O. Zettinig, A. Shah, C. Hennersperger, M. Eiber, C. Kroll, H. Kübler, T. Maurer, F. Milletari, J. Rackerseder, C. Schulte zu Berge, E. Storz, B. Frisch, N. Navab
International Journal of Computer Assisted Radiology and Surgery
Trans-rectal ultrasound (TRUS) guided random prostate biopsy is, in spite of its low sensitivity, the gold standard for the diagnosis of prostate cancer. The recent advent of PET imaging using a novel dedicated radiotracer, 68-Ga labeled PSMA (Prostate Specific Membrane Antigen), combined with MRI provides improved pre-interventional identification of suspicious areas. This work proposes a multimodal fusion image-guided biopsy framework that combines PET-MRI images with TRUS, using automatic TRUS segmentation and registration, and offering real-time guidance. The prostate PET-MRI and TRUS images are automatically segmented with a Hough transform based random forest approach. The registration is based on the Coherent Point Drift algorithm to align surfaces elastically and to propagate the deformation field calculated from thin plate splines to the whole gland. The method, which has minimal requirements and temporal overhead in the existing clinical workflow, is evaluated in terms of surface distance and landmark registration error with respect to the clinical ground truth. A clinical evaluation confirms the validity of this approach.