Image registration: enabling technology for image guided surgery and therapy.

Imaging looks inside the patient's body, exposing the patient's anatomy beyond what is visible on the surface. Medical imaging has a very successful history for medical diagnosis. It also plays an increasingly important role as enabling technology for minimally invasive procedures. Interventional procedures (e.g. catheter based cardiac interventions) are traditionally supported by intra-procedure imaging (X-ray fluoro, ultrasound). There is realtime feedback, but the images provide limited information. Surgical procedures are traditionally supported with pre-operative images (CT, MR). The image quality can be very good; however, the link between images and patient has been lost. For both cases, image registration can play an essential role -augmenting intra-op images with pre-op images, and mapping pre-op images to the patient's body. We will present examples of both approaches from an application oriented perspective, covering electrophysiology, radiation therapy, and neuro-surgery. Ultimately, as the boundaries between interventional radiology and surgery are becoming blurry, also the different methods for image guidance will merge. Image guidance will draw upon a combination of pre-op and intra-op imaging together with magnetic or optical tracking systems, and enable precise minimally invasive procedures. The information is registered into a common coordinate system, and allows advanced methods for visualization such as augmented reality or advanced methods for therapy delivery such as robotics.