An important test for making a diagnosis of pneumonia is a chest x-ray. Chest x-rays can reveal areas of opacity (seen as white) which represent consolidation, pleural effusion, air bronchogram and/or cavitations. Pneumonia is not always seen on x-rays, either because the disease is only in its initial stages, or because it involves a part of the lung not easily seen by x-ray.

• The American Thoracic Society recommends that all patients with a suspicion of nosocomial pneumonia should have a chest x-ray to confirm diagnosis and determine the severity of the disease.^[1]
• A chest X-ray also helps to determine pleural effusions or cavitations, as a possible complication.
• Ideally, the chest X-ray should be posteroanterior and lateral, but this will depend on the patient’s condition.
• Findings include the following:^[2]

• Unilateral or bilateral consolidation
• Air bronchogram
• Pleural effusion
• Cavitation
• Ground glass opacities

• Chest X-ray is also used to assess improvement or lack of clinical response in hospitalized patients.