title: Effects of refocusing flip angle modulation and view ordering in 3D fast spin echo.
abstract: Recent advances have reduced scan time in three-dimensional fast spin echo (3D-FSE) imaging, including very long echo trains through refocusing flip angle (FA) modulation and 2D-accelerated parallel imaging. This work describes a method to modulate refocusing FAs that produces sharp point spread functions (PSFs) from very long echo trains while exercising direct control over minimum, center-k-space, and maximum FAs in order to accommodate the presence of flow and motion, SNR requirements, and RF power limits. Additionally, a new method for ordering views to map signal modulation from the echo train into k(y)-k(z) space that enables nonrectangular k-space grids and autocalibrating 2D-accelerated parallel imaging is presented. With long echo trains and fewer echoes required to encode large matrices, large volumes with high in- and through-plane resolution matrices may be acquired with scan times of 3-6 min, as demonstrated for volumetric brain, knee, and kidney imaging.
authors: GE Healthcare, MR Applied Science Lab, Madison, Wisconsin 53717, USA. reed.busse@ge.com
authors: Reed F
authors: RF
authors: Busse
authors: Anja C S
authors: AC
authors: Brau
authors: Anthony
authors: A
authors: Vu
authors: Charles R
authors: CR
authors: Michelich
authors: Ersin
authors: E
authors: Bayram
authors: Richard
authors: R
authors: Kijowski
authors: Scott B
authors: SB
authors: Reeder
authors: Howard A
authors: HA
authors: Rowley
mesh_terms: D000465:Algorithms; D005583:Fourier Analysis; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*