Department of Radiology, Stanford University, Stanford, California, USA.
Department of Bioengineering, Stanford University, Stanford, California, USA.
Magn Reson Med. 2017 Dec;78(6):2136-2148. doi: 10.1002/mrm.26577. Epub 2017 Jan 11.
To develop a radial, double-echo steady-state (DESS) sequence with ultra-short echo-time (UTE) capabilities for T measurement of short-T tissues along with simultaneous rapid, signal-to-noise ratio (SNR)-efficient, and high-isotropic-resolution morphological knee imaging.
THe 3D radial UTE readouts were incorporated into DESS, termed UTEDESS. Multiple-echo-time UTEDESS was used for performing T relaxometry for short-T tendons, ligaments, and menisci; and for Dixon water-fat imaging. In vivo T estimate repeatability and SNR efficiency for UTEDESS and Cartesian DESS were compared. The impact of coil combination methods on short-T measurements was evaluated by means of simulations. UTEDESS T measurements were compared with T measurements from Cartesian DESS, multi-echo spin-echo (MESE), and fast spin-echo (FSE).
UTEDESS produced isotropic resolution images with high SNR efficiency in all short-T tissues. Simulations and experiments demonstrated that sum-of-squares coil combinations overestimated short-T measurements. UTEDESS measurements of meniscal T were comparable to DESS, MESE, and FSE measurements while the tendon and ligament measurements were less biased than those from Cartesian DESS. Average UTEDESS T repeatability variation was under 10% in all tissues.
The T measurements of short-T tissues and high-resolution morphological imaging provided by UTEDESS makes it promising for studying the whole knee, both in routine clinical examinations and longitudinal studies. Magn Reson Med 78:2136-2148, 2017. © 2017 International Society for Magnetic Resonance in Medicine.
开发一种具有超短回波时间（UTE）能力的径向双回波稳态（DESS）序列，用于测量短 T 组织的 T 值，同时实现快速、信噪比（SNR）高效和各向同性高分辨率的膝关节形态成像。
将 3D 径向 UTE 读取器整合到 DESS 中，称为 UTEDESS。多回波时间 UTEDESS 用于对短 T 的肌腱、韧带和半月板进行 T 弛豫测量，以及进行 Dixon 水脂成像。比较了 UTEDESS 和笛卡尔 DESS 的 T 估计重复性和 SNR 效率。通过模拟评估线圈组合方法对短 T 测量的影响。将 UTEDESS 的 T 测量结果与笛卡尔 DESS、多回波自旋回波（MESE）和快速自旋回波（FSE）的 T 测量结果进行比较。
UTEDESS 可在所有短 T 组织中生成具有高 SNR 效率的各向同性分辨率图像。模拟和实验表明，平方和线圈组合高估了短 T 测量值。半月板的 UTEDESS T 测量值与 DESS、MESE 和 FSE 测量值相当，而肌腱和韧带的测量值比笛卡尔 DESS 的测量值偏差更小。所有组织的 UTEDESS T 重复性变化平均值均低于 10%。
UTEDESS 提供的短 T 组织 T 测量值和高分辨率形态成像使其有望用于研究整个膝关节，无论是在常规临床检查还是纵向研究中。磁共振医学杂志 78:2136-2148, 2017。© 2017 国际磁共振学会。
