Projection reconstruction MR imaging for the reduction of artifacts caused by interview motion

Projection reconstruction (PR) magnetic resonance (MR) imaging is considered. The purpose of the authors´ study was to develop a new PR method which allows to minimize the influence of rigid motion on the quality of MR images. As a first step of the method, motion during the MR data acquisition is detected with a time resolution of one repetition time. Next, the authors correct for both translational and rotational motion separately, by tracking the motion of the object´s center of mass, and by estimating object rotations, respectively. Besides, an alternative PR imaging sequence is proposed. In this sequence, the raw-data is acquired in an interleaved way. The authors´ method does not require any a priori information concerning the motion, which is an important advantage compared with other methods for the correction of motion artifacts. Experiments show that the authors´ method is very efficient for correcting rigid-motion artifacts, especially in the case of brain imaging.