[Diagnosis of lung embolism]

Area of Science:

• Medical Imaging
• Diagnostic Medicine
• Cardiovascular Research

Background:

• Pulmonary embolism (PE) diagnosis is problematic, with only 20% of autopsy-proven cases identified during life.
• Current lung scan interpretations (high, indeterminate, low probability) often require pulmonary angiography, which is underutilized.
• Clinically silent PE and low pre-test probability complicate accurate diagnosis.

Purpose of the Study:

• To evaluate the diagnostic utility of lung scans for pulmonary embolism.
• To assess the impact of incorporating deep vein thrombosis (DVT) assessment on PE diagnosis.
• To improve the accuracy of diagnosing pulmonary embolism (PE).

Main Methods:

• Review of perfusion/ventilation (inhalation) scan interpretations and comparison with pulmonary angiography.
• Analysis of diagnostic probabilities based on scan results (high, indeterminate, low).
• Application of Bayes' theorem to evaluate post-test probability with and without considering co-existing thrombosis.

Main Results:

• High and low probability scans allow for definitive PE diagnosis, but the indeterminate group requires further testing.
• Pulmonary angiography, while definitive, is infrequently performed for PE diagnosis.
• Including thrombosis assessment increases PE pre-test probability to 55-60%, leading to >95% post-test probability.

Conclusions:

• Lung scan interpretation alone has limitations in diagnosing pulmonary embolism.
• Integrating deep vein thrombosis (DVT) assessment significantly enhances the diagnostic certainty of pulmonary embolism (PE).
• Improved diagnostic strategies are needed to address the challenges in identifying pulmonary embolism.