A Chest x-ray is obtained either in a physician's office or in the hospital. To obtain a standard PA or postero-anterior view (it is called postero-anterior because the x-ray beam comes from the posterior or back and moves through the chest to the anterior or front). The patient is positioned so that his or her chest touches the container of the x-ray film. The x-ray machine sends a beam from the back and records an image on the film, as shown below. Frequently, a "lateral" film is obtained by having the patient stand sideways in front of the film. This allows the physician to examine the chest from the side. This may help pickup, confirm, or rule out an abnormality suspected in the other view.
Thus, one can easily see the cost-effectiveness of this relatively simple test. In patient's with lung or heart disease, chest x-rays obtained at yearly, or longer, intervals may provide information about the progression, stability or improvement of disease.
The figure shown above is a section of the heart, as viewed from the front. It demonstrates the four chambers. You will also notice that there is an opening between the right atrium (RA) and the right ventricle (RV). This is actually a valve known as the tricuspid valve (pronounced try-CUS-pid). It is made of three flexible thin parts, known as leaflets, that open and shut. The figure below shows the tricuspid valve, as seen from above, in the open and shut position.