Ultrafast functional magnetic resonance imaging (fMRI) can measure blood oxygen level dependent (BOLD) signals with high sensitivity and specificity. Here we propose a novel method: simultaneous multi-slice inverse imaging (SMS-InI) - a combination of simultaneous multi-slice excitation, simultaneous echo refocusing (SER), blipped controlled aliasing in parallel imaging echo-planar imaging (EPI), and regularized image reconstruction. Using a 32-channel head coil array on a 3 T scanner, SMS-InI achieves nominal isotropic 5-mm spatial resolution and 10 Hz sampling rate at the whole-brain level. Compared with traditional inverse imaging, we found that SMS-InI has higher spatial resolution with lower signal leakage and higher time-domain signal-to-noise ratio with the optimized regularization parameter in the reconstruction. SMS-InI achieved higher effective resolution and higher detection power in detecting visual cortex activity than InI. SMS-InI also detected subcortical fMRI signals with the similar sensitivity and localization accuracy like EPI. The spatiotemporal resolution of SMS-InI was used to reveal that presenting visual stimuli with 0.2 s latency between left and right visual hemifield led to 0.2 s relative hemodynamic response latency between the left and right visual cortices. Together, these results indicate that SMS-InI is a useful tool in measuring cortical and subcortical hemodynamic responses with high spatiotemporal resolution.
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http://dx.doi.org/10.1038/s41598-017-16976-0 | DOI Listing |
Tomography
January 2025
NextGen Precision Health, Department of Radiology, University of Missouri Columbia, 1030 Hitt Street, Columbia, MO 65201, USA.
: The increased SNR available at 7T combined with fast readout trajectories enables accelerated spectroscopic imaging acquisitions for clinical applications. In this report, we evaluate the performance of a Hadamard slice encoding strategy with a 2D rosette trajectory for multi-slice fast spectroscopic imaging at 7T. : Moderate-TE (~40 ms) spin echo and J-refocused polarization transfer sequences were acquired with simultaneous Hadamard multi-slice excitations and rosette in-plane encoding.
View Article and Find Full Text PDFMagn Reson Imaging
January 2025
Functional and Molecular Imaging Key Laboratory of Sichuan Province, West China Hospital of Sichuan University, No.37 Guo Xue Alley, Chengdu, Sichuan 610041, China. Electronic address:
Microstructural parameters are essential in tumor research, aiding in the understanding tumor pathogenesis, grading, and therapeutic efficacy. The imaging microstructural parameters using limited spectrally edited diffusion (IMPULSED) model is the most widely used MR cell size imaging technique, demonstrating success in measuring microstructural parameters of solid tumors in vivo. However, its clinical application is limited by the longer scan times required for both pulsed gradient spin-echo (PGSE) and multiple oscillating gradient spin-echo (OGSE) acquisitions across a range of b-values, which can be burdensome for patients and disrupt clinical workflows.
View Article and Find Full Text PDFDentomaxillofac Radiol
January 2025
Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China.
Objectives: To compare integrated slice-specific dynamic shimming (iShim) and simultaneous multi-slice (SMS) readout-segmented echo-planar imaging (RESOLVE) for diffusion-weighted imaging (DWI) of malignant head and neck tumours.
Methods: In this prospective study, 45 patients with malignant head and neck lesions underwent iShim- and SMS-RESOLVE imaging with two b-values (0, 800 s/mm2) at 3 T. Subjective image quality scores (lesion distortion, signal loss, fat saturation, and artefacts), quantitative lesion distortion, quantitative image quality [signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and SNR efficiency], ADC values, and total acquisition times of iShim- and SMS-RESOLVE imaging were evaluated and compared.
J Magn Reson Imaging
December 2024
Utah Center for Advanced Imaging Research (UCAIR), Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, Utah, USA.
Background: Modified Look-Locker imaging (MOLLI) T1 mapping sequences are acquired during breath-holding and require ECG gating with consistent R-R intervals, which is problematic for patients with atrial fibrillation (AF). Consequently, there is a need for a free-breathing and ungated framework for cardiac T1 mapping.
Purpose: To develop and evaluate a free-breathing ungated radial simultaneous multi-slice (SMS) cardiac T1 mapping (FURST) framework.
Cureus
November 2024
Department of Joint Research in Advanced Medicine for Electromagnetic Engineering, Shimane University, Izumo, JPN.
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