Utility of opportunistic CT Hounsfield Units determined bone quality in chilean women




Ratko Yurac-Barrientos, Department of Orthopedic and Traumatology, School of Medicine, University Del Desarrollo, Santiago; Department of Traumatology, Spine Unit, Clínica Alemana de Santiago, Santiago; Chile
Paula Mardones González, Department of Traumatology, Spine Unit, Clínica Alemana de Santiago, Santiago, Chile
Marilaura Núñez-Mardones, Center for Clinical Studies, Instituto de Ciencias e innovación en Medicina (ICIM) University del Desarrollo, Clínica Alemana de Santiago, Santiago, Chile
Oscar Bravo-Olivares, Department of Traumatology, Spine Unit, Hospital Clínico Mutual de Seguridad, Santiago; Department of Traumatology, Spine Unit, Hospital Clínico Fuerza Aérea Chile, Santiago; Chile
Guísela Quinteros-Rivas, Department of Traumatology, Spine Unit, Clínica Alemana de Santiago, Santiago; Department of Traumatology, Spine Unit, Hospital Regional Talca, Talca; Chile
Antonio Ariztía-Fuenzalida, Department of Traumatology, Spine Unit, Clínica Alemana de Santiago, Santiago, Chile
Catalina Nazar-Meier, Department of Radiology, Clínica Alemana de Santiago, Santiago, Chile
Andrea Marré-Chadwick, School of Medicine, University del Desarrollo, Santiago, Chile


Objective: To describe the correlation between Hounsfield Units in opportunistic computed tomography (CT scan) and T-score measured by dual energy X-ray absorptiometry (DXA) in the Chilean population. Method: Female patients over 50 years old with CT scan and DXA performed within 6 months. Hounsfield units (HU) were measured by circular regions-of-interest placed on axial slice image of the L1 vertebral body in the CT scan. T-score was obtained through DXA scan in L1-L4 vertebrae. Results: 144 female patients were included with a mean age in years of 68.39 ± 8.75. A moderate correlation was found between T-score and HU (Pearson coefficient of 0.6, p < 0.001). The mean values of HU differ significantly between the groups of Osteoporosis (OP) (89.46 ± 20.20), Osteopenia (110.87 ± 30.74) and normal bone mineral density (154.53 ± 38.90) (p < 0.01). The area under curve for diagnostic capacity was 0.81 (95% CI 0.72-0.9). The HU thresholds for the diagnosis of OP were 101 (sensitivity 75%, specificity 75%). Conclusion: Opportunistic CT scan is a useful tool in Chilean population to perform a screening for OP.



Keywords: Osteoporosis. Spine. Hounsfield Units. Computed tomograo scan. DXA.