Nuclear medicine is one of the most useful ? and fascinating ? of the diagnostic imaging modalities. The use of radioactive materials for medical purposes was first suggested in 1934 but it wasn?t until 1946, when radioactive iodine (I-131) was used to treat thyroid cancer that it became a reality.
Nuclear medicine remains a powerful diagnostic tool that is unlike any of its cousins. Why? Because nuclear medicine actually shows how organs, tissues and bones function at the cellular level. Even the most sophisticated MRI cannot do that!
?Even with a 70-year track record of success, patients still have doubts about nuclear medicine, especially in terms of radiation exposure,? said Karen Harter, certified nuclear medicine technologist with Lexington Diagnostic Center and Open MRI. ?The often ask me if they?re going to ?glow? as a result of the exam,? she said. Phrased as a joke, the concern behind the question is sincere.
?The quick answer is ? of course not,? Karen added. ?For most nuclear medicine studies, the amount of radiation received is within the range of a chest X-ray.? The body excretes the radioactive substance (the ?tracer?) quickly, usually within 24 hours. ?The dosage patients receive is the lowest possible level as determined by the Food and Drug Administration and other regulatory and certifying organizations,? Karen noted.
So how does nuclear medicine work?
The principle is simple. Various organs and tissues in the body have a natural affinity for certain types of substances. For example, iodine is a substance used by the thyroid. Because of this, a tracer of radioactive iodine will be taken up by the thyroid. When the thyroid is functioning normally, we see a certain pattern of ?uptake.? When it isn?t, uptake patterns are disturbed with either too much or too little being absorbed.
?Knowing this, we can diagnose hypothyroid (low function) or hyperthyroid (high function) by analyzing the amount of radioactive Iodine in the tissues of the thyroid,? Karen said. Further, higher doses of radioactive iodine can be given to disable the thyroid, if necessary. This allows patients to avoid the trauma and expense of surgery.
This is probably the most commonly known use of nuclear medicine, but it is not the whole story! Nuclear medicine can be used to study the function of the brain, bones, endocrine system, liver, kidneys and digestive system. It can also be used to evaluate tumor growth (as in cancer) and to detect infection in the body.
Because nuclear medicine scans show function, they are very good at finding problems early in the course of a disease. Other modalities can determine the extent of the problem after physical change has occurred, but they cannot image the damage in process.
Nuclear medicine scans take about an hour. ?Other than the brief discomfort of a needle stick, they are completely painless,? she said, adding, ?Patients are able to resume their normal daily activities immediately.?
If your physician or provider orders a nuclear medicine study for you ? don?t worry. You won?t glow and it won?t hurt. But it will provide incredibly valuable information to your provider that he or she can use to properly diagnose and treat your condition.
For more information about nuclear medicine studies at Lexington Diagnostic Center and Open MRI, call the office at (859) 278-SCAN (7226).