Interpretation of Ventilation-Perfusion Lung Scans |
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| Scan Interpretation | Frequency of Pulmonary Embolism | Indicated Course |
| High Probability Two or more near-segmental or larger perfusion defects without matching ventilation defects |
86-88% | Anticoagulation |
| In determinant Not fitting into other categories |
21-33% | Pulmonary Arteriogram |
| Low Probability
a. Subsegmental perfusion defects b. Single moderate perfusion defects c. Matched ventilation-perfusion defects d. Perfusion defects associated with roentgenographic infiltrates |
16-40% | a. If clinical suspicion of pulmonary embolism is low,
no further testing. b. If clinical suspicion of roentgenographic infiltrates pulmonary embolism is high, pulmonary arteriogram |
| Normal/Near-normal Perfusion | 0-4% | No further testing |