CORRELATION OF PERFUSION-WEIGHTED AND DIFFUSION-WEIGHTED MRI WITH NIHSS SCORE IN ACUTE (LESS-THAN-6.5 HOUR) ISCHEMIC STROKE

Background: Diffusion-weighted (DWI) and perfusion-weighted (PWI) MRI are powerful new techniques for the assessment of acute cerebral ische mia. However, quantitative data comparing the severity of clinical neu rologic deficit with the results of DWI or PWI in the earliest phases of stroke are scarce. Such information is vital if MRI is potentially to be used as an objective adjunctive measure of stroke severity and o utcome. Objective: The authors compared initial DWI and PWI lesion vol umes with subsequent 24-hour neurologic deficit as determined by Natio nal Institutes of Health Stroke Scale (NIHSS) score in acute stroke pa tients. Initial DWI and PWI volumes were also compared with T2W MRI le sion volume at 1 week to assess the accuracy of these MRI techniques f or the detection of acute cerebral ischemia. Methods: Patients with st roke underwent MRI scanning within 6.5 hours of symptom onset. Lesion volumes on DWI and PWI were measured and compared with 24-hour NIHSS s core. Initial DWI and PWI volumes were also compared with T2W lesion s ize at 1 week. Results: There was a high correlation between 24-hour N IHSS score and lesion volume as determined by PWI (r = 0.96, p < 0.001 ) or DWI (r = 0.67, p = 0.03). A similar high correlation was seen bet ween T2W stroke size at 7 days and initial DWI and PWI lesion size (r = 0.99, p < 0.00001). Conclusions: Both DWI and PWI are highly correla ted with severity of neurologic deficit by 24-hour NIHSS score. These findings may have substantial implications for the use of MRI scanning in the assessment and management of acute stroke patients.