplexed fluorescent bead-based immunoassay. The size of each part of the hindbrain and hot cross bun sign (HCBS) in the pons was studied by magnetic resonance imaging. Granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-6, IL-7, IL-12, and IL-13 levels were significantly higher in MSA-C and SCA compared with OND. In MSA-C, IL-5, IL-6, IL-9, IL-12, IL-13, platelet-derived growth factor-bb, macrophage inflammatory protein (MIP)-1α, and GM-CSF levels positively correlated with anteroposterior diameters of the pontine base, vermis, or medulla oblongata. By contrast, in SCA patients, IL-12 and MIP-1α showed significant negative correlations with anteroposterior diameters of the pontine base, and unlike MSA-C, there was no cytokine with a positive correlation in SCA. IL-6 was significantly higher in MSA-C patients with the lowest grade of HCBS compared with those with the highest grade. Macrophage chemoattractant protein-1 (MCP-1) had a significant negative correlation with disease duration only in MSA-C patients. Tumor necrosis factor-alpha, IL-2, IL-15, IL-4, IL-5, IL-10, and IL-8 were all significantly lower in MSA-C and SCA compared with OND, while IL-1ra, an anti-inflammatory cytokine, was elevated only in MSA-C. IL-1β and IL-8 had positive correlations with Unified Multiple System Atrophy Rating Scale part 1 and 2, respectively, in MSA-C. Although CSF cytokine/chemokine/growth factor profiles were similar between MSA-C and SCA, pro-inflammatory cytokines, such as IL-6, GM-CSF, and MCP-1, correlated with the disease stage in a way higher at the beginning only in MSA-C, reflecting early stronger intrathecal inflammation.

8 May 2018 in European Radiology
Verified
Journal Article
Closed access
PDF file
OTOsamu Togao
Osamu Togao
AHAkio Hiwatashi
Akio Hiwatashi
MOMakoto Obara
Makoto Obara
KYKoji Yamashita
Koji Yamashita
DMDaichi Momosaka
Daichi Momosaka
HHHiroshi Honda
Hiroshi Honda

1 June 2007 in American Journal of Neuroradiology
Verified
Journal Article
Open access
PDF file
AHAkio Hiwatashi
Akio Hiwatashi
PWP.L. Westesson
P.L. Westesson
BACKGROUND AND PURPOSE: Repeat fractures after percutaneous vertebroplasty can be seen in patients with osteoporotic compression fractures. The purpose of this study was to identify characteristics of patients with new fractures after vertebroplasty.