Diffusion-Weighted Magnetic Resonance Imaging in the Diagnosis of Cerebral Venous Thrombosis : A Meta-Analysis

Abstract

Objective: A role of diffusion-weighted imaging (DWI) in the diagnosis of cerebral venous thrombosis (CVT) is not wellunderstood. This study evaluates the effectiveness of DWI in the diagnosis of CVT.

Methods: Literature search was conducted in electronic databases for the identification of studies which reported the outcomes of patients subjected to DWI for CVT diagnosis. Random-effects meta-analyses were performed to achieve overall estimates of important diagnostic efficiency indices including hyperintense signal rate, the sensitivity and specificity of DWI in diagnosing CVT, and the apparent diffusion coefficient (ADC) of DWI signal areas and surrounding tissue.

Results: Nineteen studies (443 patients with 856 CVTs; age 40 years [95% confidence interval (CI), 33 to 43]; 28% males [95% CI, 18 to 38]; symptom onset to DWI time 4.6 days [95% CI, 2.3 to 6.9]) were included. Hyperintense signals on DWI were detected in 40% (95% CI, 26 to 55) of the cases. The sensitivity of DWI for detecting CVT was 22% (95% CI, 11 to 34) but specificity was 98% (95% CI, 95 to 100). ADC values were quite heterogenous in DWI signal areas. However, generally the ADC values were lower in DWI signal areas than in surrounding normal areas (mean difference-0.33×10-3 mm2/s [95% CI, -0.44 to -0.23]; p<0.00001).

Conclusion: DWI has a low sensitivity in detecting CVT and thus has a high risk of missing many CVT cases. However, because of its high specificity, it may have supporting and exploratory roles in CVT diagnosis.

Keywords: Diagnosis; Magnetic resonance imaging, Diffusion weighted; Sensitivity; Specificity; Thrombosis, Cerebral venous.

Fig. 1.

A flowchart of study screening and selection process.

Fig. 2.

A funnel plot corresponding to the meta-analysis of diffusion-weighted imaging hyperintense signal rate showing the outcomes of trim and fill method of publication bias assessment. Circles show studies included in the meta-analysis whereas circles within squares show possible missing studies. S.E. : standard error.

Fig. 3.

A forest plot showing the overall effect size of percent rate of hyperintense signal on DWI in cerebral venous thrombosis cases. In study identities, in case of Linn et al.[18]fi, first values are for cortical vein, and second for superior sagittal sinus. In case of Sadigh et al.[25], fifirst and second values denote investigator 1 and 2. ES : effect size, CI : confidence interval, DWI : diffusion-weighted imaging.

Fig. 4.

A forest plot showing the pooled sensitivity and specificity values in diagnosing cerebral venous thrombosis by diffusion-weighted imaging. ES : effect size, CI : confidence interval, AUC : area under curve, PPV : positive predictive value, NPV : negative predictive value.

Fig. 5.

A forest plot showing the mean difference between ADC values in thrombosed areas and surrounding areas of patients with cerebral venous thrombosis. DWI : diffusion-weighted imaging, ADC : apparent diffusion coefficient, SD : standard deviation, CI : confidence interval.