MRI (Magnetic Resonance Imaging)
by Pat Bowen, CMT
| MRI
(magnetic resonance imaging) is considered to be one the greatest wonders of modern
medicine. It is regarded as one of the most finite sources for detection of herniated
disks and tumors. MRI was first described in the 1940s, but it was not until the early
1970s that the first MRI was produced. MRI is the noninvasive imaging technique that uses radiofrequency coils and a magnet to obtain cross-sectional images of the body tissues. It uses no radiation and no iodine-containing additives to produce images of various organs of the body. This is considered a far safer diagnostic tool compared to CT and x-ray studies which both emit a great deal of radiation. However, contraindications include patients with pacemakers, hip pins, or other metallic implants in the body which cause a serious conflict with the giant magnet being used to scan the patient. |
Each organ of the body is comprised of different densities, water content, proton concentration and patterns of movements. Simply put, the radio waves bounce off the different types of tissues, and the results are recorded in a computer for translation into final images. Fat and marrow produce higher signals with brighter images; bone and air produce low-intensity, weaker signals for darker images. These images are converted from the monitor to image printouts as well as cine motion studies.MRI is particularly sensitive in assessing anatomical structures, organs and soft tissues for the detection of pathological conditions. MRI can differentiate between benign and malignant growths and may be used to stage cancers as well as evaluate the response to treatment of malignancies. The most common MRI studies are done of the brain and spinal cord as well as of the abdomen and chest. More recently, there is MRI imaging of the breast, the eye, pituitary gland, and the urinary tract. |