The use of a Phase Field method for medical image
segmentation is proposed in this paper. The Allen-Cahn
equation, a mathematical model equation, is used in this
method. The Finite Difference method is used for numerical
discretization of model equations and semi-algebraic equations integrated over time using the second
-order Runge-Kutta method. Numerical algorithms are implemented into computer programming using the serial and parallel C programming language based on GPU CUDA. Based on image segmentation calculations, the Phase Field method has high accuracy. It is indicated by the Jaccard Index and Dice Similarity values that are close to one. The range of Jaccard Index values is 0.859 - 0.952, while the Dice Similarity value range is 0.926 - 0.976. In addition, it is shown that parallel programming with GPU CUDA can accelerate 45.72 times compared to serial programming.