Iranian Journal of Nuclear Medicine

Iranian Journal of Nuclear Medicine

Comparative analysis of quality control results of 22 dual-energy X-ray absorptiometry (DEXA) systems across six manufacturers using a comprehensive one-day protocol

Articles in Press

Document Type : Original Article

Authors
Fatemeh Abbasi 1
Reza Faghihi 1
Seyed Mohammad Entezarmahdi 2
Farshid Gheisari 2
Mahdi Haghighatafshar 2
1 Department of Nuclear Engineering, Shiraz University, Shiraz, Iran
2 Department of Nuclear Medicine, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
10.22034/irjnm.2026.130431.1734
Abstract
Introduction: International societies involved in bone mineral densitometry emphasize the necessity of regular quality control (QC) for dual-energy X-ray absorptiometry (DEXA) systems. However, the current recommended procedures are not comprehensive and do not assess certain critical performance aspects—such as system stability under varying soft-tissue thickness and differing attenuation coefficients—that may affect measurement reliability. This study introduces and applies a one-day QC protocol designed to evaluate five key aspects of DEXA performance: in-vitro short-term precision (IV-STP), repeatability, stability across varying soft-tissue thickness (St-Thi), stability across differing attenuation coefficients (St-Att), and accuracy.
Methods: Twenty-two DEXA scanners from six manufacturers were evaluated using a lumbar phantom with Plexiglass slabs or a water tank to simulate soft-tissue variations. IV-STP, repeatability, St-Thi, and St-Att were expressed as coefficients of variation (%CV), while accuracy - defined here as phantom-based agreement with the reference BMD value - was reported as the complement of the mean absolute error (%MAE).
Results: %CV values for IV-STP and repeatability ranged from 0.50–1.49 and 0.61–1.24, respectively. St-Thi and St-Att tests showed %CV ranges of 0.93–6.65 and 0.32–3.87. Phantom-based accuracy varied between 81.48% and 92.75%. These results indicated heterogeneity and suboptimal stability and accuracy among some systems.
Conclusion: The proposed five-step QC protocol revealed performance variations among DEXA systems, including aspects not addressed in existing recommendations by international societies. This structured approach provides a more comprehensive framework for routine QC and can uncover latent deficiencies in system stability and accuracy, thereby enhancing diagnostic reliability and supporting regulatory standardization.
Keywords
Bone mineral densitometry
Dual-energy X-ray absorptiometry
Quality Control
Stability
Precision
Subjects
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Iranian Journal of Nuclear Medicine

Articles in Press, Accepted Manuscript
Available Online from 28 September 2026