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Chest Imaging

E2735. Respiratory Physician Input in Increasing the Diagnostic Yield of Pulmonary CT Angiography

Ross T,  Dimigen M,  Prabhakar C. Royal Prince Alfred Hospital, Sydney, Australia

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Objective: Pulmonary CT angiography (CTA) is increasingly used in the diagnosis of acute pulmonary embolus (PE); however, this comes with the consequence of increasing radiation dose to the patient and overuse of the test with resultant decline in the yield of the study. Current guidelines would recommend evaluation of the pretest probability of PE before the use of pulmonary CTA. The aim of this study is to assess whether preapproval for pulmonary CTA by a respiratory physician affects the positive yield of pulmonary CTA for acute PE.

Materials and Methods: A retrospective cohort study was undertaken reviewing 1018 consecutive pulmonary CTA studies at a tertiary referral hospital over a period of 18 months. The rates of positive pulmonary CTA were compared between the groups that did and did not have respiratory preapproval for the study.

Results: After exclusions, a total of 966 studies were analyzed. Acute PE was diagnosed in 20.5%. Respiratory preapproval was obtained in 86.1% of studies, with a positive rate of 21.8%, compared to 12.7% (p < 0.05).

Conclusion: Preapproval for pulmonary CTA by an experienced respiratory physician may be a valid tool for assessing pretest probability and subsequently reducing the overuse of pulmonary CTA.