Department of Radiology, University of California, San Diego, California 92103-8756, USA.
Magn Reson Med. 2010 Sep;64(3):834-42. doi: 10.1002/mrm.22474.
In this study, we report the use of a novel ultrashort echo time T(1)rhoT(1) sequence that combines a spin-lock preparation pulse with a two-dimensional ultrashort echo time sequence of a nominal echo time 8 microsec. The ultrashort echo time-T(1)rho sequence was employed to quantify T(1)rho in short T(2) tissues including the Achilles tendon and the meniscus. T(1)rho dispersion was investigated by varying the spin-lock field strength. Preliminary results on six cadaveric ankle specimens and five healthy volunteers show that the ultrashort echo time-T(1)rho sequence provides high signal and contrast for both the Achilles tendon and the meniscus. The mean T(1)rho of the Achilles tendon ranged from 3.06 +/- 0.51 msec for healthy volunteers to 5.22 +/- 0.58 msec for cadaveric specimens. T(1)rho increased to 8.99 +/- 0.24 msec in one specimen with tendon degeneration. A mean T(1)rho of 7.98 +/- 1.43 msec was observed in the meniscus of the healthy volunteers. There was significant T(1)rho dispersion in both the Achilles tendon and the meniscus. Mean T(1)rho increased from 2.06 +/- 0.23 to 7.85 +/- 0.74 msec in normal Achilles tendon and from 7.08 +/- 0.64 to 13.42 +/- 0.93 msec in normal meniscus when the spin-lock field was increased from 250 to 1,000 Hz.
在这项研究中，我们报告了一种新型的超短回波时间 T(1)rhoT(1)序列的使用，该序列结合了自旋锁定制备脉冲和二维超短回波时间序列，标称回波时间为 8 微秒。超短回波时间-T(1)rho 序列用于量化包括跟腱和半月板在内的短 T(2)组织中的 T(1)rho。通过改变自旋锁定场强来研究 T(1)rho 弥散。在六个尸体踝关节标本和五个健康志愿者中的初步结果表明，超短回波时间-T(1)rho 序列为跟腱和半月板提供了高信号和对比。健康志愿者的跟腱 T(1)rho 平均值范围为 3.06 +/- 0.51 毫秒，尸体标本为 5.22 +/- 0.58 毫秒。在一个有肌腱变性的标本中，T(1)rho 增加到 8.99 +/- 0.24 毫秒。健康志愿者的半月板 T(1)rho 平均值为 7.98 +/- 1.43 毫秒。跟腱和半月板均存在明显的 T(1)rho 弥散。在正常跟腱中，T(1)rho 从 2.06 +/- 0.23 增加到 7.85 +/- 0.74 毫秒，在正常半月板中，T(1)rho 从 7.08 +/- 0.64 增加到 13.42 +/- 0.93 毫秒，当自旋锁定场从 250 增加到 1000 Hz 时。
