Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Diagnostic Imaging
Diagnostic imaging in horses encompasses a range of techniques used to visualize the internal structures of the equine body for the purpose of diagnosis and treatment planning. These techniques include radiography, ultrasonography, magnetic resonance imaging (MRI), computed tomography (CT), and nuclear scintigraphy. Each modality offers unique advantages in assessing different tissues and conditions, such as bone fractures, soft tissue injuries, and joint abnormalities. Radiography is commonly employed for evaluating bone structures, while ultrasonography is frequently used for soft tissue assessment. MRI and CT provide detailed cross-sectional images, facilitating the examination of complex anatomical regions. Nuclear scintigraphy can detect areas of increased bone activity, often used in lameness evaluations. This page compiles peer-reviewed research studies and scholarly articles that explore the applications, advancements, and comparative effectiveness of diagnostic imaging modalities in equine veterinary practice.
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...
Magnetic resonance and radiographic diagnosis of osseous resorption of the flexor surface of the distal phalanx in the horse. Osseous resorption of the flexor surface of the distal phalanx of the horse has been identified previously using magnetic resonance (MR) imaging; however, little is known about the prevalence and characteristics of this lesion. Objective: To establish the MR prevalence of resorptive lesions in the flexor surface of the distal phalanx and identify concurrent lesions associated with this finding and associations between the MR and radiographic findings. Methods: Horses with distal extremity MR and radiographs performed within 2 weeks of each other were included in the study. The flexor surface o...
Influence of head and neck position on radiographic measurement of intervertebral distances between thoracic dorsal spinous processes in clinically sound horses. Reductions in distances between dorsal spinous processes on radiographs are used as criteria for the diagnosis of impingement of the thoracic dorsal spinous processes in horses but are potentially altered by spine motion and different head and neck positions. Objective: To determine the influence of head and neck positions on intervertebral distances between dorsal spinous processes on radiographs of thoracic spines of clinically sound horses. Methods: Lateral-lateral radiographs were obtained from 23 horses in 3 head and neck positions. The width of the thoracic dorsal spinous processes and i...
Non-terminal animal model of post-traumatic osteoarthritis induced by acute joint injury. Develop a non-terminal animal model of acute joint injury that demonstrates clinical and morphological evidence of early post-traumatic osteoarthritis (PTOA). Methods: An osteochondral (OC) fragment was created arthroscopically in one metacarpophalangeal (MCP) joint of 11 horses and the contralateral joint was sham operated. Eleven additional horses served as unoperated controls. Every 2 weeks, force plate analysis, flexion response, joint circumference, and synovial effusion scores were recorded. At weeks 0 and 16, radiographs (all horses) and arthroscopic videos (OC injured and sham joints) ...
Mechanical ventilation and respiratory mechanics during equine anesthesia. The mechanical ventilation of horses during anesthesia remains a crucial option for optimal anesthetic management, if the possible negative cardiovascular side effects are managed, because this species is prone to hypercapnia and hypoxemia. The combined use of capnography and pitot-based spirometry provide complementary information on ventilation and respiratory mechanics, respectively. This facilitates management of mechanical ventilation in conditions of changing respiratory system compliance (ie, laparoscopy) and when investigating new ventilatory strategies including alveolar recruitment m...
Comparison of inversion recovery gradient echo with inversion recovery fast spin echo techniques for magnetic resonance imaging detection of navicular bone marrow lesions in horses. To compare navicular bone marrow lesion (BML) conspicuity in the feet of horses as determined via 2 fat-suppressed MRI techniques, including standard short tau inversion recovery (STIR) and inversion recovery gradient echo (IRGE). Methods: Feet (n = 150) of horses with lameness referable to the distal portion of the digit. Methods: STIR and IRGE sequences were obtained prospectively in all feet with a standing low-field equine MRI system. Presence of a BML was ascertained by identification of a characteristic combination of marrow alterations in T1-weighted, T2*-weighted, T2-weighted, and STIR...
Effects of infrared camera angle and distance on measurement and reproducibility of thermographically determined temperatures of the distolateral aspects of the forelimbs in horses. To assess effects of camera angle and distance on measurement and reproducibility of thermographically determined temperatures of the distolateral aspect of the forelimbs in horses. Methods: Evaluation study. Methods: 10 adult horses. Methods: Thermographic images of both forelimbs were obtained at 3 times during the day (replicates 1, 2, and 3); maximum surface temperature over 1 region (distolateral aspect of the third metacarpal bone and metacarpophalangeal joint) was measured. Standard images were obtained every 5 minutes for 1 hour with the camera positioned at an angle of 90° and a dist...
Reliability and identification of aortic valve prolapse in the horse. The objectives were to determine and assess the reliability of criteria for identification of aortic valve prolapse (AVP) using echocardiography in the horse. Results: Opinion of equine cardiologists indicated that a long-axis view of the aortic valve (AoV) was most commonly used for identification of AVP (46%; n=13). There was consensus that AVP could be mimicked by ultrasound probe malignment. This was confirmed in 7 healthy horses, where the appearance of AVP could be induced by malalignment. In a study of a further 8 healthy horses (5 with AVP) examined daily for 5 days, by two echocardiog...
Diagnostic accuracy of a duplex real-time reverse transcription quantitative PCR assay for detection of African horse sickness virus. Blood samples collected from 503 suspect cases of African horse sickness (AHS) and another 503 from uninfected, unvaccinated South African horses, as well as 98 samples from horses from an AHS free country, were tested with an AHS virus (AHSV) specific duplex real-time reverse transcription quantitative PCR (RT-qPCR) assay and virus isolation (VI). The diagnostic sensitivity and specificity of this AHSV RT-qPCR assay and VI were estimated using a 2-test 2-population Bayesian latent class model which made no assumptions about the true infection status of the tested animals and allowed for the p...
Ultrasonographic features of PMEL17 (Silver) mutant gene-associated multiple congenital ocular anomalies (MCOA) in Comtois and Rocky Mountain horses. (1) To describe the ultrasonographic appearance of multiple congenital ocular anomalies (MCOA) in the eyes of horses with the PMEL17 (Silver) mutant gene. (2) To compare the accuracy of B-mode ocular ultrasound to conventional direct ophthalmoscopy. Methods: Sixty-seven Comtois and 18 Rocky Mountain horses were included in the study. Methods: Horses were classified as being carriers or noncarriers of the PMEL17 mutant allele based on coat color or genetic testing. Direct ophthalmoscopy followed by standardized ultrasonographic examination was performed in all horses. Results: Seventy-five of 8...
Magnetic resonance protocols in equine lameness examination, used sequences, and interpretation. Magnetic resonance is a great diagnostic tool in equine lameness examination. Its value is most significantly visible in evaluating distal extremities. Problems with podotrochlear apparatus, laminitis or distal interphalangeal joint osteoarthritis are the most common disorders diagnosed in equine patients. Without using magnetic resonance it was impossible to clearly assess which structures are involved in each of these diseases. One of the most important things in MRI is the choice of sequence. Most commonly used are T1 GE, T2 FSE, STIR and T2* GE, in sagittal, transverse and dorsal planes. T...
Diagnostic sensitivity and interobserver agreement of radiography and ultrasonography for detecting trochlear ridge osteochondrosis lesions in the equine stifle. Osteochondrosis lesions commonly occur on the femoral trochlear ridges in horses and radiography and ultrasonography are routinely used to diagnose these lesions. However, poor correlation has been found between radiographic and arthroscopic findings of affected trochlear ridges. Interobserver agreement for ultrasonographic diagnoses and correlation between ultrasonographic and arthroscopic findings have not been previously described. Objectives of this study were to describe diagnostic sensitivity and interobserver agreement of radiography and ultrasonography for detecting and grading osteoch...
Exercise affects joint injury risk in young Thoroughbreds in training. The aim of this study was to identify exercise-related risk factors for carpal and metacarpo- and metatarso-phalangeal (MCP/MTP) joint injury occurrence in young Thoroughbreds in flat race training. In a 2-year prospective cohort study, daily exercise and joint injury data were collected from horses in 13 training yards in England. Four injury categories were defined: (1) localised to a carpal or MCP/MTP joint based on clinical examination and/or use of diagnostic analgesia with no diagnostic imaging performed; (2) localised to a carpal or MCP/MTP joint with no abnormalities detected on diagno...
Investigation of a progressive facial deformity and stridor in an adult horse with a bone sequestrum and subsequent sinonasal abscess. Advanced diagnostic imaging and histopathological investigation were performed in an adult horse with chronic facial swelling due to a bone sequestrum and abscessation. In contrast to other cases, there were no draining tracts, difficulty eating, weight loss, head shaking, or fistula formation between the oral cavity and the maxillary sinus. Une investigation d’imagerie diagnostique avancée et un examen histopathologique ont été réalisés chez un cheval adulte présentant de l’enflure faciale chronique attribuable à un séquestre osseux et à une abcédation. Par contraste à d’aut...
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.
The role of MRI in selected equine case management. Magnetic resonance imaging (MRI) allows for excellent evaluation of many types of soft tissue and osseous lesions. Using MRI as a diagnostic modality can help in developing an individualized treatment protocol. Case management can include both surgical and medical intervention. Various MRI findings and associated treatment protocols are described.
Imaging of the equine proximal suspensory ligament. Injury to the suspensory ligament can result in significant lameness. Multiple imaging modalities may be required to fully characterize injury to the suspensory ligament. Ultrasonography of the suspensory ligament is challenging, due to the normal anatomy. This article describes imaging of the proximal suspensory ligament in the front and hind limbs of the horse.
Biochemical evaluation of equine articular cartilage through imaging. The use of molecular imaging of cartilage is the next vital step in understanding, treating, and training the equine athlete. Because of the logistics of precontrast and postcontrast medium imaging, the clinical usefulness of the examination has come into question. With the large number of horses undergoing high-field magnetic resonance imaging, the use of contrast medium administration and T1 mapping or T2 imaging precontrast and postcontrast medium administration may add a limited amount of time to the scan and has the potential to provide more detailed information about the chemical composi...
The basics of musculoskeletal magnetic resonance imaging: terminology, imaging sequences, image planes, and descriptions of basic pathologic change. The usefulness of magnetic resonance (MR) imaging in the diagnosis of equine lameness is unquestionable. As with most imaging modalities, advances in technology happen quickly, and the information that can be obtained can seem limitless. An understanding of MR sequences, expected signal intensity of normal tissues, and the role of multiplanar imaging is the foundation for interpreting MR images. The rapid development of new techniques and sequences and the potential for biochemical changes to be indirectly assessed using MR spectroscopy offer possibilities for the continued development of this...
Influence of atrioventricular interaction on mitral valve closure and left ventricular isovolumic contraction measured by tissue Doppler imaging. The influence of atrioventricular (AV) interaction on mitral valve closure (MVC) and left ventricular (LV) isovolumic contraction is not fully clarified. We investigated the relationship among AV delay, MVC, and LV isovolumic contraction using a horse model because of the low heart rate and physiologically long AV delay. Results: Six horses were evaluated during sinus rhythm, right ventricular pacing without preceding atrial contraction, and dual-chamber pacing at AV delays of 150 to 350 ms, programmed at a constant rate. Right parasternal 4-chamber views were recorded for simultaneous measure...
Hind foot lameness: results of magnetic resonance imaging in 38 horses (2001-2011). The distribution of lesions detected using magnetic resonance imaging (MRI) of hind feet has not been reported. Objective: To evaluate type and distribution of lesions detected using MRI in hind feet of lame horses and to compare the findings with those reported in front feet; to document follow-up information. Methods: Horses were selected if hindlimb lameness was abolished by plantar nerve blocks performed at the base of the proximal sesamoid bones. Magnetic resonance images were acquired using either a low-field or a high-field magnet, and all images were evaluated retrospectively by both a...
Response to injection of the navicular bursa with corticosteroid and hyaluronan following high-field magnetic resonance imaging in horses with signs of navicular syndrome: 101 cases (2000-2008). To determine treatment outcome on the basis of pathological changes identified on MRI and lameness duration in horses with navicular syndrome that underwent injection of corticosteroid and hyaluronan into the navicular bursa. Methods: Retrospective case series. Methods: 101 horses with navicular syndrome. Methods: Medical records of horses with signs of navicular syndrome evaluated between January 2000 and December 2008 were reviewed. Data on signalment, use of the horse, history, affected limbs, duration of lameness, findings on lameness examination, radiographic findings, MRI findings, treat...
Evaluation of growth models for follicle development and ovulation in Lusitano mares. Several growth models are commonly used in the biological sciences, to model the follicle growth occurring in the estrous cycle. The aim of this project was to find the model that best fit the follicular size growth data for Lusitano mares. Retrospective data collected from reproduction book records of n=84 mares and n=124 cycles was used to find the series to be fitted to the models. The exponential, Gompertz, logistic, von Bertalanffy, Richards and Weibull models were used, and the most parsimonious and best fit was achieved with the logistic model (r(2)=0.999). The logistic model fits the L...
Use of intravenous gadolinium contrast in equine magnetic resonance imaging. The use of intravenous gadolinium contrast during equine magnetic resonance imaging (MRI) is a new technique that has been infrequently used in clinical imaging. This article describes the development of an effective contrast dose and the use of gadolinium contrast in clinical equine MRI. Gadolinium contrast improves lesion conspicuity across a broad range of lesion types. Contrast-enhanced MRI is potentially a valuable imaging tool in the assessment of the equine athlete.
An approach to imaging algorithms for equine lameness diagnosis. Tremendous growth and advancement in equine diagnostic imaging necessitates a systematic approach to the application of these modalities to lameness diagnosis. This systematic approach must include attention to the history, physical and clinical examinations, and parameters set forth by the client. It also must include an understanding of which imaging modality is most appropriate given the details of the case. This article presents a basic framework with an underlying algorithmic foundation that can be applied when selecting imaging modalities during lameness evaluation and includes case exam...
Evaluation of motion correction processing in equine bone scintigraphy by Scheffé’s method of paired comparisons. Equine bone scintigraphy is usually performed with horses in standing position under sedation. However, swaying motion often leads to poor-quality images. To examine the usefulness of motion correction (MC) processing, equine bone scintigrams were evaluated using Scheffé's method of paired comparisons. A significant difference in evaluation scores was detected by analysis of variance (F test, P<0.01). According to all observers, Yardstick analysis scores were higher for images use of MC processing than for those no use of MC processing, for all parts. Overall scores of 5 observers were as ...
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...
Removal of ureteral calculi in two geldings via a standing flank approach. Two geldings, aged 11 and 17 years, were examined for treatment of ureteroliths located approximately 10 cm proximal to the bladder. Results: Ureteral obstruction was an incidental finding in 1 horse that was referred because of urinary tract obstruction and a cystic calculus. This horse did not have clinical or laboratory evidence of renal failure, although severe hydronephrosis was evident on transabdominal ultrasonography. The second patient had a serum creatinine concentration of 6.3 mg/dL (reference range, 0.8 to 2.2 mg/dL) and mild hydronephrosis of the affected left kidney. Results: In ...
