Bone Mineral Density Testing
Dual energy X-ray absorptiometry (DXA) is the most common method to measure a patient’s bone density. Bone density is the best predictor of fracture risk that we have available to us in the field of medicine. The test is easy to perform and the amount of radiation exposure is very low. The bone density is quantitated by passing two x-ray beams through the spine, hip, and possibly the forearm. Based on the difference of the energy of the two beams a sensor on the undersurface of the body can determine a density or thickness of the bone. Measurements from one site actually predict the likelihood of fractures of other body sites as well as of that particular site.
Note: On the day of the test, you may eat a normal meal, but you should avoid taking your calcium supplement for 24 hours prior to the test. The test takes 10 to 20 minutes and is painless. There is no IV or other injections needed for this test.
Radioactive Iodine Therapy
Radioactive iodine is commonly prescribed for the treatment of an overactive thyroid (hyperthyroidism), and following surgery for thyroid cancer. It has been used for more than 50 years. Patients drink it in a small amount of water, through a straw. Most patients need only one dose for either hyperthyroidism or thyroid cancer. Radioactive iodine therapy is available as an outpatient treatment in the Beaumont Hospital Nuclear Medicine Department in our West Bloomfield building. Associated Endocrinologists’ doctors and the Beaumont Nuclear Medicine technical staff work together to give this therapy. It can usually be scheduled at a convenient time of day.
A pertechnetate or radioactive iodine nuclear medicine scan shows the shape of the thyroid gland and identifies areas of the thyroid that are functioning either more or less actively than the rest of the gland. This information is helpful in evaluating the cause of overactive thyroid conditions, enlargement of the thyroid (goiter), and lumps (nodules) within the thyroid. The amount of radiation received from this procedure is very low and there are no side effects from either pertechnetate or the form of radioactive iodine, I-123, used in this test.
This simple test uses sound waves to image the thyroid. The sound waves are emitted from a small hand-held transducer which is passed over the thyroid. You will lie on your back with your neck hyperextended (with a pillow under your shoulders) as best as you can. A lubricant jelly is placed on the skin so that the sound waves transmit easier through the skin and into the thyroid and surrounding structures. This test is quick, accurate, painless, inexpensive, and completely safe. It usually takes about 10 minutes and the results can be known almost immediately. The only preparation needed for an ultrasound is to wear a low or open collar shirt (try to avoid turtlenecks) and remove any jewelry from your neck.
Ultrasound-Guided Fine Needle Aspiration Biopsy
Thyroid fine needle aspiration (FNA) biopsy is the only non-surgical method which can differentiate malignant and benign nodules in most, but not all, cases. If a thyroid nodule is larger than 1 – 1.5 cm and/or has any worrisome characteristics, a fine needle aspirate biopsy is commonly recommended. In high risk patients (those who have had radiation exposure in the past or have a family member with thyroid cancer), nodules under 1 cm may also need a biopsy. Using ultrasound to guide the needle tip increases the quality of the biopsy specimens and allows the doctor to know where the needletip is at all times.