The CIVA software platform developed by CEA-LIST offers various simulation and data processing modules dedicated to non-destructive testing (NDT). In particular, ultrasonic imaging and reconstruction tools are proposed in the purpose of localizing echoes and identifying and sizing the detected defects. Because of the complexity of data processed, computation time is now a limitation for the optimal use of available information. In this article, we present performance results on parallelization of one computationally heavy algorithm on general purpose processors (GPP) and graphic processing units (GPU). Although GPU implementation makes an intensive use of atomic intrinsics, it gave the highest performances. Only a dual 6-core GPP catches up its performances. Both architectures have been evaluated with different APIs: OpenMP, CUDA and OpenCL.