A client with a suspected pneumonia presents to the emergency department. Which diagnostic test does the nurse anticipate being ordered for this client?

A. Computed tomography (CT) scan of the chest: A chest CT provides detailed images and can detect subtle infiltrates or complications, but it is not the first-line diagnostic tool for suspected pneumonia due to higher cost, increased radiation exposure, and the need for contrast in some cases. CT is typically reserved for complicated or atypical presentations. B. Chest X-ray: Chest X-ray is the standard initial diagnostic test for suspected pneumonia. It can identify areas of consolidation, infiltrates, or pleural effusions, confirming the presence and extent of infection. It is widely available, quick, and provides sufficient information for initial diagnosis and treatment planning. C. Ultrasound: Chest ultrasound is not routinely used to diagnose pneumonia. It can be useful in detecting pleural effusions or guiding thoracentesis but lacks the ability to reliably visualize lung parenchyma and infiltrates compared with a chest X-ray. D. Magnetic resonance imaging (MRI) of the chest: MRI provides excellent soft tissue detail but is rarely used for pneumonia diagnosis because it is costly, time-consuming, and less practical in an emergency setting. It is reserved for complex thoracic pathology or mediastinal evaluation.