SPECT Ventilation/Perfusion Imaging for Acute Pulmonary Embolism: Meta-analysis of Diagnostic Test Accuracy

This study aimed to evaluate the diagnostic accuracies of ventilation/perfusion-single photon emission computed tomography (V/Q-SPECT) imaging modalities for acute pulmonary embolism (PE). These included, in addition to V/Q-SPECT, V/Q-SPECT with low-dose computed tomography (CT; V/Q-SPECT-CT), Q-SPECT with low-dose CT (Q-SPECT-CT), and Q-SPECT.

PubMed, Embase, CINAHL, and Web of Science databases were searched, and studies included if they studied ≥10 adult participants with acute PE and reported data on the imaging tests' diagnostic performance. Data were meta-analyzed using bivariate random effects regression model.

Data from participants totaling 4146 from 11 V/Q-SPECT studies, 785 from 7 V/Q-SPECT-CT studies, 1196 from 7 Q-SPECT-CT studies, and 728 from five Q-SPECT studies were separately meta-analyzed. The bivariate weighted mean sensitivity and specificity were 0.94 (95% confidence interval [CI]: 0.88-0.97) and 0.95 (95% CI: 0.87-0.98) for V/Q-SPECT, 0.95 (95% CI: 0.88-0.98) and 0.99 (95% CI: 0.92-1.00) for V/Q-SPECT-CT, 0.92 (95% CI: 0.79-0.97) and 0.92 (95% CI: 0.83-0.96) for Q-SPECT-CT, and 0.89 (95% CI: 0.76-0.95) and 0.86 (95% CI: 0.67-0.95) for Q-SPECT studies. The positive and negative likelihood ratios (+LRs and -LRs) were 17.4 (6.9-44.0) and 0.06 (0.03-0.13), 76.7 (11.8-498.0) and 0.06 (0.02-0.13), 11.0 (5.3-22.9) and 0.09 (0.04-0.23), and 6.4 (2.6-15.8) and 0.13 (0.07-0.27) for V/Q-SPECT, V/Q-SPECT-CT, Q-SPECT-CT, and Q-SPECTs, respectively.

In the diagnosis of acute PE, this meta-analysis showed that V/Q-SPECT-CT had the highest specificity and +LR. Conversely, Q-SPECT showed the lowest specificity and an unfavorably high -LR.