Differences of white matter structure for diffusion kurtosis imaging using voxel-based morphometry and connectivity analysis


Conversion Map from Quantitative Parameter Mapping to Myelin Water Fraction: Comparison with R1·R2* and Myelin Water Fraction in White Matter.

Magnetic Resonance Materials in Physics, Biology and Medicine


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

To evaluate the degree of cerebral atrophy for Alzheimer's disease (AD), voxel-based morphometry has been performed with magnetic resonance imaging. Detailed morphological changes in a specific tissue area having the most evidence of atrophy were not considered by the machine-learning technique. To develop a machine-learning system that can capture morphology features for determination of atrophy of brain tissue in early-stage AD and classification of healthy participants or patients. Three-dimensional T1-weighted (3D-T1W) data were obtained from AD Neuroimaging Initiative (200 healthy controls and 200 patients with early-stage AD). Automated segmentation of 3D-T1W data was performed. Deep learning (DL) and support vector machine (SVM) were trained using 66-segmented volume values as input and AD diagnosis as output. DL was performed using 66 volume values or gray matter (GM) and white matter (WM) volume values. SVM learning was performed using 66 volume values and six regions with high variable importance. 3D convolutional neural network (3D-CNN) was trained using the segmented images. Accuracy and area under curve (AUC) were obtained. Variable importance was evaluated from logistic regression analysis. DL for GM and WM volume values, accuracy 0.6; SVM for all volume values, accuracy 0.82 and AUC 0.81; DL for all volume values, accuracy 0.82 and AUC 0.8; 3D-CNN using segmental images of the whole brain, accuracy 0.5 and AUC 0.51. SVM using volume values of six regions, accuracy 0.82; image-based 3D-CNN, highest accuracy 0.69. Our results show that atrophic features are more considerable than morphological features in the early detection of AD.


M1/precuneus ratio as a surrogate marker of upper motor neuron sign in ALS

To investigate whether primary motor cortex (M1) volume measured with an automated approach in MRI reflects upper motor neuron dysfunction and whether it can serve as a potential diagnostic and/or disease-tracking biomarker for amyotrophic lateral sclerosis (ALS). In this retrospective study, we enrolled 95 subjects, including 33 possible or laboratory supported probable ALS, 26 probable or definite ALS (Prob/Def), 2 primary lateral sclerosis patients, 8 progressive muscular atrophy patients, 19 normal controls (NC) and 7 ALS patients having a second structural MRI scan. Some subjects also underwent functional MRI. We calculated M1, primary sensory cortex, precuneus volumes, and total gray matter volume (TGMV) with FreeSurfer. The sensorimotor network (SMN) was identified using independent component analysis. The M1/precuneus ratio showed a significant difference between the NC and Prob/Def groups (p < 0.05). The diagnostic accuracy of the M1/precuneus ratio was moderate for distinguishing Prob/Def from NC (cutoff = 1.00, sensitivity = 0.42, specificity = 0.90). Two of eight cases without upper motor neuron dysfunction could be diagnosed with ALS using M1/precuneus ratio as a surrogate marker. A negative correlation between M1/precuneus ratio and functional activity was found in Brodmann area 6 in the SMN in all subjects. TGMV tended to decrease with disease progression (p = 0.04). The M1/precuneus volume ratio, associated with the SMN, may have potential as a surrogate biomarker of upper motor neuron dysfunction in ALS. Furthermore, TGMV may serve as an ALS disease-tracking biomarker.


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


Obsessivecompulsive symptoms are negatively correlated with motor severity in patients with generalized dystonia

We aimed to clarify the correlations between motor symptoms and obsessive-compulsive symptoms and between the volumes of basal ganglia components and obsessive-compulsive symptoms. We retrospectively included 14 patients with medically intractable, moderate and severe generalized dystonia. The Burke-Fahn-Marsden Dystonia Rating Scale and Maudsley Obsessional Compulsive Inventory were used to evaluate the severity of dystonia and obsessive-compulsive symptoms, respectively. Patients with generalized dystonia were divided into two groups; patients whose Maudsley Obsessional Compulsive Inventory score was lower than 13 (Group 1) and 13 or more (Group 2). Additionally, the total Maudsley Obsessional Compulsive Inventory scores in patients with dystonia were significantly higher than normal volunteers' scores (p = 0.025). Unexpectedly, Group 2 (high Maudsley Obsessional Compulsive Inventory scores) showed milder motor symptoms than Group 1 (low Maudsley Obsessional Compulsive Inventory scores) (p = 0.016). "Checking" rituals had a strong and significant negative correlation with the Burke-Fahn-Marsden Dystonia Rating Scale (ϱ = - 0.71, p = 0.024) and a strong positive correlation with the volumes of both sides of the nucleus accumbens (right: ϱ = 0.72, p = 0.023; left: ϱ = 0.70, p = 0.034). Our results may provide insights into the pathogenesis of obsessive-compulsive disorder and dystonia.


Myelin-weighted imaging derived from quantitative parameter mapping

We developed a novel method which is applicable to visualize contrast according to myelin components in the human brain using relaxation time derived from quantitative parameter mapping magnetic resonance imaging (QPM-MRI). Using healthy volunteer data (n = 10), we verified that our method demonstrated that the myelin-weighted contrast increased proportionally by products R and R*, i.e., QPM-myelin-weighted image, in which modified T-weighted/T-weighted (Tw/Tw) ratio mapping method was applied. We compared measurement values in white matter (WM) and gray matter (GM) regions of the Tw/Tw ratio and R·R* product maps of healthy volunteers. Linear regression analysis between each value. Mann Whitney U test between WM and GM signals in each myelin map. In addition, Additionally, QPM-myelin-weighted image was applied to a 32-year-old female MS patient. Linear regression analysis showed a highly significant correlation between conventional Tw/Tw ratios and R·R* products derived from QPM (R = 0.73, P < 0.0001). Moreover, there is a significant difference between WM and GM structures in each myelin images (both, P < 0.0001). Additionally, in a clinical case, MS lesions enabled observation of not only MS plaques but also heterogeneous myelin signal loss associated with demyelination more clearly than Tw image and conventional Tw/Tw ratio image. Our myelin-weighted imaging technique using QPM may be useful for myelin visualization and is expected to become independent of measurement conditions due to having quantitative characteristics of QPM itself.


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


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


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


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.


Quantitative parameter mapping of contrast agent concentration and relaxivity and brain tumor extracellular pH

In clinical magnetic resonance imaging, gadolinium-based contrast agents are commonly usedfor detecting brain tumors and evaluating the extent of malignancy. We present a new method toevaluate relaxivity (r1) and contrast agent concentration separately in contrast-enhanced lesions usingquantitative parameter mapping (QPM). Furthermore, we also aimed to estimate the extracellularpH (pHe) of tumor lesions. We demonstrated that it is possible to evaluate pathophysiological tumorchanges due to therapeutic efficacy by measuring r1 in contrast-enhanced lesions. In this study, theprimary brain tumor group showed significantly higher r1 values than other brain disease groups(P< 0.001). Moreover, mean pHe value showed a trend for tumor malignancy having a lower pHevalue and primary brain tumor having a significantly lower pHe than other brain diseases (P< 0.001).Our results might suggest that QPM can separately quantify r1 and CA concentration in brain tumorsand that pHe brain tumor mapping could serve as a tumor biomarker. In conclusion, our method haspotential clinical applications for assessing the treatment effects.


Daily Dietary Supplementation with Steamed Soybean Improves Muscle Volume and Strength in Healthy People Lacking Exercise.

Various dietary protein supplements are used by the elderly and bedridden to maintain their skeletal muscle mass and functions. High-quality proteins act as an anabolic driver and help to improve muscle strength and performance. Previously, we reported that soy protein significantly attenuates denervation-induced loss of muscle mass and myofiber cross sectional area in mice with inhibition of ubiquitination and degradation of IRS-1 in tibialis anterior muscle. It also increased muscle volume and strength in bedridden patients. In the present study, we investigated the effects of dietary soybean supplementation on muscle functions in taxi drivers lacking vigorous physical exercise. We conducted a case-control study on 25 healthy, male taxi drivers between the ages of 36 and 71 y performing minimal physical exercise. They were divided into two dietary groups: the soybean diet group (n=13) who ate daily meals (dinner) supplemented with 50 g of steamed soybean for 30 d and the control diet group (n=12) who received no soybean supplement. Next, we measured the muscle cross-sectional area (CSA) and muscle strength and function in both the groups before and after 30 d of soybean intake. The body weights of both diet groups did not differ significantly over time. However, after 30 d of soybean supplementation, the soybean-fed group developed significantly higher muscle CSA and grip strength compared to the control groups. In conclusion, dietary soybean supplementation improved muscle function in taxi drivers who lacked exercise.

Journal of Nutritional Science and Vitaminology


MR spectroscopy and imaging-derived measurements in the supplementary motor area for biomarkers of amyotrophic lateral sclerosis


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


Myelin imaging derived quantitative parameter mapping compared to myelin water fraction


Can Pallidal Deep Brain Stimulation Rescue Borderline Dystonia? Possible Coexistence of Functional (Psychogenic) and Organic Components.

The diagnosis and treatment of functional movement disorders are challenging for clinicians who manage patients with movement disorders. The borderline between functional and organic dystonia is often ambiguous. Patients with functional dystonia are poor responders to pallidal deep brain stimulation (DBS) and are not good candidates for DBS surgery. Thus, if patients with medically refractory dystonia have functional features, they are usually left untreated with DBS surgery. In order to investigate the outcome of functional dystonia in response to pallidal DBS surgery, we retrospectively included five patients with this condition. Their dystonia was diagnosed as organic by dystonia specialists and also as functional according to the Fahn and Williams criteria or the Gupta and Lang Proposed Revisions. Microelectrode recordings in the globus pallidus internus of all patients showed a cell-firing pattern of bursting with interburst intervals, which is considered typical of organic dystonia. Although their clinical course after DBS surgery was incongruent to organic dystonia, the outcome was good. Our results question the possibility to clearly differentiate functional dystonia from organic dystonia. We hypothesized that functional dystonia can coexist with organic dystonia, and that medically intractable dystonia with combined functional and organic features can be successfully treated by DBS surgery.


Reproducibility and Variability of Quantitative Cerebral Blood Flow Measured by Multi-delay 3D Arterial Spin Labeling According to Sex and Menstrual Cycle

Purpose : To determine the reproducibility of corrected quantitative cerebral blood flow (qCBF) through measurement of transit flow time using multi-delay three-dimensional pseudo-continuous arterial spin labeling (pCASL) in healthy men and women and to evaluate the differences in qCBF between not only men and women, but also the follicular and luteal phases of the women's menstrual cycle. Methods : The participants were 16 healthy volunteers (8 men and 8 women ; mean age, 25.3 years). Two MRI were conducted for all participants ; female participants were conducted in the follicular and luteal phases. The reproducibility of qCBF values was evaluated by the intraclass correlation coefficient (ICC) and differences between the two groups were estimated by voxel-based morphometry (VBM) analysis. Results : The qCBF values were lower in men than in women, and those in females were significantly different between the follicular and luteal phases (P < 0.05). In VBM analysis, the qCBF values of the lower frontal lobes were significantly higher in women than in men (P < 0.05). The qCBF values of the frontal pole were significantly higher in the follicular phase than in the luteal phase (P < 0.01). Conclusion : Multi-delay pCASL can reveal physiological and sex differences in cerebral perfusion. J. Med. Invest. 67 : 321-327, August, 2020.

The Journal of Medical Investigation : JMI


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

Proceedings of the 28th Virtual Conference of ISMRM


Chemical Exchange Saturation Transfer Imaging for Atherosclerotic Plaques

Proceedings of 28th Virtual Meeting of ISMRM


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


Multicomponent T1 Relaxometry Analysis using Quantitative Parameter Mapping Magnetic Resonance Imaging


Multi-delay arterial spin labeling brain magnetic resonance imaging study for pediatric autism.

Arterial spin labeling (ASL) is a non-invasive magnetic resonance imaging (MRI) technique that can measure regional cerebral blood flow (rCBF) without radiation exposure. This study aimed to evaluate rCBF in individuals with autism and their age-matched controls, globally and regionally.

We concluded that patients with ASD showed a statistically significant decline in CBF in regions associated with the mirror neuron system. The advantages of ASL MRI include low invasiveness (no radiation exposure) and short imaging time (approximately 5 min). Studies with larger sample sizes are required to establish the diagnostic value of ASL MRI for ASD.


Proceedings of the 27th Annual Meeting of ISMRM


Myelin imaging derived from quantitative parameter mapping


Appropriate echo time selection for quantitative susceptibility mapping.

The purpose of our study was to clarify the dependence of quantitative susceptibility mapping (QSM) on echo time (TE). We constructed a phantom consisting of six tubes; three tubes were filled with different concentrations (0.5, 1.0, and 2.5 mM) of gadopentetate dimeglumine (Gd-DTPA), and three were filled with different concentrations (100, 200, and 350 mg/mL) of calcium hydroxyapatite. Real and imaginary images from multi-echo spoiled gradient-echo data (12 echoes) were acquired. We then used four datasets with three serial echoes. The QSM procedure consists of four steps: field map estimation, phase unwrapping, background removal, and dipole inversion. For each sample, we compared the measured mean susceptibility value with the theoretical susceptibility value and conducted a linear regression analysis. Accordingly, the relationship between the measured susceptibility and concentration of Gd-DTPA was shown to agree well with the theoretical values (TEs = 16.4, 20.8, and 25.2 ms; slope = 0.24, R = 1.00). Furthermore, the relationship between the measured susceptibility and concentration of hydroxyapatite also showed good linearity (TEs = 16.4, 20.8, and 25.2 ms; slope = - 0.00121, R = 1.00). In conclusion, the optimization of the TE in QSM makes it possible to obtain more detailed information regarding the susceptibility of biomaterials.


Activation of mirror neuron system during gait observation in sub-acute stroke patients and healthy persons.

The observation of walking improves gait ability in chronic stroke survivors. It has also been suggested that activation of the mirror neuron system contributes to this effect. However, activation of the mirror neuron system during gait observation has not yet been assessed in sub-acute stroke patients. The objective of this study was to clarify the activation of mirror neuron system during gait observation in sub-acute stroke patients and healthy persons. In this study, we sequentially enrolled five sub-acute stroke patients who had undergone gait training and nine healthy persons. We used fMRI to detect neuronal activation during gait observation. During the observation period in the stroke group, neural activity in the left inferior parietal lobule, right and left inferior frontal gyrus was significantly higher than during the rest period. In the healthy group, neural activity in the left inferior parietal lobule, left inferior frontal gyrus, left middle frontal gyrus, left superior temporal lobule and right and left middle temporal gyrus was significantly higher than during the rest period. The results indicate that the mirror neuron system was activated during gait observation in sub-acute stroke patients who had undergone gait training and also in healthy persons. Our findings suggest that gait observation treatment may provide a promising therapeutic strategy in sub-acute stroke patients who have experienced gait training.


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

Proceedings of the 26th Annual Meeting of ISMRM


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


Development of correction for signal-to-noise ratio using a T2* with improved Phase method

This study aims to improve the signal-to-noise ratio (SNR) of the phase image focusing T2 and to develop an improved phase (iPhase) image acquired high SNR. The iPhase images of phantom and brain were acquired with multi-echo spoiled gradient-echo. The phantom component was a gadopentetate dimeglumine (Gd-DTPA) solution made of different concentrations (0.1, 0.5, and 1 wt%) and Gd-DTPA (0.1, 0.5, and 1 wt%) with agar (1.0 wt%). We applied the iPhase image to susceptibility weighed image (SWI) and evaluated SNR of SWI. In phantom study, SNRs of conventional SWI at each sample were 19.8, 15.7, 7.4, 20.0, 17.4, and 27.3, respectively. Signal-to-noise ratios of SWI derived from iPhase method were 29.5, 33.7, 21.7, 28.5, 24.3, and 14.7, respectively. Then, the SNR showed an improvement of 196% at maximum (for the Gd-DTPA 1 wt% sample). In healthy volunteer study, SWI derived from iPhase method had the good contrast between white matter and gray matter. The iPhase image was able to improve the phase SNR. Moreover, iPhase method makes it possible to obtain a high SNR image when applying to SWI.


Baseline of Chemical Exchange Saturation Transfer Imaging for Brain

Proceedings of the 25th Annual Meeting of ISMRM


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


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.


Simple noise reduction for diffusion weighted images

Our purpose in this study was to reduce the noise in order to improve the SNR of Dw images with high b-value by using two correction schemes. This study was performed with use of phantoms made from water and sucrose at different concentrations, which were 10, 30, and 50 weight percent (wt%). In noise reduction for Dw imaging of the phantoms, we compared two correction schemes that are based on the Rician distribution and the Gaussian distribution. The highest error values for each concentration with use of the Rician distribution scheme were 7.3 % for 10 wt%, 2.4 % for 30 wt%, and 0.1 % for 50 wt%. The highest error values for each concentration with use of the Gaussian distribution scheme were 20.3 % for 10 wt%, 11.6 % for 30 wt%, and 3.4 % for 50 wt%. In Dw imaging, the noise reduction makes it possible to apply the correction scheme of Rician distribution.


Simple improvement method of uniformity of MR elastography on liver

Proceedings of the 24th Annual Meeting of ISMRM


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


Noise estimation for diffusion weighted MR image


Characterization of Movement Disorders Using Multimodal Neuroimaging


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


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

Proceedings of the 2022 ISMRM & SMRT ANNUAL MEETING & EXHIBITION, No.3783, 2022


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

Proceedings of the 2021 ISMRM & SMRT ANNUAL MEETING & EXHIBITION


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

Proceedings of the 28th Annual Meeting of ISMRM


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

Proceedings of the 27th Annual Meeting of ISMRM


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


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


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


Chemical exchange saturation transfer imaging for neurodegenerative diseases

Proceedings of the 26th Annual Meeting of ISMRM