Investigating human bone microarchitecture and dielectric properties in microwave frequency range

Dielectric properties of bones are proposed to monitor bone quality. However, no study has investigated the relationship between bone dielectric properties and microarchitecture of bone, which is of paramount importance for bone quality assessment. This paper reports the first in-vitro investigation of relationship between dielectric properties of human trabecular bone (n = 45) and its microarchitecture parameters (trabecular number, trabecular thickness and trabecular spacing). The objective of the study was to investigate the difference between osteoporotic (n = 23) and osteoarthritis (n = 22) patients in terms of microarchitectural parameters and dielectric properties and to examine any relationship between microarchitectural parameters and dielectric properties. A significant difference was observed between osteoporotic and osteoarthritis patients in terms of microarchitecture parameters. The trabecular number and trabecular thickness were found to be significantly high for osteoarthritis patients in comparison to osteoporotic patients. The percentage difference for trabecular number and trabecular thickness between both patients group was found to be 27% and 31% respectively. Trabecular spacing was lower in osteoarthritis patients compared to osteoporotic patients. Similar differences were also observed between both patients group in terms of dielectric properties. More importantly, the dielectric properties were significantly higher for osteoarthritis patients than osteoporotic patients with a percentage difference of 42% and 32% at 900 MHz in terms of relative permittivity and conductivity respectively. These preliminary findings support the idea of using dielectric properties to as a method to differentiate bone quality.