Fig. 8. Transverse ultrasound images of the cranial aspect of the medial meniscus. A, Weight bearing image shows two regions of decreased echogenicity in the distal aspect of the medial meniscus with an irregular tibial margin. B, Non–weight bearing image shows enlargement and coalescence of the previously identified regions of abnormality with a further decrease in echogenicity consistent with presence of fluid and fiber loss, indicating a tear in the medial meniscus.
axis of the tendon or ligament fibers. By use of variations in the ultrasound beam angle, regions of scarring and injury in soft-tissue structures can be identified. Scarring is echogenic regardless of ul-
trasound beam angle. Areas of fiber disruption are anechoic regardless of beam angle. Therefore, com- paring the echogenicity of soft tissues structures with on-beam angle (perpendicular) and off-beam
Fig. 9. Ultrasound (A) and MR (B, C) images of an 11-year-old Dutch Warmblood mare that presented for right forelimb lameness localized to the digital sheath. No significant soft tissue lesions were identified on initial ultrasound examination. High-field MRI was performed under general anesthesia of the left fore fetlock region and revealed abnormalities in the deep digital flexor tendon and straight sesamoidean ligament with associated synovial proliferation. A, On retrospective ultrasound examination, these abnormal- ities could be identified after flexion of the limb and manual displacement of the ergot. B, MR image at the level of the injuries. C, Localizer image denoting the slice position relative to the ergot. Note that tissue manipulation of the ergot is necessary to fully examine the tendons at the level of the fetlock. Medial is to the left of each image.
