Microwave imaging of the knee: On sensitivity, resolution and multiple tears detection.

Microwave imaging has been extensively studied in the past several years as a new technique for early stage breast cancer detection. Besides this, other medical applications were proposed concerning the analysis of cardiac tissues, soft tissues and bones. Recently, the use of radar-based microwave imaging was investigated by the authors for the diagnosis of knee-injuries, with focus on meniscal tears. The results, both numerical and experimental, suggest that radar-based microwave imaging has potential for knee imaging. Imaging tears as small as 3.4 times 8 mm appears feasible, and could be useful for monitoring the progression of degenerative disease after injury. In this paper we report on further investigation of the approach. We performed experimental evaluation of the sensitivity and resolution of the method and of its capability of detecting multiple tears. Results show that tears as small as 1.3 mm times 8 mm are successfully imaged, that multiple tears can be detected and that tears separated by 9 mm can be imaged as distinct lesions.