Krypton-81m ventilation scintigraphy for the diagnosis of pulmonary emboli.

The value of ventilation studies in conjunction with pulmonary perfusion scintigraphies for the diagnosis of pulmonary emboli is reviewed. A retrospective study of 273 consecutive cases and comparison with 42 angiographic results provides the data base. The data are compared with previously reported results and confirm the diagnostic gain obtained by ventilation studies. Possible advantages of the use of krypton-81m for the ventilation study are suggested. Finally, with the observed prevalence of six possible scintigraphic outcomes and assuming that two outcomes are diagnostic, it can be shown that the addition of a ventilation study in the diagnostic work-up decreases the average cost of the diagnosis.