Measurement reproducibility of magnetic resonance imaging-based finite element analysis of proximal femur microarchitecture for in vivo assessment of bone strength

Osteoporosis is a disease of weak bone. Our goal was to determine the measurement reproducibility of magnetic resonance assessment of proximal femur strength. This study had institutional review board approval, and written informed consent was obtained from all subjects. We obtained images of proximal femur microarchitecture by scanning 12 subjects three times within 1 week at 3T using a high-resolution 3-D FLASH sequence. We applied finite element analysis to compute proximal femur stiffness and femoral neck elastic modulus. Within-day and between-day root-mean-square coefficients of variation and intraclass correlation coefficients ranged from 3.5 to 6.6 % and 0.96 to 0.98, respectively. The measurement reproducibility of magnetic resonance assessment of proximal femur strength is suitable for clinical studies of disease progression or treatment response related to osteoporosis bone-strengthening interventions.