Imaging of Patients Suspected of Having Pulmonary Thrombo-Embolic Disease; The Value of Chest X-Ray Combined with Perfusion Scan

Objective: To determine the value of a recent chest x-ray (done within 24 hours of the perfusion scan) combined with perfusion in diagnosing acute pulmonary thromboembolism in clinical settings. Methodology: Retrospective analysis of 155 consecutive patients clinically suspected with pulmonary thromboembolism between January 2017 and January 2019, who underwent a lung scintigraphy. Results: Most of the study participants (75.5%) were black Africans. The overall population studied had a mean age of 50.09 years (SD 16.78). A recent chest x-ray was found in 40.1% of the projected sample size of 386 patients. The sensitivity and specificity of the PISAPED 1 reader were 96% and 97%, respectively, with a NPV and PPV of 99% and 89%. The sensitivity and specificity of the PISAPED 2 reader were both 96%, with a NPV and PPV of 86%and 99%, respectively. The PIOPED II and the PISAPED 1 had an agreement of 88.39% (Kappa value of 0.7348) while the PIOPED II and the PISAPED 2 had an agreement of 88.39% (Kappa value of 0.7444). Conclusion: Chest x-ray in conjunction with perfusion scintigraphy is accurate and can be used where ventilation/perfusion scintigraphy cannot be done in the diagnosis of pulmonary embolism.