The most attractive feature of 2D B-mode ultrasound for intra-operative use is that it is both a real time and a highly interactive modality. Most 3D freehand reconstruction methods, however, are not fully interactive because they do not allow the display of any part of the 3D ultrasound image until all data collection and reconstruction is finished. We describe a technique whereby the 3D reconstruction occurs in real-time as the data is acquired, and where the operator can view the progress of the reconstruction on three orthogonal slice views through the ultrasound volume. Capture of the ultrasound data can be immediately followed by a straightforward, interactive nonlinear registration of a pre-operative MRI volume to match the intra-operative ultrasound. We demonstrate the our system on a deformable, multi-modal PVA-cryogel phantom and during a clinical surgery.
David G. Gobbi, Terry M. Peters