Assessment On The Accuracy Of The Independent Development Of Three-dimensional Reconstruction Module Of Spinal Virtual Surgery System

[Objective]Evaluation of the accuracy of reconstructed image in the independent development of three-dimensional reconstruction module of spinal virtual surgery system, to clear its clinical value for the populariation and application,and to improve the accuracy of spinal disease diagnosis and treatment.[Materials and Methods]1.Based on PC and Windows XP2 operating system platform, based on VC6.0 for the development environment, object-oriented C++ language combining VTK and clinical needs, to build spinal virtual surgery system basic platform with the core function of three-dimensional reconstruction and measurement—three-dimensional reconstruction module system. Then training the software was to improve, enhance and upgrade.2. After the image data with DICOM format of the early eight male cervical spine specimens by MSCT scanning collated , introduced into the spinal virtual surgery system for VR and MPR. According to the parameter requirements of lower cervical pedicle fixation, 10 parameters was used to do individual measurements. Then the data that early in the MSCT workstation had measured as the control group, this experiment data was seen as the experimental group,then two sets of data was analyzed by SPSS11.0.3.Using the image reconstruction and measurement function of module to carry out individual condition assessment, preoperative plan and postoperative evaluation. From June 2009 to March 2010, 6 patients who received screw insertion in lower cervical spines were given MSCT scanning and this module 3D reconstruction to evaluate the preoperative illness situation, to collect the parameters of aim pedicle screw insertion, and to clear screw perforation rate of postoperative.[Results]1 .The module implements a preliminary three-dimensional reconstruction of the spinal reconstruction, simulated osteotomy, rotation and measurement.Then adjust the software operation problems,simplified user interface, improved reconstruction algorithm, added a new texture features, auxiliary selection surface measurements. So that the stability of system increased significantly, the quality and speed of image reconstruction improved obviously, and it is simple and fast to select the reconstruction image measurement profile.2.Eight groups of specimen data were found that a group reconstruction data corruption.It could not reconstructe completely;7 specimens of reconstruction found that one pedicle missing and four coronal diameter of the pedicle <3 mm. The results consistent with MSCT data completely. Corresponds with the MSCT data, including a smaller C5 pedicle,a total of 66 pedicles were measured.Statistical analyzed that C3 left pedicle height,C4 pedicle width on both sides,C4 right pedicle spongy width,C6 left pedicle entry point to cut the outer edge of the lateral mass distance,C3 pedicle entry point to the right and left edge under the joint distance,C3 both sides and C5 left side sagittal distance of entry point to anterior vertebral pedicle,C3 both sides and C5 left side and C6 right side axial distance of entry point to anterior vertebral pedicle,a total of 14 groups of data from the two systems compared , P<0.05,86 sets of data from the two systems compared, P> 0.05.3.Clinical application of this system assistant six cases of patient set lower cervical pedicle screw 34. Postoperative examination found that a total of 30 screws (88.24%) were placed completely in pedicles,4 screw(11.76%) penetrated.Grade 1 perforation and grade 2 perforation were two screws (5.88%). Compared with the screw perforation rate(11.84%%) of MSCT assisted , there was no statistically significant difference (P> 0.05). [Conclusion]1. System realized three-dimensional reconstruction of the spine, rotate, cut bone and measurement on PC.CT graphics workstation was out of the shackles of the doctors.2.The improved reconstruction algorithm and the add texture features made systematic three-dimensional image quality and speed improved significantly relative to the CT workstation.3.The new three-view 2D display window could be realized with 3D interactive images, so that the pedicle axis was found more efficient. Measurement window adjust brightness and size enlarged made a more accurate measurement of the system. Scenes perspective allowed the selection and fine-tuning profile measurement more convenient and efficient.Virtual screw made the measurements more objective.4.The consistent of sample measurements data and the similarity of clinical screws perforation rate showed that the accuracy of the reconstructed image of two systems is basically consistent.Thus,in the process of diagnosis and treatment of spinal diseases, this system can be used to implement on each individual patient condition assessment, individualized treatment program development, and even assisted surgery, postoperative effects assessment and rehabilitation exercise guidance.Same time, this system will develop the ideal platform for surgical skills training ,surgical navigation and visual teaching.This system has strong practicability and expansibility.