Proposal of a differential diagnostic index for recurrent brain metastasis or radiation-induced brain necrosis by radiomics analysis using C-11 methionine PET


Determining Imaging Parameters of a Gradient-echo Technique for Myelin Water Fraction.


The differential diagnosis of recurrent brain metastasis or radiationinduced brain necrosis by radiomics analysis using C-11 methionine positron emission tomography


Quantitative Parameter Mapping of Brain Structure and Components in Parkinsons Disease and Progressive Supranuclear Palsy

RSNA2023 (Radiological Society of North America)


Metabolic Analysis Within an Atherosclerotic Plaque Using Chemical Exchange Saturation Transfer Imaging

The 109th Scientific Assembly and Annual Meeting of the Radiological Society of North America (RSNA2023)


Proposal of a rigid registration method for contrast-enhanced MRI and C-11 methionine PET using iterative closest point and convolutional Neural Network

ISMRM JPC2023, The 8th Annual Scientific Meeting of the ISMRM Japanese Chapter


Imaging biomarker in Prodromal Parkinson's disease using a novel network index of resting state fMRI

29th Annual Meeting of The Organization for Human Brain Mapping,Montréal, Canada


Myelin Water Atlas Template Derived from Quantitative Parameter Mapping


Evaluation of Biological Metabolic Activity within an Atherosclerotic Plaque using Chemical Exchange Saturation Transfer Imaging


Diffusion weighted-viscosity imaging for atherosclerotic plaques


Development of a B1 correction method without additional scanning VFA T1 map.


Evaluation of Blood Flow and Plaque Vulnerability in Carotid Artery Stenosis Focusing on Morphological and Component Characteristics


Evaluation of brain tumor and surrounding tissue activity using multi-pool CEST imaging on 3 Tesla scanner

Joint Annual Meeting ISMRM-ESMRMB & ISMRT 31st Annual Meeting


Development of self-calibrating B1 correction for three-dimensional variable flip angle T1 mapping


Conversion map from quantitative parameter mapping to myelin water fraction


Determination of Alzheimer's disease based on morphology and atrophy using machine learning combined with automated segmentation.


Variable flip angle T1 mapping without acquiring data for B1 correction

Joint International Conference on Radiological Physics and Technology


Determination of white matter structure index for voxel basedmorphometry and connectivity analysis.


Endogenous/exogenous tracers in CEST for pH measurement at 3T MRI


Characterization of Movement Disorders Using Multimodal Neuroimaging


What Is The Extracellular pH Of Brain Tumors And How Can We Detect Brain Tumors Using Gadolinium-based-contrast Agents?

RSNA2021 (Radiological Society of North America)


Is it possible to evaluate morphological carotid artery stenosis information using NASCET criteria?


Radial Correlation and Radial Similarity Contrast Reveal Abnormal Brain Networks in Dystonia

27th Annual Meeting of The Organization for Human Brain Mapping, web conference


Brain Tumor Characterization and Assessment using Automatic Detection of Extracellular pH Change


Derivation of Water Exchange Constants between Components using Quantitative Parameter Mapping (QPM)


Myelin imaging derived quantitative parameter mapping compared to myelin water fraction


Calculation of Concentration of Contrast Media, Relaxivity, Extracellular pH and Oxygen Extraction Fraction for Brain Tumor Characterization


Characterization of Brain Tumors using Amide Proton and Nuclear Overhauser Effect at 3 Tesla MR Scanner


Chemical Exchange Saturation Transfer Imaging for Atherosclerotic Plaques


Multicomponent T1 Relaxometry Analysis using Quantitative Parameter Mapping Magnetic Resonance Imaging


Multi-components analysis of brain using ultrashort echo time magnetic resonance imaging


How does synthetic MRI depict biological information? A step toward planning for deep brain stimulation (DBS)


Simultaneously Calculation of Concentration of Contrast Media, Relaxivity, and Oxygen Extraction Fraction using Quantitative Parameter Mapping

RSNA2019 (Radiological Society of North America)


Calculation of molar relaxivity and concentration map of Gd-DTPA map using quantitative parameter map before and after injection for brain metastasis


Chemical exchange saturation transfer imaging depending on several neurodegenerative diseases at 3T


Myelin imaging derived from quantitative parameter mapping


Why are shear stiffness and estimated intravoxel incoherent motion map correlated in the liver?


Which number of b-value is better for accurate calculation of virtual MR elastography?


Chemical exchange saturation transfer imaging for brain tumors

RSNA2018 (Radiological Society of North America)


Does the amount of signal change depend on calcium concentration in lipid-rich core plaque?


T1 dependency of magnetization transfer effect in human brain


Nuclear Overhauser enhancement effect of low B1 power CEST RF in human brain at 3.0 T


Chemical exchange saturation transfer imaging for neurodegenerative diseases


Which is More Important for Quantitative Susceptibility Mapping? SNR of Phase vs Spin Dephasing.

Radiological Society of North America (RSNA)


Can OSL dosimetry measurement be applied to MR imaging during MR-LINAC treatment?

RSNA2017 (Radiological Society of North America)


Baseline of Chemical Exchange Saturation Transfer Imaging for Brain


Phase Correction for Quantitative Susceptibility Mapping (QSM) using T2* Mapping

The 5th International Congress on Magnetic Resonance Imaging

Objectives : The purpose of this study is to develop a phase correction method focusing on the SNR of phase and to improve the quantitative measurement of QSM. Methods : On a 3.0 T MRI system (Discovery MR750; GE Healthcare), using three-dimensional spoiled gradient-echo (3D-SPGR) sequence with multiple TEs were used in this study. The imaging parameters were TE, 12 echoes from 3.1 to 51.7 ms (ΔTE = 4.4 ms); repetition time, 55.5 ms; spatial resolution, 1.0 × 1.0 × 1.0 mm; and pixel bandwidth, 244.1 Hz. We conducted a phantom experiment in this study. Five tubes were filled with different concentrations (100, 150, 200, 250, and 300 mg/mL) of calcium hydroxyapatite samples. In this study, we focused on the computation of off-set frequency of each voxel (i.e., field map estimation). At first, we calculate the TE having the maximum for our setting number of echo from the measured T2* map. Second, the ``appropriate TE dataset'' was defined as the maximum SNR dataset with appropriate TE and two datasets with neighboring TE. Third, after estimating the field map using the appropriate TE dataset, a corrected phase angle at each phase angle of the appropriate TE dataset was calculated from a mean resultant length which is the length of the average vectors calculated from all phase angles. Then, the corrected phase angle was defined from mean resultant length. Finally, all phase angles in FOV were corrected for each appropriate TE dataset. Results : The linearity of the relationship between the measured susceptibility and the concentration of hydroxyapatite in the corrected phase dataset was significantly higher than other methods (R = 0.30 VS 0.97). Conclusions : The correction method in QSM using phase correction method makes it possible to more accurately obtain susceptibility information of tissue having a short T2*.


T1 dependence of magnetization transfer effect for macromolecules

Purpose: To assess the relationship between T1 and magnetization transfer (MT) effect on macromolecules, we determined T1 map derived from variable flip angle (VFA) method with MT pulse. Materials and Methods: On a 3.0 T magnetic resonance (MR) system, we performed a phantom study using spoiled gradient-echo sequences; TR, 600 ms; TE, 5.8 ms; FA, 5, 20, 40, 60, and 90 degrees; without and with MT pulse (offset frequency, 800 ,1200 , and 1600 Hz). The phantom components were six samples; water and polyethylene glycol (PEG) solutions at different concentrations (10, 20, 30, 40, and 50 wt%). We calculated T1 maps from image datasets without and with MT pulse. Then, the MT ratio (MTR) maps were calculated from each FA image. Results: The mean T1 range without MT pulse for each sample was from 1200 to 2039 ms. The mean T1 ranges with MT pulse of each sample were from 1322 to 1886 at 800 Hz; from 1310 to 1926 ms at 1200 Hz; from 1300 to 1909 ms at 1600 Hz. The MTR of each sample showed the highest value at FA 5 degrees and offset 800 Hz. The mean MTR values of each sample were 6.54 ± 2.78, 3.94 ± 1.92, 2.50 ± 1.67, 1.96 ± 1.33, 1.44 ± 1.15, and 1.78 ± 1.53%. Conclusion: Determination of T1 with MT pulse makes it possible to obtain more detailed information of macromolecules.


An improvement of signal-to-noise ratio for phase image


Proposal of an appropriate echo time-input function for quantitative susceptibility mapping.

International Conference On Medical Physics (ICMP) 2016

Purpose To improve the quantitative assessment for both diamagnetic and paramagnetic materials, we developed a quantitative susceptibility mapping (QSM) method using an appropriate echo time (TE)-input function. Methods On 3.0 T MR system, we performed a phantom experiment using a multi-echo spoiled gradient-echo (12 echos; delta TE = 4.4 ms). The phantom consisted of gadopentetate dimeglumine (Gd-DTPA) and hydroxyapatite samples, which were made using three different concentrations of each material. After a multiple TE dataset was acquired, T2* values were calculated from the dataset. When a field map estimation was computed, the appropriate T2* value was used as TE-input function. Next, phase unwrapping and background removal were performed. Finally, the reconstruction of QSM was performed. Moreover, we compared susceptibility values derived from TE-input function and conventional methods. Results The mean T2* values of each Gd-DTPA and hydroxyapatite sample were 365 ± 74, 194 ± 9, 86 ± 3, 24 ± 2, 14 ± 1, and 11 ± 1 ms, respectively. Compared with the conventional method, the proposed TE-input function method indicated good positive linearity for the relationship between the Gd-DTPA concentration and susceptibility (slope = 0.26 ppm/mmol/L, R2 = 0.97, P = 0.11). Additionally, the proposed TE-input function method indicated good negative linearity for the relationship between the concentration and hydroxyapatite susceptibility (slope = -0.0019 ppm/mg/mL, R2 = 1.00, P = 0.02). Conclusions QSM with the TE-input function makes it possible to evaluate simultaneously diamagnetic and paramagnetic materials. e.g. Gd-DTPA and hydroxyapatite.


How do you Determine the Echo Time When Calculation of Quantitative Susceptibility Mapping (QSM)?

Radiological Society of North America (RSNA) 2016

TEACHING POINTS The purpose of this exhibit is to learn that 1. It is important to know dependence of signal loss due to T2* decay, corresponding to echo time (TE) and susceptibility of biomaterial. 2. Magnetic susceptibility have paramagnetic and diamagnetic characterization, i.e., these indicate positive and negative values, respectively. TABLE OF CONTENTS/OUTLINE -Aims The aim of our study is to investigate the difference in magnetic susceptibility for various TEs. -Method On a 3.0 T MR system, we performed a phantom experiment. The phantom consisted of Gd-DTPA and hydroxyapatite samples which were made using three different concentrations of each. In order to investigate the difference in the magnetic susceptibility of each TE, multiple TEs were acquired and several TE datasets were made. Then, we analyzed with each dataset. -Results The TEs = 3.1, 7.5 and 11.9 ms datasets indicated highest positive linearity for the Gd-DTPA samples (slope = 0.244, R2 = 0.998, P = 0.021). Moreover, the TEs = 3.1, 7.5 and 11.9 ms datasets indicated highest negative linearity for the hydroxyapatite samples (slope = -0.001, R2 = 0.997, P = 0.035). -Conclusion QSM makes it possible to accurately calculation of magnetic susceptibility by using the appropriate TE.


Hybrid assessment of gadopentetic acid and bone structure with ultrashort echo time imaging

Purpose To clarify the phase cycles of Gd-DTPA and calcium carbonate (CaCO3), we evaluated the quantitative susceptibility map (QSM) for dual-ultrashort echo time (UTE) imaging in a phantom experiment. Materials and Methods On a 3.0 T MR system, we performed a phantom study using a three-dimensional dual UTE sequence (TE, 32 µs and 3.2 ms). The phantom components were made from different concentrations of a Gd-DTPA solution (0.1, 0.5, and 1 wt%) and CaCO3 sections. The QSM algorithm was applied to the dual (32 µs and 3.2 ms) and single (32 µs) UTE datasets. We then set the region-of-interest for each material section on QSM images, and measured susceptibility values. Furthermore, linear regression analyses were used to determine the significance between Gd-DTPA concentration and susceptibility for each TE dataset. Results The mean susceptibility value of CaCO3 calculated from the dual UTE showed 1.09 ± 0.35 ppm. Additioally, the mean susceptibility values of 0.1, 0.5, and 1.0 wt% Gd-DTPA calculated from the dual UTE were -0.14 ± 0.03, -0.61 ± 0.02, and -1.24 ± 0.03 ppm. Moreover, there was a negative correlation between Gd-DTPA concentration and susceptibility derived from dual UTE (R2 = 0.9995, P = 0.0141). In contrast, there was no correlation between these values derived from single UTE (R2 = 0.00157, P = 0.9747). Conclusion QSM using dual UTE imaging makes it possible to simultaneously evaluate Gd-DTPA and CaCO3, i.e., bone tumor imaging with contrast-enhanced MRI.


Comparison with statistical analysis of signal correction in diffusion weighted MR image


Noise estimation for diffusion weighted MR image


Basic Considerations for the Development of Gadolinium Contrast Agents with High pH Sensitivity


Development of Extracellular pH Mapping Method using Quantitative Parameter Mapping(QPM)and Gadolinium-based Contrast Agents


転移性脳腫瘍に対する放射線治療後の脳壊死と再発を鑑別する11C-Mthionine PET Radiomicsモデルの開発


第26回日本ヒト脳機能マッピング学会

第26回日本ヒト脳機能マッピング学会


AcidoCEST contrast media exhibiting pH dependence on a 3T clinical MRI system


Proposal of a rigid transformation method for contrast-enhanced MRI and C-11 methionine PET using iterative closest point and convolutional Neural Network


QSMを用いた視床下核の面先・磁化率評価は進行性核上性麻痺の診断に有用である

QSMを用いた視床下核の面先・磁化率評価は進行性核上性麻痺の診断に有用である

第64回日本神経学会学術大会

第64回日本神経学会学術大会


アテローム性動脈硬化症におけるプラーク性状評価のための粘稠度MRI

アテローム性動脈硬化症におけるプラーク性状評価のための粘稠度MRI

第 79 回日本放射線技術学会総会学術大会

第 79 回日本放射線技術学会総会学術大会


安静時fMRIを用いた前駆期パーキンソン病の新しい画像バイオマーカーの提案

安静時fMRIを用いた前駆期パーキンソン病の新しい画像バイオマーカーの提案

第25回日本ヒト脳機能マッピング学会

第25回日本ヒト脳機能マッピング学会


Quantitative parameter mapping of brain tumor extracellular pH for therapeutic efficacy


Development of a neural network based skull stripping algorithm for quantitative parameter mapping both before and after injection of contrast media


EPI-589の筋萎縮性側索硬化症を対象とした探索的医師主導試験(EPIC-ALS)

第63回日本神経学会学術大会

第63回日本神経学会学術大会


Review of Multimodality Imaging in Small Bowel Tumors: a review of old and new techniques

第81回日本医学放射線学会総会

第81回日本医学放射線学会総会


Voxel-to-Voxelコネクトーム解析を用いたパーキンソン病の安静時fMRI

第24回日本ヒト脳機能マッピング学会

第24回日本ヒト脳機能マッピング学会


全身性ジストニアと強迫性障害の重症度についての検討

全身性ジストニアと強迫性障害の重症度についての検討

日本定位・機能神経外科学会機関紙

日本定位・機能神経外科学会機関紙


全身性ジストニアと強迫性障害の重症度についての検討

全身性ジストニアと強迫性障害の重症度についての検討

第61回日本定位・機能神経外科学会

第61回日本定位・機能神経外科学会


肝内胆管癌との鑑別に苦慮した悪性リンパ腫の一例

肝内胆管癌との鑑別に苦慮した悪性リンパ腫の一例

第135回日本医学放射線学会中国・四国地方会

第135回日本医学放射線学会中国・四国地方会


第12回 日本安定同位体 生体ガス医学応用学会

第12回 日本安定同位体 生体ガス医学応用学会


全身性ジストニアの重症度と強迫観念の関係性についての検討

全身性ジストニアの重症度と強迫観念の関係性についての検討

日本脳神経外科学会学術総会

日本脳神経外科学会学術総会


A pilot study of extracellular pH measurement using iopamidol acido-chemical exchange transfer imaging on a 3T MRI


VFA法における多変量正規分布の確率密度関数を用いたB1補正手法の提案

VFA法における多変量正規分布の確率密度関数を用いたB1補正手法の提案

第49回日本磁気共鳴医学会大会

第49回日本磁気共鳴医学会大会


白質領域に対する非剛体処理に伴う数値解析の影響

白質領域に対する非剛体処理に伴う数値解析の影響

第49回日本磁気共鳴医学会大会

第49回日本磁気共鳴医学会大会


Myelin Water Fraction(MWF)におけるT2* cut-off値の検討

第49回日本磁気共鳴医学会大会

第49回日本磁気共鳴医学会大会


蒸し大豆食品の継続摂取が運動不足の健常人の筋量や筋力に及ぼす影響

蒸し大豆食品の継続摂取が運動不足の健常人の筋量や筋力に及ぼす影響

第75回日本栄養・食糧学会大会

第75回日本栄養・食糧学会大会


腫瘍悪性度の定量に向けた造影剤濃度，緩和能，細胞外pHの同時算出手法 の開発

腫瘍悪性度の定量に向けた造影剤濃度，緩和能，細胞外pHの同時算出手法 の開発

日本分子イメージング学会

日本分子イメージング学会


Automatic detection of extracellular pH change in brain tissue using deep learning based semantic segmentation

Japanese Journal of Radiological Technology


第77回日本放射線技術学会総会学術大会

第77回日本放射線技術学会総会学術大会


可変フリップアングル法を用いたT1値算出における線形近似と非線形近似の比較

可変フリップアングル法を用いたT1値算出における線形近似と非線形近似の比較

第77回日本放射線技術学会総会学術大会

第77回日本放射線技術学会総会学術大会


Voxel-to-voxel コネクトーム解析を用いた ジストニアの安静時fMRI

第23回日本ヒト脳機能マッピング学会(WEB開催)

第23回日本ヒト脳機能マッピング学会(WEB開催)


第60回 日本定位・機能神経外科学会

第60回 日本定位・機能神経外科学会


Quantitative Parameter Mapping(QPM) を用いたコンポーネント間スピン交換定数の導出

第48回日本磁気共鳴医学会大会Web開催

第48回日本磁気共鳴医学会大会Web開催


Which contrast agent is more sensitive to extracellular pH change on brain tumor ?


Comparison of functional connectivity using resting state functional MRI in movement disorders.

運動異常症の安静時 fMRIにおける脳機能ネットワークの検討

第48回日本磁気共鳴医学会大会Web開催

第48回日本磁気共鳴医学会大会Web開催


Spatially smoothing processing of quantitative values in voxel-based morphometry (VBM) analysis

第76回日本放射線技術学会総会学術大会WEB開催

第76回日本放射線技術学会総会学術大会WEB開催


Simultaneous Quantitative Calculation of Concentration of Contrast Agent, Relaxivity, and Extracellular pH Map


頸動脈狭窄の定量評価を目的とした4D-flow流体解析

頸動脈狭窄の定量評価を目的とした4D-flow流体解析


Calculation of extracellular pH using quantitative parameter mapping


Comparison of estimation parameters of relaxation rate and susceptibility for myelin content with quantitative parameter mapping

To evaluate myelin content derived from QPM, we compared relaxation rate and susceptibility using simultaneously acquired imaging datasets. The relaxation rate and susceptibility derived from QPM enabled us to simultaneously and specifically evaluate structural changes and brain iron homeostasis.


第75回日本放射線技術学会総会学術大会

第75回日本放射線技術学会総会学術大会


Calculation of molar relaxivity and concentration map of Gd-DTPA map using quantitative parameter map before and after injection for brain metastasis


Comparison of curve fitting models of intravoxel incoherent motion analysis for shear stiffness

第46回日本放射線技術学会秋季学術大会

第46回日本放射線技術学会秋季学術大会

【目的】 拡散強調画像(DWI)から生体の硬さを推定するために，intravoxel incohernet motion(IVIM)手法を用いた3つの曲線解析手法を評価した． 【方法】 1.5テスラMRI装置(GE社製)にて，ファントム実験を行なった．ファントムは，異なる濃度のagar(0.75，1.0，1.5，2.0wt%)をアクリルボックスの中に配列し，1 wt%のagarで満たした．DWIはsingle shot echo planner imagingを用いて，複数のb値(0，20，50，100，200，400，600，800，1000，1200，1500 s/mm2)に設定し撮像した．MR elastography(MRE)はMR touchを用いて，ドライバー周波数120 Hzに設定し撮像した．DWIは，関心領域を各サンプル内に設定し，各b値の信号値を取得した後，mono-exponential, bi-exponential, stretched-exponentialモデルを用いて曲線解析を行い，各種パラメータ(ADC，f，D*，D，DDC，α)を算出した．このとき，MREのせん弾性率とDWIから取得した各種パラメータを比較した． 【結果】 MREから算出した0.75，1.0，1.5，2.0 wt%ファントムのせん弾性率は，6.5，10.6，30.8，40.0 kPaであった．bi-exponentialモデルから算出したD*は，MREのせん弾性率と負の相関を示した(r = 0.57)．stretched-exponentialモデルから算出したα値は，MREのせん弾性率と負の相関を示した(r = 0.80)． 【結論】 stretched exponential モデルを用いた拡散解析は，生体内の組織の硬さを測定するのに有用な手法である．


Quantitative Parameter Mapping(QPM)を用いたミエリン描出能の検討: ポリエチレングリコールを用いた ファントム実験

第46回日本放射線技術学会秋季学術大会

第46回日本放射線技術学会秋季学術大会

【目的】 quantitative parameter mapping(QPM)-MRIは，一度の撮像で定量値マップや任意のコントラスト画像を計算できる手法である．本研究は，myelinと分子量の近いポリエチレングリコール(PEG)と水の含有量の違いによる信号変化を定量するために，QPM-MRIを用いて検討した. 【方法】 3テスラMRI装置(日立社製)にて，3D-partially radio frequency-spoiled steady state gradient-echo法を用いてファントム実験を行った． PEG(平均分子量，420)と水の含有量が異なる水溶液(0-50 wt%)サンプルを配置したファントムを作成した．QPM-MRIの撮像条件は，TE，4.6-22.1 ms(∆TE，3.5 ms);TR，20，40 ms;フリップ角，10，25，35，40 deg.;RF phases，2，5，8，20，22とした．QPMデータセット撮像後，T1，T2*，PDの定量値マップを作成した．定量値画像の各サンプル内に関心領域を設定し，定量値を比較した． 【結果】 PEG溶液(0，10，20，30，40，50 wt%)の測定した定量値は，T1，510 ± 25，342 ± 19，229 ± 13，152 ± 21，130 ± 17，118 ± 14 ms;T2*，338 ± 22，300 ± 22，275 ± 39，214 ± 36，179 ± 23，189 ± 28 ms;PD，218 ± 15，142 ± 6，99 ± 6，84 ± 10，71 ± 4，77 ± 12であった．PEG濃度が高くなるとT1，T2*，PDの減少する傾向を示した． 【結論】 分子量の近いmyelinでも同様の傾向を示すことが予想されるので，水含有量の変化がmyelinの信号変化に影響を及ぼす可能性があることを実験的に示すことができた．QPM-MRIは，加齢や疾患によるmyelin体積減少の評価に応用できる可能性がある．


Evaluating reproducibility and gender differences of cerebral perfusion in healthy volunteers observed by multi-delay post labeling delay time ASL Multi-PLD

ASL法により観察された健常ボランティアにおける脳灌流の再現性と性差の評価

第46回日本磁気共鳴学会大会

第46回日本磁気共鳴学会大会


Determination of the thresholding values for virtual MR elastography


Construction of voxel-based morphometry of R1 and R2* derived from quantitative parameter mapping

第46回日本磁気共鳴医学会大会

第46回日本磁気共鳴医学会大会

The aim of our study is to construct of VBM using relaxation rate derived from QPM magnetic resonance imaging, i.e., novel Synthetic MRI. VBM of relaxation rates derived from QPM enable to made high quality and accuracy region matching for quantitative analysis of hemodynamic in brain.


Chemical exchange saturation transfer imaging for brain tumors

日本分子イメージング学会

日本分子イメージング学会


Virtual MR elastography using IVIM stretched model

Japanese Journal of Radiological Technology


Virtual-magnetic resonance elastography (MRE) using intravoxel incoherent motion (IVIM) stretched model

第129回日本医学放射線学会中国・四国地方会

第129回日本医学放射線学会中国・四国地方会


第45回日本放射線技術学会秋季学術大会

第45回日本放射線技術学会秋季学術大会


lipid-rich-core プラークの物性に着目したマルチコンポーネント解析MRI

第45回日本放射線技術学会秋季学術大会

第45回日本放射線技術学会秋季学術大会


Off-set frequency correction in brain for quantitative susceptibility mapping


定量的磁化率マッピング(QSM)のためのオフセット周波数補正法の提案

定量的磁化率マッピング(QSM)のためのオフセット周波数補正法の提案

Society of Advanced Medical Imaging (SAMI) 2017


Evaluation of Mechanical Waves of MR Elastography

[Purpose] The purpose of our study is to assess the mechanical waves that occur during MR elastography using circular statistical analysis. [Methods] On a 1.5 T MR system, we performed a phantom experiment. The phantom was composed of two blocks of agar at a concentration of 0.75 and 1.0 wt%. All imaging data were acquired using gradient echo (GRE) specialized for MRE. The imaging parameters were TE, 19.4 ms; repetition time, 50 ms; field of view, 420 × 420 mm; slice thickness, 80 mm; bandwidth 32.3 kHz; motion-encoding gradient frequency, 60 Hz; driver amplitude, 70. After acquiring the dataset, MRE images were calculated from a multi scale direct inversion algorithm. Additionally, we measured mean wavelength values of offset phase images obtained during MRE using circular statistical analysis. [Results] Mean shear stiffness values at 0.75 wt% and 1.0 wt% agar concentrations were 1.95 ± 0.35 and 6.45 ± 0.97 kPa, respectively. Mean wavelength values for each agar concentration at three column line profile settings (from left to right side) were 1000 and 1920 mm for the 20th column, 760 and 1880 mm for the 90th column, and 160 and 1960 mm for the 160th column, respectively. [Conclusion] Circular statistical analysis makes it possible to obtain and evaluate more detailed information during MRE.


How to make a phantom for quantitative susceptibility mapping.

第44回日本放射線技術学会秋季学術大会

第44回日本放射線技術学会秋季学術大会


MTパルスを付加したT1値の算出

MTパルスを付加したT1値の算出

第44回日本放射線技術学会秋季学術大会

第44回日本放射線技術学会秋季学術大会


第44回日本放射線技術学会秋季学術大会

第44回日本放射線技術学会秋季学術大会


Noise estimation of phantom phase image in ultra-short echo time imaging

Purpose: To estimate accurately noise of phase rotation, we evaluated a signal phase of ultra-short echo time (UTE) imaging. Materials and Methods: On 3.0T MR system, we performed a phantom experiment using a dual-echo UTE imaging. The imaging parameters were TE, 0.032 ms (first-echo) and 3.3 ms (second-echo); matrix sizes, 256 ×256; slice, 16. The phantom consisted of Gd-DTPA and hydroxyapatite samples, which were made using three different concentrations of each material; Gd-DTPA, 0.5, 1.0, and 2.5 mmol/L; hydroxyapatite, 100, 200, and 350 mg/mL. Then, region of interest analysis was performed on two phase images, e.g., first-echo, and second-echo phase images. Results: The mean first-echo phase values on each Gd-DTPA (0.5, 1.0, and 2.5 mmol/L) and hydroxyapatite (100, 200, and 350 mg/mL) sample were 32.4 ± 0.04, 32.2 ± 0.04, 32.0 ±0.01, 32.4 ± 0.02, 43.6 ± 0.03, and 60.0 ± 0.01 degree, respectively. The mean second-echo phase values on each Gd-DTPA (0.5, 1.0, and 2.5 mmol/L) and hydroxyapatite (100, 200, and 350 mg/mL) sample were 39.1 ± 0.04, 36.0 ± 0.04, 35.5 ± 0.05, 137.9 ± 0.06, 83.4 ± 0.06, and 88.02 ± 0.06 degree, respectively. The mean background phase value first-echo, and second-echo were 33.5 ± 0.11 and 87.1 ± 0.12 degree, respectively. Discussion & Conclusion: The phase rotation of hydroxyapatite occurred difference of phase value in each sample, i.e., this leads good contrast in UTE image. In contrast, the phase rotation of Gd-DTPA at TE 0.032 ms is small enough to estimate noise because the Gd-DTPA phase values were almost equal. Thus, UTE imaging may lead to noise derived from a phase rotation. Noise estimation using UTE imaging may render it possible to obtain more detailed information of paramagnetic materials, e.g., Gd-DTPA.


Dependence on echo time for quantitative susceptibility mapping (QSM) MRI.


Normalization of time-dependent signal change of MRI


Comparison of normalization methods for linearity of MR signal

MR信号の線形評価を目的とした正規化手法の比較

第43回日本放射線技術学会秋季学術大会

第43回日本放射線技術学会秋季学術大会


Comparison with statistical analysis of noise correction in diffusion weighted MR image

拡散強調画像の統計学的信号補正の比較

第43回日本放射線技術学会秋季学術大会

第43回日本放射線技術学会秋季学術大会


Signal correction of diffusion weighted MR imaging with application of the Rician distribution

ライス分布を用いた拡散強調画像の信号補正

第43回日本磁気共鳴医学会大会

第43回日本磁気共鳴医学会大会


Development of quantitative motion analysis portable device for movement disorders

ジストニア・運動異常症のための定量的動作時解析ポータブルデバイズの開発とMRIを用いた統合的評価ワークフレームの開発

公益社団法人 計測自動制御学会 ライフエンジニアリング部門シンポジウム2021

公益社団法人 計測自動制御学会 ライフエンジニアリング部門シンポジウム2021


ロボットスーツHALを用いた脳卒中急性期リハビリテーションの当院での取り組み

ロボットスーツHALを用いた脳卒中急性期リハビリテーションの当院での取り組み

第8回日本脳神経HAL研究会

第8回日本脳神経HAL研究会