ABSTRACT
When electromagnetic energy is delivered into biological tissue, a portion of the energy is absorbed by the tissue and converted to heat. A temperature gradient is then produced by the heating based on the energy absorption pattern, and subsequently ultrasonic waves are generated through thermal expansion. This is called thermoacoustic effects (Jin 2007, Foster & Finch 1974, Gutfeld 1980).Thermoacoustic computed tomography (TACT) is a new imaging modality based on thermoacoustic effects. In recent years, there is an increasing interest in studying it and it has attracted the attentions of researchers from various fields.
