INFORMATION FOR OWNERS OF HORSES HAVING MRI
Magnetic Resonance Imaging (MRI) is a diagnostic technique that involves placing the part of the body to be imaged inside a strong magnetic field. This is a relatively new technique in equine medicine that can be used to image the lower part of the leg in standing horses. Our clinic was the first in the world to use this technology and has played a central role in its development. Prior to this, MRI could only be undertaken in horses at a few centres around the world using human systems with the horse under general anaesthesia.
The standing equine MRI scanner uses low field (0.27 tesla) technology and horses are scanned under standing sedation, similar to that used for dentistry. Both front and/or hind shoes (depending on the affected limb) need to be removed prior to undertaking the procedure. The entire scanning process usually takes between 2 to 4 hours depending on the area being scanned and the temperament of the horse. As far as it is known, the procedure is perfectly safe and it does not involve exposure to any form of ionising radiation.
MRI allows evaluation of both bone and soft tissue at the same time. The technique has specific indications for the evaluation of certain types of lameness. In most cases the area being scanned must be accurately localised by the means of nerve blocks, prior to the procedure taking place.
One of the most useful indications for standing MRI is in the evaluation of lameness in the foot. Our experience has shown that many horses with chronic foot lameness have a variety of concurrent soft tissue injuries. These particular injuries cannot be accurately diagnosed using conventional techniques. MRI has also proven to be very useful in diagnosing bone disease, which can be difficult to identify with certainty in any other way.
WHAT YOU NEED TO KNOW
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If your horse is insured, you should inform the insurance company that we intend to undertake an MRI examination and, where appropriate, check that the insurers are prepared to cover the costs of this examination. This should be done well in advance of your appointment.
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Please bring details of your insurance policy (company name, and policy number) with you.
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Your horse will need to be sedated for the scan. If you know of any reason why this cannot be done safely or of any previous problems that the horse has encountered when being sedated, please inform us prior to arrival.
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Please bring your horse’s passport with you.
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Shoes need to be removed before the procedure can be carried out. If your horse is having its forelimbs scanned only its front shoes need to be removed, and only hind shoes for hind limb scanning. If your horse is coming specifically for MRI then shoes can be removed before the horse arrives at the clinic. However, if your horse is being examined prior to MRI at Bell Equine, shoes must be left on so we can assess the lameness.
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Unfortunately, any purple or blue spray applied to the feet can seriously affect the image quality. To improve this please stop using this product at least 5 days prior to the scan, and make sure that any spray left on your horse is thoroughly cleaned off.
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Your horse may have to remain at the clinic for the whole day. Although the initial scanning procedure will take a few hours, having your horse here for longer will allow time for further scans to be taken if deemed necessary.
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You will be informed when your horse can leave the clinic as soon as the image collection has been completed and they have been checked for diagnostic quality.

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Unfortunately, due to the large amount of information collected during the procedure, it is unlikely that you will receive any results before your horse is discharged. In most cases a full report will be produced within 3-5 days, and copies will be sent to yourself and your vet.
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Routine X rays will be taken of horses having MRI of the feet prior to the procedure. This is for our own research and development purposes and there will not be a charge for this. It also gives us the opportunity to check for any broken clenches or rust that has been left in the feet which will have to be removed as it will affect the image quality.
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In some cases, the MRI scans will identify a problem where we believe further imaging (such as radiography, ultrasonography or nuclear scintigraphy) will be helpful in providing more diagnostic information. In such cases we may request permission to perform these added tests before your horse goes home.
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In a small number of horses, sedation may predispose them to mild colic. If your horse is prone to colic, it might be prudent to feed a laxative diet for 24 hours or so after your horse returns home. If feasible, walking exercise can also be helpful to promote gut motility.
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In view of our interests in researching the applications of MRI to lameness diagnosis in horses, we are always interested in hearing how individual horses have faired after they have returned home from having a MRI scan. We may contact you and your vet in the future to find out how your horse has got on.
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Equine MRI is still in its infancy, and it continues to reveal many new conditions that we are trying to learn more about. An important way of increasing our knowledge is by correlating the results of MRI and post-mortem examinations. If for any reason, a horse that has previously had an MRI scan has to be destroyed, then we would welcome the opportunity to perform a post-mortem examination of the scanned area. In this way we can further increase our knowledge and expertise for the benefit of horses in the future.
If you have any further questions or require any more information, then please do not hesitate to contact us.