In the diagnosis of Acute Respiratory Distress Syndrome (ARDS), which imaging finding is typically expected?

In the context of diagnosing Acute Respiratory Distress Syndrome (ARDS), bilateral infiltrates on chest X-ray are a hallmark finding. This imaging characteristic reflects the pathological process occurring in ARDS, where there is widespread inflammation in the lungs, leading to increased permeability of the alveolar-capillary membrane. This results in the accumulation of fluid in the alveoli, ultimately manifesting as bilateral opacities on imaging.

These infiltrates typically appear as patchy or diffuse areas of opacity, indicative of edema and atelectasis, and they are crucial for differentiating ARDS from other respiratory disorders. The presence of bilateral infiltrates is essential in the diagnostic criteria for ARDS per the Berlin Definition, which classifies the syndrome based on timing, origin of edema, and severity.

While the other options may be encountered in various respiratory conditions, they are not definitive diagnostic criteria for ARDS. For example, pleural effusions can occur in numerous other contexts and are not a specific feature of ARDS; decreased lung volumes on pulmonary function tests (PFTs) might indicate restrictive lung disease, and elevated BNP levels are more closely associated with heart failure than lung disorders. Thus, the presence of bilateral infiltrates on chest X-ray is the most characteristic imaging finding