Comparison of results of scanning electron microscopy and magnetic resonance imaging before and after administration of a radiographic contrast agent in the tendon of the deep digital flexor muscle obtained from horse cadavers

Objective-To analyze the tendon of the deep digital flexor (TDDF) muscle of the forelimb in horses by use of a contrast radiographic agent (gadopentate dimeglumine [Gd-DTPA/Dimeg]) and magnetic resonance imaging (MRI) and to determine the concentration of water protons in the tendons by use of MRI. Sample Population-8 TDDF harvested from the forelimbs of 6 horse cadavers. Procedure-Examinations were performed on the same portion of each tendon. Tendons were examined by use of two techniques: MRI before and after treatment with Gd-DTPA/Dimeg as well as scanning electron microscopy. Results-Tendons did not have detectable signal intensity on MRI before treatment with Gd-DTPA/Dimeg; however, intravascular injection of Gd-DTPA/Dimeg allowed evaluation of the internal structure of the tendons. Scanning electron microscopy images correlated well with images obtained by use of MRI before and after administration of Gd-DTPA/Dimeg. Localized spectra revealed the concentration of water protons in the TDDF. Conclusions and Clinical Relevance-The techniques used in this study provided information about internal organization of the TDDF in horses. Analysis of results revealed that the best technique involved vascular injection of contrast medium. Results of MRI correlated well with results for scanning electron microscopy. After administration of Gd-DTPA/Dimeg, MRI provided additional information about tendon morphologic characteristics. This technique may be of value for examination of tendons in lame horses.