FPGA-based real-time 3D image preprocessing for image-guided medical interventions

Minimally invasive image-guided interventions (IGIs) are time and cost efficient, minimize unintended damage to healthy tissue, and lead to faster patient recovery. One emerging trend in IGI workflow is to use volumetric imaging modalities such as low-dose computed tomography (CT) and 3D ultrasound to provide real-time, accurate anatomical information intraoperatively. These intraoperative images, however, are often characterized by quantum (in low-dose CT) or speckle (in ultrasound) noise and must be enhanced prior to any advanced image processing. Anisotropic diffusion filtering and median filtering have been shown to be effective in enhancing and improving the visual quality of these images. However, achieving real-time performance, as required by IGIs, using software-only implementations is challenging because of the sheer size of the images and the arithmetic complexity of the filtering operations. We present a field-programmable gate array-based reconfigurable architecture for real-time preprocessing of intraoperative 3D images. The proposed architecture provides programmable kernels for 3D anisotropic diffusion filtering and 3D median filtering within the same framework. The implementation of this architecture using an Altera Stratix-II device achieved a voxel processing rate close to 200 MHz, which enables the use of these processing techniques in the IGI workflow prior to advanced operations such as segmentation, registration, and visualization.