A bone density test, technically known as a Dual-Energy X-ray Absorptiometry (DEXA) scan, is a non-invasive imaging procedure. This test uses low-dose X-rays to measure bone mineral density, typically focusing on the hip and lower spine. The results help healthcare providers assess bone health and evaluate the risk of fracture or osteoporosis. Proper preparation is important for ensuring the most accurate results possible. This article outlines appropriate attire and necessary actions before your appointment.
Selecting Garments for the Scan
The choice of clothing directly impacts the quality of the DEXA scan images. Ideal attire is loose-fitting, non-restrictive, and comfortable. This simplifies positioning the body correctly on the scanning table. The technician may need to adjust limbs or shift the torso slightly to target the precise areas of the hip and spine, and restrictive clothing makes this difficult.
Selecting soft and flexible fabrics is highly recommended for the bone density test. Materials like cotton, jersey knit, or thin synthetic blends are preferred because they do not interfere with the low-dose X-ray beam. These fabrics ensure that the X-ray energy passes cleanly through the body without distortion. Stiff clothing, such as denim jeans, can introduce subtle artifacts into the image data, skewing the density calculations.
Appropriate items include simple t-shirts, comfortable pajama-style pants, or non-metallic yoga pants and leggings. Since the test involves lying still for several minutes, the clothing should not create pressure points or cause discomfort. Avoiding tight waistbands or restrictive elastic is advised for ease of breathing and relaxation during the procedure.
Mandatory Removal of Metal and Accessories
Any metal object located within the scanning field must be removed because it compromises the accuracy of the results. The DEXA machine uses X-ray technology to measure density, and metal components create bright white shadows. These shadows, known as artifacts, block the X-rays and lead to falsely elevated or inaccurate density readings in the affected area.
Patients should leave all jewelry at home, including necklaces, bracelets, rings, and earrings. Even small metal fasteners, such as those found on watches or hair clips, can distort the image if they are near the region of interest. Any body piercings located on the torso or hip area must also be taken out before the procedure begins.
Many common clothing items contain metal components that must be avoided on the day of the test. This includes pants or shirts with zippers, snaps, or metal buttons, which are often concentrated near the hip and spine. Underwire bras also pose a problem, as the metal wire can interfere with the scan, even if the primary focus is the lower body.
Belt buckles are another common metal culprit that must be removed entirely before entering the scanning room. It is best to choose an outfit that is completely free of any metallic embellishments or hardware. If clothing with unavoidable metal is worn, the technician will likely ask the patient to change into a hospital gown to ensure a clean field of view for the X-ray.
Crucial Preparation Steps Beyond Attire
Preparation for a bone density test extends beyond simply choosing the right outfit. One specific dietary restriction involves supplements that can temporarily affect bone density readings. It is advised to discontinue taking any calcium supplements or multivitamins containing calcium for a full 24 hours before the scheduled DEXA scan.
Calcium particles circulating in the bloodstream or digestive tract can artificially inflate the measured bone mineral density. This temporary suspension ensures that the reading reflects the body’s true structural bone density rather than recently ingested supplement content. Patients should confirm this 24-hour suspension window with their ordering physician or the testing facility to prevent the need for a re-scan.
Recent Imaging Procedures
A more significant scheduling consideration involves recent medical imaging procedures. If a patient has recently received an intravenous contrast dye for a CT scan, MRI, or nuclear medicine study, they must wait a specific period. The contrast agent remains in the body and can interfere significantly with the DEXA scan’s ability to accurately measure bone density. The lingering agent can absorb X-rays in a similar way to high-density tissue.
Most facilities require a waiting period of 7 to 14 days following a procedure that used contrast agents. Patients should inform the scheduling staff about any recent imaging tests to avoid needing to reschedule the appointment upon arrival. Finally, notify the technician immediately if there is any possibility of pregnancy, as the test utilizes low-dose X-ray radiation that is generally avoided during gestation.