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Objective: The purpose of this article is to prospectively determine the feasibility of using blood oxygenation level-dependent (BOLD) MRI at 3 T in differentiating various renal lesions.
Subjects And Methods: Seventy-one patients (mean age, 53.8 years; range, 22-80 years) underwent kidney MRI, including BOLD MRI at 3 T. BOLD MRI was performed using a multiple fast-field echo (FFE) sequence to acquire 20 T2(*)-weighted images within a single breath-hold. The rate of spin dephasing (R2(*)) values of solid and benign cystic renal lesions were compared, and the results of four subgroups--simple cysts, renal cell carcinomas (RCCs), hemorrhagic cysts, and angiomyolipomas (AMLs)--were analyzed. The degree of overall imaging quality in BOLD MRI was also assessed.
Results: One hundred three renal lesions were detected in the 71 patients. The mean (± SD) R2(*) values of 45 solid lesions (30.6 ± 19.4 1/s) were significantly higher than those of 58 benign cystic lesions (4.5 ± 4.8 1/s; p < 0.001). The mean R2(*) values of simple cysts, RCCs, hemorrhagic cysts, and AMLs were 1.7 ± 1.7, 22.6 ± 12.6, 10.7 ± 3.7, and 48.0 ± 25.5 1/s, respectively (p < 0.001). The degree of overall imaging quality in all patients was satisfactory or better.
Conclusion: Renal BOLD MRI at 3 T is a feasible technique and may be useful for differentiating various renal lesions.
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http://dx.doi.org/10.2214/AJR.10.6319 | DOI Listing |
Stroke
September 2025
Brain Language Laboratory, Freie Universität Berlin, Germany (A.-T.P.J., M.R.O., A.S., F.P.).
Background: Intensive language-action therapy treats language deficits and depressive symptoms in chronic poststroke aphasia, yet the underlying neural mechanisms remain underexplored. Long-range temporal correlations (LRTCs) in blood oxygenation level-dependent signals indicate persistence in brain activity patterns and may relate to learning and levels of depression. This observational study investigates blood oxygenation level-dependent LRTC changes alongside therapy-induced language and mood improvements in perisylvian and domain-general brain areas.
View Article and Find Full Text PDFComput Biol Med
September 2025
Department of Biomedical Engineering, Linköping University, Linköping, Sweden; Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden; School of Medical Sciences and Inflammatory Response and Infection Susceptibility Centre (iRiSC), Faculty of Medicine
Functional magnetic resonance imaging (fMRI) is a pivotal tool for mapping neuronal activity in the brain. Traditionally, the observed hemodynamic changes are assumed to reflect the activity of the most common neuronal type: excitatory neurons. In contrast, recent experiments, using optogenetic techniques, suggest that the fMRI-signal could reflect the activity of inhibitory interneurons.
View Article and Find Full Text PDFMagn Reson Med
September 2025
A.I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland.
Since its introduction more than 30 years ago, the blood oxygenation level-dependent (BOLD) contrast remains the most widely used method for functional MRI (fMRI) in humans and animal models. The BOLD contrast is typically acquired with echo planar imaging (EPI) to obtain sensitization of the signal during the echo time (TE) to dynamic changes in deoxyhemoglobin content, while achieving high spatiotemporal resolution and full brain coverage. However, EPI-based fMRI also faces multiple shortcomings, including sensitivity to body motion, susceptibility-related signal dropouts, interference with multimodal sensors, and loud acoustic noise.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
September 2025
Department of Psychology, University of Amsterdam, Amsterdam 1018 WS, The Netherlands.
Decision making and learning processes together enable adaptive strategic behavior. Animal studies demonstrated the importance of subcortical regions in these cognitive processes, but the human subcortical contributions remain poorly characterized. Here, we study choice and learning processes in the human subcortex, using a tailored ultra-high field 7T functional MRI protocol combined with joint models.
View Article and Find Full Text PDFMultivariate pattern analysis (MVPA) methods are a versatile tool to retrieve information from neurophysiological data obtained with functional magnetic resonance imaging (fMRI) techniques. Since fMRI is based on measuring the hemodynamic response following neural activation, the spatial specificity of the fMRI signal is inherently limited by contributions of macrovascular compartments that drain the signal from the actual location of neural activation, making it challenging to image cortical structures at the spatial scale of cortical columns and layers. By relying on information from multiple voxels, MVPA has shown promising results in retrieving information encoded in fine-grained spatial patterns.
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