3-D reconstruction of the sphenoid sinus from monocular endoscopic views: First results

For intervention at the pituitary gland, the shortest and most subtle method is an operation through the paranasal sinuses and especially through the sphenoid sinus. To avoid dangerous interference with adjacent nerves and organs, the physician has to orient himself in the very small sphenoid cavity and navigate across the hollow to breakthrough the sellar floor to the pituitary gland above. Especially in re-operations and anatomical variants such as so-called kissing carotids, transsphenoidal surgery is a challenge even in experienced hands. To support such a surgery, image systems can be applied, such as preoperative CT or intra-operative endoscopy. While preoperative CT-data is used for operation planning and navigation support, endoscopy is currently used only for examination of the surfaces inside the sphenoid sinus. In this work, we present a 3-D reconstruction of the sphenoid sinus for navigation support, based on a monocular endoscopic sequence of images, yielding a grid describing the walls of the sphenoid sinus.