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.
Accuracy Quantification of the Reverse Engineering and High-Order Finite Element Analysis of Equine MC3 Forelimb. Shape is a key factor in influencing mechanical responses of bones. Considered to be smart viscoelastic and inhomogeneous materials, bones are stimulated to change shape (model and remodel) when they experience changes in the compressive strain distribution. Using reverse engineering techniques via computer-aided design (CAD) is crucial to create a virtual environment to investigate the significance of shape in biomechanical engineering. Nonetheless, data are lacking to quantify the accuracy of generated models and to address errors in finite element analysis (FEA). In the present study, rever...
A Computed Tomographic (CT) and Pathological Study of Equine Cheek Teeth Infundibulae Extracted From Asymptomatic Horses. Part 1: Prevalence, Type and Location of Infundibular Lesions on CT Imaging. Equine maxillary cheek teeth infundibulae are frequently affected by developmental and acquired disorders, but the computed tomographic (CT) imaging features of normal and abnormal infundibulae remain incompletely understood. To examine infundibulae with various grades of occlusal caries and control teeth by standard CT in order to assess the prevalence, type and location of subocclusal infundibular lesions present. original study. One hundred maxillary cheek teeth, including 82 with, and 18 without infundibular occlusal caries, were extracted from horses of different ages and imaged by s...
Surgical enlargement of the nasomaxillary aperture and transnasal conchotomy of the ventral conchal sinus: Two surgical techniques to improve sinus drainage in horses. To evaluate 2 surgical techniques for establishing and/or improving paranasal sinus drainage in cadaver heads and horses with sinusitis and evaluate the feasibility of postoperative transnasal sinus endoscopy. Methods: Ex vivo study (equine cadaver heads) and case series. Methods: Nine adult equine cadaver heads and 8 horses with recurrent sinusitis. Methods: For the ex vivo study, the following procedures were performed on 9 cadaver heads: preoperative and postoperative computed tomography (heads 1-6), endoscopy-guided transnasal conchotomy of the ventral conchal sinus (TCVCS) and surgical en...
In vitro evaluation of a medial approach for intra-articular injection of the tarsometatarsal joints of horses. To develop a reliable method for injection of the tarsometatarsal (TMT) joint of horses through a medial approach and to characterize anatomy of the synovial recesses of the TMT joint with CT. Methods: 13 pairs of fresh cadaveric equine tarsi. Methods: TMT joints were assessed with radiography and CT. Twelve pairs of TMT joints were assigned to an experienced veterinarian (8 joints) or veterinary student (16 joints) for injection with contrast medium through a medial or a lateral approach. Every TMT joint was then reexamined radiographically and with CT to assess diffusion of contrast medium. ...
Use of non-contrast-enhanced computed tomography to identify deep digital flexor tendinopathy in horses with lameness: 28 cases (2014-2016). To describe the use of non-contrast-enhanced CT to identify deep digital flexor (DDF) tendinopathy in horses with lameness attributed to pain in regions distal to the metatarsophalangeal or metacarpophalangeal joints. Methods: Retrospective case series. Methods: 28 client-owned horses. Methods: Medical records were searched to identify horses that underwent non-contrast-enhanced CT with or without high-field MRI as part of an evaluation for lameness localized to areas distal to the metacarpophalangeal or metatarsophalangeal joint in ≥ 1 limb. Horses were included in the study if they had ≥...
The Risk of a Shod and Unshod Horse Kick to Create Orbital Fractures in Equine Cadaveric Skulls. The aim of this study was to compare the potential of an unshod and shod hoof to cause an orbital fracture in the event of a kick. Methods: Thirty-four equine cadaveric orbitae were exposed to a steel or horn impactor in a dropping test set-up. An impactor velocity of 7 m/s was used for both materials. Testing was repeated on the same orbit at a velocity of 10 m/s with the horn impactor if no damage occurred. A high-speed camera was used to analyse the impact process. Physical parameters (peak force and impact duration) were calculated based on quantitative video-tracking. Computed tomog...
Fluoroscopically guided neocanalization for treatment of nasolacrimal atresia in two horses. A yearling Thoroughbred stallion and an 8-year-old Saddlebred mare were evaluated for persistent mucoid ocular discharge. Results: Examination of both horses revealed copious yellow-tan mucoid ocular discharge with a negative Jones I test, absent nasal punctum, and unsuccessful anterograde nasolacrimal duct (NLD) irrigation. Clinical abnormalities were present on the right side only in one horse and bilaterally in the other. Computed tomography (CT) with contrast confirmed nasolacrimal duct atresia in both horses. Results: Under general anesthesia, the affected NLD was catheterized anterograde...
Usefulness of caudomedial-craniolateral oblique radiographic views for the diagnosis of injury to the origin of the cranial cruciate ligament in two horses. CASE DESCRIPTION A 12-year-old mixed-breed mare (horse 1) and 6-year-old Friesian gelding (horse 2) were examined for chronic lameness associated with the stifle joint. CLINICAL FINDINGS Lameness examination revealed effusion of the right (horse 1) or left (horse 2) femoropatellar and medial femorotibial joints and grade 3/5 (horse 1) or 4/5 (horse 2) lameness. A diagnosis of cranial cruciate ligament (CCL) injury with associated mineralization and avulsion (horse 1) or mineralization alone (horse 2) was facilitated in both horses with a caudomedial-craniolateral oblique radiographic view obta...
Computed tomographic dimensions of the normal adult equine eye. There are limited data on whether the dimensions of the equine eye and its internal structures change with bodyweight in horses. The aim of this study was to identify whether the size of the equine eye and its individual structures varied in a predictable manner with bodyweight, and to examine the reliability of computed tomography (CT) scans in the measurement of the equine eye. Ninety horses which had undergone CT examination of the head for non-ocular disease were included. All measurements of the eye were performed twice on all eyes by the same operator to quantify intra-operator agreement...
Three-dimensional CT observation of position and movability of the scapula in the horse using carcasses of Falabella. The three-dimensionally real position and movement of the scapula in the lateral side of the ribcage could not be clarified in the horse, since the body size of the horse is too large to apply the CT scanning and image analysis methods. In this study, therefore, we examined the position and the movability of scapula using a carcass of the Falabella which is one of the smallest breeds of the horse. The whole skeletal system in thoracic part of the Falabella could be three-dimensionally observed by CT scanning method. The three-dimensional images show that the scapula cranially slides and the ve...
Osteochondroma of the First Phalanx in Tbourida Horses. This study aimed at describing anatomo-histopathological and imaging features, using computed tomography and magnetic resonance imaging on six forelimbs of Tbourida horses, that presented a particular bone exostosis on the dorsal and proximal part of the first phalanx, diagnosed by X-ray. Gross anatomy of the bone exostosis revealed an irregular surface with poly-lobulated tissue masses showing a cauliflower shape. The diameter/depth varied from 0.5 to 5.1 cm with a mean of 3.9 ± 0.9 cm. The capsule of the metacarpophalangeal joint was hypertrophic and showed many invaginations in the inner ...
Communication between the distal interphalangeal joint and the navicular bursa in the horse at Computed Tomography Arthrography. Diffusion of drugs injected into the distal interphalangeal joint or the navicular (podotrochlear) bursa can influence diagnosis and treatment of foot pain. Previous anatomical and radiographic studies of the communication between these synovial structures have produced conflicting results and did not identify the location of any communication if present. This anatomic study aimed to assess the presence and site of communication between the distal interphalangeal joint and the navicular bursa in the horse by computed tomography arthrography. Sixty-six pairs of cadaver forelimbs were injected w...
Outcome following computed tomographic imaging and subsequent surgical removal of keratomas in equids: 32 cases (2005-2016). OBJECTIVE To describe the use of CT in the diagnosis of and presurgical planning for equids with keratomas treated by hoof wall resection and determine postoperative complications and outcome. DESIGN Retrospective case series. ANIMALS 29 horses and 3 mules with keratomas treated by partial or complete hoof wall resection following CT imaging of the distal portion of the affected extremity from 2005 through 2016. PROCEDURES For each equid, physical examination and lameness evaluation were performed, followed by imaging of the distal portion of the affected extremity. A tentative diagnosis of ke...
Impact of a void in the equine medial femoral condyle on bone stresses and peak contact pressures in a finite element model. To predict bone and medial meniscal stresses and contact pressures in an equine stifle with a medial femoral condyle (MFC) intact or with a 2-cm subchondral bone void, under varying degrees of internal femoral rotation (IFR). Methods: Finite element model (FEM) of a cadaveric equine stifle loaded to 8000 N. Methods: The FEM was constructed from computed tomography (CT) of the right, extended stifle of a yearling. The CT image was segmented into relevant anatomic structures and meshed into 4-node tetrahedrons. Bone material properties were assigned according to Hounsfield units, soft tissue p...
Quantitative Evaluation of Equine Articular Cartilage Using Cationic Contrast-Enhanced Computed Tomography. To investigate the diffusion trajectory of a cationic contrast medium (CA4+) into equine articular cartilage, and to assess normal and degenerative equine articular cartilage using cationic contrast-enhanced computed tomography (CECT). In the first experiment (Exp1), equine osteochondral specimens were serially imaged with cationic CECT to establish the diffusion time constant and time to reach equilibrium in healthy articular cartilage. In a separate experiment (Exp2), articular cartilage defects were created on the femoral trochlea (defect joint) in a juvenile horse, while the opposite joint...
The prevalence of temporal bone fractures is high in horses with severe temporohyoid osteoarthropathy. Temporohyoid osteoarthropathy is a well-recognized cause of equine neurologic disease. Temporal bone fractures associated with temporohyoid osteoarthropathy have been recognized with CT, however, little information is available regarding these fractures. The aims of this retrospective analytical study were to assess the prevalence of these fractures and to describe the specific configurations and associated imaging and clinical features. Fracture of the temporal bone was identified with CT in 16 of 39 included horses. All fractures were unilateral, minimally displaced and extended through the ...
In vitro comparison of linear vs triangular screw configuration to stabilize complete uniarticular parasagittal fractures of the proximal phalanx in horses. To assess fracture gap reduction and stability of linear vs triangular 4.5-mm lag screw repair of experimental, uniarticular, and complete forelimb proximal phalanx (P1) fractures. Methods: Experimental. Methods: Fourteen equine cadaver limbs/horses. Methods: Simulated fractures were repaired with 2 lag screws under 4-Nm insertion torque (linear repair). Computed tomography (CT) imaging was performed with the leg unloaded and loaded to forces generated while walking. The fracture repair was revised to include 3 lag screws placed with the same insertion torque (triangular repair) prior to CT. T...
Extradural spinal hydatid cyst causing hindlimb ataxia in a horse. This case report describes a 13-year-old cob-cross gelding presented for evaluation of recent onset hindlimb ataxia. The gelding had undergone general anaesthesia and tenoscopy of the right hindlimb digital flexor tendon sheath at a nearby clinic three months earlier and had appeared normal at routine post-operative assessments until the sudden onset of neurological deficits. Spinal trauma was suspected initially but radiography and scintigraphy were unremarkable. Due to the severity and progressive nature of the clinical signs the -gelding was subjected to euthanasia. Post mortem examinations...
Use of an aiming device and computed tomography for assisted debridement of subchondral cystic lesions in the limbs of horses. To describe the use of an aiming device (AD) and computed tomography (CT) for preoperative planning and intraoperative guided debridement of subchondral cystic lesions (SCL) in the limbs of horses and to determine the outcome 12 months after surgery. Methods: Prospective case series. Methods: Twelve horses referred because of lameness caused by 1 or 2 SCL (total of 14 SCL). Methods: All horses underwent CT-guided debridement of the SCL. The entry point of the drill bit and direction of drilling were planned and controlled by using a series of CT images and the AD. The SCL were curetted and fil...
Diffusion of charged and uncharged contrast agents in equine mandibular condylar cartilage is not affected by an increased level of sugar-induced collagen crosslinking. Nutrition of articular cartilage relies mainly on diffusion and convection of solutes through the interstitial fluid due to the lack of blood vessels. The diffusion is controlled by two factors: steric hindrance and electrostatic interactions between the solutes and the matrix components. Aging comes with changes in the cartilage structure and composition, which can influence the diffusion. In this study, we treated fibrocartilage of mandibular condyle with ribose to induce an aging-like effect by accumulating collagen crosslinks. The effect of steric hindrance or electrostatic forces on the d...
18 F-sodium fluoride positron emission tomography of the racing Thoroughbred fetlock: Validation and comparison with other imaging modalities in nine horses. Early and accurate detection of stress remodelling in racehorses is of utmost importance to prevent catastrophic injuries. Current imaging techniques have limitations in assessing early changes predisposing to catastrophic breakdowns. Positron emission tomography (PET) using F-sodium fluoride ( F-NaF) is a sensitive method for the detection of early bone turnover and may improve early recognition of subtle injuries. Objective: To validate the clinical use of F-NaF PET in Thoroughbred racehorses, to assess the value of PET in the detection of bone lesions and to compare PET results with findi...
Disease-Modifying Osteoarthritis Treatment With Interleukin-1 Receptor Antagonist Gene Therapy in Small and Large Animal Models. Gene therapy holds great promise for the treatment of osteoarthritis (OA) because a single intraarticular injection can lead to long-term expression of therapeutic proteins within the joint. This study was undertaken to investigate the use of a helper-dependent adenovirus (HDAd)-mediated intraarticular gene therapy approach for long-term expression of interleukin-1 receptor antagonist (IL-1Ra) as sustained symptomatic and disease-modifying therapy for OA. In mouse models of OA, efficacy of HDAd-IL-1Ra was evaluated by histologic analysis, micro-computed tomography (micro-CT), and hot plate ana...
Cervical stabilization with polyaxial pedicle screw and rod construct in horses: A proof of concept study. To evaluate safety and efficacy of a novel technique for cervical stabilization. Methods: In vivo experimental. Methods: Four normal adult quarterhorse crossbreed horses (2-4 years of age, > 250 kg). Methods: One mid-cervical spinal unit (C3-C4) was distracted with a porous metal interbody fusion device (IFD) and stabilized with a polyaxial pedicle screw and rod construct. Neurologic examinations were performed preoperatively and postoperatively. Radiographs of the fusion site and adjoining vertebrae were obtained preoperatively and monthly. Horses were euthanized at 8 months and spin...
Aging does not change the compressive stiffness of mandibular condylar cartilage in horses. Aging can cause an increase in the stiffness of hyaline cartilage as a consequence of increased protein crosslinks. By induction of crosslinking, a reduction in the diffusion of solutions into the hyaline cartilage has been observed. However, there is a lack of knowledge about the effects of aging on the biophysical and biochemical properties of the temporomandibular joint (TMJ) cartilage. Hence, the aim of this study was to examine the biophysical properties (thickness, stiffness, and diffusion) of the TMJ condylar cartilage of horses of different ages and their correlation with biochemical p...
Use of crown height of the maxillary first molar tooth to approximate the age of horses. OBJECTIVE To identify whether age, sex, or breed is associated with crown height of the left and right maxillary first molar tooth (M1) measured on CT images, to develop a mathematical model to determine age of horses by use of M1 crown height, and to determine the correlation between M1 crown height measured on radiographic and CT images. SAMPLE CT (n = 735) and radiographic images (35) of the heads of horses. PROCEDURES Crown height of left and right M1 was digitally measured on axial CT views. Height was measured on a lateral radiographic image when available. Linear regression analysis was...
Diagnosis of Skeletal Injury in the Sport Horse. This article discusses the basis of image formation of radiography, scintigraphy, PET, computed tomography (fan beam and cone beam), and magnetic resonance as it relates to imaging of musculoskeletal injury in the sport horse. The benefits and drawbacks of each modality are discussed with particular emphasis on sensitivity, specificity, and accuracy of identification of subchondral bone injury. Examples of straightforward as well as confounding lesions are provided, emphasizing the need for appropriate clinical workup and diagnostic analgesia, where appropriate.
Arthroscopic approach and intra-articular anatomy of the equine atlanto-occipital joint. To develop arthroscopic approaches to the atlanto-occipital (A-O) and describe associated arthroscopic anatomy. Methods: Experimental ex vivo study and clinical case report. Methods: Ten equine cadaver joints and 1 clinical case. Methods: CT arthrograms of 8 A-O joints were performed to determine the placement of an arthroscopic portal. Arthroscopy was performed via dorsal and/or ventral approaches (dorsal or ventral to the longissimus capitis tendon) in 10 cadaveric A-O joints and the A-O joint of a 2-week-old foal with septic arthritis. Accessible cartilage was debrided in 3 cadaver joints. ...
Echocardiographic identification of atrial-related structures and vessels in horses validated by computed tomography of casted hearts. Echocardiography is the imaging technique of choice for the equine heart. Nevertheless, knowledge about ultrasonographic identification of dorsally located structures and vessels, related to the atria, in horses is scarce. Objective: To describe the echocardiographic approach and the identification of structures and vessels in relation to the atria in healthy horses. Methods: CT images from two equine hearts, casted with self-expanding foam, were segmented and used to identify atrial-related structures and vessels. These images were compared with standard and nonstandard ultrasound images from...
Comparison of conventional radiography and computed tomography as aids in the diagnosis of osteomyelitis in 11 foals. Conventional radiography is currently the most common imaging modality used by veterinarians investigating foals with suspected osteomyelitis. Emerging evidence in adult horses and humans suggests computed tomography (CT) is a superior modality for evaluation of osseous changes in general. This study aimed to evaluate the potential benefits of CT versus conventional radiography in cases of osteomyelitis in foals. Methods: Cases of osteomyelitis in foals under 6 months of age admitted over a 6-year period at a single referral hospital that had both CT and conventional radiography images were ...
Evaluation of the equine mental foramen block: cadaveric and in vivo injectate diffusion. To describe injectate diffusion for two equine mental foramen block techniques. Methods: Descriptive anatomic study. Methods: A total of 12 equine heads and three live horses. Methods: Equine heads were longitudinally sectioned to create 24 hemi-heads for testing two mental foramen block techniques (T1 and T2) and two injectate volumes (3 and 5 mL) of mixed dye and contrast medium. T1 needles were directed rostrocaudally into the mental foramen for 3 cm, and T2 needles were directed dorsolaterally to ventromedially into the foramen for 1 cm. Hemi-heads were randomly assigned one injection tech...