Abstract
BACKGROUND: Quantitative computed tomography (QCT) has received growing attention for its utility in bone mineral density (BMD) assessment and osteoporosis diagnosis. OBJECTIVE: To assess the accuracy and precision of lumbar spine BMD measurements obtained using low-dose iCare QCT, based on the European Spine Phantom (ESP). METHODS: Paired t-test was employed to compare BMD values measured under normal-dose and low-dose scan protocols using Mindways and iCare QCT systems. Accuracy was evaluated using relative measurement error (RME), and precision was assessed via relative standard deviation (RSD). Pearson correlation coefficients and Bland-Altman analysis were used to examine measurement correlation and agreement. RESULTS: For Mindways QCT, RMEs of L1-L3 were 11.89%, 6.94%, and 6.72% under normal-dose, and 6.65%, 10.5%, and 6.31% under low-dose, respectively. For iCare QCT, RMEs were 1.21%, 4.28%, and 8.88% under normal-dose, and 2.14%, 4.96%, and 8.59% under low-dose, respectively. RSDs of L1-L3 for Mindways QCT were 5.16%, 2.85%, and 0.47% under normal-dose, and 9.08%, 4.69%, and 0.49% under low-dose, respectively. For iCare QCT, RSDs were 1.11%, 0.81%, and 0.45% under normal-dose, and 2.34%, 0.85%, and 0.33% under low-dose, respectively. The radiation dose in the low-dose protocol was significantly reduced compared with the normal-dose protocol. CONCLUSION: Low-dose iCare QCT exhibited high accuracy and precision in measuring lumbar spine BMD, achieving an approximately 85% reduction in radiation dose. These findings highlight its potential as a safer and reliable tool for clinical application.