Both MRI and CT scans make cross-sectional images (slices) of pretty much any area of the body using a sophisticated computer system. The major difference is that an MRI uses a large magnet and radio waves to produce images while a CT scanner uses x-rays. Therefore, with the MRI studies, there is no exposure to x-rays.

Computed Tomography (CT) uses x-rays to create a cross-sectional image of the body part being examined. Magnetic Resonance Imaging (MRI) uses a high field strength magnet and radio waves to generate a cross-sectional image.

CT and MRI differ in two basic ways.CT uses x-rays to detect and record the radiation absorbed by different tissues, and sends the data to a computer to transform into images. MRI does not use x-rays. Instead, MRI employs a powerful magnetic field to monitor the nuclei of hydrogen atoms in water, the most abundant element in the body.

CT and MRI provide different kinds of information. Your doctor determines which is the most appropriate test for you, and sometimes both are necessary. While both scanners are similar in appearance, CT scanners make images is by using x-rays to plot the difference in electron density of adjacent tissues, and MR scanners, as described above, make images based on differences in the density and behaviour of hydrogen protons.

MRI scan is excellent at showing soft tissue such as spinal cord, nerve roots and herniated discs. A CT scan shows bone detail and some soft tissue. When looking for herniated discs or tumors, an MRI image will usually reveal much more detail.

A PET scan produces images of metabolic activity as opposed to images of the body's physical structures that are derived from these other imaging tests. This is important because functional changes often predates structural changes in tissues. PET images may therefore demonstrate changes long before they would be revealed by modalities like CT and MRI.

MRI stands for Magnetic Resonance Imaging and does not utilize radiation. Instead, a strong magnetic field and radio waves are combined to create high-quality images of soft tissue which cannot be detected by an X-ray.

One of the most basic differences between the two tests is that CAT Scanning uses x-rays and MRI does not. In most situations, MRI is superior to CAT in the demonstration of soft tissue pathology. Your doctor can best advise which test would be most appropriate for you.

CT stands for Computerized Tomography, which refers to the way this exam is performed. In actuality, a CT scan is an x-ray procedure which is enhanced by a computer. This results in a three-dimensional view (referred to as a "slice") of a particular part of the body. During a routine x-ray, dense tissues can block other areas.

CT imaging itself is painless. The patient is required to remain motionless during the examination (which is difficult for some people), but the actual scan causes no bodily sensation.

Numerous studies have shown that even for people who have large body tattoos there is little to no potential for irritation resulting from an MRI. In the rare instance where discomfort resulted, it was localized and very temporary. Most people have more metal in their fillings than they would ever have in tattoo work. Copyright ? 1996-2007 Society of Permanent Cosmetic Professionals, All rights reserved and strictly enforced.

After your test, call the office to schedule a follow-up appointment. Dr. Stanley will explain and discuss your results at this time.

Because an MRI scan uses a magnet and does not use X-ray or particle beams, an MRI scan produces no ionizing radiation.

MRI is more sensitive to subtle changes in soft tissues, particularly the brain and spinal cord. It is the primary imaging method for evaluation of joints, especially the knee, ankle, shoulder, and wrist.