Chest X-ray

In diagnostic imaging, the chest x-ray is one of the most common and useful examinations, a basic screening test in chest pain, but also providing information both on diseases of the chest (e.g., heart enlargement or lung scarring) or on some aspects of trauma, such as broken ribs.

Equipment and technique

It is one of the simpler x-ray procedures, which is best done in a regular X-ray room with a proper table and a support for the patient while standing, but can be done with a portable X-ray machine at the bedside. The essential parts of the machine are the X-ray generating apparatus, and a separate box that holds either X-ray photographic film, or, increasingly, a solid-state digital recorder.

While additional views are sometimes ordered, the two basic views taken are anterior-posterior (A-P) and lateral. The classic A-P view is taken with the patient standing and facing the X-ray tube, which is perpendicular to the vertical axis of the body. In other words, the image is straight through from front to back. The lateral view, again ideally with a standing patient, is taken from one side, the ribs facing the X-ray source.

Standing views are preferred because the internal organs will spread downward due to the influence of gravity, allowing best visualization of all. If the patient cannot stand, it is still usually preferable to take a supine A-P view in the X-ray suite, which puts the patient on a table, the positioning and stability of which is greater than a bed can be. When bedside views are needed, the recording mechanism is simply slid under the patient as best as the clinical situation permits.

The most obvious variant view is taken from the left side.

Limitations and alternatives

X-rays visualize blood and soft tissue poorly, so if these are the areas of interest, ultrasound or computed X-ray tomography are more likely to give information of interest.

Cardiology

The chest x-ray can help detect heart failure.

The chest x-ray can help detect pneumonia.