Computed Tomography (CT) works by combining multiple X-ray images taken from different angles around the body and using computer processing to create cross-sectional images of the inside of the body. In our clinic, we offer two distinct technical modalities of CT scanning: multislice CT and cone beam CT.
Multislice CT under general anesthesia
As the name suggests, in helical multislice CT, the patient is positioned on a table that moves through a tunnel or gantry with a rotating X-ray tube, allowing for the creation of cross-sectional images composed of various slices acquired in a helical pattern.
MSCT offers a detailed view of the bone structures and provides a comprehensive overview of the soft tissue in various areas of the horse's body, including the lower leg, stifle, elbow, head, and neck. At our clinic, we have a high-voltage large bore CT scanner that also enables imaging of the shoulder and pelvis in most horses. By adding a contrast-enhanced acquisition (CECT) the activity of soft tissue injuries or the extent of cartilage lesion can be detailed as well.
Indications for a head or neck CT scan include issues with teeth, sinuses, jaw or skull fractures, cervical facet joint osteoarthritis, or neurological problems related to the brain or cervical spinal cord. A limb CT scan is beneficial for diagnosing multiple issues within the same leg or for horses unable to undergo a standing MRI due to temperament. In some cases, the diagnostic examination is immediately followed by a therapeutic surgical procedure, either in the fully-equipped surgical theater within the CT room or as a CT-guided procedure. Equitom is renowned as one of the global leaders in CT-guided procedures, particularly for fracture repair and treatment of osseous cyst-like lesions.
Cone beam CT in the standing horse
At our clinic, we have a state-of-the-art robotics-controlled cone beam CT scanner (EDAMIS), which enables precise CT imaging while the horse is standing. In cone beam CT, low-exposure pulsed X-rays are emitted from a high-voltage X-ray tube and projected in a conical volume onto a plate detector for image acquisition. Our robotic system is features with a high quality patented motion correction mechanism using a metallic bead sleeve. Since only a 210° rotation is necessary for a full 360° image, we can scan legs up to the knee and hock, as well as the caudal neck, with the horse in a standing position. This technique utilizes volumetric voxels for image acquisition, resulting in the highest spatial resolution (0.25-0.35mm) and exceptional bone imaging capabilities. Continuous advancements in technology are being made, with the possibility of CT imaging of the back becoming feasible in the near future. The main advantages of standing CT include the avoidance of general anesthesia, rapid examination, and the ability to combine it with standing MRI. CT images are obtained under mild sedation and so diagnoses can be made before, during or after the competition season providing accurate follow-up on lesion progression and management. Additionally, standing CT is also becoming the new gold standard for pre-operative planning of fracture repair and bone surgery in general.