A novel design of thermal anomaly for mammary gland tumor phantom for microwave radiometer

Microwave radiometry is a spectral measurement technique for resolving electromagnetic radiation of all matter whose temperature is above absolute zero. This technique utilizes the electromagnetic noise field generated by a thermal volume similar to the mechanism existing in biological tissues. One particular application of microwave radiometry is for analyzing temperature differentials inside the human body to detect and diagnose some crucial pathological conditions. For the general evaluation of a microwave radiometer, we propose a new type of phantom containing a mammary gland tumor imitator by considering biological heat diffusion effects propagated by a real tumor. Theoretical research on human tumors revealed the fact that the temperature distribution of tissues around a tumor displayed Gaussian statistics. To comply with the physiological property of the real tumor, we built a mammary gland tumor imitator composed of two parts (pseudotumor and thermal anomaly) and observed its temperature distribution when it was placed inside a phantom. Our results showed that the thermal properties of the tumor imitator agreed well with heat-transfer properties of a real tumor and that a proportional linear relationship existed between the location of the tumor imitator and the intensity of radiometer measurements. From this relationship, we could also estimate several parameters related to our phantom, such as the minimum detectable size and maximum detectable depth of a tumor imitator.