Microwave Imaging

Abstract

AbstractThe overview of applications of microwaves in medical diagnostics is presented. The advantages and disadvantages of passive and active microwave imaging systems, radiometry, tomography, and the confocal radar technique, are analyzed. The limited spatial resolution as well as difficulties in image reconstruction and interpretation of the results do not allow microwave imaging to be successful in competition with technologies for traditional medical imaging. However, microwave imaging provides higher sensitivity with respect to physical or physiological factors of clinical interest, such as temperature, water content, blood‐flow rate, and vascularization/angiogenesis. The data achieved by microwave technology may be possible to relate to the biology of physiological processes, especially in the brain and heart; infections; hyperplasia; and cancer.The potential advantages of active microwave imaging arise mainly from the high contrast of electrical properties between normal and malignant human breast tissues. Active microwave imaging for the detection of breast tumors is an emerging technique to complement existing x‐ray mammography. The nonionizing microwave radiation does not cause changes on an atomic and a molecular level and is much less harmful for biological tissues than ionizing radiation. A short historical overview about microwave radiometry and tomography is done. The theoretical background of radiometric measurements as well as a short description of different methods and instrumentation developed for data visualization and image reconstruction are presented.