Dxa Bone Density Axial Skeleton:
DXA is most often used to diagnose osteoporosis, a condition that often affects women after menopause but may also be found in men and rarely in children. Osteoporosis involves a gradual loss of bone, as well as structural changes, causing the bones to become thinner, more fragile and more likely to break. In children and some adults, the whole body is sometimes scanned.
You’ll be asked to remove keys or wallets from your pockets, along with jewelry and any metal objects. Let your doctor know if you’ve recently had a barium exam (another kind try what he says of X-ray procedure), or if you’ve had contrast material injected for a CT scan or nuclear medicine test. These materials can interfere with the accuracy of your test.
Membership in BHOF will help build your practice, keep your team informed, provide CME credits, and allow you access to key osteoporosis experts. Join our community to learn more about osteoporosis, or connect with others near you who are suffering from the disease. The scan is painless and relatively quick, usually taking 10’30 minutes, depending on the equipment and the areas being scanned. Some experts report that it can take just 6 minutes or 10’20 minutes.
In response to mechanical loading, osteocytes seem to respond in a binary manner with respect to calcium influx (Schaffler and Kennedy, 2012), with each osteocyte in either a ‘loaded’ or ‘non-loaded’ state. The type of force applied, like tensile, compressive, or stretch, can also influence the molecular response (Josephson and Morgan, 2023). The overall distribution and number of these ‘loaded’ and ‘non-loaded’ osteocytes contributes to the tuning of local bone mass. DEXA (dual x-ray absorptiometry) scans measure bone density (thickness and strength of bones) by passing a high and low energy x-ray beam (a form of ionizing radiation) through the body, usually in the hip and the spine.
Parathyroid hormone-analog treatments are highly effective at preserving and restoring bone mass through an increase in osteoblast number and matrix deposition, due in part to ‘-catenin pathway upregulation (Tian et al., 2011). A bone density test, otherwise known as a dexa scan or bone density scan, is a specialized x-ray that measures how much calcium and bone minerals exist in the bone segment(s) being tested. The most common areas tested during a bone density scan are the hip, spine, and forearm or wrist. The DXA measurement helps physicians assess the likelihood of developing fractures that may occur during normal living activities, or after minimal trauma. For example, more than 30 percent loss of bone mass in the hip leads to a significant increase in the fracture rate. Alterations of bone strength in certain endocrine disorders are not always reflected in the BMD values, as their cause may lie in the microarchitecture of the bone.
Bone scans require an injection beforehand and are usually used to detect fractures, cancer, infections and other abnormalities in the bone. DEXA scanning focuses on two main areas ‘ your hip and your spine. If you can’t test those, you can get a DEXA scan on your forearm. These areas can give your doctor a good check these guys out idea of whether you’re likely to get fractures in other bones in your body. If your osteoporosis is more severe, the doctor may advise that you take one of the many drugs that are designed to strengthen bones and lessen bone loss. A DEXA scan is used to determine your risk of osteoporosis and bone fracture.
Even if you have bone loss of less than 2%, DEXA can detect it. Depending on your clinical circumstances and risk factures, your healthcare provider may also include a vertebral fracture assessment (VFA) for the spine and/or a femur fracture assessment (FFA) for the hip. DXA bone mineral density for different sites on the skeleton is reported as grams per centimeter squared (gm2) ‘ measuring the amount of calcium and other bone materials packed in to a segment of bone. Values are compared to others of the same age and gender (Z-scores) or healthy young adults at peak bone mass (T-scores). Osteoporosis has been called a “silent” disease because the loss of bone progresses gradually without pain or symptoms until a fracture occurs.
Your healthcare provider will then make a personalized plan for how to assess and protect your bone health. Osteoporosis is a term used to describe brittle bones and also the risk for having a broken bone. Osteoporosis literally means ‘porous bone.’ DEXA tests help your healthcare provider track your bone density and risk for having a broken bone over time. Providers often use DEXA tests to help diagnose osteoporosis.
An X-ray technician performs the scan on an outpatient basis. A person may need to change into a hospital gown and remove any metal objects that they are wearing, such as jewelry and eyeglasses. We are Northwell Health’and together, we’re raising the standard of health see care. Z score ‘ This number compares your amount of bone with others of your age, gender, and size. If this score is unusually high or low, you might need further testing. This test is quick and painless, and the amount of radiation you get from the X-rays is low.
An additional procedure called Vertebral Fracture Assessment (VFA) is now being done at many centers. VFA is a low-dose x-ray examination of the spine to screen for vertebral fractures that is performed on the DXA machine. The DXA test can also assess an individual’s risk for developing fractures. The risk of fracture is affected by age, body weight, history of prior fracture, family history of osteoporotic fractures and life style issues such as cigarette smoking and excessive alcohol consumption. These factors are taken into consideration when deciding if a patient needs therapy.
Black et al. demonstrated that BMD and history of nonvertebral fracture could predict fractures in a period as long as 20’25 years in a large cohort of postmenopausal women [14]. The most widely used tool for fracture prediction, FRAX, provides the fracture probability for a period of 10 years [15]. An extended DXA measurement of the hip diaphysis is recommended in patients on long-term treatment with bisphosphonates in order to detect early signs of atypical femur fractures [16]. ISCD recommends the use of BMD as assessed by DXA for antiosteoporotic treatment follow-up [17]. When doctors need to tell whether a person has low bone density, or whether the condition is worsening, a DEXA scan tends to be more accurate than a typical X-ray because it can detect even small changes in bone loss.
You should not take calcium supplements for at least 24 hours before your exam. A trained Bone Density Technologist certified by the International Society for Clinical Densitometry (ISCD) performs the DXA scan. The specialist physicians at the Bone Health Program, most of whom are ISCD Certified Clinical Densitometrists, will interpret the results and discuss it with you at the visit, in most cases immediately after the test. The physician will also submit a report including detailed measurement data to your physician within a few days. DEXA scans are different from other imaging procedures because they are used to screen for a specific condition. Learn more about the benefits and risks of imaging tests, including nuclear medicine, and how to reduce your exposure to radiation.
If your results indicate osteopenia or osteoporosis, your doctor will discuss with you what you can do to slow bone loss and stay healthy. The World Health Organization (WHO) established DEXA as the best technique for assessing bone mineral density in postmenopausal women. Osteoporosis anywhere in your body is osteoporosis everywhere. For example, if the T-score in your spine is -2.7 and the T-score in your hip is -2.2, the diagnosis is osteoporosis.
It is incorrect to say there is osteoporosis in the spine and osteopenia in the hip. Low-level X-rays, equivalent to less than two day’s exposure to natural background radiation, measure important bone sites (detailed below). Most people don’t need to change their daily routine before a DEXA scan.