Pulmonary embolism-diagnosis by lung perfusion scintigraphy or digital subtraction angiography

A consecutive series of 40 patients with suspicion of acute pulmonary embolism was examined with digital subtraction angiography and perfusion scintigraphy. Ventilation scintigraphy was used in some patients with equivocal findings at the other examinations. Perfusion scintigraphy and DSA was evaluated independently first and then together for establishment of a consensus of which diagnosis was correct. Eighteen of the 40 patients were diagnosed to have lung emboli. Scintigraphy and DSA were in accord in 75% of the patients. A positive predictive value 0.77 was found for scintigraphy and 1.0 for DSA while negative predictive value was 0.94 and 0.85 respectively. The cause of the lower negative predictive value for DSA was poor image quality due to lacking patient cooperation