Magnetic Resonance Imaging (MRI)

The Marion duPont Scott Equine Medical Center has an MRI for horses

Magnetic Resonance Imaging (MRI) is a relatively new type of imaging for

horses. It works differently from x-rays and ultrasound by detecting

abnormal tissue density and fluid in both soft tissue and bone based on the

tissue response to magnetization.  In humans, it is used for almost all body

systems to identify both bone, joint and soft tissues including the brain

and spinal cord. This has revolutionized detection of disease by

understanding the metabolism changes, which occur in different tissues with

a disease.

MRI for horses has been used for approximately 2 decades. Initially, MRI

studies could only be completed with horses under general anesthesia in high

field units made for humans.  In 2003 a low field open magnet was created by

Hallmarq Veterinary Imaging for use in standing horses. The Marion duPont

Scott Equine Medical Center (EMC) installed the Hallmarq MRI in 2004. Since

then, the predominant use has been for foot diseases, but with improved

software images of the pastern, fetlock, cannon bone and knee are now

possible if the horse stays still during image capture.

Horses need to be sedated so they can stand quietly in open magnet. The

magnet moves so that the region of interest (ROI) is in the center of the

magnet. Different image sequences are used to identify the different tissues

and the abnormalities.  This can take from 1-3 hours to get all the

different image slices needed to see all the structures.

The greatest advantage of MRI in horses is the ability to detect damage to bones, tendons, and ligaments that can't be diagnosed in any other way.  

This is particularly true in the horse's foot, which because of the hoof

visualization of the soft tissue structures is limited. Because MRI creates

images in multiple slim slices, a 3-dimensional reconstruction can provide

the exact location and severity of the injury.

The most common injuries in the foot are deep digital flexor tendinopathy,

navicular bone inflammation, coffin joint collateral ligament desmopathy,

bone bruises and joint distention. These injuries can only be detected by

MRI. Additionally, EMC has developed MRI guided injection techniques for

injuries to the deep digital flexor tendon and collateral ligaments in the

foot. This provides an accurate placement of platelet-rich plasma (PRP) and

stem cells to help treat these injuries.

Nathaniel A. White, II

DVM, MS, Diplomate ACVS

Professor Emeritus of Equine Surgery

The Marion duPont Scott Equine Medical Center is a premier, full-service

equine hospital located in Leesburg, Virginia, and one of two hospitals of

the Virginia-Maryland College of Veterinary Medicine. We offer advanced

specialty care, 24-hour emergency treatment, and diagnostic services for all

ages and breeds of horses. Our team of equine specialists in internal

medicine, reproduction, sports medicine and rehabilitation, and surgery is

committed to providing exceptional treatment for patients; superior service

to clients; education for referring veterinarians, future veterinarians, and

clients; and cutting-edge research to the equine industry.

Images to accompany this article are available if required. For more

information about the Marion duPont Scott Equine Medical Center, please

visit https://emc.vetmed.vt.edu/ or email us at speart@vt.edu

<mailto:speart@vt.edu> , or call us at (703) 771-6842.  Don't forget to

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