Optimizing Marker Design to Improve Precision of Optical Camera-Based Rigid-Body Motion Tracking and Correction in Medical Imaging

Abstract

In this work we evaluated the performance of a camera-based rigid body motion correction solution using a 2D checkerboard marker and a 3D encoded marker. The context of the results presented is in PET/MR imaging, but in principle this motion compensation method could be used in any type of medical imaging modality. A high precision, computer-controlled motion stage with four degrees of freedom was used to control the marker positions and orientations (a.k.a. ‘poses’). Still images of the markers taken in different poses mimicking a patient moving her/his head from side to side, were used to assess performance of this method. Comparing the known stage motion to the estimated motion, our results indicate that the 2D marker achieves better angular accuracy while the 3D marker’s translational (linear) accuracy is superior. For all axes, the angular error was less than 0.96, 0.35 [deg], and the translational error was less than 2.24, 4.76 [mm] for the 3D and 2D markers, respectively.