Using chest radiography in the intensive care unit.

To purchase reprints, contact The InnoVision Group, 101 Columbia, Aliso Viejo, CA 92656. Phone, (800) 809-2273 or (949) 362-2050 (ext 532); fax, (949) 362-2049; e-mail, [email protected]. tion that penetrate matter. A radiograph is created when x-rays penetrate a structure and produce images on a piece of photographic film. In a person, the different shades of black and white in the images are due to the way the body structures or tissues absorb the x-ray beam. X-rays that penetrate body tissue produce dark or black areas on the film. Two of the most common radiographs are posteroanterior (PA) and anteroposterior (AP) views of the chest. For PA views, the x-ray beam passes through the chest from the back to the front. For AP views, the beam passes through the chest from the front to the back. For acutely ill patients who cannot stand up for a PA view, AP views are obtained with a portable x-ray machine. AP views obtained with a portable machine have some disadvantages. Structures in the anterior part of the chest are magnified on AP views, so structures such as the heart are not as distinct as on PA views and may even be distorted. This phenomenon occurs because decreased x-ray energy is available when portable x-ray machines are used to create the images. In addition, PA views are sharper and more distinct Using Chest Radiography in the Intensive Care Unit