Which radiologic finding indicates acute respiratory distress syndrome (ARDS)?

• A. Widened costophrenic angles
• B. Ground glass opacities
• C. Kerley-A lines
• D. Decreased lung sliding

Answer: (B)

The key idea is that ARDS produces diffuse, hazy opacities in the lungs due to widespread alveolar damage and edema. When the alveolar-capillary barrier is injured, protein-rich fluid leaks into the interstitium and air spaces, causing partial filling of the alveoli. On imaging this shows up as ground-glass opacities—hazy areas that blur the edges of vessels but don’t completely obscure them. These opacities are typically bilateral and can be basilar-predominant, reflecting the global nature of the injury in ARDS.

This pattern helps distinguish ARDS from other findings. Widened costophrenic angles suggest a pleural effusion, not the diffuse alveolar damage of ARDS. Kerley lines indicate interstitial edema often seen with cardiogenic causes like heart failure. Decreased lung sliding is an ultrasound finding that points toward pneumothorax or pleural issues, not the diffuse alveolar involvement characteristic of ARDS. So, ground-glass opacities best align with ARDS imaging features.