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Topic:Computed Tomography
Computed Tomography (CT) in horses is an advanced imaging technique used to obtain detailed cross-sectional images of equine anatomy. This non-invasive method utilizes X-ray technology combined with computer processing to create detailed images of bones, soft tissues, and other internal structures. CT is particularly useful for diagnosing complex conditions in the head, neck, and limbs of horses, offering enhanced visualization compared to traditional radiography. The technique is valuable for identifying fractures, dental issues, sinus diseases, and other abnormalities. This page compiles peer-reviewed research studies and scholarly articles that explore the applications, advancements, and clinical implications of computed tomography in equine medicine.
Medial femoral condyle morphometrics and subchondral bone density patterns in Thoroughbred racehorses. To characterize medial femoral condyle (MFC) morphometrics and subchondral bone density patterns in Thoroughbred racehorses and to determine whether these variables differ between left and right limbs. Methods: Stifle joints harvested from 6 Thoroughbred racehorses euthanized for reasons other than hind limb lameness. Methods: The distal portion of the left and right femurs of each cadaver was scanned via CT. Hounsfield units were converted to dipotassium phosphate equivalent densities through use of a phantom on each specimen. Medial femoral condyle width, length, height, and curvature; subch...
Basilar skull fracture in a Thoroughbred colt: radiography or computed tomography? A two-year-old Thoroughbred colt was presented to the Equine Clinic, Onderstepoort Veterinary Academic Hospital for head trauma after rearing and falling backwards, hitting his head on the ground. Following medical therapy for acute onset neurological impairment secondary to a suspected basilar skull fracture, the horse was anaesthetised and computed tomography of the skull was performed. A diagnosis of a comminuted basilar skull fracture was made and skull radiographs were taken for comparison. The horse was subsequently euthanased owing to the poor prognosis; necropsy findings were compatibl...
Imaging diagnosis-aortic aneurysm and ureteral obstruction secondary to umbilical artery abscessation in a 5-week-old foal. A 5-week-old foal was evaluated for fever and hematuria of 3 days duration. Cystoscopy localized the blood to be originating from the left ureter. Abdominal ultrasonography revealed left hydronephrosis, hydroureter, and omphaloarteritis of the left umbilical artery with abscess formation that communicated with an arterial structure. Computed tomography (CT) revealed a large aortic aneurysm within the center of the abscess. An exploratory celiotomy was performed and the infection was nonresectable. The prognosis for life was grave; therefore the colt was euthanized. Necropsy findings confirmed ...
Computed tomographic arthrography of the intercarpal ligaments of the equine carpus. Injuries of the intercarpal ligaments are an important cause of lameness in performance horses. The purpose of this prospective cadaver study was to determine whether computed tomography (CT) arthrography would be a feasible method for visualizing and characterizing intercarpal ligaments in the horse. One cadaver limb from each of eight nonlame horses was collected immediately after euthanasia. For each limb, overlapping 2.0 mm CT images were acquired before and after injection of iodinated contrast medium into the antebrachiocarpal joint, middle carpal joint, and carpal sheath. Spin echo magn...
Large segmental mandibulectomy for treatment of an undifferentiated sarcoma in a horse. To describe a large segmental (sub-total) mandibulectomy for removal of an undifferentiated sarcoma in a horse. Methods: Clinical report. Methods: A 10-year-old mare. Methods: A combination of methods including computed tomography (CT) were used to diagnose a large undifferentiated sarcoma of the right mandible. A large segmental mandibulectomy extending from 3 cm below the right temporomandibular joint to immediately caudal to tooth 407 was used to perform an en-bloc resection of the mass under general anesthesia. Results: Surgery time was 11 hours and 35 minutes and total anesthesia time, 12...
Advances in equine computed tomography and use of contrast media. Advances in equine computed tomography have been made as a result of improvements in software and hardware and an increasing body of knowledge. Contrast media can be administered intravascularly or intrathecally. Contrast media is useful to differentiate between tissues of similar density. Equine computed tomography can be used for many different clinical conditions, including lameness diagnosis, fracture identification and characterization, preoperative planning, and characterization of skull diseases.
Pneumocephalus in five horses. Pneumocephalus is occasionally encountered in horses but poorly described in the literature. The study aimed to describe historical, clinical and diagnostic imaging findings and outcome in horses to increase the awareness and recognition of the condition amongst equine practitioners, allowing appropriate management of these cases. Cases of pneumocephalus from 4 participating institutions were identified and case details extracted from the medical records. Five cases of pneumocephalus were identified. Head trauma with suspected or confirmed fractures of the sinuses was the underlying cause in 4...
Computed tomographic arthrography of the equine stifle joint. Computed tomographic arthrography is an imaging technique used for the evaluation of the internal structures of a joint, especially the soft tissues and subchondral bone defects that may communicate with the joint space. Clinical indications, technical aspects, principles of image interpretation, and advantages and disadvantages of this imaging technique for the evaluation of the equine stifle joint are discussed in this article.
Ultrasound-guided retrobulbar nerve block in horses: a cadaveric study. To develop an ultrasound-guided technique for retrobulbar nerve block in horses, and to compare the distribution of three different volumes of injected contrast medium (CM) (4, 8 and 12 mL), with the hypothesis that successful placement of the needle within the retractor bulbi muscle cone would lead to the most effective dispersal of CM towards the nerves leaving the orbital fissure. Methods: Prospective experimental cadaver study. Methods: Twenty equine cadavers. Methods: Ultrasound-guided retrobulbar injections were performed in 40 cadaver orbits. Ultrasound visualization of needle placement...
The dental cavities of equine cheek teeth: three-dimensional reconstructions based on high resolution micro-computed tomography. Recent studies reported on the very complex morphology of the pulp system in equine cheek teeth. The continuous production of secondary dentine leads to distinct age-related changes of the endodontic cavity. Detailed anatomical knowledge of the dental cavities in all ages is required to explain the aetiopathology of typical equine endodontic diseases. Furthermore, data on mandibular and maxillary pulp systems is in high demand to provide a basis for the development of endodontic therapies. However, until now examination of the pulp cavity has been based on either sectioned teeth or clinical co...
Finite element analysis of stress in the equine proximal phalanx. To improve understanding of the internal structure of the proximal phalanx (P1), response of the bone to load and possible relation to the pathogenesis of fractures in P1. Objective: To model the P1 and replicate the loads experienced by the bone in stance, walk, trot and gallop using finite element analysis. Methods: The geometry of the P1 was captured using micro-computed tomography (μCT) and was reconstructed in 3 dimensions. Values for material properties and forces experienced at stance, walk, trot and gallop were taken from the literature and were applied to the reconstructed model. Usi...
Morphology of distal border synovial invaginations of the equine distal sesamoid bone: comparison between computed tomography and a hoof-specific radiographic projection. To compare the difference and agreement of the morphology of distal border synovial invaginations on a dorsoproximal-palmarodistal oblique (DPr-PaDiO) projection with hoof-specific angle versus computed tomography. Methods: Computed tomography (CT) images and a DPr-PaDiO radiographic projection with hoof-specific angle were obtained on 50 cadaveric forefeet from 25 Warmblood horses. Computed tomography was assumed to be the gold standard. The number, shape and depth of penetration of distal border synovial invaginations into the distal sesamoid bone were evaluated with both methods, and the co...
Contrast-Enhanced Micro-Computed Tomography in Evaluation of Spontaneous Repair of Equine Cartilage. Contrast-enhanced computed tomography (CECT) has been introduced for the evaluation of cartilage integrity. Furthermore, CECT enables imaging of the structure and density of subchondral bone. In this laboratory study, we investigate the potential of microCECT to simultaneously image cartilage and subchondral bone for the evaluation of tissue healing. Methods: Osteochondral lesions (Ø = 6 mm) were surgically created in equine intercarpal joints (n = 7). After spontaneous healing for 12 months, the horses were sacrificed and osteochondral plugs (Ø = 14 mm), including the repair cartilage and a...
Episodic blindness and ataxia in a horse with cholesterinic granulomas. An 11-year-old Oldenburg mare presented following three episodes of acute, transient blindness, ataxia, and disorientation within the preceding 7 months. Clinical improvement, including return of vision, occurred within 1 week of initiating corticosteroid therapy for each of the three episodes. However, mild right-sided miosis was a consistent finding on ophthalmic examinations. Routine clinicopathologic testing revealed no significant abnormalities, and testing of cerebral spinal fluid for selected infectious diseases was unrewarding. Computed tomography of the brain demonstrated a hyperatten...
Results of computed tomography in horses with ethmoid hematoma: 16 cases (1993-2005). To determine whether CT provides unique information about the treatment or prognosis for horses with ethmoid hematoma (EH). Methods: Retrospective case series. Methods: 16 horses with EH. Methods: Horses with a diagnosis of EH that had undergone a diagnostic CT study were included. Clinical features, treatment, outcome, radiographic and CT images, and histologic specimens were reviewed. Results: CT provided new diagnostic information that affected treatment in 10 of 16 horses. Bilateral disease occurred in 8 of 16 horses and was undetected in 5 horses prior to CT. Paranasal sinus involvement o...
Necrosis of the femoral condyles in a four-week-old foal: clinical, imaging and histopathological features. A 4-week-old Thoroughbred filly foal with a history of sepsis was evaluated for right hindlimb lameness. Bilateral femoropatellar and femorotibial joint effusions were detected. Ultrasonography and radiography of the right stifle revealed signs of joint collapse and periarticular swelling. Computed tomography revealed abnormalities in the bone density of the medial femoral condyle of the right hindlimb and lateral femoral condyle of the left hindlimb. Euthanasia was recommended based on the severity of the lesions. Gross and microscopic examinations revealed extensive separation of the articul...
Imaging diagnosis–nasofrontal suture exostosis in a horse. A 14-year-old Quarter Horse had chronic facial swelling and a more recent history of progressive bilateral epiphora. Radiographic findings were compatible with exostosis of the nasofrontal suture. Computed tomography (CT) of the head, including CT dacryorhinocystography, confirmed the diagnosis and allowed presurgical planning of resection of the exostosis, which resulted in resolution of the clinical signs.
Differences in the morphology of distal border synovial invaginations of the distal sesamoid bone in the horse as evaluated by computed tomography compared with radiography. Distal border synovial invaginations of the distal sesamoid bone are radiographically assessed during the selection process of horses admitted as breeding stallions or in purchase examinations. Nowadays, many moderately or some deeply penetrating proximally enlarged synovial invaginations are considered as moderate or severe radiographic findings. Objective: To measure the difference between and agreement of the morphology of distal border synovial invaginations on radiography vs. computed tomography (CT). It was hypothesised that the morphology of distal border synovial invaginations would be...
Relationship between cartilage and subchondral bone lesions in repetitive impact trauma-induced equine osteoarthritis. To correlate degenerative changes in cartilage and subchondral bone in the third carpal bone (C3) of Standardbred racehorses with naturally occurring repetitive trauma-induced osteoarthritis. Methods: Fifteen C3, collected from Standardbred horses postmortem, were assessed for cartilage lesions by visual inspection and divided into Control (CO), Early Osteoarthritis (EOA) and Advanced Osteoarthritis (AOA) groups. Two osteochondral cores were harvested from corresponding dorsal sites on each bone and scanned with a micro-computed tomography (CT) instrument. 2D images were assembled into 3D reco...
Comprehensive surface-based morphometry reveals the association of fracture risk and bone geometry. Surface-based morphometry method is advantageous in its objectivity and increased capability in detecting focal morphological changes, but has not been applied in bone-related research. Orthopedics research in human has confirmed the association of the bone geometry in proximal femur and its fracture. In this study, surface-based morphometry is used to test the hypothesis that there is relationship between bone geometry and fracture risk of the proximal sesamoid bone (PSB) in forelimbs of Thoroughbred racehorses. The PSB surfaces were extracted from CT images of nonfractured forelegs (i.e., ri...
Computed tomographic appearance of equine sinonasal neoplasia. The computed tomography (CT) features of tumors involving the nasal cavity and/or paranasal sinuses of 15 horses were reviewed. The 15 tumors included five neuroendocrine tumors/neuroblastomas, two undifferentiated carcinomas, two myxosarcomas, and one each of nasal adenocarcinoma, hemangiosarcoma, chondroblastic osteosarcoma, anaplastic sarcoma, myxoma, and ossifying fibroma. All tumors except the ossifying fibroma were iso- or hypoattenuating relative to masseter muscle. Thirteen of the fifteen tumors exhibited moderate or marked osteolysis of adjacent cortical bone and 14/15 were characteri...
Epilepsy in horses: aetiological classification and predictive factors. In contrast with reports in man and small animals, a systematic classification of seizures in horses is lacking. Objective: The purpose of this study was to classify seizures based on their aetiology and to characterise epilepsy in 104 horses presented for seizures at the Ohio State University Veterinary Medical Center between 1988 and 2009. Methods: In a retrospective observational study, seizures were classified by aetiology based on history, clinical observations, diagnostic investigations (e.g. electroencephalograms, cerebrospinal fluid and computed tomography imaging of the head) and post...
Abdominal computed radiography for the diagnosis of enterolithiasis in horses: 142 cases (2003?2007). To evaluate the sensitivity and specificity of abdominal computed radiography (CR) for the diagnosis of enterolithiasis in horses and to examine how these parameters are affected by the number and anatomic location of enteroliths and by gas distension of the gastrointestinal tract. Methods: Retrospective case series. Methods: Horses ? 1 year old that underwent abdominal CR and subsequent exploratory laparotomy or postmortem examination. Methods: 3 reviewers blinded to signalment, history, clinical signs, and diagnoses separately evaluated abdominal computed radiographs of horses included in th...
Ultrasonographic appearance of bony abnormalities at the dorsal aspect of the fetlock joint in geriatric cadaver horses. This article describes the ultrasonographic (US) appearance of bony abnormalities on the dorsal aspect of the third metacarpal/metatarsal bone of the equine fetlock in cadavers with radiographic signs of osteoarthrosis. After US, computed tomography was undertaken to better characterise the lesions. Twelve fetlock joints were collected and all had more than one bone abnormality on US. Normal subchondral bone appeared on US as a well-defined and regular hyperechoic line with distal acoustic shadowing. Bone abnormalities detected on US included (1) gaps in the proximal subchondral bone filled wi...
Detection of articular pathology of the distal aspect of the third metacarpal bone in thoroughbred racehorses: comparison of radiography, computed tomography and magnetic resonance imaging. To compare digital radiography (DR), computed tomography (CT), and magnetic resonance imaging (MRI) for detection of pathology of the distal aspect of the third metacarpal bone (MC3) and to assess whether arthrography would improve detection of articular cartilage or subchondral bone cracking. Methods: Cross-sectional study. Methods: Limb specimens from 17 Thoroughbred horses after catastrophic injury and 4 age-matched control horses. Methods: Standard DR, CT, and MRI images of the metacarpophalangeal joint were acquired before and after iohexol injection. Pathologic features detected with ima...
Advanced imaging of the nervous system in the horse. Neuroimaging underwent a dramatic revolution during the past few decades due to the development of new technologies that produce exquisite images of patient morphology and function, new technologies that store and distribute information more efficiently, and research that has improved understanding of pathogenesis and effective clinical use of new imaging methods. Advanced equine neuroimaging is a specialized field with unique challenges associated with patient size, availability of equipment, using equipment designed for humans, small sample size for various diseases, and issues associated wi...
Comparison of cross-sectional anatomy and computed tomography of the tarsus in horses. To compare computed tomography (CT) images of equine tarsi with cross-sectional anatomic slices and evaluate the potential of CT for imaging pathological tarsal changes in horses. Methods: 6 anatomically normal equine cadaveric hind limbs and 4 tarsi with pathological changes. Methods: Precontrast CT was performed on 3 equine tarsi; sagittal and dorsal reconstructions were made. In all limbs, postcontrast CT was performed after intra-articular contrast medium injection of the tarsocrural, centrodistal, and tarsometatarsal joints. Images were matched with corresponding anatomic slices. Four tar...
Computed tomographic findings in the pituitary gland and brain of horses with pituitary pars intermedia dysfunction. Pituitary pars intermedia dysfunction (PPID) is the most common endocrinologic disorder of aged horses. Objective: Pituitary glands of PPID-affected horses are larger than those of aged horses without signs of PPID, and the size difference can be detected using computed tomography (CT) imaging. Methods: Eight horses with clinical signs of PPID and supportive endocrinologic test results and 3 aged control (PPID-negative) horses. Methods: Computed tomography examination of the brain and pituitary gland was performed twice in 10 of the 11 horses, approximately 6 months apart. Six PPID-affected ho...
Catastrophic scapular fractures in Californian racehorses: pathology, morphometry and bone density. To enhance understanding of the nature and pathogenesis of scapular fractures in racehorses. Objective: Scapular fractures in racehorses have a consistent configuration related to sites of pre-existing stress modelling and remodelling. Methods: Fractured and intact scapulae collected post mortem were examined visually and with computed tomography (CT). Scapular fracture configuration, bone modelling changes and standardised CT morphometry and density measurements were recorded. Statistical comparisons were made between fractured, nonfractured contralateral and control scapulae. Results: Thirty...
