State of the Art of Ultrasound-Based Registration in Computer Assisted Orthopedic Interventions

The preferred modality for intraoperative imaging in orthopedic interventions is fluoroscopic imaging. But the exposure of the patient and the surgical team to high dose of x-ray radiation and the inappropriate handling of the fluoroscopic c-arm limit its application. In contrast to fluoroscopy, ultrasound imaging does not expose the patient to harmful ionizing radiation. Due to its excellent spatial resolution, B-mode ultrasound imaging is commonly used in the clinical routine to examine soft tissue such as muscles and organs. Thus, it is perfectly suited for preoperative diagnosis and is an essential tool in prenatal care. However, ultrasound images are subject to various types of artifacts, degrading the quality of the data and making the perception and interpretation rather difficult. Despite its known drawbacks, ultrasound imaging has the potential to become an efficient modality for intraoperative imaging. But the integration of ultrasound into the clinical workflow of a computer-assisted orthopedic surgery gives rise to new challenges. In this chapter the advantages and disadvantages of using ultrasound imaging in image-guided orthopedic interventions are pointed out. Moreover, an overview of the latest clinical applications and the current research is given. A special focus will be on the application of B-mode ultrasound imaging for intraoperative registration in image-guided interventions.