[Reliability of pulmonary perfusion and ventilation scintigraphy compared with angiopneumography for the diagnosis of pulmonary embolism].

Fourty-six patients suspected clinically of having a pulmonary embolism (PE) were investigated by angiopneumography (AGP) and perfusion (99m-Tc aggregates) and ventilation (99m-Tc colloid) scintigraphy (SPV Tc). Findings were assessed under blind conditions. A positive diagnosis of pulmonary embolism was made in 19 patients. The SPV Tc was considered as positive if perfusional deficiencies were greater than ventilatory defects, and this was evaluated as such in 23 cases (19 true and 4 false positives). False negatives were not observed. The 4 false positive results corresponded to scintigraphic anomalies suggestive of pulmonary emboli subsegmental in size; true positives were either subsegmental (8), segmental (6) or lobar (5). Sensitivity of the SPV Tc wis therefore 100%; its specificity, all results considered was 76%, but was 100% if only images of lobar or segmental lesions are considered.