Background: Ultrahigh-field MRI at 8 T offers unprecedented resolution for imaging brain structures and microvasculature.
Objective: The aim of this study is to apply high-resolution MRI for stroke imaging and to characterize findings at 1.5 and 8 T.
Methods: Seventeen subjects with minor ischemic infarcts were studied using T2-weighted gradient echo (GE) and rapid acquisition with relaxation enhancement (RARE) images at 8 T with resolution up to 200 microm. In 10 subjects, T1- and T2-weighted fast spin echo (FSE) and fluid-attenuated inversion recovery (FLAIR) images were also acquired at 1.5-T MRI.
Results: The 8-T images showed infarcts as sharply demarcated areas of high-signal intensity (n=21) and revealed more infarctions than 1.5-T images (n=14) (P<.003). The low-signal intensity areas that surrounded infarctions were suggestive of hemosiderin deposits. The 8-T characteristics of microvessels terminating within the infractions were distinct from normal vasculature. The 8-T images revealed an angioma at the site of a second stroke, not apparent on 1.5-T images.
Conclusions: Ultrahigh-field MRI at 8 T is feasible for stroke imaging. The 8-T MRI visualized infarcts and microvasculature with high resolution, revealing infarcts and vascular pathologies that were not apparent at 1.5 T.
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http://dx.doi.org/10.1016/j.mri.2005.02.010 | DOI Listing |
Bioengineering (Basel)
January 2025
Division of Ultrahigh Field MRI, Iwate Medical University, 1-1-1 Idaidori, Yahaba 028-3694, Japan.
The neuropathological diagnosis of Alzheimer's disease (AD) relies on amyloid beta (Aβ) deposition in brain tissues. To study the relationship between Aβ deposition and brain structure, as determined using C-Pittsburgh compound B (PiB) and magnetic resonance imaging (MRI), respectively, we developed a regression model with PiB and MRI data as the predictor and response variables, respectively, and proposed a regression method for studying the association between them based on a supervised sparse multivariate analysis with dimension reduction based on a composite paired basis function. By applying this method to imaging data of 61 patients with AD (age: 55-85), the first component showed the strongest correlation with the composite score, owing to the supervised feature.
View Article and Find Full Text PDFQuant Imaging Med Surg
January 2025
School of Medicine, Nankai University, Tianjin, China.
Background: It is well known that dysfunction of thalamocortical circuity generates the motor signs that lead to distinct disease processes and prognoses in Parkinson's disease (PD). This study aimed to leverage ultrahigh-field magnetic resonance imaging (MRI) to identify the connectivity alterations of thalamocortical circuity and clarify their relation to motor signs in early PD.
Methods: Patients with early-stage PD (n=55) and healthy controls (HCs, n=56) were recruited from March 2022 to July 2023.
Proc IEEE Int Symp Biomed Imaging
May 2024
Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, United States.
Parallel transmission (pTx) is an important technique for reducing transmit field inhomogeneities at ultrahigh-field (UHF) MRI. pTx typically involves solving an optimization problem for radiofrequency pulse design, with hard constraints on specific-absorption rate (SAR) and/or power, which may be time-consuming. In this work, we propose a novel approach towards incorporating hard constraints to physics-driven neural networks.
View Article and Find Full Text PDFJ Neurosurg
January 2025
19Division of Medical Statistics, Division of Data Science, Foundation for Biomedical Research and Innovation at Kobe; and.
Objective: Studies have demonstrated the effectiveness of hydrogel-coated coils (HGCs) to achieve the composite endpoint of decreased recanalization rates and greater safety. Herein, the authors aimed to assess the true ability of second-generation HGCs to prevent recanalization.
Methods: This randomized controlled study, the HYBRID (Hydrocoil Versus Bare Platinum Coil in Recanalization Imaging Data) trial, comparing HGCs with bare platinum coils (BPCs), was conducted in 43 Japanese institutions.
Magn Reson Med
December 2024
Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, Massachusetts, USA.
Purpose: Proton magnetic resonance spectroscopic imaging ( -MRSI) provides noninvasive spectral-spatial mapping of metabolism. However, long-standing problems in whole-brain -MRSI are spectral overlap of metabolite peaks with large lipid signal from scalp, and overwhelming water signal that distorts spectra. Fast and effective methods are needed for high-resolution -MRSI to accurately remove lipid and water signals while preserving the metabolite signal.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!