Chronic subdural hematoma: demonstration by magnetic resonance.

The ability of magnetic resonance (MR) to identify intracranial hematomas was tested in five patients with clinical and computed tomographic signs of chronic subdural hematoma. The extracerebral collections were displayed as a zone of bright intensity using the T1-weighted inversion recovery (IR 1,500/400) 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, thus increasing the specificity of this pulse scheme for detection of chronic blood collections. Although in two of the five patients the subdural hematomas were in the isodense CT phase, all were easily visualized with MR.