PURPOSE: The purpose of this study was to compare the clinical utility of diffusion-weighted images(DWI) withthat of apparent diffusion coefficient(ADC) maps for detecting early ishemic strokes. MATERIALS AND METHODS: In22 patients with infarct, lesion conspicuity as seen on T2-weighted images(T2WI), low diffusion-weightedimages(DWI ; b value 300 sec/mm2), high DWI(b value 1000 sec/mm2), and ADC maps was retrospectively compared. Theinfarct was hyperacute (< 6 hours) in six, acute (< 48 hours) in six, and subacute (< 2 weeks) in ten. All imageswere obtained using an echo-planar spin echo sequence; lesion conspicuity was graded from 0 to 2 by tworadiologists. Signal intensity was analysed in 17 patients[hyperacute (n=5); acute (n=4); and subacute (n=8)].Lesion-to-controlateral normal side signal intensity ratio(SIR) and contrast-to-noise ratio(CNR) were measured andcompared between four different types of images. RESULT: With regard to lesion conspicuity, high DWI wassuperior to the other images for detecting hyperacute strokes(Grade 2, 6/6). In such cases, an ADC map showedgrade 0 lesion conspicuity in one case, grade 1 in three, and grade 2 in two. There was no significant differencein lesion conspicuity in acute and subacute strokes between DWI(low