What is a common radiological feature of atelectasis?

The common radiological feature of atelectasis is the presence of an air bronchogram. This occurs when the air-filled bronchi stand out against collapsed lung tissue, allowing visualization of the bronchi on an imaging study. In atelectasis, alveoli collapse, leading to decreased lung volume and potentially obstructing airways. As a result, the surrounding lung tissue may no longer be adequately aerated, making the air-filled bronchi visible, which present as dark branching structures on X-ray or CT images.

Understanding this feature is crucial for radiologists and healthcare providers because it aids in diagnosing conditions associated with incomplete lung expansion or obstruction. Other options, while they have their respective conditions, do not specifically indicate atelectasis. For instance, blunting of costophrenic angles is more commonly associated with pleural effusion, ground-glass opacities can indicate interstitial lung disease or pulmonary edema, and patchy infiltrates suggest pneumonia or lung infections. None of these features directly point to atelectasis as prominently as the air bronchogram does.