Doctor Visits, Medical Procedures and Medical Insurance / Question
Published: May 24, 2005
Dear TeenHealthFX,
I have two questions... what is a catscan? What is an MRI?
Signed: What is a Cat Scan? What is an MRI?
Dear What is a Cat Scan? What is an MRI?,
CAT scans (Computed Axial Tomography) is the process of using computers to generate a three-dimensional image from flat (i.e., two-dimensional) x-ray pictures, one slice at a time. An x-ray beam is passed through the body and moved in a circle around the body taking images from a number of angles. The body is made of bone, fat and water dense tissue that absorbs radiation at different levels, which a computer interprets and uses to create a picture. It is a relatively safe and painless procedure. A CAT scan can last from 5-30 minutes. Because it is a rather quick study, CAT scans are often used to assess trauma victims for injuries of different internal organs such as the spleen, liver, and kidneys. A CT scan is also useful in diagnosing various types of cancer.
Magnetic resonance imaging (MRI) is another type of imaging modality that is better for looking at soft tissues of the body such as the brain, spine, and joints. An MRI uses a magnetic field and radio waves to produce images on a computer. The detail and clarity of the images generated vary according to how the radio frequency pulses are sent and received. It is normal to hear a knocking noise during an MRI, which are basically the magnets of the machine turning on and off. An MRI like a CT scan is a relatively safe and painless procedure. The MRI can last from 30-60 minutes and patients are asked to remain still during parts of the scan. MRIs are commonly ordered to evaluate sports related injuries of the knee, back, and shoulder. A specialized type of MRI called an MRA is used to evaluate blood vessels in the body. A big advantage of MRI is that there is no radiation exposure unlike a CAT scan. One disadvantage is that patients who have had surgery that required placing metal hardware into their body cannot have an MRI because the machine contains a large magnet, which may "pull" on these objects. Patients are normally screened to prevent this.
Signed: TeenHealthFX
Adolescents are more likely than young adults to become dependent on prescription medications.
