Ordered tissue like tendon is known to exhibit the magic-angle phenomenon in magnetic resonance investigations. Due to the anisotropic structure the transverse relaxation time T2 depends on the orientation of the tendon in the magnetic field. In medical imaging, relaxation measurements of tendon orientation are restricted by the size of the object and the space available in the magnet. For humans, tendon orientation can only be varied within small limits. As a consequence, the magic-angle phenomenon may lead to a misjudgement of tendon condition. It is demonstrated that the NMR-MOUSE (mobile universal surface explorer), a hand-held NMR sensor, can be employed to investigate the anisotropy of T2 in Achilles tendon in vivo. The NMR-MOUSE provides a convenient tool for analyzing the correlation of T2 and the physical condition of tendon.
Haken, B. Blümich, Anisotropy in Tendon Investigation in vivo by a Portable NMR Scanner, the NMR-MOUSE, J. Magn. Reson. 144 (2000) 195-199; https://doi.org/10.1006/jmre.2000.2040