Background and Purpose-Using newly developed computerized image analysis, we studied the heterogeneity of apparent diffusion coefficient of water (ADC w ) values in human ischemic stroke within 10 hours of onset. Methods-Echo-planar trace diffusion-weighted images from 9 patients with focal cortical ischemic stroke were obtained within 10 hours of symptom onset. An Iterative Self-Organizing Data Analysis (ISODATA) clustering algorithm was implemented to segment different tissue types with a series of DW images. ADC w maps were calculated from 4 DW images on a pixel-by-pixel basis. The segmented zones within the lesion were characterized as low, pseudonormal, or high, expressed as a ratio of the meanϮSD of ADC w of contralateral noninvolved tissue. Results-The average ADC w in the ischemic stroke region within 10 hours of onset was significantly depressed compared with homologous contralateral tissue (626.6Ϯ76.8 versus 842.9Ϯ60.4ϫ10 Ϫ6 mm 2 /s; PϽ0.0001). Nevertheless, ISODATA segmentation yielded multiple zones within the stroke region that were characterized as low, pseudonormal, and high. The mean proportion of low:pseudonormal:high was 72%:20%:8%. Conclusions-Despite low average ADC w , computer-assisted segmentation of DW MRI detected heterogeneous zones within ischemic lesions corresponding to low, pseudonormal, and high ADC w not visible to the human eye. This supports acute elevation of ADC w in human ischemic stroke and, accordingly, different temporal rates of tissue evolution toward infarction. (Stroke. 1998;29:1778-1782.)
Juvenile Huntington's disease is a rare neurodegenerative disorder that first affects the basal ganglia. Presented here is a case of juvenile Huntington's disease in an 8-year-old male. Clinical features included epilepsy and developmental delay. Imaging findings showed severe atrophy of the caudate nuclei and putamina which prompted a genetic evaluation. The diagnosis was confirmed via molecular analysis which revealed the amplified CAG triplet characteristic of this disorder. This case report highlights the imaging features common in this rare cause of pediatric epilepsy.
Infantile vanishing white matter disease is an uncommon cause of developmental delay and seizures in children. Presented here is a case of vanishing white matter disease diagnosed at 6 months of age. Imaging findings demonstrated widespread white matter abnormalities throughout the supratentorial and infratentorial brain. The diagnosis of infantile vanishing white matter disease was confirmed via molecular analysis which revealed a rare mutation in the gene responsible for this disorder.
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