Volumetric computed tomography Hounsfield unit analysis: a superior method for opportunistic osteoporosis screening...

This study investigated the correlation between two-dimensional and volumetric Hounsfield unit (HU) measurements from computed tomography (CT) and T-scores from dual-energy X-ray absorptiometry (DXA), assessing their interchangeability for opportunistic osteoporosis (OP) screening.

A retrospective analysis included 97 patients (15 males, 82 females; mean age 66.48 ± 9.97 years) who underwent lumbar CT and DXA within 7 months. Two-dimensional HU values were measured from axial images (L1-L4), whereas volumetric HU values were obtained using 3D segmentation. Correlations with DXA T-scores were analyzed, and agreement between methods was assessed using Bland-Altman analysis and intraclass correlation coefficients (ICC).

Both HU methods significantly correlated with DXA T-scores (p < 0.001), with volumetric HU showing stronger correlations (r = 0.572 vs. r = 0.532). Osteoporotic patients had lower HU values, with volumetric HU offering better differentiation. Bland-Altman analysis revealed a systematic bias, with two-dimensional HU underestimating values. ICC showed excellent agreement, with volumetric HU achieving higher reliability (ICC = 0.963 vs. ICC = 0.918).

Volumetric HU measurements provide a more reliable and sensitive assessment of trabecular bone density, making them a superior method for opportunistic OP screening and treatment monitoring.