Intra-arterial digital subtraction angiography for suspected cerebrovascular disease--current status

Sixty-four patients with suspected atherosclerotic cervical and intracranial vascular disease were examined by intra-arterial digital subtraction angiography (IA-DSA), following placement of a catheter in the aortic arch. The commonest abnormality demonstrated was the presence of an atherosclerotic plaque, most commonly on the posterior wall of the proximal internal carotid at its origin in the neck. The quality of the images obtained were assessed and in all patients, the carotid arteries in the neck could be adequately visualised if both oblique views of the neck were obtained. The intracranial arteries and the anterior and middle cerebral arteries were also adequately visualised in all patients although the basilar-posterior cerebral arteries were poorly seen in 8%. DSA examinations of the carotid and intracerebral vessels can also be performed by the intravenous route (IV-DSA). However IV-DSA is associated with significant limitations which include inadequate visualisation of intracranial circulation, larger volume of contrast medium required and higher risk of contrast reactions. IA-DSA gives adequate visualisation of the aortic arch, cervical vessels and intracranial circulation in most patients without selective catheterisation. Examination time is shorter, procedure is safe and film costs are reduced. Disadvantages include small field size and inferior spatial resolution compared to conventional angiography but in no patients was there a need to resort to conventional angiography.