The subpetrous carotid wall hematoma: a sign of spontaneous dissection of the internal carotid artery on non-enhanced computed tomography - a retrospective study.

PURPOSE: Spontaneous dissection of the internal carotid artery (CAD) is an increasingly recognized cause for stroke especially in young and middle-aged patients. We hypothesized that non-enhanced cranial computed tomography (NECCT) can visualize the subpetrous carotid wall hematoma and thus enable identification of patients with CAD.
MATERIALS AND METHODS: We retrospectively reviewed patients with confirmed CAD (n = 21) and a control group with ischemic symptoms but without CAD (n = 42) who received NECCT at admission. Two independent neuroradiologists rated the presence and shape of SPH, density and diameter of the subpetrous internal carotid artery. Additionally, we correlated the shape of the subpetrous carotid wall hematoma with the grade of stenosis on subsequent angiographic imaging.
RESULTS: The subpetrous carotid wall hematoma was present in 14 of 21 patients (Cohen's κ = 0.67). Mean diameter was 6.95 ± 1.05 mm in dissected vessels and 5.71 ± 1.52 mm in the contralateral vessel (p < 0.05). Mean difference in vessel density was 15.05 ± 8.01 HU (p < 0.01). Median grade of stenosis was significantly higher in patients with a full moon- shaped (n = 11) than crescent-shaped (n = 3) subpetrous carotid wall hematoma (21 % vs. 80 %, p < 0.05).
CONCLUSION: Two-thirds of patients with CAD  were correctly identified on NECCT. The extracranial carotid artery should be evaluated in patients with symptoms of cerebral ischemia. © Georg Thieme Verlag KG Stuttgart · New York.