研究者詳細 - 田岡　俊昭

論文 - 田岡　俊昭

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Increased Dendritic Orientation Dispersion in the Left Occipital Gyrus is Associated with Atypical Visual Processing in Adults with Autism Spectrum Disorder 査読有り国際誌

Matsuoka, K; Makinodan, M; Kitamura, S; Takahashi, M; Yoshikawa, H; Yasuno, F; Ishida, R; Kishimoto, N; Yasuda, Y; Hashimoto, R; Taoka, T; Miyasaka, T; Kichikawa, K; Kishimoto, T

CEREBRAL CORTEX 30 巻 ( 11 ) 頁： 5617 - 5625 2020年11月

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

In autism spectrum disorder (ASD), the complexity-specific hypothesis explains that atypical visual processing is attributable to selective functional changes in visual pathways. We investigated dendritic microstructures and their associations with functional connectivity (FC). Participants included 28 individuals with ASD and 29 typically developed persons. We explored changes in neurite orientation dispersion and density imaging (NODDI) and brain areas whose FC was significantly correlated with NODDI parameters in the explored regions of interests. Individuals with ASD showed significantly higher orientation dispersion index (ODI) values in the left occipital gyrus (OG) corresponding to the secondary visual cortex (V2). FC values between the left OG and the left middle temporal gyrus (MTG) were significantly negatively correlated with mean ODI values. The mean ODI values in the left OG were significantly positively associated with low registration of the visual quadrants of the Adolescent/Adult Sensory Profile (AASP), resulting in a significant positive correlation with passive behavioral responses of the AASP visual quadrants; additionally, the FC values between the left OG and the left MTG were significantly negatively associated with reciprocal social interaction. Our results suggest that abnormal V2 dendritic arborization is associated with atypical visual processing by altered intermediation in the ventral visual pathway.

DOI： 10.1093/cercor/bhaa121

Neurofluid Dynamics and the Glymphatic System: A Neuroimaging Perspective 国際誌

Taoka, T; Naganawa, S

KOREAN JOURNAL OF RADIOLOGY 21 巻 ( 11 ) 頁： 1199 - 1209 2020年11月

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

The glymphatic system hypothesis is a concept describing the clearance of waste products from the brain. The term “glymphatic system” combines the glial and lymphatic systems and is typically described as follows. The perivascular space functions as a conduit that drains cerebrospinal fluid (CSF) into the brain parenchyma. CSF guided to the perivascular space around the arteries enters the interstitium of brain tissue via aquaporin-4 water channels to clear waste proteins into the perivascular space around the veins before being drained from the brain. In this review, we introduce the glymphatic system hypothesis and its association with fluid dynamics, sleep, and disease. We also discuss imaging methods to evaluate the glymphatic system.

DOI： 10.3348/kjr.2020.0042

Aging Impacts the Overall Connectivity Strength of Regions Critical for Information Transfer Among Brain Networks

Bagarinao, E; Watanabe, H; Maesawa, S; Mori, D; Hara, K; Kawabata, K; Yoneyama, N; Ohdake, R; Imai, K; Masuda, M; Yokoi, T; Ogura, A; Taoka, T; Koyama, S; Tanabe, HC; Katsuno, M; Wakabayashi, T; Kuzuya, M; Hoshiyama, M; Isoda, H; Naganawa, S; Ozaki, N; Sobue, G

FRONTIERS IN AGING NEUROSCIENCE 12 巻頁： 592469 2020年10月

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

Recent studies have demonstrated that connector hubs, regions considered critical for the flow of information across neural systems, are mostly involved in neurodegenerative dementia. Considering that aging can significantly affect the brain’s intrinsic connectivity, identifying aging’s impact on these regions’ overall connection strength is important to differentiate changes associated with healthy aging from neurodegenerative disorders. Using resting state functional magnetic resonance imaging data from a carefully selected cohort of 175 healthy volunteers aging from 21 to 86 years old, we computed an intrinsic connectivity contrast (ICC) metric, which quantifies a region’s overall connectivity strength, for whole brain, short-range, and long-range connections and examined age-related changes of this metric over the adult lifespan. We have identified a limited number of hub regions with ICC values that showed significant negative relationship with age. These include the medial precentral/midcingulate gyri and insula with both their short-range and long-range (and thus whole-brain) ICC values negatively associated with age, and the angular, middle frontal, and posterior cingulate gyri with their long-range ICC values mainly involved. Seed-based connectivity analyses further confirmed that these regions are connector hubs with connectivity profile that strongly overlapped with multiple large-scale brain networks. General cognitive performance was not associated with these hubs’ ICC values. These findings suggest that even healthy aging could negatively impact the efficiency of regions critical for facilitating information transfer among different functional brain networks. The extent of the regions involved, however, was limited.

DOI： 10.3389/fnagi.2020.592469

Change of White Matter Integrity in Children With Hematopoietic Stem Cell Transplantation 国際誌

Sakaguchi, Y; Natsume, J; Kidokoro, H; Tanaka, M; Okai, Y; Ito, Y; Yamamoto, H; Ohno, A; Nakata, T; Nakane, T; Kawai, H; Taoka, T; Muramatsu, H; Naganawa, S; Takahashi, Y

PEDIATRIC NEUROLOGY 111 巻頁： 78 - 84 2020年10月

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

Background: Advances in hematopoietic stem cell transplantation have improved the survival rate of malignant diseases and congenital immunodeficiencies. It has become important to assess long-term complications in survivors. To assess neurological abnormalities in children treated by transplantation, diffusion tensor imaging was performed. Methods: Forty children who underwent head diffusion tensor imaging before and after their first transplantation were enrolled. Patients with brain lesions on conventional MRI were excluded. Fractional anisotropy and mean diffusivity were compared between patients and 28 control subjects using tract-based spatial statistics. The Strengths and Difficulties Questionnaire was administered as a behavioral evaluation after transplantation, and diffusion tensor images of patients with and without behavioral abnormalities were compared. Results: The age of patients and controls was 0 to 19 years and 0 to 16 years, respectively. The date of diffusion tensor imaging was 10 to 57 days before and 40 to 153 days after transplantation. Tract-based spatial statistics showed fractional anisotropy reduction in widespread white matter in patients before and after transplantation. Mean diffusivity was high before transplantation and normalized after transplantation. Analysis comparing before and after hematopoietic stem cell transplantation shows no difference in fractional anisotropy and significantly high mean diffusivity before hematopoietic stem cell transplantation. In patients with behavioral abnormalities, low fractional anisotropy and high mean diffusivity remained after transplantation. Conclusions: Longitudinal diffusion tensor imaging showed white matter abnormalities in children without conventional MRI abnormalities, which were related to behavioral problems after transplantation. Diffusion tensor imaging is useful for behavioral assessment in children undergoing transplantation.

DOI： 10.1016/j.pediatrneurol.2020.06.008

特集時系列から学ぶ中枢神経疾患の画像診断-MR Retroscopy- Ⅳ.脊髄　1 頸髄の変形と異常信号

田岡俊昭

画像診断 40 巻 ( 10 ) 頁： 1100 - 1103 2020年8月

Changes in white matter fiber density and morphology across the adult lifespan: A cross-sectional fixel-based analysis 国際誌

Choy, SW; Bagarinao, E; Watanabe, H; Ho, ETW; Maesawa, S; Mori, D; Hara, K; Kawabata, K; Yoneyama, N; Ohdake, R; Imai, K; Masuda, M; Yokoi, T; Ogura, A; Taoka, T; Koyama, S; Tanabe, HC; Katsuno, M; Wakabayashi, T; Kuzuya, M; Hoshiyama, M; Isoda, H; Naganawa, S; Ozaki, N; Sobue, G

HUMAN BRAIN MAPPING 41 巻 ( 12 ) 頁： 3198 - 3211 2020年8月

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

White matter (WM) fiber bundles change dynamically with age. These changes could be driven by alterations in axonal diameter, axonal density, and myelin content. In this study, we applied a novel fixel-based analysis (FBA) framework to examine these changes throughout the adult lifespan. Using diffusion-weighted images from a cohort of 293 healthy volunteers (89 males/204 females) from ages 21 to 86 years old, we performed FBA to analyze age-related changes in microscopic fiber density (FD) and macroscopic fiber morphology (fiber cross section [FC]). Our results showed significant and widespread age-related alterations in FD and FC across the whole brain. Interestingly, some fiber bundles such as the anterior thalamic radiation, corpus callosum, and superior longitudinal fasciculus only showed significant negative relationship with age in FD values, but not in FC. On the other hand, some segments of the cerebello-thalamo-cortical pathway only showed significant negative relationship with age in FC, but not in FD. Analysis at the tract-level also showed that major fiber tract groups predominantly distributed in the frontal lobe (cingulum, forceps minor) exhibited greater vulnerability to the aging process than the others. Differences in FC and the combined measure of FD and cross section values observed between sexes were mostly driven by differences in brain sizes although male participants tended to exhibit steeper negative linear relationship with age in FD as compared to female participants. Overall, these findings provide further insights into the structural changes the brain's WM undergoes due to the aging process.

DOI： 10.1002/hbm.25008

Steroid-responsive recurrent tumefactive demyelination with multiple petechial hemorrhages along non-displaced medullary veins 査読有り国際誌

Tsuboi, T; Harada, Y; Suzuki, M; Ando, T; Atsuta, N; Ohka, F; Takeuchi, K; Taoka, T; Ohba, S; Nakaguro, M; Abe, M; Nakashima, I; Yoshida, M; Katsuno, M

CLINICAL NEUROLOGY AND NEUROSURGERY 193 巻頁： 105764 - 105764 2020年6月

White matter microstructural changes in tuberous sclerosis: Evaluation by neurite orientation dispersion and density imaging (NODDI) and diffusion tensor images 査読有り国際誌

Taoka, T; Aida, N; Fujii, Y; Ichikawa, K; Kawai, H; Nakane, T; Ito, R; Naganawa, S

SCIENTIFIC REPORTS 10 巻 ( 1 ) 頁： 436 - 436 2020年1月

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

Neurite orientation dispersion and density imaging (NODDI) is a novel diffusion method for evaluating tissue microstructure, and may provide additional information over conventional diffusion tensor imaging (DTI). We evaluated NODDI and DTI parameters in cases of tuberous sclerosis (TS) to assess microstructural changes in the white matter. Eleven cases of tuberous sclerosis and eight age-matched controls underwent NODDI and DTI. We performed qualitative analysis and tract-based spatial statistics (TBSS) analysis of the NODDI parameters (Ficv: intracellular volume fraction, Fiso: isotropic fraction, ODI: orientation dispersion index) as well as DTI parameters (MD: mean diffusivity, FA: fractional anisotropy). We also performed a correlation analysis between clinical symptoms and parameters. The qualitative analysis indicated that the Ficv had a lower value in TS cases particularly in the tubers adjacent to the white matter. The TBSS analysis showed that the TS cases had decreased Ficv in a greater area compared to the other parameters including MD. In particular, the Ficv was decreased in deep white matter, such as the superior longitudinal fascicles (SLF). The application of NODDI to TS cases revealed tissue microstructural changes, and particularly the Ficv could detect more widespread abnormalities in white matter structure compared to DTI parameters.

DOI： 10.1038/s41598-019-57306-w

Glymphatic imaging using MRI 査読有り国際誌

Taoka, T; Naganawa, S

JOURNAL OF MAGNETIC RESONANCE IMAGING 51 巻 ( 1 ) 頁： 11 - 24 2020年1月

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

In recent years, the existence of a mass transport system in the brain via cerebrospinal fluid (CSF) or interstitial fluid (ISF) has been suggested by many studies. The glymphatic system is hypothesized to be a waste clearance system of the CSF through the perivascular and interstitial spaces in the brain. Tracer studies have primarily been used to visualize or evaluate the waste clearance system in the brain, and evidence for this system has accumulated. The initial study that identified the glymphatic system was an in vivo tracer study in mice. In that study, fluorescent tracers were injected into the cisterna magna and visualized by two-photon microscopy. MRI has also been used to evaluate glymphatic function primarily with gadolinium-based contrast agents (GBCAs) as tracers. A number of GBCA studies evaluating glymphatic function have been conducted using either intrathecal or intravenous injections. Stable isotopes, such as 17O-labeled water, may also be used as tracers since they can be detected by MRI. In addition to tracer studies, several other approaches have been used to evaluate ISF dynamics within the brain, including diffusion imaging. Phase contrast evaluation is a powerful method for visualizing flow within the CSF space. In order to evaluate the movement of water within tissue, diffusion-weighted MRI represents another promising technique, and several studies have utilized diffusion techniques for the evaluation of the glymphatic system. This review will discuss the findings of these diffusion studies. Level of Evidence: 5. Technical Efficacy: Stage 3. J. Magn. Reson. Imaging 2019. J. Magn. Reson. Imaging 2020;51:11–24.

DOI： 10.1002/jmri.26892

Comprehensive Evaluation of <i>B</i><sub>1</sub><SUP>+</SUP>-corrected FISP-based Magnetic Resonance Fingerprinting: Accuracy, Repeatability and Reproducibility of T<sub>1</sub> and T<sub>2</sub> Relaxation Times for ISMRM/NIST System Phantom and Volunteers 査読有り

Kato, Y; Ichikawa, K; Okudaira, K; Taoka, T; Kawaguchi, H; Murata, K; Maruyama, K; Koerzdoerfer, G; Pfeuffer, J; Nittka, M; Naganawa, S

MAGNETIC RESONANCE IN MEDICAL SCIENCES 19 巻 ( 3 ) 頁： 168 - 175 2020年

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

Purpose: This study aimed to evaluate comprehensively; accuracy, repeatability and reproducibility of T1 and T2 relaxation times measured by magnetic resonance fingerprinting using B+1-corrected fast imaging with steady-state precession (FISP–MRF). Methods: The International Society of Magnetic Resonance in Medicine/National Institute of Standards and Technology (ISMRM/NIST) phantom was scanned for 100 days, and six healthy volunteers for 5 days using a FISP–MRF prototype sequence. Accuracy was evaluated on the phantom by comparing relaxation times measured by FISP–MRF with the reference values provided by the phantom manufacturer. Daily repeatability was characterized as the coefficient of variation (CV) of the measurements over 100 days for the phantom and over 5 days for volunteers. In addition, the cross-scanner reproducibility was evaluated in volunteers. Results: In the phantom study, T1 and T2 values from FISP–MRF showed a strong linear correlation with the reference values of the phantom (R2 = 0.9963 for T1; R2 = 0.9966 for T2). CVs were <1.0% for T1 values larger than 300 ms, and <3.0% for T2 values across a wide range. In the volunteer study, CVs for both T1 and T2 values were <5.0%, except for one subject. In addition, all T2 values estimated by FISP–MRF in vivo were lower than those measured with conventional mapping sequences reported in previous studies. The cross-scanner variation of T1 and T2 showed good agreement between two different scanners in the volunteers. Conclusion: B+1-corrected FISP-MRF showed an acceptable accuracy, repeatability and reproducibility in the phantom and volunteer studies.

DOI： 10.2463/mrms.mp.2019-0016

The Space between the Pial Sheath and the Cortical Venous Wall May Connect to the Meningeal Lymphatics 査読有り

Naganawa, S; Ito, R; Taoka, T; Yoshida, T; Sone, M

MAGNETIC RESONANCE IN MEDICAL SCIENCES 19 巻 ( 1 ) 頁： 1 - 4 2020年

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 currently obtain pre-and post-contrast enhanced whole brain 3D-real inversion recovery images for the evaluation of endolymphatic hydrops. We noticed that the space between the pial sheath surrounding the cortical veins and the cortical venous wall is enhanced and this enhancement seems to connect to the meningeal lymphatics along superior sagittal sinus. This new anatomical concept regarding the outflow from the glymphatic system might be important for the future research in neuroscience.

DOI： 10.2463/mrms.bc.2019-0099

Detection of IV-gadolinium Leakage from the Cortical Veins into the CSF Using MR Fingerprinting 査読有り

Naganawa, S; Nakane, T; Kawai, H; Taoka, T; Kawaguchi, H; Maruyama, K; Murata, K; Körzdörfer, G; Pfeuffer, J; Nittka, M; Sone, M

MAGNETIC RESONANCE IN MEDICAL SCIENCES 19 巻 ( 2 ) 頁： 141 - 146 2020年

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

Purpose: It has been reported that leakage of intravenously administered gadolinium-based contrast agents (IV-GBCAs) into the cerebrospinal fluid (CSF) from the cortical veins even in healthy subjects can be detected using a highly sensitive pulse sequence such as heavily T2-weighted 3D fluid-attenuated inversion recovery and 3D-real inversion recovery (IR). The purpose of this study was to evaluate the feasibility of MR fingerprinting to detect GBCA leakage from the cortical veins after IV-GBCA. Materials: Fourteen patients with suspected endolymphatic hydrops (EH) who received a single dose of IV-GBCA (39–79 years old) were included. The real IR images as well as MR fingerprinting images were obtained at 4 h after IV-GBCA. T1 and T2 values were obtained using MR fingerprinting and analyzed in ROIs covering intense GBCA leakage, and non-leakage areas of the CSF as determined on real IR images. The scan time for real IR imaging was 10 min and that for MR fingerprinting was 41 s. Results: The mean T1 value of the ROI in the area of GBCA leakage was 2422 ± 261 ms and that in the non-leakage area was 3851 ± 235 ms (P < 0.01). There was no overlap between the T1 values in the area of GBCA leakage and those in the non-leakage area. The mean T2 value in the area of GBCA leakage was 319 ± 90 ms and that in the non-leakage area was 670 ± 166 ms (P < 0.01). There was some overlap between the T2 values in the area of GBCA leakage and those in the non-leakage area. Conclusion: Leaked GBCA from the cortical veins into the surrounding CSF can be detected using MR fingerprinting obtained in <1 min.

DOI： 10.2463/mrms.mp.2019-0048

Confirmation of Age-dependence in the Leakage of Contrast Medium around the Cortical Veins into Cerebrospinal Fluid after Intravenous Administration of Gadolinium-based Contrast Agent 査読有り

Naganawa, S; Ito, R; Kawai, H; Taoka, T; Yoshida, T; Sone, M

MAGNETIC RESONANCE IN MEDICAL SCIENCES 19 巻 ( 4 ) 頁： 375 - 381 2020年

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

Purpose: It has been reported previously that intravenously administered gadolinium-based contrast agent (GBCA) leaks into the subarachnoid space around the cortical veins at 4 h after injection in all old people over 37 years, but not in younger people up to 37 years of age in 3D-real IR images. The purpose of this study was to investigate whether there was a strict threshold of 37 years of age for the leakage of the GBCA into the subarachnoid space. Methods: The subjects included 190 patients, that were scanned for 3D-real IR images at 4 hours after intravenous injection of GBCA as a diagnostic test for endolymphatic hydrops. The patient’s age ranged from 14 to 81 years. Two experienced neuroradiologists evaluated the images to determine whether the GBCA leakage around the cortical veins was positive or negative. Any discrepancies between the two observers were discussed and a consensus was obtained. A Mann–Whitney U test and receiver operating characteristic (ROC) curve analysis were used to compare the positive and the negative group and to set the age cut-off value for the prediction of GBCA leakage. Results: The GBCA leakage around the cortical veins was negative in 35 patients and positive in 155 patients. The average age was 33 ± 11 years in the negative group, and 55 ± 12 years in the positive group (P < 0.01). In the ROC analysis for the age and leakage of the GBCA, an area under the curve was 0.905 and the cut-off age was 37.317 years (sensitivity of 0.942 and specificity of 0.771). Conclusion: Intravenously administered GBCA leaks into the subarachnoid space around the cortical veins in most patients over 37 years of age. However, it should be noted that it can be found occasionally in patients under 37 years of age.

DOI： 10.2463/mrms.mp.2019-0182

Computer-assisted cognitive remediation therapy for patients with schizophrenia induces microstructural changes in cerebellar regions involved in cognitive functions 査読有り国際誌

Matsuoka, K; Morimoto, T; Matsuda, Y; Yasuno, F; Taoka, T; Miyasaka, T; Yoshikawa, H; Takahashi, M; Kitamura, S; Kichikawa, K; Kishimoto, T

PSYCHIATRY RESEARCH-NEUROIMAGING 292 巻頁： 41 - 46 2019年10月

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

Previous studies have reported that cognitive remediation therapy (CRT) improves cognitive deficits in patents with schizophrenia. However, few studies have focused on the underlying structural alterations in the brain following Vocational Cognitive Ability Training by the Japanese Cognitive Rehabilitation Program for Schizophrenia (VCAT-J). In this study, we analyzed changes in diffusion tensor imaging parameters in 31 patients with schizophrenia after 12 weeks of intervention consisting of standard treatment alone or standard treatment plus VCAT-J, in order to determine the effect of the latter on white matter microstructural plasticity. Cognitive function was evaluated using the Japanese version of the Brief Assessment of Cognition in Schizophrenia (BACS-J) scale. The CRT group exhibited significant improvements in verbal fluency and composite BACS-J scores, relative to the treatment-as-usual (TAU) group. In addition, the CRT group exhibited significantly increased fractional anisotropy (FA) values, along with significantly decreased radial (RD) and mean diffusivity (MD) values, in the posterior lobe of the left cerebellum. Changes in RD and MD values were negatively correlated with changes in BACS-J composite scores. These suggest that VCAT-J might mediate improvements in myelin sheath composition in the posterior lobe of the left cerebellum, which may have been associated with improvements in cognitive function.

DOI： 10.1016/j.pscychresns.2019.09.001

Reorganization of brain networks and its association with general cognitive performance over the adult lifespan 査読有り国際誌

Bagarinao, E; Watanabe, H; Maesawa, S; Mori, D; Hara, K; Kawabata, K; Yoneyama, N; Ohdake, R; Imai, K; Masuda, M; Yokoi, T; Ogura, A; Taoka, T; Koyama, S; Tanabe, HC; Katsuno, M; Wakabayashi, T; Kuzuya, M; Ozaki, N; Hoshiyama, M; Isoda, H; Naganawa, S; Sobue, G

SCIENTIFIC REPORTS 9 巻 ( 1 ) 頁： 11352 - 11352 2019年8月

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

Healthy aging is associated with structural and functional changes in the brain even in individuals who are free of neurodegenerative diseases. Using resting state functional magnetic resonance imaging data from a carefully selected cohort of participants, we examined cross sectional changes in the functional organization of several large-scale brain networks over the adult lifespan and its potential association with general cognitive performance. Converging results from multiple analyses at the voxel, node, and network levels showed widespread reorganization of functional brain networks with increasing age. Specifically, the primary processing (visual and sensorimotor) and visuospatial (dorsal attention) networks showed diminished network integrity, while the so-called core neurocognitive (executive control, salience, and default mode) and basal ganglia networks exhibited relatively preserved between-network connections. The visuospatial and precuneus networks also showed significantly more widespread increased connectivity with other networks. Graph analysis suggested that this reorganization progressed towards a more integrated network topology. General cognitive performance, assessed by Addenbrooke’s Cognitive Examination-Revised total score, was positively correlated with between-network connectivity among the core neurocognitive and basal ganglia networks and the integrity of the primary processing and visuospatial networks. Mediation analyses further indicated that the observed association between aging and relative decline in cognitive performance could be mediated by changes in relevant functional connectivity measures. Overall, these findings provided further evidence supporting widespread age-related brain network reorganization and its potential association with general cognitive performance during healthy aging.

DOI： 10.1038/s41598-019-47922-x

Increased signal intensity of low-concentration gadolinium contrast agent by longer repetition time in heavily T<sub>2</sub>-weighted-3D-FLAIR 査読有り

Kato, Y; Bokura, K; Taoka, T; Naganawa, S

JAPANESE JOURNAL OF RADIOLOGY 37 巻 ( 5 ) 頁： 431 - 435 2019年5月

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

Purpose: To apply for detecting low-concentration gadolinium contrast agent (Gd), such as those in the perilymph and cerebrospinal fluid (CSF) at 4 h after intravenous administrations (IV), we tried to clarify the degree of increased signal intensity (SI) of low-concentration Gd by longer repetition time (TR) in heavily T 2 -weighed 3D-FLAIR. Materials and methods: A phantom was designed using Gd diluted with saline at 0.250–0.008 mM and obtained images by varying the TR from 9000 to 16,000. We measured the SI of five slices for each concentration and compared the mean SI (SI mean ) values. Normalized SI (SI norm ) values, defined as the SI mean value of each TR divided by the SI mean value of 9000-ms TR for each concentration were compared. Results: Longer TR increased the SI mean values in all solutions. In the 0.250 mM solution, the SI mean value of 16,000-ms TR was 1.07-times greater than that of 9000-ms TR. In contrast, the SI mean value of 16,000-ms TR was 1.67-times greater than that of 9000-ms TR in 0.008 mM solution. Conclusion: SI increased with longer TR and lower Gd concentration. Thus, longer TR was useful in detecting low-concentration Gd, such as those in the perilymph and CSF at 4 h after IV.

DOI： 10.1007/s11604-019-00828-0

特集症候別画像診断プロトコル病期診断および再発チェック　頸動脈プラークイメージ[MRI]

田岡俊昭

臨床画像 35 巻 ( 13 ) 頁： 120 - 121 2019年4月

特集症候別画像診断プロトコル 3T MRI独特のシーケンス　MRS

田岡俊昭

臨床画像 35 巻 ( 13 ) 頁： 156 - 158 2019年4月

特集症候別画像診断プロトコル 3T MRI独特のシーケンス　拡散テンソル画像

田岡俊昭

臨床画像 35 巻 ( 13 ) 頁： 159 - 161 2019年4月

Can low <i>b</i> value diffusion weighted imaging evaluate the character of cerebrospinal fluid dynamics? 査読有り

Taoka, T; Naganawa, S; Kawai, H; Nakane, T; Murata, K

JAPANESE JOURNAL OF RADIOLOGY 37 巻 ( 2 ) 頁： 135 - 144 2019年2月

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

Purpose: We aimed to investigate whether low b value diffusion-weighted imaging (DWI) can show the change of cerebrospinal fluid (CSF) dynamics. Materials and methods: The subjects of this retrospective study consisted of patients with ventricular dilatation (n = 50) and controls (n = 50). The CSF signal intensity on the b = 500 s/mm 2 DWI was evaluated by a scoring method in the lateral, 3rd and 4th ventricles, the cerebral sulci and the Sylvian fissure. The signal void findings adjacent to the septum pellucidum were also evaluated. Results: The CSF signal intensities were significantly less in lateral ventricle and 3rd ventricle of the ventricular dilatation subjects. In controls, the score for the signal void in the Sylvian fissure showed a significant positive correlation with age. However, other areas did not show a significant correlation with age. The appearance of the characteristic signal void adjacent to the septum pellucidum showed a significant correlation with ventricular dilatation. Conclusion: Our current study suggests that the CSF signal intensity on the b = 500 s/mm 2 DWI may show the changes in CSF dynamics and might be useful to evaluate the overlook of CSF dynamics.

DOI： 10.1007/s11604-018-0790-8

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