Comparison of mr sequences in early cerebral infarction at 0.5 T

Purpose: To compare the diagnostic values of fluid-attenuated inversion rec overy (FLAIR) and gradient spin-echo (GRASE) with those of conventional spi n-echo (SE) and fast SE T2-weighted sequences in the evaluation of acute ce rebrovascular lesions at 0.5 T. Material and Methods: Twenty-two consecutive patients with the clinical dia gnosis of acute cerebrovascular accident were examined by MR imaging within the first 48 h of ictus. MR examination included 5-mm axial conventional S E and turbo SE (TSE) T2-weighted, dual-echo GRASE and FLAIR sequences. The patients also had pre- and postcontrast T1-weighted axial images. Two exami ners evaluated the images and scored the conspicuity of the acute lesions. Results: Regardless of location, FLAIR provided the best lesion conspicuity in the detection of acute infarcts, followed by the GRASE sequence. In the posterior fossa, TSE and SE demonstrated the lesions better than GRASE and FLAIR techniques. In the detection of hemorrhagic elements within the isch emic region, TSE demonstrated statistically significant superiority over ot her sequences. Conclusion: In the detection of acute ischemic lesions in locations other t han the posterior fossa, FLAIR provided the best lesion conspicuity among f our T2-weighted sequences, including SE, TSE, GRASE and FLAIR. However, for the posterior fossa examination, preference of SE or TSE T2-weighted seque nces is suggested.