Influencing factors of detection on ionizing radiation-induced electron paramagnetic resonance signal in bones

Objective To study the influencing factors of detection on ionizing radiation-induced electron paramagnetic resonance (EPR) signal in mice bone. Methods Soft tissue and bone marrow samples of mice femur were collected, and femur sections were dried. The femur sections were irradiated at 10 and 50 Gy by 60Co sources with irradiation dose rate of 5 Gy/min. Bone EPR signal intensity was detected under different degrees of drying, detection direction, and microwave power, as well as various scan times. Results The water content of the bone sample was reduced, and microwave power was set to an appropriate value. Results showed that increasing scan times increased the signal intensity. Additionally, different detection directions of the same sample resulted in differences in signal intensity. Conclusion Appropriate sample preparation and detection parameters can improve bone EPR detection sensitivity. Multidirectional detection of samples and averaging of the results may reduce the effects of inhomogeneity on bone samples. Key words: Ionizing radiation; Bone; Electron paramagnetic resonance; Mice