To evaluate the performance of transcranial Doppler and transcranial color-coded duplex Doppler in patients with cerebral vasospasm due to aneurysm rupture. Angiography was considered as the gold standard comparator.
Search in MEDLINE, Embase, and Central from January 2001 to October 2017, without language restriction. Bibliographies of retrieved articles were screened for additional studies.
Randomized studies comparing transcranial Doppler or transcranial color-coded duplex Doppler with angiography in adults.
Data were extracted independently by several investigators. Sensitivity and specificity were combined across studies using a bivariate model. Preferred Reporting Items for Systematic Reviews and Meta-Analyses was used for reporting and Quality Assessment of Diagnostic Accuracy Studies-2 for quality assessment.
We included 18 studies. Fifteen tested transcranial Doppler. For the middle cerebral artery (10 studies, 1,408 tests), the pooled sensitivity was 66.7% (95% CI, 55.9–75.9) and specificity was 89.5% (80.3–94.7). Three studies (278 tests) tested transcranial color-coded duplex Doppler for the middle cerebral artery. The pooled sensitivity was 81.5% (66.0–90.0), and specificity was 96.6% (93.0–98.0). For an arbitrarily chosen prevalence of vasospasm of 70%, positive and negative predictive values were 93.7% (88.9–96.6) and 53.4% (46.7–60.9) for transcranial Doppler and 98.2% (96.4–99.1) and 69.1% (56.1–80.9) for transcranial color-coded duplex Doppler.
Assuming a high prevalence of vasospasm of the middle cerebral artery, both transcranial Doppler and transcranial color-coded duplex Doppler are likely to detect it, but neither is useful to exclude it. There is no convincing evidence that the accuracy of transcranial color-coded duplex Doppler is any better than that of transcranial Doppler. For arteries other than middle cerebral artery, there is a lack of evidence of the usefulness of transcranial Doppler.