Anisotropy of Trabecular Bone from Ultra-Distal Radius Digital X-Ray Imaging: Effects on Bone Mineral Density and Age

Abstract

Background: When applied to trabecular bone X-ray images, the anisotropic properties of trabeculae located at ultra-distal radius were investigated by using the trabecular bone scores (TBS) calculated along directions parallel and perpendicular to the forearm. Methodology: Data from more than two hundred subjects were studied retrospectively. A DXA (GE Lunar Prodigy) scan of the forearm was performed on each subject to measure the bone mineral density (BMD) value at the location of ultra-distal radius, and an X-ray digital image of the same forearm was taken on the same day. The values of trabecular bone score along the direction perpendicular to the forearm, TBS x , and along the direction parallel to the forearm, TBS y , were calculated respectively. The statistics of TBS x and TBS y were calculated, and the anisotropy of the trabecular bone, which was defined as the ratio of TBS y to TBS x and changed with subjects' BMD and age, was reported and analyzed. Results: The results show that the correlation coefficient between TBS x and TBS y was 0.72 (p < 0.001). Trabecular bone anisotropy changed with subjects' BMD and age was reported. The results showed that decreased trabecular bone anisotropy was associated with deceased BMD and increased age in the subject group. Conclusions: This study shows that decreased trabecular bone anisotropy was associated with decreased BMD and increased age.