PACS teams up with virtual endoscopy

PACS and image processing techniques are making it possible for surgeons to use virtual endoscopy in certain neurosurgical procedures. The virtual endoscopy technique, which melds CT and MR data, provides accurate presurgical anatomic visualizations that can later be stored in a PACS.

Virtual endoscopy allows a simulated 3D visualization of anatomical structures by computerized reconstruction of radiological images.

"PACS allows fast and effective administration of patient data both as a prerequisite for virtual endoscopy and to store results," said André Neubauer, a researcher at the VRVis Research Center in Vienna, Austria.

The team's virtual prototype was embedded into the commercial medical JVision workstation (Tiani Medgraph, Vienna), which has PACS capabilities and is described in the August issue of Minimally Invasive Neurosurgery (2004;47[4]:214-220).

The prototype uses both CT and MR angiography images of the patient, Neubauer said. MR data are used to segment objects of interest such as tumors, the carotid artery, pituitary gland, or optic nerve. The boundaries of investigated cavities during virtual endoscopy flythrough are then reconstructed from CT data.

MR and CT are aligned automatically using a registration technique based on mutual information to seamlessly combine these two data sets.

After the investigation, the results, including movies and images of relevant reconstructed anatomy, can be stored in the PACS.

"In the process of developing a virtual endoscopy prototype, we have demonstrated that it harbors the potential to become a valuable tool in endoscopic pituitary surgery for preoperative planning and training," Neubauer said.

Furthermore, virtual endoscopy may add to the safety of interventions in case of anatomical variations. The software employs cutting-edge visualization technology and interaction paradigms to improve its applicability both as a planning and training tool, he said.

The project has received two international awards in the computer visualization community: the Best Applications Paper award from the IEEE Visualization 2004 and the MedVis award from the Karl-Heinz-Höhne Preis in 2004.