GRASE imaging at 3 Tesla with template interactive phase-encoding.
A new method for ordering the phase-encoding gradient is proposed, and an application for short effective TE gradient- and spin-echo (GRASE) imaging is demonstrated. The proposed method calculates the phase-encoding order from the signal decay of a template scan (hence "template interactive phase-encoding" or TIPE). Computer simulations are used to compare the point spread functions of different phase-encoding orders giving short effective echo times (kb centric GRASE, centric GRASE, centric TIPE). The conventional centric phase-encoding order is also considered for GRASE. The conventional centric method is sensitive to both amplitude and phase modulation of the signal in k-space. The centric TIPE method gives the least amplitude modulation artifacts but is vulnerable to phase artifacts. The TIPE experiment was implemented on a 3 Tesla system. To the best of our knowledge, we present the first in vivo GRASE images at this field strength.
Jovicich
J
J
Max Planck Institute of Cognitive Neuroscience, Leipzig, Germany.
Norris
D G
DG
D016477:Artifacts; D055592:Biophysical Phenomena; D001703:Biophysics; D001921:Brain / Q000033:anatomy & histology*; D003199:Computer Systems; D017352:Echo-Planar Imaging / Q000295:instrumentation*; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation*; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D019047:Phantoms, Imaging; D012016:Reference Values; D012680:Sensitivity and Specificity