Agreement Between Augmented Reality and Computed Tomography Coordinate Systems: A New Approach to an Image-Guided Procedure

Purpose Aligning augmented reality (AR) objects with the actual patient’s body in the real world is challenging in interventional radiology. We aimed to propose a computed tomography (CT) guided procedure with markerless AR based that uses a coordinate system complying with Digital Imaging and Communications in Medicine (DICOM) standard. We also sought to verify the accuracy and precision of the replication of the CT coordinate system in the AR space using in-house software for smartphones. Methods Spatial anchors were placed on the laser aperture of the CT gantry to automatically calculate the CT’s isocenter and origin of the DICOM coordinates. A real phantom holder and a virtual protractor were placed at the foot side, specifically 600 mm from the isocenter, and the respective horizontal, and vertical positioning errors were measured to evaluate accuracy and precision. Results The horizontal and vertical errors were − 3.4 ± 5.5 and − 5.1 ± 4.7 mm, respectively. Conclusion The agreement between the CT coordinate system and AR space is satisfactory. In our technique, the operator can confirm the location of the lesion observed in the CT image during the procedure and can place a virtual protractor for guiding the puncture at that location.