Figure 3
RARE sequence enables different modes of signal acquisition in lines of the k -space, where k-space is the Fourier transform of the MR image measured. Figure depicts two most often used modes where lines are ordered sequentially (left) or centric (right). The darkest line is sampled first and has the lowest signal reduction due to T2 signal relaxation. Lines sampled after the first have a progressive T2 signal relaxation effect that is depicted by an increasing brightness of lines (2D k-space) or dots (signal vs. N echo plot). The centric approach has an advantage over the sequential approach in a higher SNR due to the dominant signal in the k-space center. Therefore, the centric approach was chosen for CDI applications as it provides good CDI sensitivity.