Image-guided surgery(IGS) is the general term used for any surgical procedure where the surgeon employs tracked surgical instruments in conjunction with preoperative or intraoperative images in order to indirectly guide the procedure. Most image-guided surgical procedures are minimally invasive. Image Guided Surgery/ Brain Mapping The technology was originally developed for treatment of brain tumors, but has found widest application when applied to surgery of the sinuses, where image-guided surgery helps avoid damage to brain and nervous system.