Rotational angiography of the carotid artery bifurcation: technical aspects and preliminary results

Rotational Angiography (RA), a new modality for performing conventional catheter angiography, enables an accurate evaluation of the artery to be obtained from different points of view by means of the contemporary rotation of the X-ray tube and image intensifier during intrarterial selective injection of contrast media. This paper describes the examination technique and compares the diagnostic accuracy of the RA oblique projections with the data obtained in the antero-posterior (AP) and latero-lateral (LL) projections in the study of the carotid bifurcation.

Thirty patients underwent RA of the supra-aortic vessels to evaluate the degree of a stenosis at the carotid bifurcation suspected at color Doppler imaging. The angiographic examinations were performed on a Philips Integris Allura system able to rotate the arc at a speed of 55 degrees /s with selective catheterisation of both common carotid arteries.

The frame showing the greatest degree of stenosis was compared with the frames obtained in the AP and LL projections. 57/60 carotid bifurcations were assessable (3 cases of internal carotid arteries were obstructed). The degree of stenosis evaluated on the most significant of the oblique projections was superior to that shown in the AP and LL projections for 16/30 cases on the right side and for 14/27 cases on the left side. In 4/57 cases (7%) the degree of stenosis was modified from less than 70% to more than 70%. No adverse event was observed due to catheterisation.

RA enables the complete three-dimensional evaluation of the carotid bifurcation, and generally yields more accurate information on the degree of the stenosis in comparison with AP and LL technique. The study was successfully carried out in all cases, however slightly longer examination times due to the setup requirements of the system. This was largely compensated by the quality of the information yielded, which required no additional projections to be performed. Moreover, the high frame rate of 25 frames per second showed the haemodynamic flow through the lesion.