Prospective Intra-Image Compensation for Non-Periodic Rigid Body Motion Using Active Markers
Krueger S, Schaeffter T, Weiss S, Nehrke K, Rozijn T, Boernert P
Small extra-corporal micro-coils (active markers) are used to continuously track the motion of a non-periodically rigidly moving part of the body to perform an intra-image prospective motion correction during image acquisition. At least three markers are used to form a rigid geometry attached to the region of interest. The MR control system computes and updates the required scan geometry to follow the object in real-time. The temporal resolution of this technique is limited by 3 x TR (repetition time) plus ~5ms computation time. Experiments were performed on volunteers using protocols for 3D brain imaging and for kinematic studies of joints.