[Cone beam computed tomography and cross-sectional anatomy of the carpal region in the horse].

SUBJECT MATTER AND

OBJECTIVE

The aim of this study was to display clinically relevant anatomical structures of the carpal region in healthy horses with the help of cone beam computed tomography (CBCT).

MATERIALS AND

METHODS

Twenty-eight forelimbs from 15 adult horses without orthopedic diseases were examined. Following native CBCT examination a mixture of hyperattenuating contrast medium with blue epoxy resin dye was injected in the antebrachiocarpal joint and middle carpal joint and contrast-enhanced CBCT scans were also acquired. Subsequently, the limbs were frozen and sawed in different planes corresponding to selected CBCT planes (dorsal, sagittal and transversal planes). These sawed specimens were then photographed to illustrate the sectional anatomy of the equine carpal region.

RESULTS

The anatomical structures were compared in the sectional planes of CBCT and the anatomical cross-sectional images and compiled in several images as part of an anatomical atlas. The osseous structures of the equine carpal joint were clearly visible in CBCT images. Especially following the adjustment of the soft tissue window, soft tissue structures such as extensor and flexor tendons and the carpal collateral ligaments were identifiable on CBCT images albeit the visibility was worse compared to osseous structures. Intracarpal ligaments were visualized indirectly after intraarticular contrast medium injection. Furthermore, the articular cartilage was assessable after intraarticular contrast enhancement with decrease in visibility from proximal (antebrachiocarpal joint) to distal (carpometacarpal joint).

CONCLUSION

CBCT seems to provide valuable additional data, especially in cases where other two-dimensional diagnostic imaging modalities such as radiology or ultrasonography do not offer sufficient information for a definitive diagnosis in equine carpal issues.

CLINICAL RELEVANCE: As cross-sectional imaging is becoming increasingly popular in equine orthopedic medicine, this study aims to visualize the carpal anatomy of the horse using cone beam computed tomography, to compare the acquired images with corresponding anatomical sections, and thus serve as an important basis for the application of CBCT in everyday clinical practice.