2024/09/17 更新

写真a

カン ヒロヒト
菅 博人
KAN Hirohito
所属
大学院医学系研究科 総合保健学専攻 バイオメディカルイメージング情報科学 助教
大学院担当
大学院医学系研究科
学部担当
医学部(保健学科)
職名
助教
連絡先
メールアドレス

学位 1

  1. 博士(保健学) ( 2015年3月   金沢大学 ) 

経歴 3

  1. 名古屋大学   大学院医学系研究科 総合保健学専攻 バイオメディカルイメージング情報科学   助教

    2020年4月 - 現在

  2. 名古屋大学   大学院医学系研究科 医療技術学専攻 医用量子科学   助教

    2019年9月 - 2020年3月

  3. 名古屋市立大学病院   診療技術部放射線技術科

    2011年4月 - 2019年8月

      詳細を見る

    国名:日本国

所属学協会 3

  1. International Society for Magnetic Resonance in Medicine

  2. 日本放射線技術学会

  3. 日本磁気共鳴医学会

受賞 1

  1. CyPos賞 銅賞

    2024年4月   第80回日本放射線技術学会総会学術大会   適応型緩和時間-磁化率変換係数推定を併用した磁化率分離法

    菅 博人,打田 佑人,川口 翔平,植木 美乃

     詳細を見る

    受賞区分:国内学会・会議・シンポジウム等の賞 

 

論文 60

  1. Quantitative susceptibility mapping analyses of white matter in Parkinson's disease using susceptibility separation technique.

    Nakashima M, Kan H, Kawai T, Matsumoto K, Kawaguchi T, Uchida Y, Matsukawa N, Hiwatashi A

    Parkinsonism & related disorders   128 巻   頁: 107135   2024年9月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1016/j.parkreldis.2024.107135

    PubMed

  2. Association of medullary reticular formation ventral part with spasticity in mice suffering from photothrombotic stroke.

    Isumi S, Futamura D, Hanasaki T, Sako Y, Miyata S, Kan H, Suzuki Y, Hasegawa N, Mushiake H, Kametaka S, Uchiyama Y, Osanai M, Lee-Hotta S

    NeuroImage     頁: 120791   2024年8月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1016/j.neuroimage.2024.120791

    PubMed

  3. Quantitative Susceptibility Mapping for Susceptibility Source Separation with Adaptive Relaxometric Constant Estimation (QSM-ARCS) from Solely Gradient-Echo Data.

    Kan H, Uchida Y, Kawaguchi S, Kasai H, Hiwatashi A, Ueki Y

    NeuroImage     頁: 120676   2024年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1016/j.neuroimage.2024.120676

    PubMed

  4. Alterations in subcortical magnetic susceptibility and disease-specific relationship with brain volume in major depressive disorder and schizophrenia.

    Shibukawa S, Kan H, Honda S, Wada M, Tarumi R, Tsugawa S, Tobari Y, Maikusa N, Mimura M, Uchida H, Nakamura Y, Nakajima S, Noda Y, Koike S

    Translational psychiatry   14 巻 ( 1 ) 頁: 164   2024年3月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Translational Psychiatry  

    Quantitative susceptibility mapping is a magnetic resonance imaging technique that measures brain tissues’ magnetic susceptibility, including iron deposition and myelination. This study examines the relationship between subcortical volume and magnetic susceptibility and determines specific differences in these measures among patients with major depressive disorder (MDD), patients with schizophrenia, and healthy controls (HCs). This was a cross-sectional study. Sex- and age- matched patients with MDD (n = 49), patients with schizophrenia (n = 24), and HCs (n = 50) were included. Magnetic resonance imaging was conducted using quantitative susceptibility mapping and T1-weighted imaging to measure subcortical susceptibility and volume. The acquired brain measurements were compared among groups using analyses of variance and post hoc comparisons. Finally, a general linear model examined the susceptibility–volume relationship. Significant group-level differences were found in the magnetic susceptibility of the nucleus accumbens and amygdala (p = 0.045). Post-hoc analyses indicated that the magnetic susceptibility of the nucleus accumbens and amygdala for the MDD group was significantly higher than that for the HC group (p = 0.0054, p = 0.0065, respectively). However, no significant differences in subcortical volume were found between the groups. The general linear model indicated a significant interaction between group and volume for the nucleus accumbens in MDD group but not schizophrenia or HC groups. This study showed susceptibility alterations in the nucleus accumbens and amygdala in MDD patients. A significant relationship was observed between subcortical susceptibility and volume in the MDD group’s nucleus accumbens, which indicated abnormalities in myelination and the dopaminergic system related to iron deposition.

    DOI: 10.1038/s41398-024-02862-7

    Scopus

    PubMed

  5. Anisotropy of the R1/T2* value dependent on white matter fiber orientation with respect to the B0 field.

    Kawaguchi S, Kan H, Uchida Y, Kasai H, Hiwatashi A, Ueki Y

    Magnetic resonance imaging     2024年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1016/j.mri.2024.02.010

    PubMed

  6. Longitudinal Changes in Iron and Myelination Within Ischemic Lesions Associate With Neurological Outcomes: A Pilot Study.

    Uchida Y, Kan H, Kano Y, Onda K, Sakurai K, Takada K, Ueki Y, Matsukawa N, Hillis AE, Oishi K

    Stroke     2024年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1161/STROKEAHA.123.044606

    PubMed

  7. Brain Abnormalities in Becker Muscular Dystrophy: Evaluation by Voxel-Based DTI and Morphometric Analysis.

    Maki H, Mori-Yoshimura M, Matsuda H, Hashimoto Y, Ota M, Kimura Y, Shigemoto Y, Ishihara N, Kan H, Chiba E, Arizono E, Yoshida S, Takahashi Y, Sato N

    AJNR. American journal of neuroradiology     2023年11月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.3174/ajnr.A8041

    PubMed

  8. Blood-Brain Barrier Function Associates with Brain Iron Dynamics along Developmental Trajectory: A Combined Quantitative Magnetic Resonance Imaging Study during Childhood

    Uchida, Y; Kan, H; Furukawa, G; Onda, K; Sakurai, K; Takada, K; Matsukawa, N; Oishi, K

    ANNALS OF NEUROLOGY   94 巻   頁: S209 - S210   2023年9月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Web of Science

  9. Relationship between brain iron dynamics and blood-brain barrier function during childhood: a quantitative magnetic resonance imaging study.

    Uchida Y, Kan H, Furukawa G, Onda K, Sakurai K, Takada K, Matsukawa N, Oishi K

    Fluids and barriers of the CNS   20 巻 ( 1 ) 頁: 60   2023年8月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1186/s12987-023-00464-x

    PubMed

  10. Three-compartment spectral diffusion analysis for breast cancer magnetic resonance imaging.

    Ogawa M, Kan H, Urano M, Kawai T, Nakajima H, Murai K, Miyaji H, Toyama T, Hiwatashi A

    Magnetic resonance imaging     2023年5月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1016/j.mri.2023.04.006

    PubMed

  11. Voxel-Based and Surface-Based Morphometry Analysis in Patients with Pathologically Confirmed Argyrophilic Grain Disease and Alzheimer's Disease.

    Sakurai K, Kaneda D, Morimoto S, Uchida Y, Inui S, Kimura Y, Kan H, Kato T, Ito K, Hashizume Y

    Journal of Alzheimer's disease : JAD     2023年3月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.3233/JAD-230068

    PubMed

  12. Contributions of blood-brain barrier imaging to neurovascular unit pathophysiology of Alzheimer's disease and related dementias.

    Uchida Y, Kan H, Sakurai K, Oishi K, Matsukawa N

    Frontiers in aging neuroscience   15 巻   頁: 1111448   2023年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Frontiers in Aging Neuroscience  

    The blood–brain barrier (BBB) plays important roles in the maintenance of brain homeostasis. Its main role includes three kinds of functions: (1) to protect the central nervous system from blood-borne toxins and pathogens; (2) to regulate the exchange of substances between the brain parenchyma and capillaries; and (3) to clear metabolic waste and other neurotoxic compounds from the central nervous system into meningeal lymphatics and systemic circulation. Physiologically, the BBB belongs to the glymphatic system and the intramural periarterial drainage pathway, both of which are involved in clearing interstitial solutes such as β-amyloid proteins. Thus, the BBB is believed to contribute to preventing the onset and progression for Alzheimer’s disease. Measurements of BBB function are essential toward a better understanding of Alzheimer’s pathophysiology to establish novel imaging biomarkers and open new avenues of interventions for Alzheimer’s disease and related dementias. The visualization techniques for capillary, cerebrospinal, and interstitial fluid dynamics around the neurovascular unit in living human brains have been enthusiastically developed. The purpose of this review is to summarize recent BBB imaging developments using advanced magnetic resonance imaging technologies in relation to Alzheimer’s disease and related dementias. First, we give an overview of the relationship between Alzheimer’s pathophysiology and BBB dysfunction. Second, we provide a brief description about the principles of non-contrast agent-based and contrast agent-based BBB imaging methodologies. Third, we summarize previous studies that have reported the findings of each BBB imaging method in individuals with the Alzheimer’s disease continuum. Fourth, we introduce a wide range of Alzheimer’s pathophysiology in relation to BBB imaging technologies to advance our understanding of the fluid dynamics around the BBB in both clinical and preclinical settings. Finally, we discuss the challenges of BBB imaging techniques and suggest future directions toward clinically useful imaging biomarkers for Alzheimer’s disease and related dementias.

    DOI: 10.3389/fnagi.2023.1111448

    Web of Science

    Scopus

    PubMed

  13. Assessing white matter microstructural changes in idiopathic normal pressure hydrocephalus using voxel-based R2* relaxometry analysis.

    Kano Y, Uchida Y, Kan H, Sakurai K, Kobayashi S, Seko K, Mizutani K, Usami T, Takada K, Matsukawa N

    Frontiers in neurology   14 巻   頁: 1251230   2023年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Frontiers in Neurology  

    Background: R2* relaxometry and quantitative susceptibility mapping can be combined to distinguish between microstructural changes and iron deposition in white matter. Here, we aimed to explore microstructural changes in the white matter associated with clinical presentations such as cognitive impairment in patients with idiopathic normal-pressure hydrocephalus (iNPH) using R2* relaxometry analysis in combination with quantitative susceptibility mapping. Methods: We evaluated 16 patients clinically diagnosed with possible or probable iNPH and 18 matched healthy controls (HC) who were chosen based on similarity in age and sex. R2* and quantitative susceptibility mapping were compared using voxel-wise and atlas-based one-way analysis of covariance (ANCOVA). Finally, partial correlation analyses were performed to assess the relationship between R2* and clinical presentations. Results: R2* was lower in some white matter regions, including the bilateral superior longitudinal fascicle and sagittal stratum, in the iNPH group compared to the HC group. The voxel-based quantitative susceptibility mapping results did not differ between the groups. The atlas-based group comparisons yielded negative mean susceptibility values in almost all brain regions, indicating no clear paramagnetic iron deposition in the white matter of any subject. R2* and cognitive performance scores between the left superior longitudinal fasciculus (SLF) and right sagittal stratum (SS) were positively correlated. In addition to that, R2* and gait disturbance scores between left SS were negatively correlated. Conclusion: Our analysis highlights the microstructural changes without iron deposition in the SLF and SS, and their association with cognitive impairment and gait disturbance in patients with iNPH.

    DOI: 10.3389/fneur.2023.1251230

    Web of Science

    Scopus

    PubMed

  14. Noncontrast time-resolved pulmonary magnetic resonance angiography with consecutive beam saturation pulse and variable flip angles using three-dimensional fast spin echo: A preliminary study. 国際誌

    Kan H, Mizuno K, Takizawa M, Shimohira M, Kawai T, Aoki T, Tsubokura S, Kasai H

    Magnetic resonance imaging   94 巻   頁: 80 - 88   2022年12月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Magnetic Resonance Imaging  

    To develop and validate a novel noncontrast time-resolved magnetic resonance angiography (NC TR-MRA) using consecutive beam pulses with variable flip angles for visualizing hemodynamics in the pulmonary artery, we performed phantom and volunteer studies and applied the novel NC TR-MRA to a 51-year-old woman with pulmonary arteriovenous malformation (PAVM).The novel NC TR-MRA sequence utilized consecutive multiple-beam saturation pulses with variable flip angles considering venous blood T1 relaxation to alter the visualized blood signal length. The flowing blood signal length is suppressed according to the number of beam saturation pulses. NC TR-MRA in each flow phase was assessed by subtracting the images with and without beam saturation pulses. In the flow phantom study, three flow velocities were used to simulate physiological pulmonary arterial blood flow. Signal profiles along the flow direction were evaluated in each flow phase. In the volunteer study, five healthy volunteers were recruited, and NC TR-MRA was applied to evaluate relationships between the flow-saturated time and signal enhancement rates. Four regions of interest (ROIs) were determined on the proximal and distal portions of the right basal artery. A patient with PAVM was included to validate whether a PAVM lesion could be visualized using NC TR-MRA. The visualized flow signal lengths extended proportionally with the number of beam saturation pulses in the steady-flow phantom at all velocities. In the volunteer study, NC TR-MRA images showed signal enhancement from the proximal to distal portions of the right basal artery with increase in the flow-saturated time. Signal enhancement rates in all ROIs were significantly positively correlated with the flow-saturated time (p < 0.001 in all ROIs). Further, the lesion and its hemodynamics could be explicitly visualized in the patient with PAVM. Hence, NC TR-MRA using beam saturation pulse can visualize the hemodynamics of the pulmonary artery and may be useful for diagnosing and following patients with PAVM.

    DOI: 10.1016/j.mri.2022.09.001

    Web of Science

    Scopus

    PubMed

  15. Memantine for the patients with mild cognitive impairment in Parkinson’s disease: a pharmacological fMRI study

    Kawashima S., Shimizu Y., Horiba M., Ueki Y., Akanabe R., Kan H., Kasai H., Kunitomo H., Tanaka S., Toyota T., Kawashima S., Mizuno M., Okita K., Matsukawa N.

    BMC Neurology   22 巻 ( 1 )   2022年12月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:BMC Neurology  

    Background: Mild cognitive impairment in Parkinson’s disease (PD-MCI) is associated with an increased risk of cognitive decline. PD-MCI is characterized by impairments in executive function and visuospatial recognition. The visuospatial n-back test is useful for assessing both domains. The 0-back test reflects visuospatial recognition, while the 1-back and 2-back tests reflect working memory. Cholinesterase inhibitors are effective in the treatment of PD-MCI and dementia in PD (PDD). Although some studies have reported the efficacy of memantine for PDD, the therapeutic efficacy of memantine in patients with PD-MCI remains uncertain. Methods: This study aimed to investigate the effects of memantine on brain function in patients with PD-MCI, using a randomized double-blinded crossover protocol and functional MRI (fMRI). Ten patients who completed 16 weeks of follow-up were included. They were randomly assigned to either the memantine or placebo. Patients in the memantine group received 5 mg/day of memantine in the first week. The memantine dose was increased by 5 mg/day per week, until a final dose of 20 mg/day. Patients in the placebo group received the placebo following the same regimen as memantine. After the intervention, they underwent a 4 weeks washout period. Following the crossover protocol, a second intervention was conducted after the washout period. In each intervention, fMRI and neuropsychological tests were performed at the maximum dose period. Comparing the memantine and placebo groups, we investigated difference in the brain regions using the visuospatial n-back test. Results: There were no significant regions enhanced by memantine comparing with placebo at any load of n-back tests. In contrast, exploring regions reduced by memantine, we found significant reduction of activations within right lingual gyrus and left superior frontal gyrus in comparison between 2-back and 0-back test. A number of correct answers of the 2-back test and time to complete Trail Making Test-A were worse during memantine intervention. Conclusions: Memantine did not improve visuospatial working memory of the patients with PD-MCI. Treatment for PD should be planned carefully considering the impact on cognitive function. Further study is needed to establish new therapeutic strategy. Trial registration: UMIN000046104. Retrospectively registered. First registration date: 28 Sept 2017.

    DOI: 10.1186/s12883-022-02699-x

    Scopus

  16. APOE ɛ4 dose associates with increased brain iron and β-amyloid via blood-brain barrier dysfunction. 国際誌

    Uchida Y, Kan H, Sakurai K, Horimoto Y, Hayashi E, Iida A, Okamura N, Oishi K, Matsukawa N

    Journal of neurology, neurosurgery, and psychiatry   93 巻 ( 7 ) 頁: 772 - 778   2022年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Neurology, Neurosurgery and Psychiatry  

    Objective To examine the effect of apolipoprotein E (APOE) ϵ4 dose on blood-brain barrier (BBB) clearance function, evaluated using an advanced MRI technique and analyse its correlation with brain iron and β-amyloid accumulation in the early stages of the Alzheimer's continuum. Methods In this single-centre observational prospective cohort study, 24 APOE ϵ4 non-carriers, 22 heterozygotes and 20 homozygotes in the early stages of the Alzheimer's continuum were scanned with diffusion-prepared arterial spin labelling, which estimates the water exchange rate across the BBB (k w). Participants also underwent quantitative susceptibility mapping, [11 C]Pittsburgh compound B-positron emission tomography and neuropsychological testing. Using an atlas-based approach, we compared the regional k w of the whole brain among the groups and analysed its correlation with the neuroradiological and neuropsychological findings. Results The BBB k w values in the neocortices differed significantly among the groups (APOE ϵ4 non-carriers>heterozygotes>homozygotes). These values correlated with brain iron levels (frontal lobe: r=-0.476, 95% CI=-0.644 to-0.264, p=0.011; medial temporal lobe: r=-0.455, 95% CI=-0.628 to-0.239, p=0.017), β-amyloid loads (frontal lobe: r=-0.504, 95% CI=-0.731 to-0.176, p=0.015; medial temporal lobe: r=-0.452, 95% CI=-0.699 to-0.110, p=0.036) and neuropsychological scores, after adjusting for age, sex and APOE ϵ4 dose. Interpretation Our results suggest that an increased APOE ϵ4 dose is associated with decreased effective brain-waste clearance, such as iron and β-amyloid, through the BBB.

    DOI: 10.1136/jnnp-2021-328519

    Web of Science

    Scopus

    PubMed

  17. Delineation of prostatic calcification using quantitative susceptibility mapping: Spatial accuracy for magnetic resonance-only radiotherapy planning. 国際誌

    Kan H, Tsuchiya T, Yamada M, Kunitomo H, Kasai H, Shibamoto Y

    Journal of applied clinical medical physics   23 巻 ( 2 ) 頁: e13469   2022年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Applied Clinical Medical Physics  

    To investigate the spatial accuracy of delineating prostatic calcifications by quantitative susceptibility mapping (QSM) in comparison with computed tomography (CT), we conducted phantom and human studies. Five differently-sized spherical hydroxyapatites mimicking prostatic calcification (pseudo-calcification) were arranged in the order of their sizes at the center of a plastic container filled with gelatin. This calcification phantom underwent magnetic resonance (MR) imaging, including the multiple spoiled gradient-echo sequences (SPGR) for the QSM and CT as a reference. The volume of each pseudo-calcification and center-to-center distance between the pseudo-calcifications delineated by QSM and CT were measured. In the human study, eight patients with prostate cancer who underwent radiation therapy and had some prostatic calcifications were included. The patients underwent CT and SPGR and modified DIXON sequence for MR-only simulation. The hybrid QSM processing combined with the complex signals in the SPGR and water and fat fraction maps estimated from the modified DIXON sequence were used to reconstruct the pelvic susceptibility map in humans. The threshold of CT numbers was set at 130 HU, while the QSM images were manually segmented in the calcification phantom and human studies. In the phantom study, there was an excellent agreement in the pseudo-calcification volumes between QSM and CT (y = 1.02x – 7.38, R2 = 0.99). The signal profiles had similar trends in CT and QSM. The center-to-center distances between the pseudo-calcifications in the phantom were also identical in QSM and CT. The calcification volumes were almost identical between the QSM and CT in the human study (y = 0.95x – 9.32, R2 = 1.00). QSM can offer geometric and volumetric accuracies to delineate prostatic calcifications, similar to CT. The prostatic calcification delineated by QSM may facilitate image-guided radiotherapy in the MR-only simulation workflow.

    DOI: 10.1002/acm2.13469

    Web of Science

    Scopus

    PubMed

  18. Machine learning trained with quantitative susceptibility mapping to detect mild cognitive impairment in Parkinson's disease.

    Shibata H, Uchida Y, Inui S, Kan H, Sakurai K, Oishi N, Ueki Y, Oishi K, Matsukawa N

    Parkinsonism & related disorders   94 巻   頁: 104 - 110   2022年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Parkinsonism and Related Disorders  

    Background: Cognitive decline is commonly observed in Parkinson's disease (PD). Identifying PD with mild cognitive impairment (PD-MCI) is crucial for early initiation of therapeutic interventions and preventing cognitive decline. Objective: We aimed to develop a machine learning model trained with magnetic susceptibility values based on the multi-atlas label-fusion method to classify PD without dementia into PD-MCI and normal cognition (PD-CN). Methods: This multicenter observational cohort study retrospectively reviewed 61 PD-MCI and 59 PD-CN cases for the internal validation cohort and 22 PD-MCI and 21 PD-CN cases for the external validation cohort. The multi-atlas method parcellated the quantitative susceptibility mapping (QSM) images into 20 regions of interest and extracted QSM-based magnetic susceptibility values. Random forest, extreme gradient boosting, and light gradient boosting were selected as machine learning algorithms. Results: All classifiers demonstrated substantial performances in the classification task, particularly the random forest model. The accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve for this model were 79.1%, 77.3%, 81.0%, and 0.78, respectively. The QSM values in the caudate nucleus, which were important features, were inversely correlated with the Montreal Cognitive Assessment scores (right caudate nucleus: r = −0.573, 95% CI: −0.801 to −0.298, p = 0.003; left caudate nucleus: r = −0.659, 95% CI: −0.894 to −0.392, p < 0.001). Conclusions: Machine learning models trained with QSM values successfully classified PD without dementia into PD-MCI and PD-CN groups, suggesting the potential of QSM values as an auxiliary biomarker for early evaluation of cognitive decline in patients with PD.

    DOI: 10.1016/j.parkreldis.2021.12.004

    Web of Science

    Scopus

    PubMed

  19. Penumbra Detection With Oxygen Extraction Fraction Using Magnetic Susceptibility in Patients With Acute Ischemic Stroke.

    Uchida Y, Kan H, Inoue H, Oomura M, Shibata H, Kano Y, Kuno T, Usami T, Takada K, Yamada K, Kudo K, Matsukawa N

    Frontiers in neurology   13 巻   頁: 752450   2022年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Frontiers in Neurology  

    Background: The oxygen extraction fraction (OEF) has been applied to identify ischemic penumbral tissue, but is difficult to use in an urgent care setting. This study aimed to investigate whether an OEF map generated via magnetic resonance quantitative susceptibility mapping (QSM) could help identify the ischemic penumbra in patients with acute ischemic stroke. Materials and Methods: This prospective imaging study included 21 patients with large anterior circulation vessel occlusion who were admitted <24 h after stroke onset and 21 age-matched healthy controls. We identified the ischemic penumbra as the region with a Tmax of >6 s during dynamic susceptibility contrast-magnetic resonance imaging (DSC-MRI) and calculated the perfusion-core mismatch ratio between the ischemic penumbra and infarct core volumes. The OEF values were measured based on magnetic susceptibility differences between the venous structures and brain tissues using rapid QSM acquisition. Volumes with increased OEF values were compared to the ischemic penumbra volumes using an anatomical template. Results: Eleven patients had a perfusion-core mismatch ratio of ≥1.8, and reperfusion therapy was recommended. In these patients, the volumes with increased OEF values of >51.5%, which was defined using the anterior circulation territory OEF values from the 21 healthy controls, were positively correlated with the ischemic penumbra volumes (r = 0.636, 95% CI: 0.059 to 0.895, P = 0.035) and inversely correlated with the 30-day change in the National Institutes of Health Stroke Scale scores (r = −0.624, 95% CI: −0.891 to −0.039, P = 0.041). Conclusion: Tissue volumes with increased OEF values could predict ischemic penumbra volumes based on DSC-MRI, highlighting the potential of the QSM-derived OEF map as a penumbra biomarker to guide treatment selection in patients with acute ischemic stroke.

    DOI: 10.3389/fneur.2022.752450

    Web of Science

    Scopus

    PubMed

  20. R2* relaxometry analysis for mapping of white matter alteration in Parkinson's disease with mild cognitive impairment. 国際誌

    Kan H, Uchida Y, Ueki Y, Arai N, Tsubokura S, Kunitomo H, Kasai H, Aoyama K, Matsukawa N, Shibamoto Y

    NeuroImage. Clinical   33 巻   頁: 102938 - 102938   2022年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:NeuroImage: Clinical  

    Background: R2* relaxometry analysis combined with quantitative susceptibility mapping (QSM), which has high sensitivity to iron deposition, can distinguish microstructural changes of the white matter (WM) and iron deposition, thereby providing a sensitive and biologically specific measure of the WM owing to the changes in myelin and its surrounding environment. This study aimed to explore the microstructural WM alterations associated with cognitive impairment in patients with Parkinson's disease (PD) using R2* relaxometry analysis combined with QSM. Materials and methods: We enrolled 24 patients with PD and mild cognitive impairment (PD-MCI), 22 patients with PD and normal cognition (PD-CN), and 19 age- and sex-matched healthy controls (HC). All participants underwent Montreal Cognitive Assessment (MoCA) and brain magnetic resonance imaging, including structural three-dimensional T1-weighted images and multiple spoiled gradient echo sequence (mGRE). The R2* and susceptibility maps were estimated from the multiple magnitude images of mGRE. The susceptibility maps were used for verifying iron deposition in the WM. The voxel-based R2* of the entire WM and its correlation with cognitive performance were analyzed. Results: In the voxel-based group comparisons, the R2* in the PD-MCI group was lower in some WM regions, including the corpus callosum, than R2* in the PD-CN and HC groups. The mean susceptibility values in almost all brain regions were negative and close-to-zero values, indicating no detectable paramagnetic iron deposition in the WM of all subjects. There was a significant positive correlation between R2* and MoCA in some regions of the WM, mainly the corpus callosum and left hemisphere. Conclusion: R2* relaxometry analysis for WM microstructural changes provided further biologic insights on demyelination and changes in the surrounding environment, supported by the QSM results demonstrating no iron existence. This analysis highlighted the potential for the early evaluation of cognitive decline in patients with PD.

    DOI: 10.1016/j.nicl.2022.102938

    Web of Science

    Scopus

    PubMed

  21. Quantitative susceptibility mapping as an imaging biomarker for Alzheimer's disease: The expectations and limitations.

    Uchida Y, Kan H, Sakurai K, Oishi K, Matsukawa N

    Frontiers in neuroscience   16 巻   頁: 938092   2022年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Frontiers in Neuroscience  

    Alzheimer’s disease (AD) is the most common type of dementia and a distressing diagnosis for individuals and caregivers. Researchers and clinical trials have mainly focused on β-amyloid plaques, which are hypothesized to be one of the most important factors for neurodegeneration in AD. Meanwhile, recent clinicopathological and radiological studies have shown closer associations of tau pathology rather than β-amyloid pathology with the onset and progression of Alzheimer’s symptoms. Toward a biological definition of biomarker-based research framework for AD, the 2018 National Institute on Aging–Alzheimer’s Association working group has updated the ATN classification system for stratifying disease status in accordance with relevant pathological biomarker profiles, such as cerebral β-amyloid deposition, hyperphosphorylated tau, and neurodegeneration. In addition, altered iron metabolism has been considered to interact with abnormal proteins related to AD pathology thorough generating oxidative stress, as some prior histochemical and histopathological studies supported this iron-mediated pathomechanism. Quantitative susceptibility mapping (QSM) has recently become more popular as a non-invasive magnetic resonance technique to quantify local tissue susceptibility with high spatial resolution, which is sensitive to the presence of iron. The association of cerebral susceptibility values with other pathological biomarkers for AD has been investigated using various QSM techniques; however, direct evidence of these associations remains elusive. In this review, we first briefly describe the principles of QSM. Second, we focus on a large variety of QSM applications, ranging from common applications, such as cerebral iron deposition, to more recent applications, such as the assessment of impaired myelination, quantification of venous oxygen saturation, and measurement of blood– brain barrier function in clinical settings for AD. Third, we mention the relationships among QSM, established biomarkers, and cognitive performance in AD. Finally, we discuss the role of QSM as an imaging biomarker as well as the expectations and limitations of clinically useful diagnostic and therapeutic implications for AD.

    DOI: 10.3389/fnins.2022.938092

    Web of Science

    Scopus

    PubMed

  22. Effects of a new speech support application on intensive speech therapy and changes in functional brain connectivity in patients with post-stroke aphasia.

    Katsuno Y, Ueki Y, Ito K, Murakami S, Aoyama K, Oishi N, Kan H, Matsukawa N, Nagao K, Tatsumi H

    Frontiers in human neuroscience   16 巻   頁: 870733   2022年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Frontiers in Human Neuroscience  

    Aphasia is a language disorder that occurs after a stroke and impairs listening, speaking, reading, writing, and calculation skills. Patients with post-stroke aphasia in Japan are increasing due to population aging and the advancement of medical treatment. Opportunities for adequate speech therapy in chronic stroke are limited due to time constraints. Recent studies have reported that intensive speech therapy for a short period of time or continuous speech therapy using high-tech equipment, including speech applications (apps, can improve aphasia even in the chronic stage. However, its underlying mechanism for improving language function and its effect on other cognitive functions remains unclear. In the present study, we investigated whether intensive speech therapy using a newly developed speech support app could improve aphasia and other cognitive functions in patients with chronic stroke. Furthermore, we examined whether it can alter the brain network related to language and other cortical areas. Thus, we conducted a prospective, single-comparison study to examine the effects of a new speech support app on language and cognitive functions and used resting state functional MRI (rs-fMRI) regions of interest (ROI) to ROI analysis to determine changes in the related brain network. Two patients with chronic stroke participated in this study. They used the independent speech therapy system to perform eight sets of 20 randomly presented words/time (taking approximately 20 min), for 8 consecutive weeks. Their language, higher cognitive functions including attention function, and rs-fMRI, were evaluated before and after the rehabilitation intervention using the speech support app. Both patients had improved pronunciation, daily conversational situations, and attention. The rs-fMRI analysis showed increased functional connectivity of brain regions associated with language and attention related areas. Our results show that intensive speech therapy using this speech support app can improve language and attention functions even in the chronic stage of stroke, and may be a useful tool for patients with aphasia. In the future, we will conduct longitudinal studies with larger numbers of patients, which we hope will continue the trends seen in the current study, and provide even stronger evidence for the usefulness of this new speech support app.

    DOI: 10.3389/fnhum.2022.870733

    Web of Science

    Scopus

    PubMed

  23. T-staging of rectal cancer: Utility of single-shot turbo spin-echo diffusion-weighted imaging with T2-weighted images and fusion images.

    Ogawa M, Urano M, Takaishi T, Kan H, Arai N, Takahashi H, Hara M, Saito M, Shibamoto Y

    PloS one   16 巻 ( 4 ) 頁: e0249433   2021年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PLoS ONE  

    Purpose The purpose of this study was to evaluate the usefulness of turbo spin-echo (TSE) DWI with fusion images in the T-staging compared with T2-weighted imaging (T2WI) alone and conventional echo-planner imaging (EPI) DWI. Methods In this prospective study, 4-mm-thick axial EPI-DWI, TSE-DWI, and T2WI were performed with the same slice locations for 20 patients with rectal cancer. Fusion images of DWI and T2WI were created for both EPI-DWI and TSE-DWI. Ten readers independently diagnosed the T-stages and scored the degree of confidence referring to T2WI alone and then to DWI, T2WI, and fusion images (DWI+T2WI) for each EPI-DWI and TSE-DWI. Visual score assessments of image quality were performed for each DWI. Results Inter-observer agreement of T-staging for 10 readers was slight on T2WI alone but fair on EPI-DWI+T2WI and excellent on TSE-DWI+T2WI images. No readers gave higher confidence scores for T2WI compared to EPI/TSE-DWI+T2WI and for EPI-DWI+T2WI compared to TSE-DWI+T2WI. In seven pathologically-proven cases, poor, poor to slight, and fair to perfect agreements with the pathological T-stage were observed with T2WI alone, EPI-DWI +T2WI, and TSE-DWI+T2WI, respectively. All readers gave higher scores regarding image distortion and lower scores regarding image noise for TSE-DWI compared to EPI-DWI. For DWI utility, higher scores were assigned for TSE-DWI compared to EPI-DWI in 7 readers and there were no significant differences in the other 3 readers. Conclusion TSE-DWI images might be more appropriate for image fusion with T2WI and rectal cancer T-staging compared with EPI-DWI and T2WI alone.

    DOI: 10.1371/journal.pone.0249433

    Web of Science

    Scopus

    PubMed

  24. Reply

    Arai N., Kan H.

    American Journal of Neuroradiology   41 巻 ( 4 ) 頁: E21 - E21   2020年4月

     詳細を見る

    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:American Journal of Neuroradiology  

    DOI: 10.3174/AJNR.A6473

    Web of Science

    Scopus

  25. Changes in Apparent Diffusion Coefficient (ADC) during Cardiac Cycle of the Brain in Idiopathic Normal Pressure Hydrocephalus Before and After Cerebrospinal Fluid Drainage. 国際誌

    Osawa T, Ohno N, Mase M, Miyati T, Omasa R, Ishida S, Kan H, Arai N, Kasai H, Shibamoto Y, Kobayashi S, Gabata T

    Journal of magnetic resonance imaging : JMRI   53 巻 ( 4 ) 頁: 1200 - 1207   2021年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Magnetic Resonance Imaging  

    Background: The causative mechanisms of idiopathic normal-pressure hydrocephalus (iNPH) symptoms are currently unknown. Purpose: To assess the dynamic changes in the apparent diffusion coefficient (ADC) during the cardiac cycle (ΔADC) of the brain before and after the lumbar tap and shunt surgery for the purpose of determining changes in hydrodynamic and biomechanical properties in the brain after cerebrospinal fluid (CSF) drainage for iNPH. Study Type: Retrospective. Subjects: Overall, 22 patients suspected to have iNPH were examined before and after the lumbar tap and were divided into patients who showed symptomatic improvements (positive group, n = 17) and those without improvement (negative group, n = 5) after the lumbar tap. Seven patients in the positive group were examined after the shunt surgery. Field Strength/Sequence: 1.5T, electrocardiographically synchronized single-shot diffusion echo-planar imaging. Assessment: The frontal white matter ΔADC and mean ADC (ADCmean) were compared between before and 24 hours after lumbar tap and from 1 week to 1 month after the shunt surgery. Statistical Tests: Wilcoxon signed-rank test was used. P < 0.05 was considered statistically significant. Results: The ΔADC after the lumbar tap in the positive group was significantly lower than that before (P < 0.05), whereas no significant difference was found in the negative group (P = 0.23). After the lumbar tap, ΔADC decreased in 16 of 17 patients in the positive group, whereas ADCmean did not significantly change (P = 0.96). After the shunt surgery, ΔADC decreased in all seven patients (P < 0.05), whereas ADCmean did not significantly change (P = 0.87). Data Conclusion: The frontal white matter ΔADC in iNPH decreased after the lumbar tap and shunt surgery. ΔADC analysis may provide detailed information regarding changes in the hydrodynamic and biomechanical properties through CSF drainage. Level of Evidence: 4. Technical Efficacy Stage: 4.

    DOI: 10.1002/jmri.27412

    Web of Science

    Scopus

    PubMed

  26. Evaluation of Thin-slice Coronal Single-shot Turbo Spin-echo Diffusion-weighted Imaging of the Hand: A Comparison with Conventional Echo-planar Diffusion-weighted Imaging.

    Ogawa M, Nakagawa M, Arai N, Kan H, Ohba S, Shibata S, Maki H, Shibamoto Y

    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine   19 巻 ( 4 ) 頁: 382 - 388   2020年12月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Magnetic Resonance in Medical Sciences  

    We prospectively evaluated thin-slice coronal turbo spin-echo (TSE) diffusion-weighted imaging (DWI) covering a larger area with the recently-developed techniques on a 3T MRI scanner, compared with echo-planar imaging (EPI)-DWI in patients undergoing routine hand MRI. Visual score assessment and apparent diffusion coefficient (ADC) measurement were performed for patients with suspected hand tumors. TSE-DWI was superior to EPI-DWI, with less image distortion. The visual score and ADC comparison assessments proved that the image noise of TSE-DWI was acceptable.

    DOI: 10.2463/mrms.tn-2019-0115

    Web of Science

    Scopus

    PubMed

    CiNii Research

  27. Decreasing iron susceptibility with temperature in quantitative susceptibility mapping: A phantom study. 国際誌

    Kan H, Uchida Y, Arai N, Takizawa M, Miyati T, Kunitomo H, Kasai H, Shibamoto Y

    Magnetic resonance imaging   73 巻   頁: 55 - 61   2020年11月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Magnetic Resonance Imaging  

    To clarify the temperature dependence of susceptibility estimated by quantitative susceptibility mapping (QSM) analysis, we investigated the relationship between temperature and susceptibility using a cylinder phantom with varying temperatures. Six solutions with various concentrations of superparamagnetic iron oxide (SPIO) nanoparticles were employed. These tubes were placed in a cylinder phantom and surrounded with water. The temperature of the circulated water was adjusted to change the temperature in the cylinder phantom from 25.8 °C to 42.5 °C. The cylinder phantom was scanned via a three-dimensional multiple spoiled gradient-echo sequence for R2* and QSM analyses with varying temperatures. The relationships between temperature, susceptibility, and R2* values were determined. Moreover, the temperature coefficients of susceptibility (χ-Tc) and (R2*-Tc) were calculated at each concentration and the linearities in these indices against each SPIO concentration were validated. Significant inverse correlations were found between temperature, susceptibility, and R2* values at each SPIO concentration due to the decrease in paramagnetic iron susceptibility that occurred with increasing temperature based on Curie's law. Moreover, although there were significant correlations between the susceptibility and R2* values at any temperature, the slopes of the regression lines grew in height with greater temperatures. The percentage of difference per Celsius degree in susceptibility in any SPIO concentration was lower than the corresponding finding among the R2* results. There were strong linearities between the SPIO concentration, χ-Tc (r = −0.994; p < 0.001), and R2*-Tc (r = −0.998; p < 0.001). The χ-Tc and R2*-Tc outcomes in a particular voxel varied considerably with the iron contents. Although there was an inverse correlation noted between temperature and susceptibility, the susceptibility analysis showed smaller temperature dependence relative to the R2* analysis. QSM analysis might be a more suitable option for magnetic resonance-based iron quantification in comparison with R2* relaxometry.

    DOI: 10.1016/j.mri.2020.08.012

    Web of Science

    Scopus

    PubMed

  28. Iron leakage owing to blood-brain barrier disruption in small vessel disease CADASIL. 国際誌

    Uchida Y, Kan H, Sakurai K, Arai N, Inui S, Kobayashi S, Kato D, Ueki Y, Matsukawa N

    Neurology   95 巻 ( 9 ) 頁: e1188 - e1198   2020年9月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Neurology  

    ObjectiveTo assess the relationship among iron accumulation, blood-brain barrier (BBB) damage, and cognitive function in patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL).MethodsWe enrolled 21 patients with NOTCH3 mutations and 21 age-matched healthy controls in this cross-sectional study. All participants underwent global physical and cognitive assessments and brain MRI using voxel-based quantitative susceptibility mapping (QSM; iron deposition measure) and dynamic contrast-enhanced MRI (BBB permeability measure). We compared behavioral and imaging data between the groups and analyzed the correlations in each group.ResultsAmong 21 NOTCH3 mutation carriers, 10 were symptomatic and 11 asymptomatic. Montreal Cognitive Assessment scores were significantly different among the groups (symptomatic < asymptomatic < control participants). Voxel-based QSM analysis revealed that the symptomatic group had higher QSM values than did the asymptomatic group in the putamen, caudate nucleus, temporal pole, and centrum semiovale. These QSM values were positively correlated with regional BBB permeabilities (putamen: r = 0.57, p = 0.006; caudate nucleus: r = 0.51, p = 0.019; temporal pole: r = 0.48, p = 0.030; centrum semiovale: r = 0.45, p = 0.044) and negatively correlated with Montreal Cognitive Assessment scores (caudate nucleus: r = -0.53, p = 0.012; temporal pole: r = -0.56, p = 0.008).ConclusionsThis study showed that cerebral iron burden was associated with regional BBB permeability and cognitive dysfunction in patients with CADASIL, highlighting the potential of these imaging techniques as auxiliary biomarkers to monitor the course of small vessel disease.

    DOI: 10.1212/WNL.0000000000010148

    Web of Science

    Scopus

    PubMed

  29. Magnetic Susceptibility Associates With Dopaminergic Deficits and Cognition in Parkinson's Disease. 国際誌

    Uchida Y, Kan H, Sakurai K, Inui S, Kobayashi S, Akagawa Y, Shibuya K, Ueki Y, Matsukawa N

    Movement disorders : official journal of the Movement Disorder Society   35 巻 ( 8 ) 頁: 1396 - 1405   2020年8月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Movement Disorders  

    Objective: The objective of this study was to assess the relationship between nigrostriatal magnetic susceptibility and dopamine transporter abnormality and their associations with behavioral and cognitive impairments in patients with Parkinson's disease (PD). Methods: For this case-control study, we enrolled 41 patients with PD and 20 age-matched healthy controls. All participants underwent global physical and cognitive assessments, 3-Tesla brain magnetic resonance imaging including quantitative susceptibility mapping (QSM; iron deposition measure), and 123I-N-v-fluoropropyl-2b-carbomethoxy-3b-(4-iodophenyl) nortropane single-photon emission computed tomography (dopamine transporter measure). We subdivided the striatum into the putamen, caudate nucleus, and nucleus accumbens and measured the nigrostriatal QSM values and dopamine transporter–specific binding ratios using an atlas-based approach. Results: The patients with PD had higher QSM values in the substantia nigra and subdivisions of the striatum than did the healthy controls. The striatal dopamine transporter–specific binding ratios were not correlated with the QSM values of the substantia nigra but were inversely correlated with those of the striatum (putamen, r = −0.478, P = 0.009; caudate nucleus, r = −0.462, P = 0.011). The QSM values of the putamen were positively correlated with motor parkinsonism scores (Movement Disorder Society Unified Parkinson's Disease Rating Scale, r = 0.505, P = 0.003), and those of the caudate nucleus were negatively correlated with cognitive impairment scores (Montreal Cognitive Assessment, r = −0.525, P < 0.001). Conclusions: This study showed that striatal iron accumulations were correlated with dopaminergic deficits and neurophysiological signs in patients with PD, highlighting the potential of QSM as an auxiliary biomarker for parkinsonism and cognitive dysfunction. © 2020 International Parkinson and Movement Disorder Society.

    DOI: 10.1002/mds.28077

    Web of Science

    Scopus

    PubMed

  30. Simultaneous voxel-based magnetic susceptibility and morphometry analysis using magnetization-prepared spoiled turbo multiple gradient echo.

    Kan H, Uchida Y, Arai N, Ueki Y, Aoki T, Kasai H, Kunitomo H, Hirose Y, Matsukawa N, Shibamoto Y

    NMR in biomedicine   33 巻 ( 5 ) 頁: e4272   2020年5月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:NMR in Biomedicine  

    This study aimed to develop and test a simultaneous acquisition and analysis pipeline for voxel-based magnetic susceptibility and morphometry (VBMSM) on a single dataset using young volunteers, elderly healthy volunteers, and an Alzheimer's disease (AD) group. 3D T1-weighted and multi-echo phase images for VBM and quantitative susceptibility mapping (QSM) were simultaneously acquired using a magnetization-prepared spoiled turbo multiple gradient echo sequence with inversion pulse for QSM (MP-QSM). The magnitude image was split into gray matter (GM) and white matter (WM) and was spatially normalized. The susceptibility map was reconstructed from the phase images. The segmented image and susceptibility map were compared with those obtained from conventional multiple spoiled gradient echo (mGRE) and MP-spoiled gradient echo (MP-GRE) in healthy volunteers to validate the availability of MP-QSM by numerical measurements. To assess the feasibility of the VBMSM analysis pipeline, voxel-based comparisons of susceptibility and morphometry in MP-QSM were conducted in volunteers with a bimodal age distribution, and in elderly volunteers and the AD group, using spatially normalized GM and WM volume images and a susceptibility map. GM/WM contrasts in MP-QSM, MP-GRE, and mGRE were 0.14 ± 0.011, 0.17 ± 0.015, and 0.045 ± 0.010, respectively. Segmented GM and WM volumes in the MP-QSM closely coincided with those in the MP-GRE. Region of interest analyses indicated that the mean susceptibility values in MP-QSM were completely in agreement with those in mGRE. In an evaluation of the aging effect, a significant increase and decrease in susceptibility and volume were found by VBMSM in deep GM and WM, respectively. Between the elderly volunteers and the AD group, the characteristic susceptibility and volume changes in GM and WM were observed. The proposed MP-QSM sequence makes it possible to acquire acceptable-quality images for simultaneous analysis and determine brain atrophy and susceptibility distribution without image registration by using voxel-based analyses.

    DOI: 10.1002/nbm.4272

    Web of Science

    Scopus

    PubMed

  31. Visualization of Nigrosome 1 from the Viewpoint of Anatomic Structure

    Arai N., Kan H., Ogawa M., Uchida Y., Takizawa M., Omori K., Miyati T., Kasai H., Kunitomo H., Shibamoto Y.

    AMERICAN JOURNAL OF NEURORADIOLOGY   41 巻 ( 1 ) 頁: 86 - 91   2020年1月

     詳細を見る

    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:American Journal of Neuroradiology  

    BACKGROUND AND PURPOSE: Parkinson disease is related to neurodegeneration and iron deposition in the substantia nigra pars compacta and nigrosome 1. However, visualization of nigrosome 1 via MR imaging is poor owing to the bilateral asymmetry, regardless of whether it is healthy. We focused on the magic angle and susceptibility effect and evaluated the anatomic slant structure of nigrosome 1 by tilting subjects’ heads in the B0 direction. MATERIALS AND METHODS: To investigate the effectiveness of the magic angle, we tilted the volunteers’ heads to the right and left in the B0 direction or not at all for evaluating correlations between the degree of head tilting and visualization of the right nigrosome 1 and left nigrosome 1 using 3D spoiled gradient-echo sequences with multiecho acquisitions. We evaluated the susceptibility of nigrosome 1 and the local field using quantitative susceptibility mapping to assess static magnetic field inhomogeneity. RESULTS: The heads tilted to the right and left showed significantly higher contrasts of nigrosome 1 and the substantia nigra pars compacta than the nontilted heads. No significant differences were observed in the visualization and susceptibility between the right nigrosome 1 and left nigrosome 1 for each head tilt. The effect of the magic angle was remarkable in the nontilted heads. This finding was supported by quantitative susceptibility mapping because the anatomic slant structure of nigrosome 1 was coherent between the axis of nigrosome 1 and the magic angle. CONCLUSIONS: The asymmetric visualization of nigrosome 1 is affected by the magic angle and susceptibility. The anatomic slant structure of nigrosome 1 causes these challenges in visualization.

    DOI: 10.3174/ajnr.A6338

    Web of Science

    Scopus

    PubMed

  32. Improvement of Signal Inhomogeneity Induced by Radio-frequency Transmit-related Phase Error for Single-step Quantitative Susceptibility Mapping Reconstruction.

    Kan H, Arai N, Takizawa M, Kasai H, Kunitomo H, Hirose Y, Shibamoto Y

    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine   18 巻 ( 4 ) 頁: 276 - 285   2019年10月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Magnetic Resonance in Medical Sciences  

    To mitigate the susceptibility inhomogeneity induced by radio-frequency transmit phase error through the whole brain in quantitative susceptibility mapping (QSM) using single-echo gradient echo sequence, we developed a novel single-step QSM reconstruction algorithm and compared it with a previous algorithm in five healthy volunteers. The proposed algorithm had effectively suppressed the susceptibility inhomogeneity through the whole brain and achieved acceptable quality, similar to that of the susceptibility map calculated from a multi-echo gradient echo sequence.

    DOI: 10.2463/mrms.tn.2018-0066

    Web of Science

    Scopus

    PubMed

    CiNii Research

  33. Voxel-based quantitative susceptibility mapping in Parkinson's disease with mild cognitive impairment. 国際誌

    Uchida Y, Kan H, Sakurai K, Arai N, Kato D, Kawashima S, Ueki Y, Matsukawa N

    Movement disorders : official journal of the Movement Disorder Society   34 巻 ( 8 ) 頁: 1164 - 1173   2019年8月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Movement Disorders  

    Objective: Brain iron accumulation has been proposed as one of the pathomechanisms in Parkinson's disease (PD). This study aimed to examine the whole-brain pattern of iron accumulation associated with cognitive impairment in patients with PD using voxel-based quantitative susceptibility mapping analysis. Methods: We enrolled 24 patients with PD and mild cognitive impairment, 22 patients with PD and normal cognition, and 20 age-matched healthy controls in this cross-sectional study. All participants underwent global cognitive and physical assessments and brain MRI. Using a combined method of voxel-based morphometry and quantitative susceptibility mapping, we compared the voxel-wise magnetic susceptibility of the whole brain between the groups and analyzed its correlation with the cognitive and behavioral data. Results: The PD and mild cognitive impairment group had lower Montreal Cognitive Assessment (MoCA) score than the PD and normal cognition and healthy control groups. There were no gray matter volumetric differences between the groups. In contrast, the voxel-based quantitative susceptibility mapping analysis showed that the PD and mild cognitive impairment group had significantly higher quantitative susceptibility mapping values in the cuneus, precuneus, caudate head, fusiform gyrus, and orbitofrontal cortex than did the PD and normal cognition group. These quantitative susceptibility mapping values were negatively correlated with the MoCA scores in the PD patients (cuneus: r = −0.510, P <.001; caudate head: r = −0.458, P = 0.002). Conclusions: This study suggests that cognitive impairment in PD is associated with cerebral iron burden and highlights the potential of quantitative susceptibility mapping as an auxiliary biomarker for early evaluation of cognitive decline in patients with PD. © 2019 International Parkinson and Movement Disorder Society.

    DOI: 10.1002/mds.27717

    Web of Science

    Scopus

    PubMed

  34. Geometric discrepancy of image-guided radiation therapy in patients with prostate cancer without implanted fiducial markers using a commercial pseudo-CT generation method.

    Kan H, Eguchi Y, Tsuchiya T, Kondo T, Kitagawa Y, Mekata Y, Fukuma H, Yoshida R, Kasai H, Kunitomo H, Hirose Y, Shibamoto Y

    Physics in medicine and biology   64 巻 ( 6 ) 頁: 06NT01   2019年3月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Physics in Medicine and Biology  

    MR-only simulations provide pseudo-CT images which are segmented into 5 kinds of tissues from DIXON-based images. However, it is difficult to register pseudo-CT images to cone-beam CT (CBCT) images collected for image-guided radiation therapy (IGRT), because of the lack of contrasts among tissues. We validated gaps of IGRT between pseudo-CT or planning CT and CBCT for patients without implanted markers. We also propose calcification-assisted registration for MR-only simulation. We conducted retrospective analyses to verify the registration accuracy in 15 patients who underwent volumetric modulated arc therapy (VMAT) for prostate cancer. They underwent planning CT and pseudo-CT. Pseudo-CT images after deformable image registration (DIR) to planning CT images were rendered automatic pelvic bone matching to CBCT images. Patient positions on the pseudo-CT images after DIR were shifted on the basis of tissues around the prostate. We compared registration gaps between the images of planning CT and pseudo-CT with DIR, assuming that the tissue-based matching between the planning CT and CBCT was the gold standard. To the pseudo-CT images with DIR, calcifications detected on planning CT were added. We validated IGRT accuracy for a calcification-assisted registration. The absolute registration errors of the pseudo-CT, in comparison with the planning CT, were 0.34 ± 0.50 (lateral), 1.3 ± 1.3 (longitudinal), and 1.1 ± 1.0 mm (vertical). The absolute registration errors of the pseudo-CT with calcification contouring, in comparison with the planning CT, were 0.41 ± 1.0 (lateral), 0.87 ± 0.92 (longitudinal), and 0.74 ± 0.64 mm (vertical). Reduced absolute registration errors were observed in the proposed approach in the longitudinal (P < 0.01) and vertical (P < 0.01) dimensions when using calcification-assisted registration. The tissue-based registration using the MR-only simulation was not sufficient for use in patients with prostate cancer without implanted markers. The calcification-assisted registration might help to improve IGRT accuracy using MRI alone.

    DOI: 10.1088/1361-6560/ab02cc

    Web of Science

    Scopus

    PubMed

  35. Differentiation between malignant and benign musculoskeletal tumors using diffusion kurtosis imaging. 国際誌

    Ogawa M, Kan H, Arai N, Murai T, Manabe Y, Sawada Y, Shibamoto Y

    Skeletal radiology   48 巻 ( 2 ) 頁: 285 - 292   2019年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Skeletal Radiology  

    Objective: The purpose of this study was to evaluate differences in parameters of diffusion kurtosis imaging (DKI) and minimum apparent diffusion coefficient (ADC min ) between benign and malignant musculoskeletal tumors. Materials and methods: In this prospective study, 43 patients were scanned using a DKI protocol on a 3-T MR scanner. Eligibility criteria were: non-fatty, non-cystic soft tissue or osteolytic tumors; > 2 cm; location in the retroperitoneum, pelvis, leg, or neck; and no prior treatment. They were clinically or histologically diagnosed as benign (n = 27) or malignant (n = 16). In the DKI protocol, diffusion-weighted imaging was performed using four b values (0-2000 s/mm 2 ) and 21 diffusion directions. Mean kurtosis (MK) values were calculated on the MR console. A recently developed software application enabling reliable calculation was used for DKI analysis. Results: MK showed a strong correction with ADC min (Spearman’s rs = 0.95). Both MK and ADC min values differed between benign and malignant tumors (p < 0.01). For benign and malignant tumors, the mean MK values (± SD) were 0.49 ± 0.17 and 1.14 ± 0.30, respectively, and ADC min values were 1.54 ± 0.47 and 0.49 ± 0.17 × 10 −3  mm 2 /s, respectively. At cutoffs of MK = 0.81 and ADC min = 0.77 × 10 −3  mm 2 /s, the specificity and sensitivity for diagnosis of malignant tumors were 96.3 and 93.8% for MK and 96.3 and 93.8% for ADC min , respectively. The areas under the curve were 0.97 and 0.99 for MK and ADC min , respectively (p = 0.31). Conclusions: MK and ADC min showed high diagnostic accuracy and strong correlation, reflecting the accuracy of MK. However, no clear added value of DKI could be demonstrated in differentiating musculoskeletal tumors.

    DOI: 10.1007/s00256-018-2946-0

    Web of Science

    Scopus

    PubMed

  36. Nigrostriatal Dopaminergic Dysfunction and Altered Functional Connectivity in REM Sleep Behavior Disorder With Mild Motor Impairment. 国際誌

    Yamada G, Ueki Y, Oishi N, Oguri T, Fukui A, Nakayama M, Sano Y, Kandori A, Kan H, Arai N, Sakurai K, Wada I, Matsukawa N

    Frontiers in neurology   10 巻 ( JUL ) 頁: 802 - 802   2019年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Frontiers in Neurology  

    Rapid eye movement sleep behavior disorder is parasomnia characterized by symptoms of dream enactment and loss of muscle atonia during rapid eye movement sleep. Mild motor impairment is present in some patients with rapid eye movement sleep behavior disorder and presumed to be a risk factor for conversion to synucleinopathies. The purpose of this study is to identify patients with mild motor impairment by evaluating finger tapping and to investigate its pathophysiology. Twenty-three patients with rapid eye movement sleep behavior disorder and 20 healthy control subjects were recruited in the present study. We accurately evaluated finger tapping including amplitude, peak open, and close speed with a magnetic sensing device and identified patients with mild motor impairment. Moreover, we performed 123I-2b-carbomethoxy-3b-(4-iodophenyl) nortropane SPECT and resting state functional MRI. 123I-2b-carbomethoxy-3b-(4-iodophenyl) nortropane uptake for each bilateral caudate, anterior putamen, and posterior putamen was calculated and the resting state functional connectivity of sensorimotor network was analyzed. Using finger tapping parameters, we identified eight patients with mild motor impairment. In patients with mild motor impairment, all finger tapping parameters were significantly impaired when compared to patients with normal motor function, while they exhibited no significant differences in Unified Parkinsons Disease Rating Scale part III score. 123I-2b-carbomethoxy-3b-(4-iodophenyl) nortropane uptake in the right posterior putamen, bilateral anterior putamen, and caudate was significantly lower when compared to healthy controls or patients with rapid eye movement sleep behavior disorder with normal motor function. These patients also exhibited decreased cortico-striatal functional connectivity and increased cortico-cerebellar functional connectivity when compared to healthy controls or patients with normal motor function. Our results show that mild motor impairment in rapid eyemovement sleep behavior disorder evaluated by finger tapping task presented mild nigrostriatal dopaminergic dysfunction as well as alterations in resting state sensorimotor network. Although longitudinal follow up is necessary, such patients may have higher risk of short-term conversion to synucleinopathies.

    DOI: 10.3389/fneur.2019.00802

    Web of Science

    Scopus

    PubMed

  37. Background field removal technique based on non-regularized variable kernels sophisticated harmonic artifact reduction for phase data for quantitative susceptibility mapping.

    Kan H, Arai N, Takizawa M, Omori K, Kasai H, Kunitomo H, Hirose Y, Shibamoto Y

    Magnetic resonance imaging   52 巻   頁: 94 - 101   2018年10月

     詳細を見る

    掲載種別:研究論文(学術雑誌)   出版者・発行元:Magnetic Resonance Imaging  

    DOI: 10.1016/j.mri.2018.06.006

    Web of Science

    Scopus

    PubMed

  38. Hybrid quantitative MRI using chemical shift displacement and recovery-based simultaneous water and lipid imaging: A preliminary study.

    Ohno N, Miyati T, Suzuki S, Kan H, Aoki T, Nakamura Y, Hiramatsu Y, Kobayashi S, Gabata T

    Magnetic resonance imaging   50 巻   頁: 61 - 67   2018年7月

     詳細を見る

    掲載種別:研究論文(学術雑誌)   出版者・発行元:Magnetic Resonance Imaging  

    DOI: 10.1016/j.mri.2018.03.013

    Web of Science

    Scopus

    PubMed

  39. Utility of the variable flip angle 3D fast-spin echo (isoFSE) sequence on 3T MR for diagnosing vertebrobasilar artery dissection.

    Ogawa M, Omata S, Kan H, Arai N, Asai M, Urano M, Shibamoto Y

    Radiological physics and technology   11 巻 ( 2 ) 頁: 228 - 234   2018年6月

     詳細を見る

    掲載種別:研究論文(学術雑誌)   出版者・発行元:Radiological Physics and Technology  

    DOI: 10.1007/s12194-018-0460-7

    Web of Science

    Scopus

    PubMed

  40. Novel practical SNR determination method for MRI using double echo with longest second echo time (DELSET).

    Ohno N, Miyati T, Niwa Y, Kan H, Ishida S, Kasai H, Shibamoto Y, Gabata T

    The British journal of radiology   91 巻 ( 1086 ) 頁: 20170652   2018年6月

     詳細を見る

    掲載種別:研究論文(学術雑誌)   出版者・発行元:British Journal of Radiology  

    DOI: 10.1259/bjr.20170652

    Web of Science

    Scopus

    PubMed

  41. Time-resolved magnetic resonance angiography as a follow-up method for visceral artery aneurysm treated with coil-embolisation.

    Kawai T, Shimohira M, Suzuki K, Ohta K, Kurosaka K, Hashizume T, Nishikawa H, Muto M, Arai N, Kan H, Shibamoto Y

    Polish journal of radiology   83 巻   頁: e137 - e142   2018年

     詳細を見る

    掲載種別:研究論文(学術雑誌)   出版者・発行元:Polish Journal of Radiology  

    DOI: 10.5114/pjr.2018.75622

    Web of Science

    Scopus

    PubMed

  42. Neural Basis of Self-Reflection on Self-Face Image in Patients with Social Anxiety Disorder

    KAWAGUCHI Akiko, MORITA Tomoyo, OKAMOTO Yasumasa, NAKAAKI Shutaro, KAWAGUCHI Takatsune, KAN Hirohito, YAMADA Takahiro, AKECHI Tatsuo, SADATO Norihiro

      10 巻 ( 1 ) 頁: 29-44   2018年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.14389/jsad.10.1_29

  43. Quantitative susceptibility mapping using principles of echo shifting with a train of observations sequence on 1.5T MRI.

    Kan H, Arai N, Kasai H, Kunitomo H, Hirose Y, Shibamoto Y

    Magnetic resonance imaging   42 巻   頁: 37 - 42   2017年10月

     詳細を見る

    掲載種別:研究論文(学術雑誌)   出版者・発行元:Magnetic Resonance Imaging  

    DOI: 10.1016/j.mri.2017.05.002

    Web of Science

    Scopus

    PubMed

  44. Water and lipid diffusion MRI using chemical shift displacement-based separation of lipid tissue (SPLIT).

    Ohno N, Kan H, Miyati T, Aoki T, Ishida S, Gabata T

    Magnetic resonance imaging   39 巻   頁: 144 - 148   2017年6月

     詳細を見る

    掲載種別:研究論文(学術雑誌)   出版者・発行元:Magnetic Resonance Imaging  

    DOI: 10.1016/j.mri.2017.02.006

    Web of Science

    Scopus

    PubMed

  45. Background field removal technique using regularization enabled sophisticated harmonic artifact reduction for phase data with varying kernel sizes.

    Kan H, Kasai H, Arai N, Kunitomo H, Hirose Y, Shibamoto Y

    Magnetic resonance imaging   34 巻 ( 7 ) 頁: 1026 - 33   2016年9月

     詳細を見る

    掲載種別:研究論文(学術雑誌)   出版者・発行元:Magnetic Resonance Imaging  

    DOI: 10.1016/j.mri.2016.04.019

    Web of Science

    Scopus

    PubMed

  46. Insular Volume Reduction in Patients with Social Anxiety Disorder.

    Kawaguchi A, Nemoto K, Nakaaki S, Kawaguchi T, Kan H, Arai N, Shiraishi N, Hashimoto N, Akechi T

    Frontiers in psychiatry   7 巻 ( JAN ) 頁: 3   2016年

     詳細を見る

    掲載種別:研究論文(学術雑誌)   出版者・発行元:Frontiers in Psychiatry  

    DOI: 10.3389/fpsyt.2016.00003

    Web of Science

    Scopus

    PubMed

  47. Hemodynamic Independent Analysis of &Delta;ADC in Brain Using Diffusion and Perfusion MRI

    KITANAKA Akihiro, MIYATI Tosiaki, OHNO Naoki, KAN Hirohito, MASE Mitsuhito, KOBAYASHI Satoshi, GABATA Toshifumi

      33 巻 ( 1 ) 頁: vii-xi   2016年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.11318/mii.33.vii

  48. Shortened breath-hold contrast-enhanced MRI of the liver using a new parallel imaging technique, CAIPIRINHA (controlled aliasing in parallel imaging results in higher acceleration): a comparison with conventional GRAPPA technique.

    Ogawa M, Kawai T, Kan H, Kobayashi S, Akagawa Y, Suzuki K, Nojiri S, Ozawa Y, Shibamoto Y

    Abdominal imaging   40 巻 ( 8 ) 頁: 3091 - 8   2015年10月

     詳細を見る

    掲載種別:研究論文(学術雑誌)   出版者・発行元:Abdominal Imaging  

    DOI: 10.1007/s00261-015-0491-z

    Web of Science

    Scopus

    PubMed

  49. Dynamic state of water molecular displacement of the brain during the cardiac cycle in idiopathic normal pressure hydrocephalus.

    Kan H, Miyati T, Mase M, Osawa T, Ohno N, Kasai H, Arai N, Kawano M, Shibamoto Y

    Computerized medical imaging and graphics : the official journal of the Computerized Medical Imaging Society   40 巻   頁: 88 - 93   2015年3月

     詳細を見る

    掲載種別:研究論文(学術雑誌)   出版者・発行元:Computerized Medical Imaging and Graphics  

    DOI: 10.1016/j.compmedimag.2014.12.004

    Web of Science

    Scopus

    PubMed

  50. Transfer characteristics of arterial pulsatile force in regional intracranial tissue using dynamic diffusion MRI: a phantom study.

    Kan H, Miyati T, Kasai H, Arai N, Ohno N, Mase M, Shibamoto Y

    Magnetic resonance imaging   32 巻 ( 10 ) 頁: 1284 - 9   2014年12月

     詳細を見る

    掲載種別:研究論文(学術雑誌)   出版者・発行元:Magnetic Resonance Imaging  

    DOI: 10.1016/j.mri.2014.08.026

    Web of Science

    Scopus

    PubMed

  51. Feasibility of time-resolved MR angiography for detecting recanalization of pulmonary arteriovenous malformations treated with embolization with platinum coils.

    Kawai T, Shimohira M, Kan H, Hashizume T, Ohta K, Kurosaka K, Muto M, Suzuki K, Shibamoto Y

    Journal of vascular and interventional radiology : JVIR   25 巻 ( 9 ) 頁: 1339 - 47   2014年9月

     詳細を見る

    掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Vascular and Interventional Radiology  

    DOI: 10.1016/j.jvir.2014.06.003

    Web of Science

    Scopus

    PubMed

  52. A method for assessing metabolic information on liver and bone marrow by use of double gradient-echo with spectral fat suppression.

    Kasai H, Miyati T, Kawai T, Kan H, Kawano M, Shibamoto Y

    Radiological physics and technology   7 巻 ( 2 ) 頁: 211 - 6   2014年7月

     詳細を見る

    掲載種別:研究論文(学術雑誌)   出版者・発行元:Radiological Physics and Technology  

    DOI: 10.1007/s12194-013-0254-x

    Scopus

    PubMed

  53. Delta-ADC (Apparent diffusion coefficient) analysis in patients with idiopathic normal pressure hydrocephalus

    Osawa T.

    Acta Neurochirurgica, Supplementum   114 巻   頁: 197 - 200   2012年

     詳細を見る

    掲載種別:研究論文(学術雑誌)   出版者・発行元:Acta Neurochirurgica, Supplementum  

    DOI: 10.1007/978-3-7091-0956-4_38

    Scopus

  54. Hemodynamic-independent Analysis of Water Molecules Fluctuation in Brain Using MRI

    KAN Hirohito, YORIMITSU Risa, MIYATI Tosiaki, MASE Mitsuhito, KASAI Harumasa, OHNO Naoki, KAWANO Makoto, HARA Masaki, SHIBAMOTO Yuta, KITANAKA Akihiro

      29 巻 ( 1 ) 頁: 23-27   2012年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.11318/mii.29.23

  55. Q-space Diffusion MRI in Vertebral Bone Marrow

    YORIMITSU Risa, KAWANO Makoto, MIYATI Tosiaki, KAN Hirohito, OHNO Naoki, HARA Masaki, SHIBAMOTO Yuta, KASAI Harumasa, ARAI Nobuyuki, MIZUKAMI Yuji

      29 巻 ( 1 ) 頁: 20-22   2012年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.11318/mii.29.20

  56. Idiopathic normal-pressure hydrocephalus: temporal changes in ADC during cardiac cycle.

    Ohno N, Miyati T, Mase M, Osawa T, Kan H, Kasai H, Hara M, Shibamoto Y, Hayashi N, Gabata T, Matsui O

    Radiology   261 巻 ( 2 ) 頁: 560 - 5   2011年11月

     詳細を見る

    掲載種別:研究論文(学術雑誌)   出版者・発行元:Radiology  

    DOI: 10.1148/radiol.11101860

    Web of Science

    Scopus

    PubMed

  57. [Appropriate cardiac phase for measurement of ADC of the brain using ECG-triggered diffusion MRI].

    Kan H, Miyati T, Mase M, Kasai H, Hara M, Shibamoto Y, Kawano M, Ohno N, Kitanaka A, Yorimitsu R, Minami T

    Nihon Hoshasen Gijutsu Gakkai zasshi   67 巻 ( 6 ) 頁: 661 - 5   2011年

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    PubMed

  58. [Analyses of restricted diffusion of water molecules using trabecular bone phantom].

    Minami T, Miyati T, Ueda Y, Kan H, Kitanaka A, Kasai H, Arai N, Hara M, Shibamoto Y, Yokoti S

    Nihon Hoshasen Gijutsu Gakkai zasshi   67 巻 ( 6 ) 頁: 634 - 9   2011年

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    PubMed

  59. 高速スピンエコーの短いエコー間隔が脂肪の信号およびコントラストに及ぼす影響の再検証

    菅 博人, 宮地 利明, 櫻井 亮介, 笠井 治昌, 川野 誠, 依光 里沙, 北中 章博, 三平 佐弓

    医用画像情報学会雑誌   28 巻 ( 3 ) 頁: 79-82   2011年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Fast spin echo(FSE)sequence has been widely recognized that the contrast of T<sub>2</sub> weighted image was affected by multi-refocusing pulses. The contrasts have never been investigated in case of echo space(ES)below 20msec although magnetic resonance imaging(MRI)developed such that the ES of multi-refocusing pulses could set at 5msec. To evaluate the contrasts of fat with short ES, we determined the signal intensities of the brain tissues and bottle phantom which consists of lard, water and bean oil. The signal intensities of all regions increased with decreasing echo spaces, due to the decoupling of J-coupling, excepting water signal intensity. In addition, the contrasts between the white matter and each region decreased with decreasing ES until 10ms and, however, did not change with decreasing ES over 10ms. The contrast between white and gray matter is also discussed. It is concluded that the contrast does not change in case of the echo space below 10ms.

    DOI: 10.11318/mii.28.79

  60. 心周期における脳局所の&Delta;ADC解析

    大野 直樹, 上田 優, 宮地 利明, 間瀬 光人, 笠井 治昌, 菅 博人, 朝日 美幸, 川野 誠, 原 眞咲, 芝本 雄太

    医用画像情報学会雑誌   26 巻 ( 1 ) 頁: 17-20   2009年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    金沢大学附属病院放射線部

    DOI: 10.11318/mii.26.17

▼全件表示

書籍等出版物 2

  1. 認知症専門医のための臨床神経病理学

    入江修司 編( 担当: 分担執筆)

    株式会社ワールドプランニング  2019年5月 

     詳細を見る

    記述言語:日本語 著書種別:学術書

  2. 新 腹部画像診断の勘ドコロ

    兼松雅之 編( 担当: 分担執筆)

    2014年10月 

     詳細を見る

    記述言語:日本語 著書種別:学術書

MISC 22

  1. Voxel-based quantitative susceptibility mapping in Parkinson's disease with mild cognitive impairment 査読有り

    Uchida Y, Kan H, Sakurai K, Arai N, Kato D, Kawashima S, Ueki Y, Matsukawa N  

    Movement disorders : official journal of the Movement Disorder Society34 巻 ( 8 ) 頁: 1164-1173   2019年8月

     詳細を見る

    記述言語:英語  

    DOI: 10.1002/mds.27717

    PubMed

  2. Geometric discrepancy of image-guided radiation therapy in patients with prostate cancer without implanted fiducial markers using a commercial pseudo-CT generation method 査読有り

    Kan H, Eguchi Y, Tsuchiya T, Kondo T, Kitagawa Y, Mekata Y, Fukuma H, Yoshida R, Kasai H, Kunitomo H, Hirose Y, Shibamoto Y  

    Physics in medicine and biology64 巻 ( 6 ) 頁: 06NT01   2019年3月

     詳細を見る

    記述言語:英語  

    DOI: 10.1088/1361-6560/ab02cc

    PubMed

  3. Improvement of Signal Inhomogeneity Induced by Radio-frequency Transmit-related Phase Error for Single-step Quantitative Susceptibility Mapping Reconstruction 査読有り

    Kan H, Arai N, Takizawa M, Kasai H, Kunitomo H, Hirose Y, Shibamoto Y  

    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine   2019年2月

     詳細を見る

    記述言語:英語  

    DOI: 10.2463/mrms.tn.2018-0066

    PubMed

  4. Differentiation between malignant and benign musculoskeletal tumors using diffusion kurtosis imaging 査読有り

    Ogawa M, Kan H, Arai N, Murai T, Manabe Y, Sawada Y, Shibamoto Y  

    Skeletal radiology48 巻 ( 2 ) 頁: 285-292   2019年2月

     詳細を見る

    記述言語:英語  

    DOI: 10.1007/s00256-018-2946-0

    PubMed

  5. Nigrostriatal Dopaminergic Dysfunction and Altered Functional Connectivity in REM Sleep Behavior Disorder With Mild Motor Impairment. 査読有り

    Yamada G, Ueki Y, Oishi N, Oguri T, Fukui A, Nakayama M, Sano Y, Kandori A, Kan H, Arai N, Sakurai K, Wada I, Matsukawa N  

    Frontiers in neurology10 巻   頁: 802   2019年

     詳細を見る

    記述言語:英語  

    DOI: 10.3389/fneur.2019.00802

    PubMed

  6. Background field removal technique based on non-regularized variable kernels sophisticated harmonic artifact reduction for phase data for quantitative susceptibility mapping. 査読有り

    Kan H, Arai N, Takizawa M, Omori K, Kasai H, Kunitomo H, Hirose Y, Shibamoto Y  

    Magnetic resonance imaging52 巻   頁: 94-101   2018年10月

     詳細を見る

    記述言語:英語  

    DOI: 10.1016/j.mri.2018.06.006

    PubMed

  7. Hybrid quantitative MRI using chemical shift displacement and recovery-based simultaneous water and lipid imaging: A preliminary study. 査読有り

    Ohno N, Miyati T, Suzuki S, Kan H, Aoki T, Nakamura Y, Hiramatsu Y, Kobayashi S, Gabata T  

    Magnetic resonance imaging50 巻   頁: 61-67   2018年7月

     詳細を見る

    記述言語:英語  

    DOI: 10.1016/j.mri.2018.03.013

    PubMed

  8. Utility of the variable flip angle 3D fast-spin echo (isoFSE) sequence on 3T MR for diagnosing vertebrobasilar artery dissection. 査読有り

    Ogawa M, Omata S, Kan H, Arai N, Asai M, Urano M, Shibamoto Y  

    Radiological physics and technology11 巻 ( 2 ) 頁: 228-234   2018年6月

     詳細を見る

    記述言語:英語  

    DOI: 10.1007/s12194-018-0460-7

    PubMed

  9. Novel practical SNR determination method for MRI using double echo with longest second echo time (DELSET). 査読有り

    Ohno N, Miyati T, Niwa Y, Kan H, Ishida S, Kasai H, Shibamoto Y, Gabata T  

    The British journal of radiology91 巻 ( 1086 ) 頁: 20170652   2018年6月

     詳細を見る

    記述言語:英語  

    DOI: 10.1259/bjr.20170652

    PubMed

  10. Time-resolved magnetic resonance angiography as a follow-up method for visceral artery aneurysm treated with coil-embolisation. 査読有り

    Kawai T, Shimohira M, Suzuki K, Ohta K, Kurosaka K, Hashizume T, Nishikawa H, Muto M, Arai N, Kan H, Shibamoto Y  

    Polish journal of radiology83 巻   頁: e137-e142   2018年

     詳細を見る

    記述言語:英語  

    DOI: 10.5114/pjr.2018.75622

    PubMed

  11. Quantitative susceptibility mapping using principles of echo shifting with a train of observations sequence on 1.5T MRI. 査読有り

    Kan H, Arai N, Kasai H, Kunitomo H, Hirose Y, Shibamoto Y  

    Magnetic resonance imaging42 巻   頁: 37-42   2017年10月

     詳細を見る

    記述言語:英語  

    DOI: 10.1016/j.mri.2017.05.002

    PubMed

  12. Water and lipid diffusion MRI using chemical shift displacement-based separation of lipid tissue (SPLIT). 査読有り

    Ohno N, Kan H, Miyati T, Aoki T, Ishida S, Gabata T  

    Magnetic resonance imaging39 巻   頁: 144-148   2017年6月

     詳細を見る

    記述言語:英語  

    DOI: 10.1016/j.mri.2017.02.006

    PubMed

  13. Background field removal technique using regularization enabled sophisticated harmonic artifact reduction for phase data with varying kernel sizes. 査読有り

    Kan H, Kasai H, Arai N, Kunitomo H, Hirose Y, Shibamoto Y  

    Magnetic resonance imaging34 巻 ( 7 ) 頁: 1026-33   2016年9月

     詳細を見る

    記述言語:英語  

    DOI: 10.1016/j.mri.2016.04.019

    PubMed

  14. Insular Volume Reduction in Patients with Social Anxiety Disorder. 査読有り

    Kawaguchi A, Nemoto K, Nakaaki S, Kawaguchi T, Kan H, Arai N, Shiraishi N, Hashimoto N, Akechi T  

    Frontiers in psychiatry7 巻   頁: 3   2016年

     詳細を見る

    記述言語:英語  

    DOI: 10.3389/fpsyt.2016.00003

    PubMed

  15. Shortened breath-hold contrast-enhanced MRI of the liver using a new parallel imaging technique, CAIPIRINHA (controlled aliasing in parallel imaging results in higher acceleration): a comparison with conventional GRAPPA technique. 査読有り

    Ogawa M, Kawai T, Kan H, Kobayashi S, Akagawa Y, Suzuki K, Nojiri S, Ozawa Y, Shibamoto Y  

    Abdominal imaging40 巻 ( 8 ) 頁: 3091-8   2015年10月

     詳細を見る

    記述言語:英語  

    DOI: 10.1007/s00261-015-0491-z

    PubMed

  16. Dynamic state of water molecular displacement of the brain during the cardiac cycle in idiopathic normal pressure hydrocephalus. 査読有り

    Kan H, Miyati T, Mase M, Osawa T, Ohno N, Kasai H, Arai N, Kawano M, Shibamoto Y  

    Computerized medical imaging and graphics : the official journal of the Computerized Medical Imaging Society40 巻   頁: 88-93   2015年3月

     詳細を見る

    記述言語:英語  

    DOI: 10.1016/j.compmedimag.2014.12.004

    PubMed

  17. Transfer characteristics of arterial pulsatile force in regional intracranial tissue using dynamic diffusion MRI: a phantom study. 査読有り

    Kan H, Miyati T, Kasai H, Arai N, Ohno N, Mase M, Shibamoto Y  

    Magnetic resonance imaging32 巻 ( 10 ) 頁: 1284-9   2014年12月

     詳細を見る

    記述言語:英語  

    DOI: 10.1016/j.mri.2014.08.026

    PubMed

  18. Feasibility of time-resolved MR angiography for detecting recanalization of pulmonary arteriovenous malformations treated with embolization with platinum coils. 査読有り

    Kawai T, Shimohira M, Kan H, Hashizume T, Ohta K, Kurosaka K, Muto M, Suzuki K, Shibamoto Y  

    Journal of vascular and interventional radiology : JVIR25 巻 ( 9 ) 頁: 1339-47   2014年9月

     詳細を見る

    記述言語:英語  

    DOI: 10.1016/j.jvir.2014.06.003

    PubMed

  19. A method for assessing metabolic information on liver and bone marrow by use of double gradient-echo with spectral fat suppression. 査読有り

    Kasai H, Miyati T, Kawai T, Kan H, Kawano M, Shibamoto Y  

    Radiological physics and technology7 巻 ( 2 ) 頁: 211-6   2014年7月

     詳細を見る

    記述言語:英語  

    DOI: 10.1007/s12194-013-0254-x

    PubMed

  20. Idiopathic normal-pressure hydrocephalus: temporal changes in ADC during cardiac cycle. 査読有り

    Ohno N, Miyati T, Mase M, Osawa T, Kan H, Kasai H, Hara M, Shibamoto Y, Hayashi N, Gabata T, Matsui O  

    Radiology261 巻 ( 2 ) 頁: 560-5   2011年11月

     詳細を見る

    記述言語:英語  

    DOI: 10.1148/radiol.11101860

    PubMed

  21. [Appropriate cardiac phase for measurement of ADC of the brain using ECG-triggered diffusion MRI]. 査読有り

    Kan H, Miyati T, Mase M, Kasai H, Hara M, Shibamoto Y, Kawano M, Ohno N, Kitanaka A, Yorimitsu R, Minami T  

    Nihon Hoshasen Gijutsu Gakkai zasshi67 巻 ( 6 ) 頁: 661-5   2011年

     詳細を見る

    記述言語:日本語  

    PubMed

  22. [Analyses of restricted diffusion of water molecules using trabecular bone phantom]. 査読有り

    Minami T, Miyati T, Ueda Y, Kan H, Kitanaka A, Kasai H, Arai N, Hara M, Shibamoto Y, Yokoti S  

    Nihon Hoshasen Gijutsu Gakkai zasshi67 巻 ( 6 ) 頁: 634-9   2011年

     詳細を見る

    記述言語:日本語  

    PubMed

▼全件表示

講演・口頭発表等 9

  1. 適応型緩和時間-磁化率変換係数推定を併用した磁化率分離法

    菅 博人,打田 佑人,川口 翔平,植木 美乃

    第80回日本放射線技術学会総会学術大会  2024年4月12日 

     詳細を見る

    開催年月日: 2024年4月

    会議種別:口頭発表(一般)  

  2. 脳白質の常磁性および反磁性磁化率と拡散異方性の関係

    菅 博人,打田 佑人,川口 翔平,植木 美乃

    第80回日本放射線技術学会総会学術大会  2024年4月12日 

     詳細を見る

    開催年月日: 2024年4月

    会議種別:口頭発表(一般)  

  3. Relationship between fractional anisotropy and negative susceptibility from single-orientation magnetic susceptibility separation in white matter 国際会議

    Hirohito Kan, Yuto Uchida, Yoshino Ueki, Harumasa Kasai

    ISMRM 31th Scientific Meeting and Exhibition  2023年 

     詳細を見る

    開催年月日: 2023年

    記述言語:英語   会議種別:ポスター発表  

  4. Non-contrast time-resolved MR angiography with consecutive beam pulse with variable saturation flip angle 国際会議

    Hirohito Kan, Kyosuke Mizuno, Masahiro Takizawa, Masashi Shimohira, Tatsuya Kawai, Toshitaka Aoki, Satoshi Tsubokura, Harumasa Kasai

    ISMRM 30th Scientific Meeting and Exhibition  2022年 

     詳細を見る

    開催年月日: 2022年

    記述言語:英語   会議種別:ポスター発表  

  5. Simultaneous myelin water, magnetic susceptibility, and Morphometry analyses using magnetization-prepared multiple spoiled gradient echo 国際会議

    Hirohito Kan, Yuto Uchida, Yoshino Ueki, Satoshi Tsubokura, Hiroshi Kunitomo, Harumasa Kasai, Noriyuki Matsukawa, Yuta Shibamoto

    ISMRM 29th Scientific Meeting and Exhibition  2021年 

     詳細を見る

    開催年月日: 2021年

    記述言語:英語   会議種別:ポスター発表  

  6. Sensitivity of quantitative susceptibility mapping to temperature: A phantom study 国際会議

    Hirohito Kan Yuto Uchida, Masahiro Takizawa, Toshiaki Miyati, Hiroshi Kunitomo, Nobuyuki Arai, Harumasa Kasai, Yuta Shibamoto

    ISMRM 28th Scientific Meeting and Exhibition  2020年 

     詳細を見る

    開催年月日: 2020年

    記述言語:英語   会議種別:ポスター発表  

  7. Simultaneous voxel-based magnetic susceptibility and morphometry analysis in patients with Alzheimer’s disease 国際会議

    Hirohito Kan, Yuto Uchida, Nobuyuki Arai, Yoshino Ueki, Yoshiyuki Akagawa, Harumasa Kasai, Yasujiro Hirose, Noriyuki Matsukawa, Yuta Shibamoto

    ISMRM 27th Scientific Meeting and Exhibition  2019年 

     詳細を見る

    開催年月日: 2019年

    記述言語:英語   会議種別:ポスター発表  

  8. Simultaneous analyses and reconstruction of quantitative susceptibility mapping and voxel-based morphometry using magnetization-prepared spoiled turbo multiple gradient echo 国際会議

    Hirohito Kan, Nobuyuki Arai, Satoshi Tsubokura, Masato Yamada, Yuta Nishiwaki, Kyosuke Mizuno, Harumasa Kasai Yasujiro Hirose, Yuta Shibamoto

    ISMRM 26th Scientific Meeting and Exhibition  2018年 

     詳細を見る

    開催年月日: 2018年

    記述言語:英語   会議種別:ポスター発表  

  9. Background field removal technique using non-regularized variable kernels sophisticated harmonic artifact reduction for phase data for quantitative susceptibility mapping 国際会議

    Hirohito Kan, Nobuyuki Arai, Masahiro Takizawa, Kazuyoshi Omori, Harumasa Kasai, Yasujiro Hirose, Yuta Shibamoto

    ISMRM 25th Scientific Meeting and Exhibition  2017年 

     詳細を見る

    開催年月日: 2017年

▼全件表示

科研費 6

  1. 多感覚統合異常による慢性めまいに対する認知行動療法の作用機序の解明

    研究課題/研究課題番号:24K00504  2024年4月 - 2028年3月

    科学研究費助成事業  基盤研究(B)

    近藤 真前, 関口 敦, 藤本 千里, 菅 博人

      詳細を見る

    担当区分:研究分担者 

  2. 加齢による脳局所の血液脳関門の機能障害と鉄沈着の関係解明

    研究課題/研究課題番号:23K07107  2023年4月 - 2026年3月

    科学研究費助成事業  基盤研究(C)

    菅 博人

      詳細を見る

    担当区分:研究代表者 

    配分額:4680000円 ( 直接経費:3600000円 、 間接経費:1080000円 )

  3. 安静時fMRIを用いたiNPH診療の新たなイメージングバイオマーカーの探求

    研究課題/研究課題番号:22K09211  2022年4月 - 2025年3月

    科学研究費助成事業  基盤研究(C)

    山田 紘史, 山中 智康, 間瀬 光人, 菅 博人

      詳細を見る

    担当区分:研究分担者 

    iNPHは認知量の5%を占めるとされる。髄液シャント術で症状が改善するが、高齢や他疾患の背景から、治療効果が一定せず、治療を躊躇われる場合も多い。本研究は、安静時機能的MRI(rs-fMRI)を用い、iNPH診療において、①神経症候(高次脳や運動機能)と術前rs-fMRIでの異常な脳内ネットワークとの関係性、②術後改善する神経症候とrs-fMRIでの変化との関係性を評価し、「病態および治療の要となる脳機能ネットワークの異常とは何か」を検証する。iNPH診療における手術による脳機能改善効果を予測する指標として、rs-fMRIが簡易で非侵襲的な新しいイメージングバイオマーカーとなる可能性がある。

  4. MR単独治療計画における定量的磁化率画像を利用した画像誘導放射線治療法の確立

    研究課題/研究課題番号:20K16786  2020年4月 - 2023年3月

    日本学術振興会  科学研究費助成事業  若手研究

    菅 博人

      詳細を見る

    担当区分:研究代表者  資金種別:競争的資金

    配分額:3900000円 ( 直接経費:3000000円 、 間接経費:900000円 )

    前立腺癌のMR単独放射線治療計画における定量的磁化率画像を利用した画像誘導放射線治療法の確立および,前立腺における定量的磁化率画像の再構成法の開発を目的としている.現在,MR単独放射線治療計画には金属マーカーなどの埋め込みが必要とされており,侵襲的である.また前立腺に対する定量的磁化率画像の再構成法はゴールドスタンダードがなく,放射線治療に利用できる画質は得られていない.
    MR単独放射線治療計画の画像誘導放射線治療のために石灰化を描出できる定量的磁化率画像を利用し,従来法と比較してその有用性を明らかにするとともに前立腺における定量的磁化率画像の再構成法の開発を行う.
    本年度は対象となる被検者画像の収集および解析の準備と定量的磁化率画像の再構成法の検討を中心に行った.
    被検者の画像は現在も収集中であるが,おおむね目標数を達成することができ,解析の準備を進めている.具体的には放射線治療計画用CTおよびMR単独放射線治療用のPseudo-CT画像の収集,実際の放射線治療時の画像誘導放射線治療に使用されたコーンビームCTを放射線治療計画装置に取り込みを行った.また放射線治療計画装置に収集されたPseudo-CTとCT画像それぞれに前立腺周囲の主要な臓器をコンツーリングし両画像の撮影タイミングが違うことによって生じる幾何学的位置ずれを非剛体レジストレーションを用いて補正を行った.
    一方,定量的磁化率画像の再構成は信号雑音比の悪い位相画像の位相展開を正確に行うことは非常に難しく,より効果的に行える位相展開の方法についての検討を行っている.それに加えて背景磁場抑制の手法についても現在検討を重ねている.
    さらに定量的磁化率画像と同じデータから再構成可能なR2スター画像やマルチコンポーネントR2スター解析を利用した方法も利用できないか検討を重ねており,石灰化の描出に焦点を当てれば比較的正確に描出可能であることが分かった.
    そのため定量的磁化率画像が作成できるようになったのちはR2スター,マルチコンポーネントR2スター解析から得られた石灰化像のいずれの画像がより今回の目的に適しているか再検討する予定である.
    本年度は対象となる被検者画像の収集および解析の準備と定量的磁化率画像の再構成法の検討を中心に行った.
    被検者の画像収集は現在も収集中であるが,概ね目標の人数に達しており,解析に必要なグラディエントエコー法から得た強度および位相画像,同時に収集されたCT画像はすでに実際の解析を行う放射線治療計画装置内へ取り込み済みである.また被検者の放射線治療時に取得される画像誘導放射線治療用のコーンビームCTも各被検者に対して5~7フラクションを放射線知慮装置から取り込みを開始している.またCT画像とMR単独放射線治療用Pseudo-CT画像の撮像タイミングの違いによる臓器位置のズレを一致させるためにDeformable registrationを行うが,そのためにCT,Pseudo-CT画像上に臓器ごとのコンツーリングを半数程度の患者にて行っている状況である.
    一方,定量的磁化率画像の再構成方法については,CT画像とほぼ同じ高分解能のグラディエントエコー法から得た強度および位相画像から画像処理作成を試みている.定量的磁化率画像の再構成方法に関しては信号雑音比の悪い位相画像の位相展開を正確に行うことが難しく,やや難航している.また同じ画像からR2スター画像,マルチコンポーネントR2スター解析画像を作成であることが分かったためそちらも同時に検討している.以上のように画像作成方法の準備がやや遅れている.
    より正確に石灰化を描出できると予想される定量的磁化率画像のほかにR2スター画像,マルチコンポーネントR2スター解析画像を含めて,描出される石灰化サイズをCT画像と比較し,より正確な画像化を目指す.
    それとともに対象患者のデータをまとめて2022年度後半に石灰化を利用したMR
    MR単独放射線治療における画像誘導放射線治療の有用性の解析を始められるように準備をする.

  5. 肺動静脈奇形に対する塞栓術後の新たな画像診断:造影剤を使用しない非侵襲的血流評価

    研究課題/研究課題番号:20K08002  2020年4月 - 2023年3月

    日本学術振興会  科学研究費助成事業  基盤研究(C)

    下平 政史, 中川 基生, 富田 夏夫, 荒井 信行, 河合 辰哉, 菅 博人, 小澤 良之

      詳細を見る

    担当区分:研究分担者  資金種別:競争的資金

    肺動静脈奇形に対するコイル塞栓術後の再開通は、脳梗塞の原因となるため、その診断は重要である。私たちは、Time resoloved MR angiography (TR-MRA)という正診率の高い新たな診断方法を開発し世界に先駆けて報告した。しかし、これは造影剤を静脈注射する方法であり、有害事象を生じる可能性があった。そこで本研究では、正確に診断できる非造影MRAの撮影方法を樹立し、肺動静脈奇形に対する塞栓術後の非侵襲的な再開通の診断方法を確立する。
    本研究における研究実施計画書を作成し、研究倫理審査委員会の承認を得た。次に、ファントム実験のための脈動ポンプを購入し、初期実験を行った。この結果、脈動ポンプを使用すれば、肺動脈の血流を十分に再現できることが明らかとなった。ファントムの作成に必要な機材も購入済みであり、今後、どのようなファントムが適切であるかを検証し、ファントム作成に取り組む。ファントムが作成されれば、上記の脈動ポンプと組み合わせ、ファントムの本実験を行う。その後、さらに検証を重ね、ファントムを用いたMRAの撮影実験を行い、至適プロトコールを構築していく。次の段階として、コイルをファントム内に留置し、仮想の塞栓後の肺動静脈奇形モデルおよび再開通を生じた肺動静脈奇形モデルを作成し、再発診断への応用の可能性を検討する。
    一方、これまでの経験をもとに非造影MRAのプロトコールを作成・ブラッシュアップし、これまでに3例の肺動静脈奇形の塞栓術前の症例にて撮影を実施した。いずれも問題なく検査を完遂することができた。結果として、造影剤を使用するTime resoloved MR angiography (TR-MRA)との比較では、3例中2例は、非造影MRAの画像はTR-MRAの画像に比し、優位に不良であった。これは、患者の年齢や呼吸状態により息止めが十分に得られず、画質に影響したものと考えられる。一方、残りの1例では、TR-MRAに遜色のない画像が得られた。これにより条件が整えば、非造影でも十分な画像が得られる可能性が示唆された。
    今後はファントム実験を進め、至適プロトコールを探るとともに、臨床にて症例集積し、さらなるデータの集積に努める。
    予定通り、脈動ポンプを購入し、これを使用した初期実験に成功することができた。
    また、臨床でも3例に非造影MRAを安全に施行でき、安全性・実行可能性が示唆された。
    引き続きファントム実験を重ねるとともに、臨床にてデータ集積を続ける。

  6. QSMを利用した新たな温度イメージングの開発

    研究課題/研究課題番号:17K15805  2017年4月 - 2021年3月

    日本学術振興会  科学研究費助成事業  若手研究(B)

    菅 博人

      詳細を見る

    担当区分:研究代表者  資金種別:競争的資金

    配分額:4030000円 ( 直接経費:3100000円 、 間接経費:930000円 )

    本研究では定量的磁化率画像から得られる磁化率値に温度依存性があると仮定した.その関係を調査することで非侵襲的に脳の温度を計測する新手法に発展すると考えてファントムを利用した基礎検討を行った.研究の結果,磁化率値と温度は反比例し,磁化率値が高いほど温度上昇による磁化率の減少量が大きいことも分かった.この結果をもとに,温度を考慮した磁化率値のモデル式を考案することができた.また温度イメージングをするためにはベースラインおよび温度上昇時の2回の計測が必要であることが分かった.
    QSMから得られる磁化率値と温度の関係を明らかにし,その仕組みを明らかにした報告はこれまでになく,学術的意義は高い.同時に磁化率値と同様に脳や肝臓の鉄沈着を評価できるR2スター値と磁化率値の温度による変化量を検討し,QSMはより温度に対して感度が低いことを明らかにした.従来から生体内の鉄沈着のバイオマーカーとして使用されてきR2スター値よりも温度依存性が低いQSMのほうがより正確に鉄沈着の評価できることが示唆された.本研究の結果は異常な鉄代謝を生じる疾患に対する正確な評価を行うためにR2スターではなくQSMを利用することの根拠となり得る.

▼全件表示