The chest X-ray is the most common radiologic procedure. The X-ray is projected toward the chest to show the heart and lungs, bones and soft tissues. The actual time of the average X-ray exposure is extremely short -- often less than one-half second. Some of the radiation penetrates the part of the body being examined and thus creates the X-ray image.
To understand what happens when an X-ray is taken, a comparison can be made with the use of a camera in taking a photograph.
The X-ray exposes the film to form an image just as the light exposes the film inside a camera. The film in a camera is developed and used to make a photographic print or it is used directly as a slide. The X-ray film is also developed and viewed with transmitted light on a light box or computer screen.
The chest X-ray technique in young children involves two views. The initial view is from the front, and the second is a side view.
In young children, the patient lies on the table and the hands are held above the head.
In an older patient, the child stands in upright and then in a lateral view as the images are obtained. The technologist tries to "tightly cone" the radiation beam using a light on the patient's chest. This reduces the scatter radiation to other parts of the body.
After the film is obtained, it is interpreted by a radiologist. Comparison with prior films is important, particularly in evaluating heart size and blood flow to the lungs.
A report is made and becomes part of the patient's permanent record. Results are shared with both the cardiologist and the referring physician.