Abstract
MRI findings of acute (11 cases), subaute (2 case), and chronic (1 case) stages of aneurysmal SAH were summarized and compared with those of CT. In all 11 cases of acute SAH, fluid-fluid levels indicating the presence of the blood, were found in the lateral ventricles on ρ-weighted and T2-weighted images. In 13 of 14 cases, T2-weighted images showed high intensity signals not only in the large cisterns and cerebral fissures but also in the fine sulci. Periventricular high intensity, probably corresponding to edema, was found much earlier than the appearance of periventricular lucency on CT. MRI disclosed small infarcts, but no findings indicating the presence of cerebral ischemia due to early vasospasm were found. The focus of signal void not unlike an aneurysm was seen in the absence of aneurysm.
