title: Real-time 3D image reconstruction guidance in liver resection surgery.
abstract: BACKGROUND
  Minimally invasive surgery represents one of the main evolutions of surgical techniques. However, minimally invasive surgery adds difficulty that can be reduced through computer technology.
  
  
  METHODS
  From a patient's medical image [US, computed tomography (CT) or MRI], we have developed an Augmented Reality (AR) system that increases the surgeon's intraoperative vision by providing a virtual transparency of the patient. AR is based on two major processes: 3D modeling and visualization of anatomical or pathological structures appearing in the medical image, and the registration of this visualization onto the real patient. We have thus developed a new online service, named Visible Patient, providing efficient 3D modeling of patients. We have then developed several 3D visualization and surgical planning software tools to combine direct volume rendering and surface rendering. Finally, we have developed two registration techniques, one interactive and one automatic providing intraoperative augmented reality view.
  
  
  RESULTS
  From January 2009 to June 2013, 769 clinical cases have been modeled by the Visible Patient service. Moreover, three clinical validations have been realized demonstrating the accuracy of 3D models and their great benefit, potentially increasing surgical eligibility in liver surgery (20% of cases). From these 3D models, more than 50 interactive AR-assisted surgical procedures have been realized illustrating the potential clinical benefit of such assistance to gain safety, but also current limits that automatic augmented reality will overcome.
  
  
  CONCLUSIONS
  Virtual patient modeling should be mandatory for certain interventions that have now to be defined, such as liver surgery. Augmented reality is clearly the next step of the new surgical instrumentation but remains currently limited due to the complexity of organ deformations during surgery. Intraoperative medical imaging used in new generation of automated augmented reality should solve this issue thanks to the development of Hybrid OR.
authors.affiliation: 1 IRCAD France, 2 IHU Strasbourg, 1 place de l'hôpital, 67091 Strasbourg, France.
authors.forename: Luc
authors.initials: L
authors.lastname: Soler
authors.affiliation: 1 IRCAD France, 2 IHU Strasbourg, 1 place de l'hôpital, 67091 Strasbourg, France.
authors.forename: Stephane
authors.initials: S
authors.lastname: Nicolau
authors.affiliation: 1 IRCAD France, 2 IHU Strasbourg, 1 place de l'hôpital, 67091 Strasbourg, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Pessaux
authors.affiliation: 1 IRCAD France, 2 IHU Strasbourg, 1 place de l'hôpital, 67091 Strasbourg, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Mutter
authors.affiliation: 1 IRCAD France, 2 IHU Strasbourg, 1 place de l'hôpital, 67091 Strasbourg, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Marescaux
keywords: Augmented reality (AR); computer-assisted surgery; liver surgery; virtual reality