Consistency of signal intensity and T2* in frozen ex vivo heart muscle, kidney, and liver tissue

Purpose: To investigate tissue dependence of the MRI‐based thermometry in frozen tissue by quantification and comparison of signal intensity and T2* of ex vivo frozen tissue of three different types: heart muscle, kidney, and liver. Materials and Methods: Tissue samples were frozen and imaged on a 0.5 Tesla MRI scanner with ultrashort echo time (UTE) sequence. Signal intensity and T2* were determined as the temperature of the tissue samples was decreased from room temperature to approximately −40°C. Statistical analysis was performed for (−20°C, −5°C) temperature interval. Results: The findings of this study demonstrate that signal intensity and T2* are consistent across three types of tissue for (−20°C, −5°C) temperature interval. Conclusion: Both parameters can be used to calculate a single temperature calibration curve for all three types of tissue and potentially in the future serve as a foundation for tissue‐independent MRI‐based thermometry. J. Magn. Reson. Imaging 2010;31:719–724. © 2010 Wiley‐Liss, Inc.