Non-invasive microwave radiometry thermometry

Abstract

Near-field microwave radiometry and radiometric imaging are non-invasive techniques that are able to provide temperature information at a depth of up to several centimetres in subcutaneous tissues. They are based on the measurement of microwave electromagnetic thermal noise. This paper describes the basic principles, measurement methods and limitations of the techniques and the results of clinical studies, and it reviews recent progress.

Non-Invasive Devices for Early Detection of Breast Tissue Oncological Abnormalities Using Microwave Radio Thermometry

“…The infrared imaging system uses a camera that is highly sensitive to infrared radiation in the appropriate spectrum. Microwave radiometry is based on the measurement of the electromagnetic field spontaneously emitted by a body in the microwave frequency range [Bardati & Solimini, 1983;Edrich, 1979;Leroy et al, 1998;Meyer et al, 1979]. Charged particles in motion are primary sources of incoherent thermal radiation propagating inside the body, where it is partially absorbed and partially radiated externally.…”

“…In order to solve this problem it is necessary to use zero balance radiometer with compensation of reflections between antenna and human body tissue. This principle is used in most modern microwave radiometers (Leroy et al, 1998, Hand et al, 2001& Lee et al, 2002). An overview of microwave radiometry is given in a recent publication (Hand et al, 2001).…”

Thermal Therapy, Part IV: Electromagnetic and Thermal Dosimetry

“…They are based on the measurement of microwave thermal noise. 23 The principle advantage of the microwave radiometer as a tool for biomedical imaging applications is the possibility to monitor a thermal noise produced by objects with temperature above absolute zero. Figure 4 shows the principle of imaging by microwave radiometer.…”

“…Its main attraction is the innocuous nature of this type of energy at low levels, the relatively low cost of even complex microwave systems compared to the computer-assisted tomography (CAT) and MRI, and the distinctly different permittivity of tumor tissue compared to normal tissue. 23,40 Excellent reviews of the subject are those of Foster and Cheever 21 and Rosen et al 23 Since the 1970s, several research groups have carried out clinical evaluations of microwave radiometry (passive, hybrid, and active approaches). [218][219][220][221][222][223][224][225][226][227][228][229][230][231][232][233][234][235][236][237] The most important work was done by Barret et al 220 in the fi eld of breast cancer screening.…”

“…The failure to detect these small focal areas of residual and/or recurrent tumor at an early stage may result in peripheral regrowth, often with unfavorable geometry for successful treatment. 14 In the literature, important techniques and areas of research in EM dosimetry, [15][16][17][18] thermal dosimetry, [19][20][21][22][23][24][25][26] treatment planning, 27 and imaging techniques [28][29][30][31][32][33][34][35][36] have been reviewed. Books discussing thermometry and imaging techniques are also available.…”