Ultrasound based Respiratory Motion Compensation in the Abdomen

For image-guided interventions, the patient respiratory motion has to be considered when integrating pre-operative plans and imaging into the interventional suite. Ultrasound is particularly attractive for obtaining live information about anatomical changes, without adding further radiation dose to patient and physician such as fluoroscopy. We propose a strategy to both detect and compensate for respiratory movements in the liver, relying solely on real-time information from a tracked 2D ultrasound transducer, as well as one position sensor attached to the patient’s skin. Our method does not require a patient-specific 4D model of the respiration, which would be costly to establish and might not recover entire breathing variabilities and irregularities during the procedure. Appropriate transformation models, interpolation schemes and implementation details are discussed. By means of evaluation on liver data of four volunteers, we demonstrate the usefulness of our approach for ultrasound-based guidance of abdominal biopsies and ablations.