Comparative study of pulmonary ventilation/perfusion planar imaging and pulmonary perfusion SPECT combined with low-dose CT in the diagnosis of pulmonary embolism

Objective To study the value of traditional pulmonary ventilation-perfusion(V/Q)planar imaging and pulmonary perfusion SPECT combining with low-dose CT(Q SPECT/CT) in the diagnosis of pulmonary embolism.

Methods Sixty nine patients with suspected pulmonary embolism were collected. Pulmonary V/Q planar imaging was performed in all the patients, meanwhile, pulmonary Q SPECT/CT was taken. Taking the final clinical diagnosis results as the gold standards and then compared and analyzed the diagnosis results of the two methods.

Results Among the 69 suspected pulmonary embolism patients, 43 cases were confirmed, 26 excluded. The sensitivity, accuracy, negative predictive value and the Kappa value of the final clinical diagnosis result of pulmonary Q SPECT/CT in the diagnosis of pulmonary embolism were all higher than those of V/Q planar imaging. While, the diagnostic specificity in those patients with chronic obstructive pulmonary disease(COPD) operated by pulmonary Q SPECT/CT was lower than that of V/Q planar imaging. After adjusting the impact of COPD patients, the specificity of pulmonary Q SPECT/CT improved obviously, and was higher than that of V/Q planar imaging. The consistency of pulmonary embolism detection rate by the two methods was 85%(34/40)and the difference of the detection rate between the two methods was significant(χ²=8.10, P < 0.05).

Conclusion Pulmonary Q SPECT/CT obviously improved the diagnostic value of pulmonary embolism without COPD, so it should be deliberated whether it takes the place of the V/Q planar imaging.