Real-time Positioning Method Of Percutaneous Renal Puncture Based On Three-dimensional CT-two-dimensional Ultrasound Registration

In recent years,medical image-guided percutaneous renal puncture has become an important means of establishing surgical channels in percutaneous nephrolithotomy due to its advantages of less trauma,fewer complications,and preservation of renal function.Clear and real-time medical imaging technology can improve the accuracy of intraoperative puncture and reduce the number of repeated punctures.However,in ultrasound image-guided percutaneous renal puncture surgery,the limitations of the low image spatial resolution and the narrow field of view of the two-dimensional ultrasound image,and the lack of three-dimensional,intuitive position and spatial information are the main factors that affect the accuracy and safety of the puncture.Aiming at the problems in traditional ultrasound image-guided percutaneous renal puncture surgery,this paper proposes a real-time positioning method for percutaneous renal puncture based on 3D CT-two-dimensional ultrasound registration.The overall research goal is to assist clinicians based on the puncture positioning system Perform percutaneous renal puncture operations to provide clinicians with accurate,real-time,and intuitive navigation and positioning information to improve puncture accuracy and efficiency.The key technologies involved in the proposed method are surgical instrument calibration methods,real-time registration and fusion of multi-modal images,and the construction of puncture positioning systems.The specific research contents are as follows:1)Research on calibration methods of surgical instruments based on optical positioning,including puncture needle tip calibration methods and ultrasound probe calibration methods.2)Research on real-time registration method based on preoperative threedimensional CT-intraoperative two-dimensional ultrasound image.3)Establishment of percutaneous renal puncture positioning system based on open source platform and experimental verification of phantom puncture.In the research on the calibration method of surgical instruments based on optical positioning,an improved spatial single N-line calibration model is proposed.Only a single N-line is required to obtain the spatial information in the vertical direction,which is simpler than the multi-N-line model.The experimental verification shows that the calibration error of the puncture needle is 0.330 mm,and the calibration error of the ultrasound probe is 0.998 mm.In the research of three-dimensional CT-two-dimensional ultrasound image registration method,a coarse-to-fine registration method based on the contour features of kidney organs is proposed.In the stage of rough slice matching of 3D CT-2D ultrasound,the search range of slice matching can be narrowed efficiently and widely based on the area feature and contour quantity feature of the kidney organ.Experimental verification shows that the registration error of the marked points is 0.709 mm,and the average registration operation time is 1.15 s.In the research of the percutaneous renal puncture navigation and positioning system,a puncture positioning and navigation system was built,including the establishment of a data stream transmission chain such as ultrasound images,surgical instrument tracking position and posture,and the integration of data stream processing algorithms.In the final phantom kidney puncture experiment,the diameter of the lesion tissue in the kidney organ of the phantom was about 8mm,with a puncture error of2.920 mm,which met the needs of percutaneous renal puncture surgery.In summary,the method proposed in this paper has achieved good results in terms of registration accuracy,surgical instrument calibration accuracy and puncture positioning accuracy,and basically meets the needs of percutaneous renal puncture for navigation and positioning.