Chronic subdural hematoma: demonstration by magnetic resonance.

Abstract
The ability of magnetic resonance (MR) to identify intracranial hematomas was tested in 5 patients with clinical and computed tomographic [CT] signs of chromic subdural hematoma. The extracerebral collections were displayed as a zone of bright intensity using the T1-weighted inversion recovery (IR 1500/400) sequence, reflecting the lesions'' short T1 relaxation times. The collections also showed high intensity using the spin echo (SE) sequence, with a longer delay of 100 ms and 160 ms, reflecting the long T2 relaxation time. The spin echo sequence with a repetition time of 500 ms and an echo delay of 160 ms (SE 500/160) almost effaced other structures in the image, increasing the specificity of this pulse scheme for detection of chronic blood collections. Although in 2 of the 5 patients the subdural hematomas were in the isodense CT phase, all were easily visualized with MR.