CPT® Code 77085

Dual-energy X-ray absorptiometry (DXA), bone density study, 1 or more sites; axial skeleton (eg, hips, pelvis, spine), including vertebral fracture assessment

This code reports dual-energy X-ray absorptiometry (DXA) for a bone density study, which is a crucial diagnostic tool in assessing bone health. The procedure measures bone mass or bone mineral density (BMD) to diagnose bone diseases, evaluate the progression of these diseases, or monitor treatment outcomes, particularly in patients with osteoporosis. Osteoporosis is a condition that significantly increases the risk of fractures due to decreased bone density. The DXA scan is notable for its low radiation exposure, approximately 1/30th of that of a standard chest X-ray, making it a safe option for patients. During the DXA procedure, two X-ray beams of differing energy levels are directed at the bones in alternating pulses. This technique allows for the subtraction of soft tissue absorption, enabling a precise measurement of BMD based on the bone's absorption of each beam in the scanned area. The results of the DXA scan are then compared to a reference standard, which is the average bone density of a same-sex individual at the age of 30, as this age represents the peak bone mass for both males and females. The difference between the measured BMD and this standard is expressed as the T score. A T score ranging from -1.0 to -2.4 indicates osteopenia, a condition where bone density is lower than normal but not low enough to be classified as osteoporosis. Conversely, a T score of -2.5 or lower confirms a diagnosis of osteoporosis. This code, 77085, is specifically utilized when assessing one or more sites of the axial skeleton, including the pelvis, hips, or spine, and includes a detailed evaluation of the spinal vertebrae for any signs of vertebral fractures.