An article titled "Magnetic resonance imaging characterisation of lesions within the collateral ligaments of the distal interphalangeal joint – 28 cases" was published in Equine Veterinary Education. Authors of this study were B. Beasley and S. Giguère, Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia; K. Selberg, Environmental and Radiological Health Sciences, Colorado State University; K. Allen, Virginia Equine Imaging, The Plains, Virginia.
The article summary noted that, "Collateral ligament (CL) desmopathy of the distal interphalangeal joint (DIPJ) is a known injury that is not uncommonly diagnosed in horses presenting for lameness isolated to the foot. Ultrasonography and radiography are often used as primary diagnostic tests with mixed success."
This article concluded that "a high proportion of CL lesions of the DIPJ are located distal to the coronary band and require MRI for an accurate diagnosis that would otherwise be missed by ultrasound examination alone."
You can access the article at the Wiley online library.