Dual energy x ray absorptiometry dxa

Study participants underwent BMD assessment via Dual-Energy X-ray Absorptiometry (DXA, Hologic Inc, Bedford, MA, USA, QDR 4500W, S/N 47168) at the lumbar spine (L1-L4 anteroposterior) and hip (left femoral neck), performed by trained technicians using standardized procedures and calibration schedule recommended by the producer. Speci c delimiters for regional analysis were determined by standard software (Hologic Inc, QDR 4500W S/N 47168 VER. 11.2). BMD was expressed in g/cm 2 . At each site, patients with a T score ≥ - 1 were included in the normal group, patients with a T score between < - 1 and - 2.5 were included in the osteopenia group, and patients with a T score < - 2.5 were included in the osteoporosis group, as de ned by the World Health Organization.
Bone structure and the quality of microarchitecture were estimated by the Trabecular Bone Score using the integrated software TBS iNsight, version 2.1.2.0, starting from the site-matched spine DXA scans. A TBS greater than 1.350 was considered normal, TBS between 1.200 and 1.350 was indicative of partially degraded microarchitecture and TBS < 1.200 was considered as an expression of degraded bone microarchitecture, according to previous reports [19] .