Which imaging modality is most useful for assessing progression of ARDS?

• A. Chest X-ray showing diffuse bilateral interstitial and alveolar infiltrates (CT can provide more detail)
• B. PET scan
• C. Echocardiography
• D. Abdominal ultrasound

Answer: (A)

Monitoring ARDS relies on imaging that shows how the lungs’ edema and infiltrates change over time. A chest X-ray is the best tool for this because it’s quick, portable, and repeatable at the bedside, making it ideal for tracking progression or improvement of diffuse bilateral infiltrates that characterizes ARDS. Serial chest radiographs let you see whether the edema is worsening, stabilizing, or resolving, and you can correlate those findings with ventilation changes and clinical status.

CT scans can offer more detail, but they’re not practical for routine monitoring due to the need to move a critically ill patient and higher radiation, so they’re used selectively rather than for ongoing progression assessment. PET scans don’t assess edema or lung injury progression—they measure metabolic activity. Echocardiography evaluates cardiac function and can help distinguish cardiogenic from noncardiogenic edema, but it doesn’t track the progression of ARDS itself. Abdominal ultrasound isn’t relevant to assessing lung injury progression.