Spinal subdural haematoma: a study of three cases.

AIMS: To define the clinical, computed tomography (CT) and magnetic resonance imaging (MRI) features and the role of MRI in the follow-up of spinal subdural haematoma (SSH), and to compare these findings with those of spinal epidural haematomas (SEH). METHODS: We report three cases of SSH (two women, one male, age: 50-74 years). Two patients were on anticoagulant therapy; in the other case the SSH was spontaneous. All the patients were examined 1-3 days after the onset of the symptoms. All of them had CT, two had MRI and one had angiography. Two patients underwent surgery. RESULTS: The haematoma was located in the thoracolumbar region (two) and in the thoracic region (one), extending from five (two) to 11 vertebral body levels (one). The haematomas were posteriorly located with lateral extension. The transverse shape differed with the level: biconvex, biloculated or circumferential. The haematomas were hyperdense on CT. On MRI, SSH yielded high signal on both T1 and T2. The integrity of the posterior fat pads, which was well shown on CT and MRI, and the visualization of the dura mater demonstrated the intradural location of these collections, making them easily distinguishable from spinal epidural haematoma. MRI provides better evaluation of the longitudinal extent. Our results are compared with those reported in the literature. CONCLUSION: MRI is superior to CT for diagnosis and follow-up of SSH. Our findings and those reported in the literature show that the MR features of SSH are quite specific and allow differentiation from SEH.