ACUTE AND CHRONIC STROKE - NAVIGATED SPIN-ECHO DIFFUSION-WEIGHTED MR-IMAGING

PURPOSE: The authors evaluated a phase-navigated spin-echo (SE) motion -correction sequence for use at diffusion-weighted (DW) magnetic reson ance (MR) imaging after cerebral infarction. MATERIALS AND METHODS: Tw enty-nine patients underwent 32 conventional T2-weighted fast SE and S E DW imaging after stroke (n = 25), transient ischemic attack (n = 3), or reversible ischemic neurologic deficit (n = 1). Imaging was perfor med in a standard head holder with standard padding. Apparent diffusio n coefficient (ADC) maps were reconstructed. RESULTS: DW images depict ed high signal intensity compatible with localization of the ischemic symptoms in all cases. Lesions were depicted more clearly on DW than o n T2-weighted images. On DW images, acute infarct ADC values were unif ormly low (mean, 0.401 x 10(-5) cm(2)/sec +/- 0.143 [standard deviatio n]) compared with control ADC values (mean, 0.754 x 10(-5) cm(2)/sec /- 0.201). ADC values of chronic infarcts were supranormal (mean, 1.59 1 x 10(-5) cm(2)/sec +/- 0.840) compared with control values (mean, 0. 788 x 10(-5) cm(2)/sec +/- 0.166). DW imaging did not show a change af ter transient ischemic attack. With reversible ischemic neurologic def icit, however, hyperintensity on DW images and low ADC resolved after symptoms abated. CONCLUSION: Clinical phase-navigated SE DW imaging im proved early diagnosis of stroke and helped differentiate acute from c hronic stroke. Changes on DW images are reversed after symptoms resolv e.