title: Towards real time 2D to 3D registration for ultrasound-guided endoscopic and laparoscopic procedures.
abstract: OBJECTIVE
  A method to register endoscopic and laparoscopic ultrasound (US) images in real time with pre-operative computed tomography (CT) data sets has been developed with the goal of improving diagnosis, biopsy guidance, and surgical interventions in the abdomen.
  
  
  METHODS
  The technique, which has the potential to operate in real time, is based on a new phase correlation technique: LEPART, which specifies the location of a plane in the CT data which best corresponds to the US image. Validation of the method was carried out using an US phantom with cyst regions and with retrospective analysis of data sets from animal model experiments.
  
  
  RESULTS
  The phantom validation study shows that local translation displacements can be recovered for each US frame with a root mean squared error of 1.56 +/- 0.78 mm in less than 5 sec, using non-optimized algorithm implementations.
  
  
  CONCLUSIONS
  A new method for multimodality (preoperative CT and intraoperative US endoscopic images) registration to guide endoscopic interventions was developed and found to be efficient using clinically realistic datasets. The algorithm is inherently capable of being implemented in a parallel computing system so that full real time operation appears likely.
authors.affiliation: Laboratory of Mathematics in Imaging, Brigham and Women's Hospital, Boston, MA, USA. rjosest@bwh.harvard.edu
authors.forename: Raúl
authors.initials: R
authors.lastname: San José Estépar
authors.forename: Carl-Fredrik
authors.initials: CF
authors.lastname: Westin
authors.forename: Kirby G
authors.initials: KG
authors.lastname: Vosburgh
mesh_terms: D000818:Animals; D004724:Endoscopy; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D010535:Laparoscopy; D019047:Phantoms, Imaging; D013552:Swine; D014057:Tomography, X-Ray Computed; D018084:Ultrasonography, Interventional