Pulmonary embolism: prediction of the usefulness of initial ventilation-perfusion scanning with chest radiographic findings.

PURPOSE

To evaluate the usefulness of ventilation-perfusion scanning when chest radiographic findings are abnormal to decide which patients should initially undergo angiography because of suspected pulmonary embolism.

MATERIALS AND METHODS

The records of 951 patients who underwent examination between April 1, 1992, and August 24, 1993, were reviewed, and the results of ventilation-perfusion scanning and chest radiography were correlated.

RESULTS

Approximately 8% of patients with radiographic findings of no acute disease, pleural effusion, and linear atelectasis had high-probability ventilation-perfusion scans. Pulmonary edema and parenchymal consolidation categories had fewer high-probability studies (3% and 1%, respectively; P < .01). The chance of obtaining a nondiagnostic result was similar for the first three categories (12%) but was more likely for pleural effusion and parenchymal consolidation (36% and 82%, respectively; P < .01).

CONCLUSION

The results of ventilation-perfusion scanning are not useful with focal radiographic consolidation. It may be appropriate to proceed directly to pulmonary angiography in many of these patients.