Automatic Optical Co-Registration Method of OPM-MCG and CT

Recent advancements in optically pumped magnetometers (OPMs) have driven the development of magnetocardiography (MCG) systems, which provide high-quality signals and greater flexibility at a lower cost. While the OPM sensor configuration is more flexible, it introduces new challenges to the co-registration of MCG and computed tomography (CT), which directly impacts the spatial accuracy of source localization. In this study, we present an automatic co-registration method consisting of two main components: sensor localization and sensor-to-CT registration. Sensor positions and orientations are determined within 3-D images reconstructed through optical scanning based on the bed registration unit. Abdominal surface matching is employed to automatically align anatomical images with sensor positions. The results demonstrate that the mean registration position and orientation errors across all sensors on the reference phantom are 0.49 mm and less than 0.2°, respectively, with a computational runtime of less than 10 s. Compared with existing methods involving manual procedures, such as moving digitizers to markers and removing sensors, the proposed co-registration method is more accurate and efficient.