What is the typical imaging sequence used in diagnosing pulmonary embolism, in order from initial to final confirmation?

What is the typical imaging sequence used in diagnosing pulmonary embolism, in order from initial to final confirmation?

• A. D-dimer, CT, then MRI
• B. V/Q Scan, CT, and Pulmonary Angiography
• C. Ultrasound, CT, MRI
• D. MRI, CT, and V/Q Scan

Answer: (B)

Diagnosing pulmonary embolism is done with a stepwise imaging approach that moves from noninvasive screening to definitive confirmation. A ventilation-perfusion scan can be a first noninvasive study, especially when CT with contrast is not available or is contraindicated, helping to identify mismatches that suggest PE. If the V/Q result is nondiagnostic or conflicts with the clinical picture, the next step is CT pulmonary angiography, which directly shows filling defects in the pulmonary arteries and serves as the main diagnostic test. If CT results are inconclusive or suspicion remains high despite a negative or equivocal CT, invasive pulmonary angiography provides definitive confirmation. Other options mix in tests that aren’t part of the typical imaging sequence for PE, such as relying on D-dimer alone or using MRI as a first-line diagnostic tool.

Diagnosing pulmonary embolism is done with a stepwise imaging approach that moves from noninvasive screening to definitive confirmation. A ventilation-perfusion scan can be a first noninvasive study, especially when CT with contrast is not available or is contraindicated, helping to identify mismatches that suggest PE. If the V/Q result is nondiagnostic or conflicts with the clinical picture, the next step is CT pulmonary angiography, which directly shows filling defects in the pulmonary arteries and serves as the main diagnostic test. If CT results are inconclusive or suspicion remains high despite a negative or equivocal CT, invasive pulmonary angiography provides definitive confirmation. Other options mix in tests that aren’t part of the typical imaging sequence for PE, such as relying on D-dimer alone or using MRI as a first-line diagnostic tool.