Diagnosis of carotid artery disease by CT scan “intravenous CT carotid-angiography”

Abstract

Non-invasive methods, such as radioisotope angiography, oculoplethsmography, and ultrasonic Doppler flowmetry, are used for the detection of caroid artery lesion. However, these methods are qualitative, and diagnostic accuracies are inferior to arteriography. On the other hand arteriography needs catheterization. So we tried to use CT scan and intravenous contrast enhancement for the diagnosis of carotid artery disease.
A CT/T scanner (X-2) was used, which enabled to produce computer reconstruction image of the carotid artery by use of the arrange program. 12 sequential axial images of the neck (between heights ofC2 and C5) were obtained before and during infusion of contrast material. Analysis of sequential axial images and reformatted images were obtaned in patients with cerebrovascular disease. Carotid arteriography were made in 53 arteries, lesions with stenosis and/or occlusion were demonstrated in 26/53 arteries. Intravenous CT carotid-angiography revealed lesions with stenosis and/or occlusion in 25/53 arteries. Results of statistical analysis were as follows; overall diagnostic accuracy 52/53 (98%), diagnostic sensitivity 25/26 (96%) and diagnostic specificity 27/27 (100%), respectively.
Moreover, intravenous CT carotid-angiography provided following benefits beyond arteriography.
1) Minimal calcification of the carotid wall and precise localisation of atheromatous plaque could be detected.
2) Patent arterial lumen above the occluded lesion could be found out.
3) CT carotid-angiography would be suitable for the follow-up study after carotid endoarterectomy because of the unnecessity of catheterization.
4) Thrombus formation in the internal jugular vein could be grasped.