Objective To investigate application of medical digital imaging systems and computer technologies in orthpedics. Methods The main computer-assisted surgery systems comprise the four following subcategories. Results ①A collection and recording process for digital data on each patient, including preoperative images (CT scans, MRI, standard X-rays), intraoperative visualization (fluoroscopy, ultrasound), and intraoperative position and orientation of surgical instruments or bone sections (using 3D localisers). Data merging based on the matching of preoperative imaging (CT scans, MRI, standard X-rays) and intraoperative visualization (anatomical landmarks, or bone surfaces digitized intraoperatively via 3D localiser; intraoperative ultrasound images processed for delineationof bone contours). ②In cases where only intraoperative images are used for computer-assisted surgical navigation, the calibration of the intraoperative imaging system replaces the merged data system, which is then no longer necessary. ③A system that provides aid in decisionmaking, so that the surgical approach is planned on basis of multimodal information: the interactive positioning of surgical instruments or bone sections transmitted via pre- or intraoperative images, display of elements to guide surgicalnavigation (direction, axis, orientation, length and diameter of a surgical instrument, impingement, etc.). And ④ A system that monitors the surgical procedure, thereby ensuring that the optimal strategy defined at the preoperative stage is taken into account. Conclusion It is possible that computer-assisted orthopedic surgery systems will enable surgeons to better assess the accuracy and reliability of the various operative techniques, an indispensable stage in the optimization of surgery.
Objective To investigate the consistency of regions of interest (ROI) volume among different radiological treatment planning systems (TPS) for the same group of patient data, and analyze the tendency and degree of differences caused by data transfer. Methods Between October 2010 and December 2013, the data of 10 nasopharyngeal carcinoma patients treated in West China Hospital were transferred from Monaco TPS into various other treatment planning systems. Based on different ROI volumes, they were divided into 8 groups. We counted the volume differences between these TPS and Monaco TPS, and carried out the statistical analysis. Results For small ROI volume, the calculated difference reached up to 65% in our study. As a general trend, differences became less and less with the increasing of volumes. But for single ROI, the volume difference was likely to vary randomly. The percentage of ROI volumes which were smaller than that of Monaco TPS was 70% for Raystation TPS, 38.75% for Pinnacle TPS, 88.75% for Eclipse TPS, 97.5% for Masterplan TPS, and 83.13% for iPlan TPS. Conclusions ROI volume differences exist generally among different treatment planning systems when ROIs are transferred among them by DICOM protocol. The volume variations may be affected by multiple factors. The volume consistency should be evaluated before any direct comparison of dose volu me histogram parameters which are done between different systems.