The Diagnostic Accuracy of SPECT Imaging in Patients With Suspected Pulmonary Embolism

Background This meta-analysis and systematic review assessed the diagnostic accuracy of lung SPECT compared with lung planar imaging in patients with suspected acute pulmonary embolism (PE) or chronic thromboembolic pulmonary hypertension. Patients and Methods A search of Medline, Embase, and Cochrane databases identified suitable articles published before October 2023. Meta-analyses were performed to determine the diagnostic accuracy of SPECT imaging modalities, including perfusion (Q) SPECT, ventilation (V)/Q SPECT, Q SPECT/CT, and V/Q SPECT/CT. Network meta-analyses were performed to compare the diagnostic accuracy of SPECT and planar imaging in paired-design studies. Results Twenty-four articles (total n = 6576) were included in the analysis. For suspected acute PE, the respective sensitivity and specificity of SPECT imaging modalities were as follows: Q SPECT, 0.93 (95% confidence interval [CI], 0.87–0.99; I 2 = 49%) and 0.72 (95% CI, 0.54–0.95; I 2 = 94%); V/Q SPECT, 0.96 (95% CI, 0.94–0.98; I 2 = 51%) and 0.95 (95% CI, 0.92–0.98; I 2 = 80%); Q SPECT/CT, 0.93 (95% CI, 0.87–0.98; I 2 = 66%) and 0.82 (95% CI, 0.70–0.96; I 2 = 87%); and V/Q SPECT/CT, 0.97 (95% CI, 0.93–1.00; I 2 = 7%) and 0.98 (95% CI, 0.97–1.00; I 2 = 31%). The relative sensitivity and specificity of SPECT compared with planar imaging were 1.17 (95% CI, 1.06–1.30; P < 0.001) and 1.14 (95% CI, 1.00–1.29; P = 0.05), respectively. For suspected chronic thromboembolic pulmonary hypertension, the pooled sensitivity and specificity of SPECT imaging were 0.97 (95% CI, 0.95–1.00; I 2 = 0%) and 0.91 (95% CI, 0.87–0.94; I 2 = 0%), respectively. Conclusions SPECT exhibited superior diagnostic performance for PE. V/Q SPECT/CT was the most accurate modality.