MR imaging assisted temperature calculations during cryosurgery.

MRI has the potential of becoming an important imaging modality for monitoring the extent of the frozen region during cryosurgery. However, while the temperature history inside the frozen region is of utmost importance in determining the likely outcome of a cryosurgical procedure, it cannot be accessed directly through MRI because of the extremely low signal produced by the frozen region. We have developed a new MRI-assisted numerical technique that can calculate and display the temperature distribution in the frozen region on a standard MR image. The technique combines MR imaging data with a finite difference formulation of the energy equation. Here, the technique is described and experimental results that verify the technique are shown.