Ventilation-perfusion imaging and pulmonary angiography: changing pattern of use

Area of Science:

• Medical imaging
• Pulmonary medicine
• Nuclear medicine

Background:

• The University of Virginia Medical Center observed trends in diagnostic procedures between 1976 and 1980.
• A shift was noted in the relative frequency of ventilation versus perfusion studies.
• There was a concurrent decrease in the frequency of diagnosing pulmonary embolism using ventilation-perfusion scans.

Purpose of the Study:

• To analyze trends in diagnostic imaging for pulmonary embolism.
• To evaluate the accuracy of nuclear medicine lung scans.
• To revise interpretation criteria and indications for pulmonary angiography.

Main Methods:

• Retrospective review of hospital and departmental records from 1976-1980.
• Analysis of the frequency of ventilation studies, perfusion studies, and pulmonary angiograms.
• Review of 70 patients with correlating pulmonary angiography or autopsy findings.

Main Results:

• An increasing frequency of ventilation studies relative to perfusion studies was observed.
• The frequency of diagnosing pulmonary embolism via ventilation-perfusion scans decreased.
• Pulmonary angiograms increased from 1 per 68 nuclear studies to 1 per 14.
• Nuclear medicine lung scans demonstrated 89% accuracy in a subset of 70 patients.

Conclusions:

• Nuclear medicine lung scans are highly accurate for diagnosing pulmonary embolism.
• Revised interpretation criteria and indications for pulmonary angiography enhance diagnostic utility.
• These findings support optimized diagnostic pathways for pulmonary embolism.