The Experimental And Preliminary Clinical Study Of Registration Speed And Accuracy In Multimodal Image Fusion

Objective1、To develop a navigation software, which can achieve the function of ultrasound and CT image fusion registration-"OBERON Image Guided Surgery Navigation Systems", and to validate the accuracy of registration and time-consuming through the abdominal simulation phantom experiment.2. To acquire the respiratory motion law by means of the movement of the relative position and attitude between the multi-point change on the abdominal surface, and to verify the registration accuracy in a specific breathing phase using the OBERON software by animal experiments.3. To research a combination of points located on the body surface that the most sensitive reflection of respiratory motion and to verify the feasibility of fusion precise registration using OBERON software in a specific breathing phase through an initial clinical study.Materials and Methods1. Under the condition of magnetic navigation, the abdominal simulation phantom were carried out ultrasound and CT image fusion registration, compared the differences in registration errors and time-consuming between OBERON software and commercial software and verify the accuracy in the registration of phantom using the OBERON software.2. The position and attitude of the sensor on the abdominal surface was obtained of using of mathematical algorithms, and monitoring the respiratory movement by the computer processed and an error was converted from the breathing phase. Establishment of orthotopic liver tumor mode by the iodized oil in miniature pig and eight points from different positions (near the surface of left lateral lobe of liver, inside the left lateral lobe, near the surface of right lateral lobe of liver and inside the right lateral lobe) and different sizes (diameter in 5mm and 15mm) were selected as the registration target points. Under the condition of respiratory motion, using OBERON software, the registration was carried out with the respiratory monitoring module (experimental group) and without respiratory monitoring module (control group) at various points respectively, compare the registration error between the two groups and between the various points in the experimental group, to study the ability of the OBERON software in reducing the registration error caused by respiratory motion using respiratory monitoring module.3. Obtain a combination of points on the abdominal surface that could most sensitive reflecting the breathing motion by means of the real-time position and attitude changes of sensors; selecting 18 patients who met the inclusion criteria, use the intraoperative position and fix the position with the positioning bag. The registration was carried out at various points with respiratory monitoring module (experimental group) and without respiratory monitoring module (control group) using the OBERON software, and compared the registration error between the two groups to verify feasibility of clinical application of the respiratory monitoring module in the OBERON software.Results1. A better realization was obtained in multimodality image fusion registration using the OBERON software in the abdominal simulation phantom,74 experimental operations were carried out, the registration error of the experimental group was (3.21 ± 0.79) mm, time-consuming registration was (37.82 ± 15.06) s, the registration error of control group was (3.32 ± 0.58) mm, time-consuming registration was (91.69 ± 33.81) s, There was no statistically significant in the difference of registration error between the two groups (P> 0.05), but there was statistically significant in the difference of time-consuming between the two groups (P <0.01).2. The OBERON software could present the error of breathing phases; the registration operation of target points in eight points inside the liver were successfully completed. The registration error for each point in the experimental group was less than the control group (P<0.01); in the experimental group, the registration error of the target points inside the left lateral lobe, near the surface of the right lateral lobe and inside the right lateral lobe were at the considerable level (P> 0.05), but the registration error of the target point near the surface of the left lateral lobe was greater than that of the rest target points (P<0.05).3. In this study, the best combination of points on the surface of the abdomen could be very sensitive to the reaction of the respiratory motion in the 18 male patients; the registration errors in the two groups were:the experimental group (3.41 ± 0.39) mm, the control group (3.71 ± 0.34) mm, and there was statistically significant in the difference of the error between the two groups (P<0.01).Conclusion1. The OBERON software can proceed smoothly in the registration, registration error can be controlled within the desired range, simultaneously, time-consuming was shortened than the current commercial software.2. The OBERON software can monitor the respiratory movement in real-time an d convert it into error; the respiratory monitoring module can reduce the registration error caused by the respiratory motion in the different target points of the liver, but for the target point near the surface of the left lateral lobe, the registration error is greater than that of the other target point.3. The respiratory monitoring module in the OBERON software can present the respiratory phase error and the registration error caused by respiratory motion can be reduced to some extent.