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.
Contrast-enhanced computed tomographic evaluation of the deep digital flexor tendon in the equine foot compared to macroscopic and histological findings in 23 limbs. Distal deep digital flexor tendinopathy is an important cause of foot lameness in horses that is difficult to diagnose with radiography and ultrasonography. Magnetic resonance imaging is a well-accepted and validated technique for the identification of deep digital flexor tendon (DDFT) lesions, but has some practical and financial drawbacks. Contrast-enhanced computed tomography (CECT) has been proposed as a suitable alternative, but validation studies are currently lacking. Objective: To assess the accuracy of CECT for the identification and characterisation of deep digital flexor tendinopath...
Two- and three-dimensional anatomy of paranasal sinuses in Arabian foals. The 2- and 3-dimensional (3D) anatomy and the morphometric properties of the paranasal sinuses of the foal have received little or no attention in the literature. The aim of this study was to obtain details of the paranasal sinuses using multiplane CT imaging to create 3D models and to determine morphological and morphometric data for the sinuses using the 3D models. The heads of five female foals were used in this study. The heads were scanned using computed tomography (CT) in the rostrocaudal direction. After the heads had been frozen, anatomical sections were obtained in the scan position. ...
Qualitative and quantitative interpretation of computed tomography of the lungs in healthy neonatal foals. To qualitatively describe lung CT images obtained from sedated healthy equine neonates (≤ 14 days of age), use quantitative analysis of CT images to characterize attenuation and distribution of gas and tissue volumes within the lungs, and identify differences between lung characteristics of foals ≤ 7 days of age and foals > 7 days of age. Methods: 10 Standardbred foals between 2.5 and 13 days of age. Methods: Foals were sedated with butorphanol, midazolam, and propofol and positioned in sternal recumbency for thoracic CT. Image analysis software was used to exclude lung from nonlung str...
Intradiploic hematoma of the frontal bone with secondary exophthalmos in a mare. A 13-year-old cob mare was presented with exophthalmos and periocular swelling of the left eye. The diagnostic work-up included ocular ultrasound, sonographic examination through the thinned frontal bone, radiography, standing computed tomography of the skull and exploratory osteoplastic surgery. Histopathology was consistent with an organized hematoma. An intradiploic hematoma of the frontal bone was diagnosed 5 years after head trauma, with progressive expansion and deformation of the skull resulting in exophthalmos. Exophthalmos with facial bone deformation was the only clinical finding of ...
Pilonidal sinus disease. Pilonidal disease is a frequent suppurative condition that occurs twice as often in men as in women, usually between the ages of 15 and 30. Pilonidal disease is located beneath the skin of the sacro-coccygeal region. It presents acutely as an abscess under tension while the chronic form gives rise to intermittent discharge from pilonidal sinus(es). Diagnosis is clinical and usually straightforward. In the large majority of cases, treatment is surgical but there is no consensus as to the 'ideal' technique. Acute abscess must be evacuated and an off-midline incision seems preferable. Excision is...
Using semi-automated segmentation of computed tomography datasets for three-dimensional visualization and volume measurements of equine paranasal sinuses. The system of the paranasal sinuses morphologically represents one of the most complex parts of the equine body. A clear understanding of spatial relationships is needed for correct diagnosis and treatment. The purpose of this study was to describe the anatomy and volume of equine paranasal sinuses using three-dimensional (3D) reformatted renderings of computed tomography (CT) slices. Heads of 18 cadaver horses, aged 2-25 years, were analyzed by the use of separate semi-automated segmentation of the following bilateral paranasal sinus compartments: rostral maxillary sinus (Sinus maxillaris ros...
Computed tomographic features of lesions detected in horses with tarsal lameness. Tarsal pain is a common cause of hindlimb lameness in horses. Diagnosis can usually be made with radiography and ultrasonography; however, in some cases, these techniques are inconclusive and additional imaging is necessary. No studies describing computed tomography (CT) features of different tarsal lesions in horses with tarsal lameness are reported. Objective: Our aims were as follows: 1) to characterise CT abnormalities in horses with tarsal lameness; 2) to compare CT findings with those from other imaging techniques; and 3) to assess whether CT can help to diagnose tarsal pathology. ...
Intramodality and intermodality agreement in radiography and computed tomography of equine distal limb fractures. Computed tomography (CT) is increasingly accessible in equine referral hospitals. Objective: To document the level of agreement within and between radiography and CT in characterising equine distal limb fractures. Methods: Retrospective descriptive study. Methods: Images from horses that underwent radiographic and CT evaluation for suspected distal limb fractures were reviewed, including 27 horses and 3 negative controls. Using Cohen's kappa and weighted kappa analysis, the level of agreement among 4 observers for a predefined set of diagnostic characteristics for radiography and CT separately...
Evaluation of osteochondral sample collection guided by computed tomography and magnetic resonance imaging for early detection of osteoarthritis in centrodistal joints of young Icelandic horses. To evaluate the use of CT and MRI for guidance of osteochondral sample collection for histologic detection of early osteoarthritic lesions in centrodistal (distal intertarsal) joints of horses. Methods: Right tarsal joints from the cadavers of 24 Icelandic horses aged 29 to 31 months. Methods: CT and MRI were used to evaluate the extent of suspected osteoarthritic changes in centrodistal joints, which were graded with a semiquantitative system. The anatomic regions with the highest grade of change were identified, and osteochondral samples were obtained from these regions. Samples were also ob...
Advanced imaging in equine dental disease. Dental and sinus disorders are relatively common and of major clinical importance in equine medicine. Advanced diagnostic imaging has become an integral part of equine veterinary medicine. Advanced imaging has progressed the understanding, diagnosis, and treatment of dental- and sinus-related diseases. As a clinician, it is important to realize the value of advanced diagnostic imaging. Although computed tomography and magnetic resonance imaging are both significantly more expensive compared with other diagnostic tools, the financial cost of inaccurate diagnosis and treatment can often result i...
Bone mineral density (BMD) and computer tomographic measurements of the equine proximal phalanx in correlation with breaking strength. Despite the fact that bone mineral density (BMD) is an important fracture risk predictor in human medicine, studies in equine orthopedic research are still lacking. We hypothesized that BMD correlates with bone failure and fatigue fractures of this bone. Thus, the objectives of this study were to measure the structural and mechanical properties of the proximal phalanx with dual energy X-ray absorptiometry (DXA), to correlate the data obtained from DXA and computer tomography (CT) measurements to those obtained by loading pressure examination and to establish representative region of interest (...
New ways to diagnose and treat equine dental-related sinus disease. The diagnosis and treatment of equine dental-related sinus disease is often challenging. Dental-related sinus disease is common and knowledge of these diseases is becoming increasingly important in veterinary medicine. Diagnostic capabilities are continually improving, leading to early diagnostic and therapeutic successes. With advanced imaging modalities, such as computed tomography and magnetic resonance imaging, understanding of the intimate anatomic relationship between teeth and the paranasal sinuses continues to progress. There are many therapeutic options available for the treatment of ...
Shock absorbing ability of articular cartilage and subchondral bone under impact compression. Despite the important role of subchondral bone in maintaining the integrity of the overlying articular cartilage, little research has focused on measuring its mechanical behavior, particularly under injurious load conditions such as impact compression. In this study, the stiffness and the absorbed energy of subchondral bone were compared to that of its overlying cartilage by applying impact compression to equine cartilage-bone specimens. Deformations of the cartilage and subchondral bone were examined independently within the cartilage-bone unit by analyzing real-time images of cartilage-bone ...
Computed tomography and magnetic resonance imaging in the study of joint development in the equine pelvic limb. Osteochondrosis dissecans (OCD) is a focal failure of endochondral ossification of the epiphysis characterized by the presence of cartilage flaps and osteochondral fragments. The objective of this study was to image epiphyseal development in the equine pelvic limb to determine whether there was a variation in site maturation that could be a predisposing factor for OCD. Pelvic limbs (fetuses and foals) were studied post-mortem. The epiphyses of the distal femur, tibia and talus were scanned with computed tomography (CT) and 1.5T magnetic resonance imaging (MRI) to investigate the degree and pat...
Validation of a photogrammetric technique for computing equine hoof volume. Assessment of equine foot conformation is often based on linear and angular measurements performed on lateral digital photographs. However, quantification of external foot conformation requires more comprehensive assessments to capture the shape of the entire foot. Volumetric measurements of the hoof capsule represent a summary measure quantifying foot shape. The aim of this study was to develop a method for computation of virtual foot models from digital foot images allowing precise and accurate volumetric measurements. This photogrammetric technique was then assessed for the characterization...
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...