Which radiographic signs are classically described for pulmonary embolism on chest X-ray?

Which radiographic signs are classically described for pulmonary embolism on chest X-ray?

• A. Westermark's sign and Hampton's hump
• B. Klebsiella pneumonia signs
• C. Lung hyperinflation
• D. Diffuse hazy markings

Answer: (B)

The main idea here is that chest X-ray findings for pulmonary embolism are classically described as two signs, though they’re not highly sensitive. The first is Westermark’s sign, which is a focal pruning or cutoff of the pulmonary vessels beyond the level of the embolus due to reduced blood flow (oligemia) distal to the blockage. The second is Hampton’s hump, a wedge-shaped, pleural-based opacity that represents a small infarct at the lung edge next to the pleura. These signs are historically described for PE, but many emboli do not produce them, and the chest X-ray can be normal in PE. That’s why imaging for PE relies more on CT pulmonary angiography or, when those aren’t available or feasible, a ventilation-perfusion scan, rather than on chest X-ray findings alone. The other options aren’t used to describe pulmonary embolism on chest X-ray: signs of Klebsiella pneumoniae would point to bacterial pneumonia; lung hyperinflation is typical of obstructive airway diseases; diffuse hazy markings are non-specific and can reflect edema, many infections, or other processes, not PE.

The main idea here is that chest X-ray findings for pulmonary embolism are classically described as two signs, though they’re not highly sensitive. The first is Westermark’s sign, which is a focal pruning or cutoff of the pulmonary vessels beyond the level of the embolus due to reduced blood flow (oligemia) distal to the blockage. The second is Hampton’s hump, a wedge-shaped, pleural-based opacity that represents a small infarct at the lung edge next to the pleura.

These signs are historically described for PE, but many emboli do not produce them, and the chest X-ray can be normal in PE. That’s why imaging for PE relies more on CT pulmonary angiography or, when those aren’t available or feasible, a ventilation-perfusion scan, rather than on chest X-ray findings alone.

The other options aren’t used to describe pulmonary embolism on chest X-ray: signs of Klebsiella pneumoniae would point to bacterial pneumonia; lung hyperinflation is typical of obstructive airway diseases; diffuse hazy markings are non-specific and can reflect edema, many infections, or other processes, not PE.