Magnetic resonance imaging (MRI) uses strong magnetic fields and radiofrequency pulses to produce images with superior bone and soft tissue detail. MRI is capable of sectioning the limb in multiple planes in many thin slices. This allows the diagnostician to view all tissues of the region from numerous angles in order to precisely locate the problem. We routinely diagnose lesions in anatomic regions as diverse as the foot, suspensory ligament, brain, and upper airway.
Most horses that are referred for MRI have problems that have shown few or no abnormalities with radiographs, ultrasound, nuclear scintigraphy, or even computed tomography (CT). In many cases, MRI is considered the gold standard. Rood and Riddle is one of a handful of private equine hospitals in the country with this level of MRI technology.
The MRI unit at Rood and Riddle is a 1.5 Tesla high-field magnet. The doughnut-shaped magnet enables imaging in large horses up to the knee and hock, the head, and portions of the neck. In foals, weanlings, and miniature horses, the recumbent unit can often image any area of the body, including the thorax, abdomen, neck, and stifle. Due to the design of the MRI, horses must undergo general anesthesia during the procedure, which takes between one and two hours.