Abstract: Objective To establish the technological route of ultrasound and CT image fusion based on optical tracking system and to apply in soft tissue navigation of craniomaxillofacial surgery. Methods (1) To acquire two-dimensional ultrasound images and three-dimensional reconstruction through the nearest neighboring difference algorithm;(2) Ultrasound and CT image fusion through the dLDP algorithm independently researched; (3) Clinial verification and evaluation of the effect of image fusion. Results The independently researched image fusion algorithm based on dLDP realized the fusion of craniomaxillofacial ultrasound and CT, the average error was about 1.96 mm. Conclusion The accuracy and display effect based on the dLDP algorithm can meet the clinical requirements. It has important significance in independent research of craniomaxillofacial soft tissue navigation system.

Key words: Ultrasound, Computed tomogrphy, Craniomaxillofacial soft tissue, Navigation, Image fusion