Accuracy of swirl sign for predicting hematoma enlargement in intracerebral hemorrhage: a meta-analysis

Background: Hematoma enlargement happens in about 30% patients with intracerebral hemorrhage, which is reported to be closely correlated with poor prognosis. Swirl sign has been reported to have correlation with hematoma enlargement. This meta-analysis analyzed the accuracy of swirl sign for predicting hematoma enlargement in intracerebral hemorrhage. Methods: Five databases were searched for potentially eligible literature. Studies were included if they were about the predictive properties of swirl sign for hematoma enlargement in intracerebral hemorrhage. Sensitivity and specificity of swirl sign for hematoma enlargement prediction were pooled. Pooled positive and negative likelihood ratios were also calculated. Results: Six studies with 2647 patients were finally included in meta-analysis. The pooled sensitivity and specificity of swirl sign were 0.45 (95%CI 0.32-0.59) and 0.79 (95%Cl 0.73-0.84), respectively. The pooled positive likelihood ratio of swirl sign was 2.2 (95%CI 1.8-2.5). In contrast, the pooled negative likelihood ratio of swirl sign was 0.69 (95%CI 0.57-0.84). Conclusions: This meta-analysis suggests that swirl sign has the relatively high specificity for hematoma enlargement prediction in patients with intracerebral hemorrhage.