Initial clinical experience with spiral CT and 3D arterial reconstruction in intracranial aneurysms and arteriovenous malformations.

We studied 32 consecutive patients with known or suspected cerebrovascular abnormalities studied with spiral CT following a intravenous bolus injection of iodinated contrast medium with a power injector. Flow was 3 or 4 ml/s. In an attempt to define the appropriate delay time and scan duration a cranial angio-CT without table increment was performed on 10 patients. Enhancement was measured by manually placed regions of interest within the left middle cerebral artery and the inferior sagittal sinus. All patients except one had intraarterial angiography (DSA) for comparison. In 6 patients with an arteriovenous malformation (AVM) follow-up was possible after one and/or two embolisation procedures. These patients had plain and contrast-enhanced spiral CT. The diagnosis was aneurysm in 9 (8 berry aneurysms, one giant fusiform aneurysm), AVM in 13 (all supratentorial) and traumatic arteriovenous fistula in one. In 9 patients there were no detectable pathological vascular findings. After 3D reconstruction the size (between 5 and 28 mm), location and the relationship to the parent vessel of the aneurysms, the extent of the AVMs and the distribution of the embolisation material could be demonstrated clearly. The main feeding vessel(s), nidus and draining veins were reliably shown. The decreased extent of the AVMs after embolisation was clearly demonstrated. There was no difference in diagnosis when DSA and 3D-CT were compared by two independent radiologists. We consider arterial spiral CT with 3D reconstruction to have the potential of offering important diagnostic information for the treatment of intracranial AVMs and aneurysms.