A comparison of ventilation perfusion combined with pulmonary perfusion fusion tomography imaging and CT pulmonary angiography for diagnosis of pulmonary embolism

Abstract

Objective To compare the diagnostic value of ventilation/perfusion (V/Q) combined with pulmonary perfusion single photon emission computed tomography combined with CT (SPECT/CT) fusion tomography imaging and computed tomographic pulmonary angiography (CTPA) in evaluation of pulmonary embolism. Methods We retrospectively analyzed 60 patients with clinically suspected pulmonary embolism diagnosed in Shanxi Dayi Hospital from May 2015 to May 2017. All patients underwent pulmonary V/Q imaging and lung perfusion SPECT/CT fusion tomography, and CTPA inspections were completed within 3 days. The final clinical diagnosis and follow-up confirmed the presence or absence of pulmonary embolism. The diagnostic efficacy of two imaging methods for pulmonary embolism were calculated and compared. Results Of the 60 cases of patients, 33 cases were diagnosed with pulmonary embolism; the sensitivity, specificity, and accuracy of V/Q combined with pulmonary perfusion SPECT/CT fusion tomography were 96.97% (32/33), 92.59% (25/27) and 95% (57/60), respectively; the sensitivity, specificity, and accuracy of CTPA were 81.82% (27/33), 92.59% (25/27) and 86.67% (52/60), respectively; both have no diagnostic uncertainty, there was no significant difference in the qualitative diagnosis of pulmonary embolism between the two examination methods (P>0.05). V/Q combined with pulmonary perfusion SPECT/CT fusion tomography found 253 lung segment and 50 unmatched sub-pulmonary segments, including 15 V/Q mismatch lung segment and 5 sub-segment caused by lung lesions which were confirmed by lung perfusion SPECT/CT fusion image (5 interlobular or pleural effusion, 4 local emphysema and pulmonary bulla, 3 interlobular hypertrophy, 8 pulmonary parenchymal inflammation); CTPA found 3 sub-segmental pulmonary filling defects, 6 cases of false-negative cases were multiple sub-pulmonary segment pulmonary embolism. Conclusions V/Q combined with pulmonary perfusion SPECT/CT fusion tomography is similar to CTPA in diagnosing pulmonary embolism, and both of them have better diagnostic efficacy; the former has advantages in the diagnosis of sub-pulmonary segment pulmonary embolism, and can exclude false-positive diagnoses due to other lung lesions and provide additional diagnostic information for lung disease. Key words: Pulmonary embolism; Tomography, emission-computed, single-photon; Radionuclide imaging; Angiography; Tomography, spiral computed