BMD test: One of the most important tests in radiology department which is helpful to measure the bone density in the body is BMD test. It is very helpful method to reduce the risks of fracture and help the radiologist to make a diagnosis for many diseases such as osteoporosis. Who should get tested for BMD:- A person which have an increased risk of osteoporosis. – Older men and women between age (65 and 70) which are at high risk to get osteoporosis because osteoporosis is a disease which is increased with age and make bone tissue fragile.
1) Risks related to BMD test):BMD test use little amount of radiation, so the doses are small and the risks of BMD test that related to radiation exposure will be low. 2) Treatment:It is very important to try changing your lifestyle which can help to improve your bone health by many ways. For example: Eating healthy and balanced diet which include high amount of calcium.
Increase the levels of vitamins such as vitamin D. Doing exercises such as walking. Stop cigarette smoking and reduce alcohol intake. 3) Diagnosis:Radiologist must measure the level of osteoporosis.Both osteoporosis and osteopenia are diseases that have a decrease in bone mineral density. – Osteoporosis: Is a condition that makes bones fragile and increase the likelihood of them to break. Also, Osteoporosis can be diagnosed if the person has a previous history of broken bone in the spine or hip without major trauma. – Osteopenia: BMD test shows that the bone density level is decrease, but not enough to called as osteoporosis and the bone density is lower than normal peak density. 4) Applications or Purpose: BMD test is can be used to: – Identify and determine the risk of fractures. – To make a diagnosis of osteoporosis. – To know bone loss. – Evaluate patient response to osteoporosis therapy.5) Indications and Contraindications: Many factors can increase the risks for bone loss (osteoporosis). The Indications are: – Age: older women’s and men’s (over 65 or over age 70)- Medications and Medical conditions such as: hyperthyroidism, rheumatoid arthritis and drugs such as: corticosteroids.- Family history of osteoporosis. – Smoking. – Excessive alcohol intake. – Fracture . (Contraindications):- Pregnancy is contraindicated because of using ionizing radiation involved in the procedure. – Recent x-ray examination with contrast media. – Bilateral hip pins or replacement. Principle of operation of BMD test: (How does a DXA scan work?) DXA is a scan that used to identify the density of bone. DXA works by sends low-dose x-rays which then will be absorbed by soft tissues and bones. It used a low amount of radiation. The denser bone, the less x-rays get through to the detector. Then, the information is sent to a computer which measure and calculate a score of average density of the bone, 6) BMD preparation – No special preparation for this procedure. – If there is a chance that you may a pregnant please tell the doctor, so test may not be performed to avoid the risk of radiation to the fetes. – No need to fast. – Patient can take his medications as normal. But maybe he will asked not take calcium supplements for at least 1 day before the exam. – Gown is needed especially if there are metal objects such as zippers which can interfere with the scan and make an artifact. 7) Types of BMD tests:Different kinds of machines can do BMD exam. The most common one is the (DEXA) scan that uses low dose x-rays. Two types of BMD tests are:1) Central DXA: This test looks at whole skeleton especially spine and hips. It involves dual energy x-ray absorptiometry and quantitative computed tomography. It takes around 15 to 20 min. The patient will ask to lie on a table and may also be asked to hold his breath while the x-ray is taken. DXA now is used to make a diagnosis of osteoporosis and help to know and predict for future risk. 2) Peripheral: Which Looks and focus on extremities such as: fingers, wrist and ankle. Many kinds of Peripheral tests are: QUS (quantitative ultrasound) PDXA (peripheral dual energy x-ray absorptiometry) PQCT (Peripheral quantitative computed tomography) When a central DXA is not available, we can use this test. Peripheral test cannot diagnose osteoporosis accurately and should not be used to see osteoporosis in working condition. 8) Understanding BMD results: T-score shows how much bone mass differs from the bone mass of an average healthy 30-year-old adult. It means that we can Compare bone density with a healthy young person). Z-score Compare bone density to the average bone density of people in the patient age and gender. WHO classified T-score as: In normal range if it is -1 or above. Between -1 and -2 SD (osteopenia).At or below -2.5 SD (Osteoporosis). – If the T-score is positive, this indicate that the bone is stronger than normal. If the T-score is negative, this indicate that the bone is weaker than normal. Z score Z score is not used to make a diagnosis for osteoporosis in postmenopausal women and men in age 50 and older. If below -2: Patient bone density is lower than it must be for someone in his age. – Understanding BMD test results are essential to make a good diagnosis and to find suitable treatment. mass. In both scores, the negative number means that you have thinner bones than standard.