title: Motion-correction techniques for standing equine MRI.
abstract: Magnetic resonance imaging (MRI) of the distal extremities of the standing, sedated horse would be desirable if diagnostic quality images could be obtained. With the availability of extremity and special purpose magnet designs on the market, a system to safely accommodate the standing horse may gain increasing popularity. This paper considers the issue of motion that will need to be addressed to achieve successful, diagnostic quality images. The motion of the carpus and tarsus of five standing, sedated horses was quantified. The obtained motion records were then used to induce motion in cadaveric joint specimens during several MRI scans. The measured dorsal-palmar/plantar, medial-lateral, and proximal-distal random wobbling motions in the standing sedated horse were several centimeters in magnitude and generated severe motion-artifacts during axial MRI of the cadaveric specimens. Two retrospective motion-correction techniques (autocorrection and navigator-based adaptive correction) were used to correct the corrupted images. The motion artifacts were nearly eliminated with the use of both techniques in series. Although significant hurdles remain, these results suggest promise for allowing diagnostic quality MRI of the carpus and tarsus in the standing horse.
authors.affiliation: School of Veterinary Medicine, University of Pennsylvania, New Bolton Center, 382 West Street Rd., Kennett Square, PA 19348, USA. alexiajl@vet.upenn.edu
authors.forename: Alexia L
authors.initials: AL
authors.lastname: McKnight
authors.forename: Armando
authors.initials: A
authors.lastname: Manduca
authors.forename: Joel P
authors.initials: JP
authors.lastname: Felmlee
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Rossman
authors.forename: Kiaran P
authors.initials: KP
authors.lastname: McGee
authors.forename: Richard L
authors.initials: RL
authors.lastname: Ehman
mesh_terms: D000818:Animals; D002350:Carpus, Animal / Q000502:physiology*; D006736:Horses / Q000502:physiology*; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000662:veterinary*; D009038:Motion; D011187:Posture; D012016:Reference Values; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013643:Tarsus, Animal / Q000502:physiology*