Ultrashort TE T 1 rho (UTE T 1 rho) imaging of the Achilles tendon and meniscus

In this study, we report the use of a novel ultrashort echo time T 1 rho T 1 sequence that combines a spin‐lock preparation pulse with a two‐dimensional ultrashort echo time sequence of a nominal echo time 8 μsec. 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. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.