Journal of neuroimaging : official journal of the American Society of Neuroimaging
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To determine the ability of diffusion-weighted imaging (DWI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to predict long-term response of brain metastases prior to and within 72 hours of stereotactic radiosurgery (SRS). ⋯ Quantitative DWI and DCE-MRI are feasible imaging methods in the pre- and early (within 72 hours) post-SRS evaluation of brain metastases. DWI- and DCE-MRI-derived parameters demonstrated physiologic changes (tumor cellularity and vascularity) and offer potentially useful biomarkers that can predict treatment response. This allows for initiation of alternate therapies within an effective time window that may help prevent disease progression.
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Gait impairment is a hallmark of Parkinson's disease (PD). Natural walking involves more cognitive demand than treadmill walking or in-laboratory walking tests because patients have to actively work on navigation and top-down cognitive control which taxes cognitive reserve in the prefrontal cortex. To mimic the prefrontal engagement occurring with natural walking in a controlled and safe environment, dual-task (DT) treadmill walking has been developed. In this study, we tested the feasibility of imaging DT walking-related changes in brain glucose metabolism in patients with PD. ⋯ This study confirms the feasibility of imaging glucose metabolism during DT walking in patients with PD. We also report that during DT walking, there is a lesser degree of prefrontal engagement in the patients with more progressed disease compared to those with less progressed disease, implying increased degrees of frontal dysfunction with PD progression.
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To date, treatment response to stereotactic radiosurgery (SRS) in brain metastases (BM) can only be determined by MRI evaluation of contrast-enhancing lesions in a long-time follow-up. Sodium MRI has been a subject of immense interest in imaging research as the measure of tissue sodium concentration (TSC) can give valuable quantitative information on cell viability. We aimed to analyze the longitudinal changes of TSC in BM measured with 23 Na MRI before and after SRS for assessment of early local tumor effects. ⋯ Changes in TSC using 23 Na MRI shows the possible capability to detect radiobiological changes in BM after SRS.
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A high variability of brain MRI volume change measurement renders challenging its interpretation in multiple sclerosis (MS). Occurrence and clinical relevance of observed apparent brain volume increase (BVI) in MS patients have not been investigated yet. The objective was to quantify the prevalence and factors associated with BVI. ⋯ BVI occurs in a great proportion of MR scans over short-term follow-up and is not associated with disease stabilization. Although BVI can be caused by several factors, the results indicate that measurement error may contribute to BVI in the majority of cases. Clinicians should be aware of the frequent occurrence of apparent BVI, interpret brain volume changes in MS patients with great caution, and use methods with precise quantification of brain volume changes.
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The fetal brain changes significantly throughout gestation. From a smooth (lissencephalic) cortex, it transforms into its convolved (gyrencephalic) state. Despite its importance, the diagnosis of delay in brain gyrogenesis is a challenge for many sonographers. This study presents a novel semiautomatic image processing algorithm for simple quantification of sagittal sulci maturation in the third trimester. ⋯ We found that fetal gyrogenesis is linear throughout the third trimester of pregnancy. The use of a computer algorithm to measure fetal sulci can be used as a simple prenatal screening test for delayed gyral maturation of the fetal brain.