Comparative Ultrasonographic and Angiographic Study of Carotid Arterial Lesions in Takayasu's Arteritis

Abstract

The purpose of this study was to compare the usefulness of ultrasonography to that of angiography for studying arterial lesions in Takayasu's arteritis.

Ultrasonographic and angiographic findings from 44 carotid arteries of 22 patients with Takayasu's arteritis (2 men and 20 women; mean age, 41.2 years) were compared. Angiography was used to classify the patency of the carotid arteries into three groups: nonstenotic, stenotic, and occlusive. Ultrasonography was also used to classify the same arteries into four groups: nonstenotic, mildly stenotic, moderately stenotic, and occlusive. Thickness of the wall (intima-media complex) of the carotid artery was measured with high-frequency transducers.

Angiography showed 23 carotid arteries to be nonstenotic; 12, stenotic; and 9, occlusive; whereas ultrasonography showed 16 to be nonstenotic; 18, mildly stenotic; 7, moderately stenotic; and 3, occlusive. Results of the two diagnostic modalities correlated closely (P < 0.0001). Ultrasonography, aided by color flow imaging, detected six instances of a marginal but definite blood flow that angiography had failed to reveal. Arterial wall thickness correlated closely with the severity of ultrasonographic stenosis (P < 0.005). This thickness was 1.3 ±0.4 mm in the nonstenotic group, 1.6 ± 0.5 mm in the mildly stenotic group, 2.2 ±0.8 mm in the moderately stenotic group, and 1.9 ±0.2 mm in the occlusive group. Even the walls of the nonstenotic arteries were significantly thicker than those of the normal carotid arteries (0.7 ±0.1 mm, P < 0.01).

Ultrasonography appeared to be more useful than angiography in estimating stenotic severity of the carotid artery in Takayasu's arteritis. Characteristic ultrasonic findings included luminal stenosis or occlusion on two-dimensional ultrasonograms, decrease in or lack of flow shown by color Doppler flow imaging, and concentric thickening of the carotid arterial walls. Ultrasonographic mural thickness was the most sensitive indicator of early, latent inflammation.