Objective and thorough validation of a 3D-2D registration method requires standardization of the validation methodology, which includes design of validation image data sets, definition of corresponding “ground truth” and its accuracy, and design of validation protocol and metrics. Currently no standardized validation methodology exists for validating 3D-2D registration algorithms to be used in endovascular interventions. In 2013 we have, therefore, developed such a standardized registration validation methodology for brain vasculature. The methodology is described in this journal paper and at: http://lit.fe.uni-lj.si/tools.php?lang=eng#Gold standard for 3D-2D registration of cerebral angiograms
F.31 Development of standards
COBISS.SI-ID: 9795156By spatial alignment of 3D and 2D+t angiographic images one can facilitate the endovascular interventions, e.g. by displaying the intra-interventional tools and contrast-agent flow in the augmented 3D+t images. To achieve the spatial alignment several 3D-2D registration methods were proposed that are concerned with finding the rigid-body parameters of the 3D image. Meanwhile, the pose of the C-arm system is usually obtained through a dedicated C-arm calibration. In practice, the calibrated C-arm pose parameters may not be exactely known. To compensate this, the 3D-2D registration should search simultaneously for the rigid-body as well as the C-arm pose parameters. For verification, we tested three 3D-2D registration methods on real, clinical 3D and 2D angiographic images of twenty patients, ten of which were imaged with attached fiducial markers to obtain a “gold standard” registration. The results indicate that, compared to searching solely the rigid-body parameters, by searching simultaneously for rigid-body and the C-arm pose parameters significantly improves the accuracy and success rate of 3D-2D registration methods.
F.01 Acquisition of new practical knowledge, information and skills
COBISS.SI-ID: 9774420The 3D-2D registration methods that have been developed within this research project are not only useful for registering medical images but are a valuable tool in industrial applications. Sensum, the company that was co-founded by the PI and another researcher on this project, and which currently has 50 employees, is developing, producing and selling visual inspection systems for the pharmaceutical industry. To visually assess the quality of a tablet or a capsule from only 2D images, it is necessary to have a 3D model of an ideal product. This model is then matched to 2D images of the inspected proucts by 3D-2D registration. The 3D-2D registration methods, developed within this project, are therefore a valuable tool in industry and this case is a good example of transfer of knowledge from academia to industry.
F.17 Transfer of existing technologies, know-how, methods and procedures into practice