Systematic review of computed tomographic angiography for assessment of carotid artery disease

Background and Purpose - To review the literature on the diagnostic accuracy of computed tomographic angiography (CTA) compared with arteriography/intra-arterial digital subtraction angiography as reference standard for assessment of symptomatic carotid artery disease. Methods - The PubMed, MEDLINE, PREMEDLINE, EMBASE, and CINAHL databases were searched to retrieve studies published between 1990 and July 2003, comparing CTA and intra-arterial digital subtraction angiography in patients with symptomatic carotid artery disease that presented raw data for detection of a < 70% or 70% to 99% stenosis or an occlusion. Two observers independently assessed methodological quality and constructed 2 x 2 tables for sensitivity and specificity of CTA for detection of a 70% to 99% stenosis versus < 70% stenosis or an occlusion, and for < 99% stenosis versus occlusion. A bivariate random effects model was used to calculate the pooled sensitivity and specificity of CTA for detection of these lesions. Results - Some 864 patients (66% male) with a mean age of 66 years were studied in the 28 studies included in the meta-analysis. In all studies, a single-slice CT-scan was used. Only 8 studies satisfied all methodological quality criteria. The pooled sensitivity and specificity for detection of a 70% to 99% stenosis were 85% (95% CI, 79% to 89%) and 93% ( 95% CI, 89% to 96%), respectively. For detection of an occlusion, the sensitivity and specificity were 97% ( 95% CI, 93% to 99%) and 99% ( 95% CI, 98% to 100%), respectively. Incomplete reporting of demographic characteristics and technical differences in the individual studies obstructed a meaningful subgroup analysis. Conclusions - CTA is an accurate modality for detection of severe carotid artery disease, especially for detection of occlusions. The fair methodological quality of the included studies must be taken into account when interpreting these results.