The Application Of DWI And ADC Mapping In Cerebral Infarction

Purpose: To study the roles of isotropic diffusion weighted imaging and ADC mapping in diagnosing early cerebral infarction, monitoring the development of cerebral infarction and defining the infarction stages. Material and methods: 81 work-ups of 70 patients with cerebral infarction (8 hyperacute, 13 acute, 32 subacute, 11 steady, 22 chronic) were imaged with both conventional IvIRI and single-shot echo-planar isotropic diffusion weighted imaging. Among them, 12 patients had CT Scanning simultaneously within 24 hours after onset. The positive rate of early infarction was compared in CT,T2WI and DWI ; 14 patients with early infarction had followp examinations and their infarct sizes as measure by T2WI were compared with their initial sizes on DWI and the relationship of the infarct lesion with the clinical manifestation was analysed The change of the infarct lesion in DWI and T2WI was also analysed. The average ADC,relative ADC (rADC) and the ADC from center to periphery of the lesion were calculated Results: 8 hyperacute cerebral ischemic regions were revealed at DWI and ADC mapping ,but CT and conventional MR were not . Hyperacute and acute infarcts appeared as areas of hyperintensity on DWI, and their average ADC was significantly depressed compared with homologous contralateral tissue (0.69 8 ?0.104 verus 0.990 ?.661 X lO3niin2/s; pKO.OO1). rADC in hyperacute and acute stage was minimized, and increased progressively as time pass and appeared as攑seudonormal?values approximately 8 to 14 days ,thereafter, rADC became greater than normal in chronic stage. There was positive correlation between rADC and time (r=0.928, p