Diffusion‐weighted MRI in patients with acute stroke
Background: Acute stroke is an abrupt non‐traumatic brain insult, caused by either brain infarction (75%) or hemorrhage (25%). Aim of the Study: To compare the sensitivity of Diffusion ‐ weighted imaging (DWI) and apparent diffusion coefficient (ADC) map in detection of acute stroke with sensitivity of conventional MRI study. Patients &methods: Thirty ‐ eight patients (24 male and 14 female with age range between 43‐90 years) with a clinically suggestive stroke and negative CT‐scan, all patients referred for MRI study within 4‐40 hours [mean of 17 hrs] of acute attack. brain MRI was performed for these patients. Starting with conventional MRI sequences done followed by diffusion weighted in the same study and follow up clinically afterwards. The study was conducted in a general hospital in Baghdad from January 2012 to January 2013 .Ratios were calculated between the apparent diffusion coefficient value of normal appearing brain in the right & left hemispheres & between apparent diffusion coefficient value of the ischemic area & the corresponding contralateral region . Results: With diffusion ‐ weighted images , 100% of the ischemic lesions were detected, and with fluid‐attenuated inversion recovery, 73.7% were detected, whereas with early T2‐weighted or T1‐weighted, only 52.6 % and 21% of lesions were detected , respectively , using McNemar test we found statistically significant differences in sensitivity between Diffusion weighted images and T1W (p<o.ooo1), diﬀusion weighted images and T2W (p<0.0001) and between diffusion weighted images and fluid attenuated inversion recovery (p< 0.002) .The mean apparent diﬀusion coeﬃcient of acute ischemic lesions was 30 % lower than the apparent diﬀusion coeﬃcient of normal appearing parts of brain .( P <0.001). Conclusions: Diffusion ‐Weighted images + apparent diffusion coefficient map Imaging is more sensitive than conventional MRI sequences in MRI detection of acute stroke .