Nine year old Arabian mare that presented to Animal Imaging for an MRI of the right front carpal region. The horse has been intermittently lame for two months. Swelling has been noted above and below the carpus on the lateral aspect in the past. The swelling seems to respond to poultices, ice, etc., but without bandaging, the swelling may reappear. On a recent lameness exam, no improvement was noted after blocking up through the origin of the suspensory. An ulnar nerve block alleviated the lameness 85 percent. Ultrasound revealed a distended carpal canal with possible hemorrhage. Radiographs of the carpus were within normal limits. Soundness was achieved by blocking the flexor sheath.