Which imaging technique is used to diagnose croup?

The appropriate imaging technique for diagnosing croup is the lateral neck X-ray. This specific type of X-ray provides a clear view of the airway structures, making it easier to identify the classic signs of croup, such as the "steeple sign," which indicates narrowing of the upper airway due to edema in the subglottic area.

Lateral neck X-rays are particularly helpful in differentiating croup from other conditions that may present with similar symptoms, such as epiglottitis, which may show different radiographic findings. By using this imaging technique, clinicians can effectively assess the severity of the condition and guide management decisions.

Other imaging methods, such as CT scans of the thorax, chest X-rays, and ultrasound of the neck, are not routinely used for diagnosing croup. A CT scan involves higher radiation exposure and is generally reserved for more complex conditions, while chest X-rays primarily evaluate lung pathology and do not provide the detailed view of the upper airway needed for croup diagnosis. Ultrasound can be useful in certain scenarios involving soft tissue evaluation but does not provide the same clarity for airway assessment as a lateral neck X-ray.