CT, MRI, and angiography of venous angiomas: a comparative study

Seventeen venous angiomas in 16 patients were evaluated radiologically at the Montreal Neurological Hospital. Radiologic investigations included contrast-enhanced computed tomograms (CECT) in 15 patients, cerebral angiograms with a long venous phase study in 15, and magnetic resonance (MR) imaging with a spin-echo pulse sequence technique in six. CECT revealed abnormalities including six nodular nonspecific enhancing lesions and nine enhanced draining veins, whereas plain CT revealed intracerebral hemorrhages in four patients and calcification in one. All the angiograms showed the characteristic pattern of venous angiomas consisting of medullary veins converging to a large draining vein during the late venous phase. All six patients examined by MR showed abnormal vascular structures; parenchymal hemorrhages were present in two patients. In five patients with venous angiomas, medullary veins converging to a large draining vein were demonstrated as echo-void curvilinear structures. In two patients, the increased signal from medullary veins in long echo delay sequences was suggestive of a slow venous flow rate. Demonstration of the venous nature of the malformation may, in the future, obviate the need for angiography.