Intravenous digital subtraction angiography and lung imaging: compared value in the diagnosis of pulmonary embolism.

In a prospective study, 42 consecutive patients with clinically suspected pulmonary embolism underwent ventilation-perfusion (V-Q) lung imaging and digital subtraction angiography (DSA) concurrently with selective conventional pulmonary angiography (CPA). Thirty-eight studies achieved within 24 hours were reviewed independently by two pairs of observers. The findings were compared using CPA as the gold standard. V-Q lung imaging had a high percentage of indeterminate results, but none were false negative nor false positive. DSA had a lower percentage of indeterminate results but missed four of the 25 positive cases and erroneously affirmed the presence of pulmonary embolism in three cases. Therefore, the authors think that V-Q lung imaging should remain the screening examination of choice for evaluating patients with suspected pulmonary embolism.