A pulse sequence for rapid in vivo spin-locked MRI




To develop a novel pulse sequence called spin-locked echo planar imaging (EPI), or (SLEPI), to perform rapid T-weighted MRI.

Materials and Methods

SLEPI images were used to calculate T maps in two healthy volunteers imaged on a 1.5-T Sonata Siemens MRI scanner. The head and extremity coils were used for imaging the brain and blood in the popliteal artery, respectively.


SLEPI-measured T was 83 msec and 103 msec in white (WM) and gray matter (GM), respectively, 584 msec in cerebrospinal fluid (CSF), and was similar to values obtained with the less time-efficient sequence based on a turbo spin-echo readout. T was 183 msec in arterial blood at a spin-lock (SL) amplitude of 500 Hz.


We demonstrate the feasibility of the SLEPI pulse sequence to perform rapid T MRI. The sequence produced images of higher quality than a gradient-echo EPI sequence for the same contrast evolution times. We also discuss applications and limitations of the pulse sequence. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc.