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.
[Endometrial cysts in the mare. 2. Clinical studies: occurrence and significance]. Endometrial cysts were found in 11 (13.4%) of 82 mares of various breeds by clinical examinations. Endometrial cysts were diagnosed by hysteroscopy and ultrasonic echography. Typical images are described. The importance of endometrial cysts is discussed with regard to differential diagnosis of early pregnancy and uterine pathology. There was no evidence of cysts in mares under 10 years of age. Mares with endometrial cysts had a 10% higher history of disturbed fertility than mares without endometrial cysts. Seven of nine mares with cystic structures in the uterus became pregnant. Endometrial cy...
[Avulsion fracture of the tendon of origin of the long extensor muscle of the toe in a horse and a cat]. An avulsion fracture of the tendon of origin of the extensor digitorum longus muscle is reported in a horse and a cat. This avulsion fracture was due to injury in both animals. There was a striking similarity of radiographic findings in these animals, with involvement of the lateral trochlear ridge and lateral condyle of the femur. The horse was slaughtered because of a poor prognosis as a riding-horse. Fixation of the avulsed fragment with two Kirschner wires resulted in complete recovery in the cat.
Subchondral osseous cystic lesions of the elbow of horses: conservative versus surgical treatment. Subchondral osseous cystic lesion of the elbow was diagnosed as a cause of lameness in 6 horses. Persistent lameness and signs of degenerative joint disease developed in the first 3 horses treated conservatively with confinement. Subsequently, 3 horses were each treated by extra-articular enucleation of the cystic cavity via the proximal-medial aspect of the radius. Compared with conservative management, better long-term success (determined by return of athletic soundness and less evidence of degenerative joint disease) was achieved with surgical curettage of elbow subchondral cystic lesions.
Pathology of the vertebral column of horses with cervical static stenosis. Specimens of ligamentum flavum, joint capsule, and dorsal lamina were collected at surgery or necropsy from 25 horses with cervical static stenosis. All horses had myelographic evidence of dorsal compression of the spinal cord caused by soft tissue and/or bone in the caudal cervical area, primarily at C6-7. Most horses also had radiographic evidence of degenerative joint disease of articular facets. Histologically 19 horses had osteosclerosis and cartilage retention in the dorsal lamina, and 24 horses had increased fibrocartilage at the ligamentum flavum attachment to dorsal lamina. The ligame...
Iopamidol myelography in the horse. The use of the non-ionic, water-soluble contrast agent iopamidol for myelography in seven horses is described. Contrast columns of diagnostic quality were produced in all seven cases and the procedure did not invoke any adverse reactions in the five cases which were recovered from general anaesthesia. It is concluded that iopamidol is a safe and effective contrast agent for myelography in the horse.
Diagnostic ultrasound in equine reproduction. This article reviews the type of equipment available, the examination techniques, and the interpretation of information derived from ultrasound in broodmare practice. The application of diagnostic ultrasound has found immediate acceptability and clinical usefulness in the genital evaluations of the broodmare.
Diseases of the liver. The ability to image the liver in horses can add valuable diagnostic information or aid in guided biopsy procedures. Anytime the size, shape, position, and texture of the liver can be determined, additional information about the horse's condition is gained. Conditions such as cholelithiasis, neoplasia, fibrosis can be detected ultrasonographically.
Uses of ultrasound in equine internal medicine. Ultrasound examination allows the diagnostician to examine peripheral soft tissues and many internal organs in a noninvasive manner. In most instances, ultrasound can be utilized to complement other diagnostic aids, but its increased use has revealed the unique advantages of this technique over more established diagnostic tools. The ease with which ultrasound interpretation can be learned and the increased availability of instruments make this approach to diagnosis a valuable asset in the diagnosis of many equine medical diseases.
General considerations for ultrasound examinations. Patient preparation and restraint, instrumentation, and methods of retaining records of ultrasound images are discussed.
Ultrasound science for the veterinarian. In order to successfully sort out the information, both real and bogus, in an ultrasonic image, one must have a fundamental understanding of the physical and electronic events that produced the image. We have looked at the basic science, signal processing, some case examples of ultrasound science in practice, and some popular illusions. It is a good starting place for the newcomer to ultrasonic imaging.
Diseases of the heart. Diagnostic ultrasound has allowed significant findings to be made in the investigation of cardiac disease in the horse. Because of the limited value of thoracic radiography in the adult horse with cardiac disease, ultrasound is the method of choice to document chamber enlargement, pericardial effusion, valvular abnormalities, and decreased contractility of the myocardium. The apparent changes in the flow characteristics and suspicion of abnormality in the right heart of racehorses need further investigation to fully document the etiopathogenesis of spontaneous contrast.
Ultrasonographic appearance and correlative anatomy of the soft tissues of the distal extremities in the horse. The diagnostician should be familiar with the normal ultrasound appearance (size, shape, position, and textural quality) of each structure examined. With these factors as reference points, one can describe lesions in the structure involved, the precise location and extent of the lesions, and the degree of structural compromise that is manifested. Documentation of lesions of tendons and ligaments enables one to make an accurate diagnosis and a more precise prognosis. Serial examination during the healing phases allows for a more accurate prediction as to when the structure in question can withs...
Diagnostic ultrasonography of equine limbs. In our 3 years of clinical experience, we have found that diagnostic ultrasound provides the veterinarian with a valuable diagnostic tool. It allows the clinician to quantify morphologic change that has occurred as a result of soft-tissue injuries, even when the clinical findings are ambiguous or insufficient. In cases in which aggressive postinjury therapy has been instituted prior to presentation, diagnostic ultrasound is often the only noninvasive method that can ascertain the extent of the horse's injury. Diagnostic ultrasound provides the technology to detect injuries before they become p...
Cross-sectional area of the aditus laryngis and rima glottidis before and after transection of the left recurrent laryngeal nerve in the horse. The ventral-to-dorsal height of the rima glottidis was measured from lateral pharyngeal radiographs after correction for magnification. The rima glottidis height was used to enlarge accurately endoscopic photographs of 5 horses taken before and after transection of the left recurrent laryngeal nerve. Areas of the rima glottidis and aditus laryngis were measured, using a computerized digitizer. Mean area of the aditus laryngis was 1,908 mm2 before neurectomy and 1,346 mm2 after neurectomy (P = 0.025). Mean area of the rima glottidis was 1,198 mm2 before neurectomy and 805 mm2 after neurectomy (...
[Endoscopic findings in horses with diseases of the upper respiratory tract]. With the aid of a flexible glassfibre endoscope, a 300 W cold light source and a special adapted camera, colour photographs of the upper respiratory tract of horses were taken. These pictures served to present especially the disease processes of the different areas of the upper respiratory tract which lead to a constriction of the lumen. These included proliferation in the nose, guttural pouch diseases and larynx diseases such as hemiplegia, subepiglottic cysts, epiglottic entrapment and rostral displacement of the plica palatopharyngica. Furthermore endoscopic findings of changes in the soft ...
Diagnostic techniques in the investigation of shoulder lameness. Methods of investigating horses with suspected shoulder lameness are described and discussed. The gait of shoulder lameness is characterised and compared with that of lower forelimb lameness. If lameness is slight, differentiation may be difficult, but if moderate, upper forelimb lameness usually results in shortening of the cranial phase of the stride and a low limb flight. Clinically, it may not be possible to differentiate between shoulder and elbow lameness without intra-articular anaesthesia. Practical aspects of intra-articular anaesthesia of the shoulder joint are reviewed. Synovial flu...
Repair of a delayed-union stress fracture of the dorsal cortex of a metacarpal bone in a horse. A delayed union metacarpal stress fracture was repaired in a horse, using lag-screw fixation in conjunction with dc electrical stimulation. Twelve weeks after surgery, radiographic and scintigraphic evaluations revealed that the fracture line was not discernible and that there was a decrease in radiopharmaceutic uptake, as compared with that in previous bone imaging studies. In this horse, DC stimulation of a delayed union stress fracture in a bone resulted in a healing pattern similar to that in human beings with delayed union fractures when treated with electrical stimulation.
Interpreting radiographs 6: Radiology of the equine head (Part 2). The value of radiology as part of an examination of the equine head is emphasised and the radiological appearances of more commonly occurring conditions are described. Even the normal anatomy of this complex site is subject to great variation and the aspiring radiologist should, therefore, have a good knowledge of the possible normal variations. A flexible approach must be used rather than a limitation to one or two ritual projections. The use of contrast media, wherever it might be useful, is advocated so that the maximum amount of information may be obtained from each examination. Finally, e...
Cystic calculi in two horses. The use of real-time ultrasound for examination of the bladder was a useful diagnostic aid in 2 cases of cystic calculi. The ultrasound procedure revealed that a firm mass palpated per rectum in the bladder of one horse was a calculus. In the other horse, ultrasound revealed additional small uroliths. To remove the uroliths in both horses, laparocystidotomy via a ventral paramedian approach was chosen because it provided the best access to the bladder lumen. The calculi were analyzed by qualitative chemical analysis and quantitative crystallography. Results differed between analysis methods. C...
Diagnostic value of contrast echocardiography in the horse. M-mode echocardiography is a safe and practical means of using ultrasound to evaluate the dynamic movements of cardiac structures. The technique can be refined by using a simple contrast medium in the form of carbon dioxide mixed with heparinised blood to provide a strong echogenic result. This technique was employed in a series of 15 normal conscious standing horses and in three animals with specific cardiac defects. In the clinical cases it was possible to confirm the diagnosis and differentiate between a congenital septal defect and mitral regurgitation. The method was found to be safe and ...
Diagnostic radiology and nuclear cardiology. Their use in assessment of equine cardiovascular disease. Survey thoracic radiography, although limited by physical considerations in the adult horse, can supply clinically useful information about changes in cardiac size and function. The radiographic features of cardiomegaly, altered pulmonary circulation, pulmonary edema, and pleural effusion as manifested in the horse are discussed. Nuclear cardiology can be performed in the standing horse. The initial transit of a radioactive tracer through the central circulation provides information about cardiac chamber size, efficiency of ventricular contraction, valvular competence, and presence of intracar...
Evaluation of the equine cardiovascular system. A thorough examination of the cardiovascular system is an integral part of a physical examination in the horse. The normal equine cardiovascular parameters are discussed, with an emphasis on auscultatory findings. The availability and application of other diagnostic techniques are discussed based upon findings of the physical examination.
Periosteal transection and stripping for treatment of angular limb deformities in foals: radiographic observations. Radiographs of 23 foals (35 forelimbs) with carpal region angular limb deformities, which later were corrected by hemicircumferential transection of the periosteum and periosteal stripping, were evaluated as to geometric and morphologic abnormalities. Geometric evaluation included deviation angle and deviation pivot point. Morphologic abnormalities were categorized as: asymmetric width of the distal radial physis; asymmetric width of the distal radial epiphysis; carpal bone collapse or fracture; carpal bone hypoplasia; carpal bone displacement; and metacarpal bone displacement. Fifty-seven per...
Use of 111In-labeled autologous leukocytes to image an abdominal abscess in a horse. Indium 111-labeled autologous leukocytes were used to image an abdominal abscess in a horse with a palpable abdominal mass and history of Streptococcus equi infection. A focal area of radioactivity was identified in the location corresponding to the abscess. Imaging of this focal uptake was optimal 48 hours after injection. Similar scans obtained in 2 clinically normal horses revealed no evidence of focal radioactivity in this region. The cell labeling procedure gave acceptable labeling efficiency (87.5%) but an excessive number of damaged WBC, resulting in persistent lung radioactivity on all...