X-rays work because the body’s tissues vary in density (thickness). Each tissue allows a different amount of radiation to pass through and expose the X-ray-sensitive film, which results in a shadow image of the organ. Bones, for example, are very dense, and most of the radiation is prevented from passing through to the film. As a result, bones appear white on an X-ray. Tissues that are less dense––such as the lungs, which are filled with air––allow more of the X-rays to pass through to the film and appear on the image in shades of gray.
What is a chest X-Ray?
A chest X-ray is a test that uses a small amount of radiation to create an image of the structures within the chest, including the heart, lungs, blood vessels and bones. During an X-ray, a focused beam of radiation is passed through your body, and a black-and-white image is recorded on special film or a computer. The X-ray image that is created looks like a negative from a black and white photograph.
Why is a chest X-Ray used?
A chest X-ray may be used to help diagnose and plan treatment for various conditions, including:
- Lung disorders such as pneumonia, emphysema, tuberculosis and lung cancer
- Heart disorders such as congestive heart failure (which causes the heart to enlarge)
- Fractures (breaks) of the bones in the chest, including the ribs and collarbone, as well as breaks in the bones of the upper spine
- Reasons for shortness of breath, a bad or persistent cough, or chest pain

BMD
Osteoporosis is a medical condition in which the bones in the body become weak and brittle due to a loss in tissue, either due to hormonal changes or a deficiency of calcium or vitamin D. It is especially a hazard for the elderly, and results in a significantly larger chance in a broken bone. Bone Mineral Density is an x-ray used to assess the density in your bones. It is used to diagnose osteoporosis and also to evaluate how the treatment of osteoporosis is progressing. This test requires you to lie on your back while a mechanical arm scans over your body. The amount of radiation emitted during this test is minimal and is even less than that exposed during a chest x-ray.
BMD preparations
- No barium or contrast studies or Nuclear Medicine tests 1 week prior to the exam.
- Do not take calcium/vitamin supplements 24 hours prior to the exam.
- Please wear a two-piece outfit with no metal zippers, buttons, or belt around the waist level, if possible.
