At Ashbrook Equine Hospital, we are very excited to be able to offer MRI investigation of lameness problems.Magnetic Resonance Imaging (MRI) provides an image of tissue when a magnetic field is applied and the molecules in the tissue then ‘resonate’ or wobble. The resulting signal is different from each type of tissue so we can build up a picture of the structures and any unexpected signal within a tissue highlights a problem area. The images are taken in ‘slices’ with each MRI consisting of about 500-600 images which are then individually interpreted by a specialist consultant.
These multiple images allow us to be incredibly precise about localising the cause of a lameness problem. A definitive diagnosis such as this means we can then provide a much more accurate prognosis and a highly specific treatment plan to help your horse return to the work he should be doing. MRI has been most beneficial for cases of persistent lameness that we know are isolated to the foot region. The hard hoof capsule limits our ability to image structures within the hoof; radiographs only provide details about the bone structure and ultrasound scanning is limited by the hoof capsule so we cannot visualise the multitude of tendons and ligaments. MRI is able to ‘see’ into the hoof capsule and provide detailed information about this very complex structure. We are now also able to use MRI to image the pastern, fetlock, cannon bone region and even the knee and some of the hock. These images can add a huge amount of additional information to the radiographs and ultrasound scans that are undertaken as part of a routine lameness investigation. We can even use repeat MRI scans to show the progression of an injury.
After traditional lameness investigation which may include nerve blocks, joint blocks, radiographs and ultrasound examination, the vet may feel they have not reached a definitive diagnosis so may recommend MRI. When a horse is admitted for MRI, we allow them a night of hospitalisation to settle into our hospital environment. A more settled horse means we will obtain higher quality images with less sedation. On the day of the MRI, the horse has an intravenous catheter placed to allow sedation to be given easily. The horse’s shoes are removed and radiographs taken to ensure no metal fragments remain in the hoof as metal will render the images as non-diagnostic.
After this preparation, the horse enters the MRI suite. The scans are taken with the horse standing and the affected limb positioned in a large U shaped magnet. The images are obtained over a 1-3 hour period, depending on which area is to be scanned. The images are sent electronically to an image interpreting specialist. We usually expect the report from the consultant to be ready within 72 hours, at which time your vet will then be able to discuss the results and formulate the most appropriate treatment plan with you.
If you would like any further information about the MRI services we offer at Ashbrook Equine Hospital, please contact one of our vets to discuss it further.
Information regarding Standing MRI scans at Ashbrook Equine Hospital
Your horse has been booked in for an MRI scan. We ask that you bring your horse into the hospital prior to scanning, usually the day before, in order for your horse to settle in. This allows the horse to become accustomed to our hospital environment and means we can use lower doses of sedation. Less sedation provides us with less movement blur and better quality images.
Please bring your passport so the horse’s vaccination status can be checked and that Section IX (exclusion from the food chain) has been signed. At Ashbrook Equine Hospital we have all the feedstuffs your horse will require; however, if your horse has any allergies, please bring your own feeding as appropriate. Please bring rugs and any medications or supplements that you would like your horse to have during their stay.
To facilitate repeat sedation doses, a catheter will be placed into the vein. It is standard practice to clip and sterilely prepare the area prior to catheter insertion. If you have concerns regarding this, please discuss it with a member of staff. The appropriate shoes will need to be removed before scanning i.e for forelimb scans both front shoes will be removed and for hindlimb scans both hind shoes will be removed.
After shoe removal radiographs will be taken to ensure there are no small pieces of metal remaining in the foot; if there is, we will remove these prior to scanning. The scan time will be determined by the areas to be imaged and the demeanour of your horse in our scanning environment. After scanning, your horse will be taken back to a stable, monitored post sedation and fed when appropriate.
Once the scan is completed, the images are sent to our selected specialist for interpretation. They will endeavour to report their findings to us within 72 hours. This report will immediately be sent to your vet so they can advise you of the diagnosis and appropriate treatment options. If your horse returns home on the same day, please ensure water is readily available and soft wet feedstuffs are given as prolonged sedation can result in decreased bowel motility and increased colic risk. These precautions minimise the colic risk; however, we advise monitoring the horse closely for the following 12-24 hours, especially with regard to faeces passed.