Archive for 'Healthy bones Osteoporosis Rheumatic'
LABORATORY TESTS FOR KNEE PROBLEMS: MAGNETIC RESONANCE IMAGING (MRI)
If a doctor suspects a patient has a ligament problem or a torn meniscus, she may order an MRI to confirm the diagnosis. The MRI is also good at identifying bone bruises—abrasions on the bone that may have been caused by an injury and could cause pain. MRI uses a strong magnetic field and radio waves to look inside the body and create images that are analyzed by a computer. For the MRI, the patient is put on a table and told to lie still. The patient is then slowly moved through a long tube in which different views of the knee are recorded. Some MRI machines are totally enclosed; some are just partially enclosed.Similar to an X ray, an MRI cannot image articular cartilage. However, as the computer software becomes more technologically sophisticated, I suspect that it probably will be able to diagnose articular cartilage problems in the future.The MRI is only as good as its human operators, and the results that I see are often inadequate. A complete MRI of the knee should take about 45 minutes, allowing for views of the knee from every 2 to 3 millimeters at many different angles. Many of the films I see are of poor quality, I suspect because the test was rushed either for cost containment or because the technician didn’t know any better. It’s a waste of your time and money. Therefore, I recommend that you only go to an MRI center that has been recommended by an orthopedist.An MRI costs about $1,000 and offers a degree of accuracy ranging from as low as 60 percent to a high of 90 percent for ligament and meniscal tears. A good clinical exam by an experienced physician can offer almost the same degree of accuracy. Therefore, there is some controversy as to whether an MRI is really that useful and cost-effective. However, in this age of «second opinions,» many insurance companies require an MRI before surgery.Another problem with the MRI is interpretation. The radiologist rarely, if ever, compares MRI films to arthroscopic findings; thus, the orthopedist usually has more constant feedback and subsequently a better ability to interpret the MRI.In some cases, the MRI may reveal nothing, and if the patient is in pain, the physician may order additional tests.*16\185\2*