Ultrashort echo time spectroscopic imaging (UTESI) of cortical bone.

摘要: Cortical bone in the mature skeleton has a short T2* and produces no detectable signal with conventional MR sequences. A two-dimensional ultrashort echo time (UTE) sequence employing half radio frequency (RF) pulse excitations radial ramp sampling reduces effective TE to 8 μs is capable of detecting signals from cortical bone. We propose time-efficient UTE spectroscopic imaging (UTESI) technique based on an interleaved variable acquisition, preceded by long suppression using either 90° gradient dephasing or inversion nulling. The projections were divided into multiple groups data for each group being collected progressively increasing projection angles. undersampled within sparsely covered k-space. view sharing sliding window reconstruction algorithm was implemented reconstruct images at TE, followed Fourier transformation domain generate images. quantified through exponential fitting line magnitude spectrum. Relative water content resonance shift due bulk susceptibility also evaluated. feasibility this demonstrated phantom volunteer studies clinical 3T scanner. Magn Reson Med 58:1001–1009, 2007. © 2007 Wiley-Liss, Inc.