Measurement of basilar artery diameter in dogs: CT evaluation correlated with arteriography

In this study we have used a computed tomographic (CT) method using profile analysis to measure the diameter of the basilar artery. In a search for a noninvasive and repeatable method to substitute for the traditional arteriography in the evaluation of the degree of cerebral vasospasm, we employed both CT and arteriography to measure the diameter of the basilar artery in eight adult mongrel dogs weighing between 7 and 12 kg. In three of these animals, assessments were made before and after subarachnoid hemorrhage (SAH) induced by injecting autologous arterial blood into the cistern magna. It was found that the basilar artery diameter as evaluated by CT was 47% larger than that measured by arteriography. However, there was a very good correlation (n = 63, r = 0.75, p less than 0.001) between the two methods. This paper presents a new model for the measurement of the basilar artery diameter, one which may also provide a safer method for the evaluation of vasospasm in humans.