What is MRI used for?
Our standing MRI scanner can be used to assess injuries from the hoof, up to and including the hock and carpus (knee). The scanner is specifically designed to image the lower limb in the standing horse, as this is the most common site of lameness. It has revolutionized our understanding of the structures of the hoof, and we can now differentiate between the multiple conditions that were encompassed as ‘navicular syndrome’.
Previously, a horse with forelimb lameness that was localized to the foot, was diagnosed with ‘navicular syndrome’. However, a lot of the time, the severity of the lameness did not fit with the mild observations noted on radiographs (X-rays). We now know, through the use of MRI, that there are many other anatomical structures that could be injured and causing the lameness. With forelimb lameness being a common problem in horses, this diagnostic imaging tool means we can target rehabilitation, farriery, and treatment more specifically.
Injuries identifiable on MRI would include deep digital flexor tendon lesions within the hoof. Without the use of MRI this condition would have been misdiagnosed, leading to inaccurate management and unsoundness. MRI can also assess ligaments within the hoof capsule, such as the collateral ligaments of the coffin joint, which are often painful when horses are lunged in a circle. This amazing imaging modality also shows us the degree of inflammation within synovial structures such as the coffin joint and navicular bursa of the foot which cannot be visualized in any other way. Not only does MRI allow us to diagnose more accurately, but it allows us to monitor the progression of conditions and carefully assess the horse’s response to treatments.
X-ray imaging is used to assess bone pathology as an initial tool. However, it can take up to 2 weeks following injury before the bone pathology is noticeable on radiographs, and sometimes it is not visualized at all. MRI is the only imaging modality that can assess inflammation within bones such as bone bruising or cysts. These can cause severe lameness and require long periods of rest but would not be diagnosed without the use of MRI.
As equine vets we are eternally grateful for these advancements in technology which have enabled us to achieve an accurate diagnosis much faster than ever before, and as we know, a faster diagnosis leads to more precise treatment and management protocols to get your horse feeling in tip-top shape again.