Rofo 2010; 182 - A9
DOI: 10.1055/s-0030-1268264

Evaluation of Magnetization Transfer Contrast Imaging in Human Achilles tendon using a 3D Ultrashort Echo Time Sequence at 3 Tesla

R Syha 1, 2, P Martirosian 1, 2, CD Claussen 1, F Schick 1, 2, F Springer 1, 2
  • 1Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Tübingen, Germany
  • 2Section on Experimental Radiology, Eberhard-Karls-University, Tübingen, Germany

Purpose: Magnetization-Transfer (MT)-Contrast Imaging is increasingly investigated to evaluate interactions between free water molecules and macromolecules in various tissues. Combined with the introduction of Ultrashort-Echo-Time (UTE) sequences to whole-body MR scanners MT-imaging can now be applied in tissues with extremely fast signal decay such as tendons.

The aim of this study was to evaluate the MT-effect of healthy Achilles tendon in vivo on a 3 Tesla whole-body MR unit.

Materials and Methods: Healthy tendons of volunteers with no history of tendon injuries were examined. A 3D-UTE sequence with a rectangular-shaped on-resonant excitation pulse and a Gaussian-shaped off-resonant saturation pulse for MT-preparation (TMT=5.12ms) was applied. Sequence parameters were set to TR=15ms, TE=0.07ms, flip angle of 12 degree, FoV=192×192 pixels, isotropic resolution of 1mm3. The off-resonance frequency of the MT pulse was systematically varied (500Hz to 5kHz). Magnetization transfer ratios (MTR) were calculated on a pixel-by-pixel basis. Results of MT-imaging were compared to conventional MR sequences(T1-, T2- and PD-weighted) and to ultrasound imaging (US).

Results: Positive contrast of Achilles tendon could be obtained for all volunteers examined. MT-contrast imaging of Achilles tendon was feasible and distribution maps of MTR-values were calculated. None of the examined tendons showed any pathology within MR and US assessment.

Conclusion: MT contrast imaging is feasible in tissues with extremely fast signal decay such as Achilles tendon. Evaluation of the MTR-distribution within tendons reveals interactions between macromolecular bound and free water protons. In the future, evaluation of pathologic conditions using MT-contrast imaging might reveal further information on cause of disease, thus, further clinical studies are warranted.