Magnetic resonance imaging of thermal coagulation effects in a phantom for calibrating thermal therapy devices

A material has been developed and tested that permanently records thermal response patterns from heating devices. The material consists of a mixture of polyacrylamide and 18% w/w bovine serum albumin. Thermal denaturation is complete when the local temperature exceeds 70 degrees C, causing a large reduction in the T-2 of the material. Three-dimensional distributions of "thermal damage" can be assessed using standard magnetic resonance imaging sequences'. The material works well with microwave heating devices and is adaptable for use with ultrasound, radio-frequency, or laser heating devices. Suggested uses include characterizing heating devices prior to treatment and developing new clinical applications for thermal therapies. (C) 2000 American Association of Physicists in Medicine. [S0094-2405(00)01705-3].