Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Physical activity may represent a disease-modifying therapy in persons with multiple sclerosis (pwMS). To date, there is limited research regarding mechanisms based on brain imaging for understanding the beneficial effects of physical activity in pwMS. This study examined the relationship between physical activity levels and thalamic and hippocampal volumes and brain metabolism in pwMS. ⋯ This study provides novel evidence for a positive association between physical activity and thalamic and hippocampal volume and metabolism in pwMS. These findings support the hypothesis that physical activity, particularly MVPA, may serve as a disease-modifying treatment by improving brain health in pwMS.
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Observational Study
Right-to-left shunt detection using transforaminal insonation of the basilar artery.
Investigation for patent foramen ovale (PFO) is warranted in patients with cryptogenic stroke (CS), as PFO closure is recommended in select CS patients for secondary stroke prevention. Transcranial Doppler (TCD) is noninvasive and has high sensitivity for PFO screening. However, 10% of the population has insufficient temporal bone windows to perform standard TCD monitoring of the middle cerebral arteries (MCAs). Prior reports showed similar diagnostic accuracy between the basilar artery and MCAs insonation. Our objective was to assess the accuracy of transforaminal insonation of the basilar artery (TIBA) in diagnosis of right-to-left shunt (RLS) in patients with inadequate temporal windows. ⋯ PFO screening accuracy using TIBA was 75%. Prospective evaluation of CS patients with TIBA and comparison to the gold-standard TEE should be performed to further guide clinical practice.
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Prenatal ultrasound (US) is the first prenatal imaging tool for screening and evaluation of posterior fossa malformations since it is noninvasive, widely available, and safe for both mother and child. Fetal MRI is a widely used secondary technique to confirm, correct, or complement questionable US findings and plays an essential role in evaluating fetuses with suspected US findings and /or positive family history. The main sequences of fetal MRI consist of T2-weighted (T2w) ultrafast, single-shot sequences. ⋯ The use of fetal MRI also aims to evaluate for associated anomalies. In addition, prenatal diagnosis of posterior fossa malformations is still a challenge but advances in knowledge in human developmental anatomy, genetic, and imaging recognition patterns have enabled us to shed some light on prognostic information that will help with the counseling of families. Finally, high-resolution late third trimester fetal MRI offers a safe alternative to early postnatal MR imaging, basically taking advantage of the uterine environment as a kind of "maternal incubator." Our goal is to discuss the spectrum of prenatal posterior fossa pathologies that can be studied by fetal MRI and their key neuroimaging features.
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Assessment of the essential white matter fibers of arcuate fasciculus and corticospinal tract (CST), required for preoperative planning in brain tumor patients, relies on the reliability of diffusion tensor imaging (DTI). The recent development of multiband DTI (mb-DTI) based on simultaneous multislice excitation could maintain the overall quality of tractography while not exceeding standard clinical care time. To address this potential, we performed quantitative analyses to evaluate tractography results of arcuate fasciculus and CST acquired by mb-DTI in brain tumor patients. ⋯ This study demonstrated the clinical potential and significant advantages of preoperative mb-DTI in brain tumor patients.
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To investigate the reorganization of the central nervous system provided by resting state-functional MRI (rs-fMRI), graph-theoretical analysis, and a newly developed functional brain network disruption index in patients with human immunodeficiency virus (HIV) infection. ⋯ Our study demonstrates that rs-fMRI combined with advanced graph theoretical analysis and disruption indices is able to detect early and subtle functional changes of brain networks in HIV patients.