Post-ischaemic hyperperfusion in traumatic middle cerebral artery dissection detected by arterial spin labelling of magnetic resonance imaging.

We report a patient with a traumatic middle cerebral artery dissection, which showed hyperperfusion in the territory supplied by the left middle cerebral artery. A 45-year-old man experienced speech disturbance and motor weakness in his right hemibody on the day following mild head trauma. His symptoms worsened on the fourth day. Magnetic resonance imaging showed narrowing in the left M1 portion of the middle cerebral artery. Angiography showed narrowing and dilatation in the left middle cerebral artery trunk. The lesion was diagnosed as a dissection of the middle cerebral artery. Arterial spin labelling of magnetic resonance imaging and single photon emission computed tomography showed increased cerebral blood flow in the left temporal region compared with the right. The patient was treated conservatively and the symptoms gradually improved. The hyperperfusion observed on arterial spin labelling and single photon emission computed tomography gradually improved and disappeared on the 25th day. This is the first reported case of traumatic middle cerebral artery dissection, which showed post-ischaemic hyperperfusion in the territory of the affected artery. To detect hyperperfusion in the brain, arterial spin labelling is a useful technique.

A chronic encapsulated intracerebral hematoma mimicking a brain tumor: Findings on arterial spin labeling of MRI.

BACKGROUND: Intracerebral hematoma usually resolves spontaneously. Chronic encapsulated intracerebral hematoma is rare and mimics a brain tumor. CASE DESCRIPTION: A 50-year-old man had developed intracerebral hematoma in the right temporal lobe. Computed tomography (CT) showed the gradually decreasing density of the hematoma. However, the hematoma did not decrease in size and it showed ring enhancement on contrast-enhanced CT for more than 1 year. Magnetic resonance imaging (MRI) revealed a lesion content showing a high intensity on both T1- and T2-weighted images with ring enhancement. The lesion was diagnosed as a chronic encapsulated intracerebral hematoma developing from an acute hematoma. Arterial spin labeling of MRI showed decreased blood perfusion even in the enhanced capsule, being different from findings of a cystic brain tumor. CONCLUSION: Arterial spin labeling might be a useful modality to distinguish a chronic encapsulated intracerebral hematoma from a cystic hypervascular brain tumor.