Florian Maier1, David T. A. Fuentes1, Jeffrey S. Weinberg2, John D. Hazle1, R. Jason Stafford1
1Department of Imaging Physics, The University of Texas M. D. Anderson Cancer Center, Houston, TX, United States; 2Department of Neurosurgery, The University of Texas M. D. Anderson Cancer Center, Houston, TX, United States
Referenceless proton resonance frequency shift thermometry algorithms require unwrapped phase maps to estimate temperature changes. Fast, robust, and fully automated unwrapping is mandatory for online monitoring. A novel phase unwrapping algorithm is proposed. Pixels are sorted according to their magnitude values and processed in descending order. Pixel clusters are merged as soon as they are connected. A region of interest for referenceless thermometry was processed in less than 40 ms. The method was successfully tested on data acquired during thermal therapy treatments of patients. In conclusion, the algorithm works robustly in vivo and allows for online temperature monitoring without noticeable delay.