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.