Accelerated Resting-State Functional Magnetic Resonance Imaging Using Multiband Echo-Planar Imaging with Controlled Aliasing

PURPOSE: To report the use of multiband accelerated echo-planar imaging (EPI) for resting-state functional MRI (rs-fMRI) to achieve rapid high temporal resolution at 3T compared to conventional EPI. MATERIALS AND METHODS: rs-fMRI data were acquired from 20 healthy right-handed volunteers by using three methods: conventional single-band gradient-echo EPI acquisition (Data 1), multiband gradient-echo EPI acquisition with 240 volumes (Data 2) and 480 volumes (Data 3). Temporal signal-to-noise ratio (tSNR) maps were obtained by dividing the mean of the time course of each voxel by its temporal standard deviation. The resting-state sensorimotor network (SMN) and default mode network (DMN) were estimated using independent component analysis (ICA) and a seed-based method. One-way analysis of variance (ANOVA) was performed between the tSNR map, SMN, and DMN from the three data sets for between-group analysis. P < 0.05 with a family-wise error (FWE) correction for multiple comparisons was considered statistically significant. RESULTS: One-way ANOVA and post-hoc two-sample t-tests showed that the tSNR was higher in Data 1 than Data 2 and 3 in white matter structures such as the striatum and medial and superior longitudinal fasciculus. One-way ANOVA revealed no differences in SMN or DMN across the three data sets. CONCLUSION: Within the adapted metrics estimated under specific imaging conditions employed in this study, multiband accelerated EPI, which substantially reduced scan times, provides the same quality image of functional connectivity as rs-fMRI by using conventional EPI at 3T. Under employed imaging conditions, this technique shows strong potential for clinical acceptance and translation of rs-fMRI protocols with potential advantages in spatial and/or temporal resolution. However, further study is warranted to evaluate whether the current findings can be generalized in diverse settings.

Resting-state Network of Brain in Leukoaraiosis Patients: A Magnetic Resonance Imaging Study / 中国康复理论与实践

@#Objective To explore the diversity of resting-state network of brain between the patients with leukoaraiosis and the healthy people. Methods 31 patients with leukoaraiosis (patients) and 27 healthy persons (controls) were checked with resting-state functional magnetic resonance imaging (rs-fMRI), and analyzed with the independent component analysis (ICA) to explore the resting-state functional brain network. Results The resting-state brain network was found in both the patients and the controls, which was coincident with the previous studies. The active areas were the same in both groups, and the activation was weaken in the patients than in the controls, especially in quadrate gyri, posterior cingulate cortex, superior temporal gyrus, superior parietal gyrus, anterior central gyrus, post central gyrus, insula and prefrontal cortex. Conclusion There is a significant diversity of resting-state network of brain between the patients with leukoaraiosis and healthy people in the activation of active areas.

Resting-state Network of Brain in Leukoaraiosis Patients:A Magnetic Resonance Imaging Study / 中国康复理论与实践

Objective To explore the diversity of resting-state network of brain between the patients with leukoaraiosis and the healthy people. Methods 31 patients with leukoaraiosis (patients) and 27 healthy persons (controls) were checked with resting-state functional mag-netic resonance imaging (rs-fMRI), and analyzed with the independent component analysis (ICA) to explore the resting-state functional brain network. Results The resting-state brain network was found in both the patients and the controls, which was coincident with the previ-ous studies. The active areas were the same in both groups, and the activation was weaken in the patients than in the controls, especially in quadrate gyri, posterior cingulate cortex, superior temporal gyrus, superior parietal gyrus, anterior central gyrus, post central gyrus, insula and prefrontal cortex. Conclusion There is a significant diversity of resting-state network of brain between the patients with leukoaraiosis and healthy people in the activation of active areas.

MRI Study on the Functional and Spatial Consistency of Resting State-Related Independent Components of the Brain Network

OBJECTIVE: Resting-state networks (RSNs), including the default mode network (DMN), have been considered as markers of brain status such as consciousness, developmental change, and treatment effects. The consistency of functional connectivity among RSNs has not been fully explored, especially among resting-state-related independent components (RSICs). MATERIALS AND METHODS: This resting-state fMRI study addressed the consistency of functional connectivity among RSICs as well as their spatial consistency between 'at day 1' and 'after 4 weeks' in 13 healthy volunteers. RESULTS: We found that most RSICs, especially the DMN, are reproducible across time, whereas some RSICs were variable in either their spatial characteristics or their functional connectivity. Relatively low spatial consistency was found in the basal ganglia, a parietal region of left frontoparietal network, and the supplementary motor area. The functional connectivity between two independent components, the bilateral angular/supramarginal gyri/intraparietal lobule and bilateral middle temporal/occipital gyri, was decreased across time regardless of the correlation analysis method employed, (Pearson's or partial correlation). CONCLUSION: RSICs showing variable consistency are different between spatial characteristics and functional connectivity. To understand the brain as a dynamic network, we recommend further investigation of both changes in the activation of specific regions and the modulation of functional connectivity in the brain network.