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.
Cervical intervertebral disc protrusion in two horses. Two horses with ataxia of all four limbs were found to have cervical intervertebral disc protrusion. Severe pelvic limb ataxia, proprioceptive deficits and spasticity were present in both horses with similar but less severe signs in the thoracic limbs. Cerebrospinal fluid analysis was within normal limits. Metrizamide myelography allowed definitive diagnosis in one case when a compression of the spinal cord was demonstrated at the level of the second intervertebral space. In the second case, an intervertebral disc protrusion between cervical vertebrae 6 and 7 was found at necropsy. Fiber degen...
Measurement of tracheal mucous transport rate in the horse. Tracheal mucous transport rates were measured in 12 nonanesthetized horses after an intratracheal injection of 99mtechnetium-sulfur colloid. The transport rate of the subsequent bolus of radioactivity was determined, using a portable scaler rate meter fitted with a high-energy gamma-scintillation probe. A gamma-scintillation camera was used to verify bolus form and movement in 1 horse. The mean tracheal mucous transport rate was 1.66 +/- 0.24 cm/min.
Fixation and orientation of the early equine conceptus. Fixation and orientation of the conceptus within the uterine lumen of 40 barren mares were examined by ultrasound daily on days 11-21 and at three-day intervals thereafter until day 48. The growth curve of the in situ conceptus had a distinct plateau between days 17-24, as determined by measurements of the width and area of conceptuses on the ultrasound images. The vesicle expanded at an average daily rate of 3-4 mm before the plateau and 2-3 mm after the plateau. Dramatic changes occurred in the shape of conceptus. The predominant shapes were approximately as follows: days 11-16, spherical; d...
Echocardiographic features of aortic valve endocarditis in a dog, a cow, and a horse. A horse, a cow, and a dog with aortic valve vegetative endocarditis were studied by M-mode echocardiography. Echocardiographic abnormalities of the aortic valve, mitral valve, and left ventricle were observed. These features were identical to those reported in human beings with aortic valve endocarditis. Abnormalities associated with aortic valve endocarditis included irregular thickening of the valve, multiple linear echoes in the aortic root, diastolic prolapse of the aortic vegetation, and diastolic fluttering of a torn aortic valve. Some of these features were found in each animal. The con...
Radiographic and arthroscopic findings in the equine stifle. The radiographic and arthroscopic findings in the equine stifle were compared. Survey radiography, contrast arthrography, and arthroscopy were performed on both stifles of 10 horses. Nine of the horses were euthanatized to evaluate the effects of the techniques on the joints. Techniques for double-contrast arthrography and arthroscopy were developed, and the findings were compared. Survey radiography identified only osseous structures. Double-contrast arthrography of the femoropatellar joint demonstrated articular surfaces of the trochlea, patella, and joint capsule. Those of the femorotibial ...
Liver scintigraphy in ponies. Six derivatives of ethylenediamine-N,N'-bis (alpha-2-hydroxy phenyl) acetic acid labeled with technetium 99m were prepared and their imaging qualities evaluated in ponies. The 6 agents produced good scintigraphic images of certain structures of the liver in the pony. For each agent, 13 different scans were taken. Dorsal views of the left lateral, right lateral, and quadrate lobe were obtained with dorsal scans. Left lateral and left lateral oblique (45 degrees) scans provided a left lateral view of the left lobe and a medial view of the right lateral lobe. Right lateral scans revealed the righ...
Radiographic changes in the lungs of horses with exercise-induced epistaxis. This paper describes the distinctive radiographic changes detected in the dorso-caudal lungfields of four racing thoroughbreds recently affected by exercise-induced epistaxis. A diffuse but localized increase in density was seen in all four cases, which demonstrated a variation from a predominantly alveolar density to an interstitial pattern and finally to increased bronchial markings. Evolution of the radiographic pattern of the pulmonary densities appeared to be related to the time that had elapsed since the bleeding incident. The implications of the changing pattern and site of the densitie...
Renal dysfunction in a case of purpura haemorrhagica. A four-year-old thoroughbred was presented with clinical manifestations of purpura haemorrhagica. Evidence of renal involvement consistent with glomerulopathy and nephrotic syndrome, characterized by heavy proteinuria and azotaemia, became apparent and may have been exacerbated by diuretic therapy. Autopsy revealed membrano- and mesangial proliferative glomerulonephritis and chronic pleuritis. Circulating immune complexes may have been responsible for the renal diseases and the purpura.
Ultrasonic echography in the mare. Ultrasonic echography in the mare allows pregnancy diagnosis as early as Day 14 after ovulation. In the 1980 and 1981 breeding seasons, a total of 7438 examinations of 4688 mares were performed on several farms with the same apparatus. The accuracy of positive pregnancy diagnosis was estimated to be greater than 95% and of non-pregnancy diagnosis greater than 84%. When abnormal pictures of vesicles are found, it has to be decided whether it is a conceptus or a cystic structure. Most small vesicles do not develop, whereas large ones, deformed shapes, presence of some echoes, or a division insid...
Clinical and radiological aspects of stifle bone cysts in the horse. Thirty-three cases with subchondral bone cysts in the stifle are reported. The condition was most commonly seen in young Thoroughbreds and produced intermittent lameness of varying degree. Radiographically distinct areas of radiolucency were found in the distal femur or proximal tibia adjacent to the femorotibial joint. Lesions were usually unilateral but 5 horses had cysts in both stifles. The cases could be divided into 2 distinct groups. Horses in Group A (28 cases) had a large circular or dome-shaped cyst in the medial femoral condyle with a distinct communication with the femorotibial joi...
Assessment of radiographic positioning for the diagnosis of navicular disease in the horse. Three of the standard radiographic views of the navicular bone were assessed in normal horses and horses with navicular disease to determine the most effective radiographic positioning. Using the upright pedal view, a pastern angulation of 20 degrees from the vertical produced the optimum result when radiographs were taken using a grid. The best result using the high coronary view was obtained with an anode-film distance of 1 1000 mm, and a tube-head angle of 50 degrees from the vertical. When the special navicular view described by Morgan was examined, the most satisfactory projection was obt...
Osteochondrosis of the shoulder joint of the horse. Osteochondrosis of the shoulder joint in the horse was diagnosed radiographically in 54 shoulders of 38 horses. Clinical signs were those of an intermittent lameness characterized as a swinging leg shoulder lameness with pain elicited by extension, flexion or abduction of the limb. Diagnosis of shoulder lameness was supported by blocking the shoulder joint with local anesthetics. Radiographic changes consisted of: (1) alteration in the contour of the humeral head and glenoid cavity, (2) periarticular osteophyte formation, (3) sclerosis of the subchondral bone, and (4) bone cyst formation. The ...
Radiographic detection and characterization of palmar lesions in the equine fetlock joint. Subchondral lesions were identified in the distal palmar region of the third metacarpus in 21 fetlock joints of 15 Thoroughbred horses. The lesions were more commonly identified on the lateromedial and flexed lateral projection, with the flexed lateral projection permitting optimal visualization of the lesion. Lesions appeared as poorly marginated, radiolucent defects and were located at the level of the base of the proximal sesamoid bones. The shape and distribution of the radiolucent defects were: crescent, 4; flattened, 4; shallow concavity, 5; deep concavity, 3; oval, 3; and circular, 2. S...