POSSIBLE PULMONARY EMBOLUS - EVALUATION WITH DIGITAL SUBTRACTION VERSUS CUT-FILM ANGIOGRAPHY - PROSPECT STUDY IN 80 PATIENTS

PURPOSE: To determine whether intraarterial digital subtraction angiog raphy (DSA) is as accurate as cut-film (film hard-copy) angiography (C FA) in the evaluation of suspected pulmonary embolus. MATERIALS AND ME THODS: Under a protocol approved by the,institutional review board, CF A and DSA images were obtained in identical posteroanterior and obliqu e projections in one lung of each patient undergoing pulmonary angiogr aphy. (n = 80). Diagnoses based on results of blinded review of each s tudy (CFA vs DSA) by three separate reviewers (80 patients x three rev iewers = 240 diagnoses for each modality) were compared with the diagn oses made by the physician who performed the procedure on the basis of CFA, DSA, and clinical data and with the:consensus diagnoses obtained by means of group review of both studies together if necessary. The r eviewers' confidence in their diagnoses was graded from 1 (certain) to 10 (uncertain). RESULTS: Pulmonary emboli were present in 13(16%) of 80 patients, Two hundred thirty-six (98.3%) of 240 DSA diagnoses and 2 31 (96.3%) of 240 CFA diagnoses were correct. The sensitivity (correct identification of emboli by all three reviewers) of DSA was 92% and o f CFA was 69% (P = .083).:The specificities of the modalities were not statistically significantly different. The reviewers confidence was S ignificantly better in their DSA diagnoses than in their CFA diagnoses (P < .004). CONCLUSION: DSA allows more confident detection of pulmon ary embolus than does CFA, with no loss in diagnostic accuracy.