Diagnostic accuracy of CT angiography and CT perfusion for cerebral vasospasm: a meta-analysis

Abstract

Background and purpose: In recent years, the role of CTA and CTP for vasospasm diagnosis in the setting of ASAH has been the subject of many research studies. The purpose of this study was to perform a meta-analysis of the diagnostic performance of CTA and CTP for vasospasm in patients with ASAH by using DSA as the criterion standard.

Materials and methods: The search strategy for research studies was based on the Cochrane Handbook for Systematic Reviews, including literature data bases (PubMed, Embase, Cochrane Database of Systematic Reviews, and the Web of Science) and reference lists of manuscripts published from January 1996 to February 2009. The inclusion criteria were the following: 1) published manuscripts, 2) original research studies with prospective or retrospective data, 3) patients with ASAH, 4) CTA or CTP as the index test, and 5) DSA as the reference standard. Three reviewers independently assessed the quality of these research studies by using the QUADAS tool. Pooled estimates of sensitivity, specificity, LR+, LR-, DOR, and the SROC curve were determined.

Results: CTA and CTP searches yielded 505 and 214 manuscripts, respectively. Ten research studies met inclusion criteria for each CTA and CTP search. Six CTA and 3 CTP studies had sufficient data for statistical analysis. CTA pooled estimates had 79.6% sensitivity (95%CI, 74.9%-83.8%), 93.1%specificity (95%CI, 91.7%-94.3%), 18.1 LR+ (95%CI, 7.3-45.0), and 0.2 LR- (95%CI, 0.1-0.4); and CTP pooled estimates had 74.1% sensitivity (95%CI, 58.7%- 86.2%), 93.0% specificity (95% CI, 79.6%-98.7%), 9.3 LR+ (95%CI, 3.4-25.9), and 0.2 LR- (95%CI, 0.04-1.2). Overall DORs were 124.5 (95%CI, 28.4-546.4) for CTA and 43.0 (95%CI, 6.5-287.1) for CTP. Area under the SROC curve was 98 ± 2.0%for CTA and 97 ± 3.0% for CTP.

Conclusions: The high diagnostic accuracy determined for both CTA and CTP in this meta-analysis suggests that they are potentially valuable techniques for vasospasm diagnosis in ASAH. Awareness of these results may impact patient care by providing supportive evidence for more effective use of CTA and CTP imaging in ASAH.

Fig 1.

SROC curve for the CTA meta-analysis. Each black diamond represents an individual research study in the CTA meta-analysis, with the size of the diamond directly proportional to the sample size of the study. The best fit curve (middle curve) lies between the other 2 curves, which demarcate its 95% CI. The circle denotes the Q*-point.

Fig 2.

Forest plot of the DOR for the CTA meta-analysis. The DOR for each research study is represented by circles. The 95% CI is represented by the horizontal lines through each circle. The pooled DOR for this meta-analysis is represented by the diamond symbol.