H-1 double-quantum-filtered MR imaging as a new tool for assessment of healing of the ruptured Achilles tendon

H-1 double-quantum-filtered magnetic resonance imaging (DQF MRI) was applie d to monitor the healing process of the Achilles tendons in rabbits after t enotomy. DQF MRI provides a new contrast, which is based on the non-zero av erage of the dipolar interaction caused by anisotropic motion of water mole cules, determined mainly by their interaction with the ordered collagen fib ers. Tissues are characterized by the dependence of their DQF signal on the DQ creation time, tau. With the use of DQF MRI, higher tissue contrast is obtained between tendon, bone, skin, and muscle. The tendons, which give we ak signals in standard MRI techniques, are highlighted in the H-1 DQF image . The image changed dramatically during the healing process of the injured Achilles tendon. These changes matched the phases of the healing process. B y using a tau-weighted contrast, the DQF images indicate the part of tendon that has not completely healed, even after the conventional MRI appeared n ormal. Magn Reson Med 42:884-889, 1999. (C) 1999 Wiley-Liss, Inc.