Abstract 1598: The Effect of Imaging Modality on Patient Management in the Evaluation of Pulmonary Embolism
AUTHORS:
T.L. Crawford, BS, C. Yoon, MD, PhD, A.M. Emerick, BS, K. Wolfson, MD, M.J. Beller, MD, J.G. Goldin, MBChB, PhD, et al.
ABSTRACT:
PURPOSE: To determine from a retrospective review of patients with suspected PE:[1] differences in clinical/risk profiles between patients who undergo V/Q scans versus CT pulmonary angiography (CTA);(2) risks factors that correlate with a positive study; and (3) the imaging modality associated with more evidence-based management.
METHOD AND MATERIALS: 149 consecutive patients who underwent CTA for suspected PE were compared with 138 consecutive patients who underwent V/Q scans during equivalent six month intervals before and after the availability of CTA. Records were reviewed for: (1) potential risk factors for PE; (2) results of all diagnostic studies for thromboembolism; and (3) management of patients relative to study results.
RESULTS: Clinical risk profiles were comparable in both cohorts. For the CTA cohort, results were negative in 119 (79.9%), positive in 23 (15.4%), and indeterminate in 7 (4.7%). For the V/Q cohort, probability scores were normal or low in 88 (63.8%), intermediate/indeterminate in 35 (25.4%), and high probability in 15 (10.9%). The following risk factors correlated with PE in patients undergoing CTA: cough, dyspnea, widened Aa gradient, lower extremity signs or symptoms of venous thrombosis, recent major surgery or trauma, and prolonged bed rest. Significant co-variates for PE in the V/Q cohort were dyspnea, widened Aa gradient, sinus tachycardia, and venous insufficiency. Of patients with diagnostic CTA, management was consistent with test results. Among 7 patients with indeterminate CTA, 6 underwent additional tests, the results upon which management was based. One patient with an indeterminate CTA had no further tests and was not treated for PE. Among patients with V/Q scans of normal/low or high probability, management was consistent with test results. In 22 patients with indeterminate V/Q scans, 10 had negative duplex exams, 1 had a negative serum D-dimer assay, and none were treated. In the remaining 11 patients, no additional tests were performed and they were not treated for PE. No patients with indeterminate V/Q scans underwent classical pulmonary angiography.
CONCLUSIONS: There was no significant difference in the risk profiles of the 2 groups. The management of patients undergoing CTA was consistent 384with test outcome in > 99% of patients, compared with 84% when V/Q scanning was used as the primary screening test.
