Fatih Erdem, Faculty of Medicine, Radiology Department, Ege University, Izmir, Türkiye
Bahar Yanık, Faculty of Medicine, Radiology Department, Balikesir University, Balikesir, Türkiye
Taha Yasin-Arslan, Radiology Clinic, Balikesir Atatürk City Hospital, Balikesir, Türkiye
Emrah Akay, Faculty of Medicine, Radiology Department, Balikesir University, Balikesir, Türkiye
Erdogan Bülbül, Faculty of Medicine, Radiology Department, Balikesir University, Balikesir, Türkiye
Gülen Demirpolat, Faculty of Medicine, Radiology Department, Balikesir University, Balikesir, Türkiye
Objectives: 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. Methods: 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). Results: 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). Conclusions: 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.
Keywords: Osteoporosis screening. Hounsfield units. Dual-energy X-ray absorptiometry. Volumetric density. Trabecular bone.