Bone Density Screening
What is a DEXA bone density scan?
Dual–energy X-ray absorptiometry (DEXA) is an imaging modality that uses a very low dose of X-ray energy to detect the presence of osteoporosis.
Women begin losing bone density in their late 30s and 40s. After menopause, bone density loss speeds up due to hormonal changes – up to 20% of bone mass can be lost in the 5 to 7 years following menopause – making women more at risk for fractures to the spine, hips and wrists. Often called the silent disease osteoporosis rarely shows symptoms until a lot of bone mass has been lost. The most visible symptoms may be loss of height and curvature of the upper spine and back area. Osteoporosis afflicts an estimated 22 million Americans – 80% of whom are women.
Our bone density tests are conducted by certified bone densitometry technologists and take approximately 15 minutes to perform. DEXA scanning can identify low bone density in patients at an early stage, allowing doctors to prescribe appropriate treatment and halt the progression of further bone density loss. Once our patient is positioned properly on the scanning table, our technologist activates the scanner to measure the bone mineral density of the hip and spine. The machine then calculates two test scores: a T-score, which compares the patient’s bone density to that of a healthy 30-year-old woman, and a Z-score, which compares the patient’s bone density to what is considered normal for a woman of the same age and body size. The machine also captures X-ray images of the patient’s hip and spine, which are sent to a board-certified radiologist for interpretation. Exam results are reported directly to the patient’s physician within 24 hours, and after approximately 72 hours, the patient’s report will be available through our patient portal.
The National Osteoporosis Foundation recommends that women get regular bone density tests beginning at age 65. However, numerous risk factors related to personal and family history, lifestyle, and ethnic background put some women at higher risk for the disease. Many physicians often recommend beginning DEXA scans at the age of 50, and recommended to schedule at the same time as your annual mammogram.
What do the test results mean?
The test compares your bone mineral density (BMD) to that of a healthy 30-year-old woman – and a Z-score, which compares the patient’s bone density to what is considered normal for a woman of the same age and body size. This information, along with other factors, helps doctors in making a diagnosis. The following T-scores define the amount of bone loss:
- Normal: T-score above -1
- Osteopenic (low bone density): T-score between -1 and -2.5
- Osteoporosis: T-score below -2.5
Your test results combined with other factors give you and your doctor an overall risk of fracture. Knowing your risk of a fracture is important, because there are many ways to prevent osteoporosis and to reduce fracture risks. After reviewing your DEXA Scan results your doctor may suggest a number of steps important in building bone strength. Suggestions may include: exercise, changes in diet, hormone therapy, or other medicines known to improve bone strength.
How do I prepare for the exam?
Please do not take any calcium supplements the morning of your exam. Wear comfortable clothing that has no metal zippers or buttons in the abdominal or pelvic areas. If you do not have clothing without metal components, we may ask you to change into a gown. You may also be asked to remove jewelry, eyeglasses and any metal objects or clothing that might interfere with the x-ray images. If you have recently undergone a barium study of any kind -such as an upper gastrointestinal (UGI) tract exam, barium enema or computed tomography (CT) scan -you should wait at least 14 days before a DEXA exam is performed. That waiting period is important to prevent any residual barium from interfering with your DEXA exam. Please let us know before your exam begins if you may be pregnant.