Diagnostic Tests Directory

Cord blood is a sample of blood collected from the umbilical cord at the time of birth.

A computed tomography (CT) scan is an imaging method that uses x-rays to create cross-sectional pictures of the body. See also: Cranial CT scan; Lumbosacral spine CT scan; Orbit CT scan; Thoracic CT scan.

An exercise stress test is a screening tool to test the effect of exercise on your heart. It provides an overall look at the health of your heart. See also: Stress echocardiography; Thallium stress test.

Magnetic resonance imaging (MRI) is a noninvasive way to take pictures of the body. Unlike x-rays and computed tomographic (CT) scans, which use radiation, MRI uses powerful magnets and radio waves. The MRI scanner contains the magnet. The magnetic field produced by an MRI is about 10 thousand times greater than the earth's. The magnetic field forces hydrogen atoms in the body to line up in a certain way (similar to how the needle on a compass moves when you hold it near a magnet. When radio waves are sent toward the lined-up hydrogen atoms, they bounce back, and a computer records the signal. Different types of tissues send back different signals. Single MRI images are called slices. The images can be stored on a computer or printed on film. One exam produces dozens or sometimes hundreds of images. For more information, see the specific MRI topics: Abdominal MRI; Chest MRI; Cranial MRI; Heart MRI; Lumbosacral spine MRI; Spine MRI.

Detailed information on mammography, including how a mammogram is performed, what conditions a mammogram shows, mammography guidelines, and the risk factors for breast cancer

A Pap smear is an examination under the microscope of cells scraped from the cervix.

A throat culture is a technique for identifying disease bacteria in material taken from the throat. Most throat cultures are done to rule out infections caused by beta-hemolytic streptococci, which cause strep throat . Hemolytic means that these streptococci destroy red blood cells.

Ultrasound involves the use of high-frequency sound waves to create images of organs and systems within the body.

Detailed information on x-ray, including information on how the procedure is performed