Pulmonary embolism: interobserver agreement in the interpretation of conventional angiographic and DSA images in patients with nondiagnostic lung scan results.

PURPOSE

To assess interobserver agreement in the interpretation of digital subtraction angiographic (DSA) images and conventional angiograms in patients with nondiagnostic lung scans.

MATERIALS AND METHODS

One hundred thirty of 397 consecutive patients (65 men, 65 women; mean age, 57 years; age range, 18-92 years) in this prospective cohort study underwent angiography. Conventional, selective series were obtained between 1991 and 1992 in 45 patients, and intraarterial DSA series were obtained between 1992 and 1994 in 85 patients. All angiograms were read immediately by the attending radiologist, independently by two radiologists after 6 months, and later by means of consensus of the two radiologists.

RESULTS

Results of the two methods were comparable. Interobserver disagreement occurred in 20%-36% (n = 9-16) of patients with conventional images and 4%-11% (n = 3-9) of patients with DSA images. Initial diagnoses were changed after the images were reviewed by means of consensus in 20% and 12% of patients with conventional and DSA series, respectively. In 70% of these patients, initial findings were false-positive; in 25%, inconclusive; and in 5%, false-negative.

CONCLUSION

Interobserver agreement is better with selective, intraarterial DSA than with conventional techniques.