More articles from Adult Brain
- Responses of the Human Brain to Mild Dehydration and Rehydration Explored In Vivo by 1H-MR Imaging and Spectroscopy
Serial T1WI and 1H-MR spectroscopy data were acquired in 15 healthy individuals at normohydration, at 12 hours of dehydration, and during 1 hour of oral rehydration. Osmotic challenges were monitored by serum measures, including osmolality and hematocrit. With dehydration, serum osmolality increased by 0.67% and brain tissue fluid decreased by 1.63%. MR imaging morphometry demonstrated corresponding decreases of cortical thickness and volumes of the whole brain, cortex, white matter, and hypothalamus/thalamus. These changes reversed during rehydration. The authors conclude that it is essential to control for hydration levels in studies on brain morphometry and metabolism in order to avoid confounding the findings.
- Ultra-High-Field MRI Visualization of Cortical Multiple Sclerosis Lesions with T2 and T2*: A Postmortem MRI and Histopathology Study
At 7T, 2D multiecho spin-echo T2WI and 3D gradient-echo T2*WI were acquired from 27 formalin-fixed coronal hemispheric brain sections of 15 patients and 4 healthy controls. Proteolipid-stained tissue sections were matched to the corresponding MR images, and lesions were manually scored on both MR imaging sequences and tissue sections. The T2WI sequence detected slightly more lesions than the T2*WI sequence (28% and 16%). When histopathologic information (type, location) was revealed to the reader, the sensitivity went up to 84%. Many lesions are still missed prospectively.
- Carotid Webs and Recurrent Ischemic Strokes in the Era of CT Angiography
Carotid web was defined on CTA as a thin intraluminal filling defect along the posterior wall of the carotid bulb just beyond the carotid bifurcation on oblique sagittal section CTA that was seen as a septum on axial CTA. In the prospective series in this study, the mean age was 50 years, and 5 of 7 patients were women. Recurrent stroke was seen in 5 of 7. Histopathology suggested a high probability of fibromuscular dysplasia. In the retrospective series, carotid webs were seen in 7 of 576 patients. Carotid web may be an important cause of ischemic stroke in patients with otherwise no determined mechanism of stroke and may present a high risk of recurrent stroke.
- Nigrosome 1 Detection at 3T MRI for the Diagnosis of Early-Stage Idiopathic Parkinson Disease: Assessment of Diagnostic Accuracy and Agreement on Imaging Asymmetry and Clinical Laterality
Nigrosomes are calbindin-poor zones within the substantia nigra pars compacta, and are the primary subregion where dopaminergic cells are lost in Parkinson disease. High-resolution 3D multiecho imaging was performed at 3T in 13 healthy subjects and 24 patients with idiopathic Parkinson disease confirmed by 18F-FP-CIT PET. Diagnostic sensitivity, specificity, and accuracy of the nigrosome 1 detection at 3T MR imaging was 100%, 84.6%, and 94.6%, respectively. Further, the clinical laterality was in high concordance with the laterality of the nigrosome 1 detection.