Diagnostic values of pulmonary ventilation perfusion planar imaging, pulmonary ventilation/perfusion SPECT/CT imaging and CTPA for pulmonary embolism

Abstract

Objective To study the diagnostic values of pulmonary ventilation-perfusion (V/Q) planar imaging, pulmonary ventilation/perfusion SPECT/CT (V/Q SPECT/CT) imaging and CT pulmonary angiography (CTPA) for pulmonary embolism (PE). Methods From October 2016 to June 2018, 54 patients (27 males, 27 females, age: (62.0±12.8) years) with suspected PE underwent V/Q planar imaging, V/Q SPECT/CT imaging and CTPA in the General Hospital of Northern Theater Command. The results of the above imaging methods were classified as definite PE, no PE and uncertain diagnosis according to the refined modified prospective investigation of pulmonary embolism diagnosis (PIOPEDⅡ) criteria, European Association of Nuclear Medicine (EANM) diagnosis criteria (2009) and the direct and indirect signs of PE, respectively. Based on the final clinical diagnosis, receiver operating characteristic (ROC) curves were drawn and the area under curves (AUCs) were compared to assess the diagnostic efficacies for PE. Kruskal-Wallis test and Wilcoxon rank sum test were used to analyze the difference of pulmonary segment and subsegment number detected by the above methods. Results Among 54 patients, 26 were definitely diagnosed as PE, and 28 were excluded. Patient numbers of uncertain diagnosis in V/Q planar imaging, V/Q SPECT/CT imaging and CTPA were 5, 1 and 4, respectively. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of the above imaging methods were 66.67%(16/24), 88.00%(22/25), 77.55%(38/49), 16/19, 73.33%(22/30); 92.31%(24/26), 92.59%(25/27), 92.45%(49/53), 92.31%(24/26), 92.59%(25/27); 69.57%(16/23), 96.30%(26/27), 84.00%(42/50), 16/17, 78.79%(26/33), respectively. The AUCs were 0.757, 0.926, and 0.809, respectively, there was a significant difference between the AUC of V/Q planar imaging and V/Q SPECT/CT (z=2.641, P 0.05). Numbers of subsegments detected by V/Q planar imaging, V/Q SPECT/CT imaging and CTPA were 2.00(0.00, 5.25), 4.00(2.75, 7.00) and 0.50(0.00, 3.25), respectively, and V/Q SPECT/CT detected more than others (z values: -3.700, -3.570, both P<0.05). Conclusion Pulmonary V/Q SPECT/CT imaging has a higher diagnostic efficacy in PE, especially in subsegmental PE. Key words: Pulmonary embolism; Radionuclide imaging; Tomography, emission-computed, single-photon; Tomography, X-ray computed; Angiography; Pulmonary artery; Technetium Tc 99m aggregated albumin