Abstract: Embodiments relate to use of microwave heating and infrared thermography for assessing perfusion. The system includes a microwave source, an antenna, and a radiometer. The microwave source generates microwave radiation at a frequency that is tuned to or near a resonance frequency by the antenna to output a microwave beam. The microwave beam is caused to be incident upon tissue and is converted to heat. The heated tissue emits infrared radiation that is monitored by the radiometer. The system allows for a low-cost, efficient, and non-invasive means to assess blood perfusion without radiofrequency interference. Use of infrared thermography is accomplished by the formation of the hole in the antenna structure. Use of an array of such antennas allows the measurement of perfusion for multiple points across a region of the body. The efficiency of the system is aided by adjusting the average microwave power by means of pulse width modulation.