Microwave bone imaging: a preliminary scanning system for proof-of-concept

This paper introduces a feasibility study of a scanning system for applications in biomedical bone imaging operating in the microwave range 0.5 – 4 GHz. Mechanical uncertainties and data acquisition time are minimized by using a fully automated scanner that controls two antipodal Vivaldi antennas. Accurate antenna positioning and synchronization with data acquisition enables a rigorous proof-of-concept for the microwave imaging procedure of a multi-layer phantom including skin, fat, muscle and bone tissues. The presence of a suitable coupling medium enables antenna miniaturization and mitigates the impedance mismatch between antennas and phantom.
The 3-D image of tibia and fibula is successfully reconstructed by scanning the multi-layer phantom due to the distinctive dielectric contrast between target and surrounding tissues. These results show the viability of a microwave bone imaging technology which is low-cost, portable, nonionizing, and does not require specially trained personnel. In fact, as no a-priori characterization of the antenna is required, the image formation procedure is very conveniently simplified.