Background : Trabecular bone score (TBS) is measured from posterio-anterior (PA) spine DXA images. A recently developed tool, Texture Research Investigational Platform (TRIP), can assess bone texture score (BTS) based on a derived approach of the lumbar spine TBS algorithm at any skeletal site and image type except the PA or AP spine. Assessing BTS on the lateral view of the spine has the advantage to exclude the posterior elements from the analysis region.
Aim: We hypothesized that BTS analysis can be performed on lumbar spine (LS) lateral vertebral fracture assessment (VFA) images and could potentially differentiate women with vertebral fracture from those without vertebral fracture.
Methods: Existing data were reviewed from DXA scans acquired at Madison, WI (USA) and Lausanne (CH) University facilities. Scans from 226 women (113 fractured and 113 non-fractured, age- and BMI-matched) of mean age 73.3 ±7.8 years and mean BMI 26.3 ±4.1 kg/m2. All women had PA lumbar DXA scans and VFA performed using Lunar iDXA (GE Healthcare, Madison, WI, USA) and TBS measured using a beta version accounting for abdominal tissue thickness. BTS was assessed using TRIP v1.0 (Medimaps, France) by manually employing 8-point morphometry on DICOM lumbar spine VFA images (L1 to L4). Fractures determined from VFA images using the Genant VSQ method. Correlation of BTS with LS BMD was performed using Spearman`s correlation coefficient; differences between fractured and non-fractured women were assessed by independent sample t-tests; and logistic regressions were used to obtain risk estimates for fracture per SD decrease in BTS, LS BMD or TBS.
Results: Fractured women had lower LS BMD (1.03±0.20 vs 1.10 ±0.20 g/cm2, p<0.05), TBS (1.25 ±0.08 vs 1.30 ±0.08, p<0.05) and BTS (0.61 ±0.19 vs 0.65 ±0.18, p<0.05) compared to control. BTS was weakly correlated with LS BMD (r=0.22). Spine BMD correlated with TBS (r=0.56) and with BTS (r=0.33). The results of the logistic regression analysis are shown in the table.
Conclusion: Despite the small sample size, this feasibility study demonstrates the possibility of obtaining BTS values at the lateral spine using VFA images. Lower BTS values were observed in subjects with prevalent vertebral fractures. Further work with a larger sample size is indicated to assess the clinical relevance of these results.