MAGNETIC RESONANCE IMAGING OF THE INITIAL ACTIVE STAGE OF EQUINE LAMINITIS AT 4.7 T

Authors


  • Funded by the American College of Veterinary Radiology and The Ohio State University Intramural Equine Research Fund.

  • Presented at the International Society for Magnetic Resonance in Medicine, Berlin, Germany, May 2007, and in part at the Joint ACVR/IVRA Meeting, Vancouver, Canada, August 2006.

  • Dr. Arble's present address is Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK.

  • Dr. Mattoon's present address is Department of Veterinary Clinical Sciences, Washington State University, Pullman, WA.

Address correspondence and reprint requests to Jason B. Arble, at the above address. E-mail: arble@okstate.edu

Abstract

Equine laminitis is a severely debilitating disease. There is a poor understanding of the underlying pathophysiology, and traditional imaging modalities have limited diagnostic capacity. High field strength magnetic resonance (MR) imaging allows direct visualization of the laminae, which other modalities do not. This would prove useful both in assessment of clinical patients and in further investigation into the pathophysiology of the disease. The objective of this study was to characterize the anatomic changes within the equine foot associated with the initial active stage of laminitis. Images obtained using a 4.7 T magnet were compared with digital radiographs using histologic diagnosis as the reference standard. Objective measurements and subjective evaluation for both modalities were evaluated for the ability to predict the histologic diagnosis in horses with clinical signs of laminitis as well as in clinically normal horses and horses that were in a population at risk for developing laminitis. Signal intensity and architectural changes within the corium and laminae were readily seen at 4.7 T, and there was a strong association with the histologic diagnosis of active laminitis. Measurements obtained with MR imaging were more sensitive and specific predictors of laminitis than those obtained radiographically. Subjective evaluation with MR imaging was more sensitive than with radiography and should become more specific with greater understanding of normal anatomy.

Ancillary