Topic:Radiology
Radiology for horses involves the use of imaging techniques to diagnose and monitor various conditions affecting equine health. These techniques include X-rays, ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI). Each modality provides different types of information, aiding in the evaluation of musculoskeletal disorders, respiratory issues, and abdominal problems, among others. Radiographic imaging is instrumental in identifying fractures, joint abnormalities, and dental issues. Ultrasound is often used for soft tissue evaluation and reproductive assessments. CT and MRI offer detailed cross-sectional images, enhancing the understanding of complex anatomical structures and pathologies. This page aggregates peer-reviewed research studies and scholarly articles that explore the applications, advancements, and findings in the field of equine radiology.
Generalized medullary infarction of the long bones in a horse. Generalized medullary infarction of the long bones was diagnosed in a 12-year-old Tennessee Walking Horse mare. The mare was referred after a 6-week course of shifting weight on her hind limbs, and kicking. Physical examination revealed mild stifle joint distention and withdrawal reactions to digital pressure over the long bones. Radiography revealed patchy areas of medullary sclerosis in the distal portion of each femur and proximal portion of each tibia. A full-thickness cortical and cancellous tibial biopsy revealed infarcted bone marrow, with cortical and periosteal osteonecrosis. The caus...
Qualitative and morphometric radiographic findings in the distal phalanx and digital soft tissues of sound thoroughbred racehorses. Lameness examinations and radiography of the distal phalanx and associated soft-tissue structures of the front feet of 103 Thoroughbred racehorses, 4 to 9 years old, were performed to determine normal radiographic appearance and morphometry. Of 103 horses examined, 41 were used in the study that were without clinical signs of foot problems or lameness, had raced at least twice prior to radiography, and had raced at least twice more in the 6 months after radiography. Lateromedial and dorsoproximal-palmarodistal radiographic views of each front distal phalanx were used to measure 28 bone and sof...
A retrospective evaluation of laminitis in horses. Case records of 202 horses treated for laminitis were reviewed with the intent of determining the long-term outcome and correlating this with digital radiographic findings and with the degree of pain associated with the laminitis. At long-term follow-up 57 horses had returned to athletic soundness (Group 1), 20 horses were intermittently lame (Group 2), 19 horses had permanent severe lameness (Group 3), 97 were dead (Group 4), and 9 were lost to follow up. Using simple regression analysis, functional outcome did not correlate with the degree of rotation (R2 = 0.004) or the presence of distal d...
Penetrating lingual foreign bodies in three horses. Three horses examined for complaints of ptyalism and dysphagia were found to have metallic lingual foreign bodies. Metallic foreign bodies were located by oral examination combined with radiography. In 1 horse clinical signs resolved without removal of the foreign body. The foreign body was extracted via an oral approach in the second horse; a mandibular symphysiotomy and radiographic guidance were necessary for removal in the third horse. In all 3 cases, the presenting clinical signs subsided.
An investigation of injection techniques for local analgesia of the equine distal tarsus and proximal metatarsus. A positive radiographic contrast agent was injected into the tarsometatarsal (TMT) joints of both hindlimbs of 10 horses. Lateromedial radiographic views were obtained at 5, 15 and 30 mins after injection. Injection was successful in 19 of 20 limbs. Communication between the centrodistal (CD) and TMT joints was identified in 7 limbs (35%). Contrast agent extended around the tendons of tibialis cranialis (TC) and fibularis tertius (FT) in 18 limbs, and in 7 limbs some contrast entered the tarsal sheath. Slight to moderate plantar and/or distal extension of contrast agent was identified in 13 li...
Ultrasonographic and histopathological findings in equine superficial digital flexor tendon injury. The ultrasonographic and histopathological findings in 12 normal and 28 injured superficial digital flexor tendons, with lesions ranging in duration from 2 days to 15 months, were compared. A consistent relationship between the ultrasonographic and histological findings was demonstrated. The echogenicity of lesions, the distinctness of their delineation from the surrounding tissue, and the presence and arrangement of the linear echoes were useful features by which to assess the ultrasonograms. Acute lesions were anechoic, a complex mixture of anechoic and hypoechoic areas, or diffusely hypoech...
Stress reactions and stress fractures of the proximal palmar aspect of the third metacarpal bone in horses: 58 cases (1980-1990). The case records, radiographs, and nuclear bone scans of 58 horses with stress reactions or stress fractures of the proximal palmar aspect of the third metacarpal bone (MC3) were reviewed. There were 47 Standardbreds, 4 Quarter Horses, 3 Thoroughbreds, 2 Arabians, 1 Oldenburg, and 1 Pony of America. Fifty-six of the horses were racehorses or performance horses. The mean and median ages of affected horses were 4 and 3 years, respectively. Lameness ranged from mild to severe. Physical findings were usually subtle and included signs of pain on deep palpation of the proximal palmar aspect of MC3 a...
Obstructive enterolith in an 11-month-old miniature horse. An obstructive enterolith was diagnosed in an 11-month-old 68-kg miniature horse with a 24-hour history of mild, intermittent colic. Abdominal radiography revealed gas distention of the cecum and the right and left ascending colon, and a radiodense elliptical structure in the area of the left kidney. During exploratory laparotomy, the right dorsal colon was noticed to contain ecchymotic hemorrhage and generalized discoloration in the portion proximal to the location of the enterolith. While exteriorizing the ascending colon, it ruptured caudal to the diaphragmatic flexure in the right dorsal c...
Primary pulmonary neoplasm in a horse. A 16-year-old Thoroughbred gelding was evaluated for respiratory disease and found to have a primary lung tumor on postmortem examination. A tentative antemortem diagnosis was made on the basis of results of radiography and cytologic examination of a needle aspirate guided by ultrasonography. A histologic diagnosis of bronchioalveolar adenocarcinoma was made. Thoracic neoplasia is rare in horses. The most frequently reported primary pulmonary tumor is the granular cell tumor.
Epiglottic augmentation by use of polytetrafluoroethylene to correct dorsal displacement of the soft palate in a standardbred horse. A 2-year-old 400-kg Standardbred colt with a history of exercise intolerance was determined to have dorsal displacement of the soft palate (DDSP). Standing endoscopy revealed a soft, flaccid, and hypoplastic epiglottis and arytenoid cartilages that moved symmetrically and abducted fully. Lateral laryngeal radiography was used to calculate a corrected thyroepiglottic length of 6.48 cm. Videoendoscopy during exercise on a high-speed treadmill at standardized treadmill speeds was performed weekly for 3 consecutive weeks. The soft palate dorsally displaced at each examination. A sternohyoideus/ste...
Fractures of the lateral malleolus of the tibia in 16 horses. Clinical and radiological features of 16 horses with fractures of the lateral malleolus of the tibia are reported. The paper describes surgical techniques used, results obtained and discusses justification for removal. Fourteen fractures were unilateral and two bilateral. There was no left:right disparity. The history included a known traumatic incident in 14 cases. All animals had a tarsocrural joint effusion and 10 had palpable thickening of the lateral collateral ligaments. Crepitus was also palpable in 10 horses. The fracture was identified in all dorsoplantar and 14 of 18 dorsomedial-plan...
Prepurchase evaluation of horses: 134 cases (1988-1990). To quantify some components of prepurchase evaluations in horses, records from 134 evaluations performed during a 2-year period were reviewed and the outcome was determined via telephone follow-up interview. Sixty-two percent of the prepurchase evaluations had been performed at the clinic and 38% had been performed in the field by the ambulatory service. All evaluations included physical and lameness examinations, whereas radiography (49%), endoscopy (15%), nerve blocking (5%), transrectal palpation (3%), hematologic analysis (2%), electrocardiography (2%), drug testing for analgesic agents (2...
Treatment of a mandibular bone cyst by use of a corticocancellous bone graft in a horse. A 1-year-old Appaloosa stallion had a mass on the right rostral hemimandible. The mass was firm, did not cause signs of pain, and was identified as a bone cyst by radiography and biopsy. Surgical correction included curettage of the cystic cavity and grafting the defect with both cortical and cancellous bone. By 5 months, the cystic cavity was ossifying; continued remodeling with an increase in bone density was apparent 22 months after surgery.
Thermal injury by in vitro incision of equine skin with electrosurgery, radiosurgery, and a carbon dioxide laser. Freshly harvested equine skin incised with an electrosurgical unit, a radiosurgical device, or a carbon dioxide (CO2) laser was examined by light microscopy to determine the extent of thermal injury caused by each instrument. There was no significant difference between the thermal injury caused by the electrosurgical unit in the pure-cut mode and the CO2 laser in the superpulse mode, or between the electrosurgical unit and the radiosurgical device in the fully filtered cut mode. However, thermal injury caused by the CO2 laser was significantly less than that caused by the radiosurgical device....
Comparison of standard and radionuclide methods for measurement of glomerular filtration rate and effective renal blood flow in female horses. Comparison of standard and radionuclide methods for measuring glomerular filtration rate (GFR) and effective renal blood flow (ERBF) was performed in 8 healthy female horses. Inulin and p-aminohippurate solutions were administered IV as a bolus, followed by sustained administration. Urine and plasma inulin and p-aminohippurate concentrations and urine volume were measured. Glomerular filtration rate and ERBF were calculated on the basis of these measurements. Glomerular filtration rate and ERBF were measured on the basis of plasma clearance of the radiopharmaceuticals, 99mTc-labeled diethylene...
[Typical presentation of the common tendon sheath of the M. flexor hallucis longus and the M. tibialis caudalis in the horse]. The possibilities for imaging soft tissue structures, especially fluid-filled cavities such as articulations, bursae or tendon sheaths, have been improved markedly by sonography in recent years. Ultrasonic examinations were performed on the common tendon sheath of the musculus flexor hallucis longus and the musculus tibialis caudalis, from the medioplantar aspect of the tarsus, in 12 sound adult draft- and warm blood horses, and in 5 animals with a distended common sheath. The diagnostic precision of the sonographic examination of the tendon sheath is excellent and is superior to conventional ...
Radiographic/morphologic investigation of a radiolucent crescent within the flexor central eminence of the navicular bone in thoroughbreds. The source of a previously described radiolucent crescent in the flexor cortex of the distal sesamoid (navicular) bone on the palmaro45 degrees proximal-palmarodistal oblique (Pa45 degrees Pr-PaDio) clinical radiographic projection was investigated in 48 forelimb navicular bones from 24 Thoroughbreds by use of high-detail radiography and x-ray computed tomography (CT). Twenty-five of these bones also were evaluated, using microradiography and histologic examinations. Of these 25 bones, 5 had been labeled in vivo with fluorochrome markers. Tetrachrome-stained 100-microns-thick nondecalcified se...
Fate and effect of autogenous osteochondral fragments implanted in the middle carpal joint of horses. Four autogenous osteochondral fragments removed from the lateral trochlear ridge of the talus were arthroscopically placed as loose bodies in a randomly selected middle carpal joint in each of 10 horses. The contralateral middle carpal joint, subjected to a sham procedure, served as control. Postoperative treatment was consistent with that for clinical arthroscopic patients. Lameness evaluation, radiographic examination, carpal circumference measurement, and synovial fluid analysis were performed before and at scheduled intervals after surgery. After a 2-month confinement, horses were subjecte...
Tubular duplication of the cervical portion of the esophagus in a foal. Tubular duplication of the cervical portion of the esophagus was diagnosed in a 10-day-old female Quarter Horse. The foal was examined because of the development of a 12- to 15-cm diameter mass at the caudal aspect of the mandible after suckling. The foal was dyspneic when in lateral recumbency. Radiography and ultrasonography revealed a fluid- and gas-filled mass. Endoscopy revealed a normal-appearing upper airway and esophagus. Complete surgical resection of the mass was successful. The mass had a 3-mm diameter communication with the esophageal lumen at the pharyngoesophageal oriface. Histol...
Comparison of two grafting methods in 4.0-mm drill defects in the third metacarpal bone of horses. In 6 horses, bilateral metacarpal vertical series of three 4.0-mm unicortical drill holes were made. At random, one of each series of 3 holes was filled using a sternal 4.0-mm cancellous bone cylinder or a slurry of cancellous bone injected into the hole or left as an empty control. All horses had lateral metacarpal xeroradiographs at monthly intervals. Three horses (6 metacarpi) were examined post mortem after 4 months and 3 others after 6 months. Immediate through 4-month post-operative xeroradiographs demonstrated increased density in the holes with cancellous cylinders and no difference co...
Healing of full-thickness cartilage compared with full-thickness cartilage and subchondral bone defects in the equine third carpal bone. The effect of lesion depth on the quality of third carpal bone cartilage repair was examined. A 1-cm diameter articular defect penetrating the calcified cartilage in one limb and the subchondral bone plate in the opposite limb was created in the radial facet of the third carpal bones. Clinical and xeroradiographic examinations were performed every 4 weeks until 4 months (3 horses) and 6 months (3 horses) after surgery. The synovial membrane, non-opposing articular surfaces and articular defects were examined grossly, histologically and histochemically. Grossly, deeper defects contained thicker...
Anaplastic sarcoma in the caudal thigh of a horse. A 16-year-old showjumping gelding was examined because of a non-painful, slowly progressive caudal thigh swelling, which was associated with 2/10th lameness at the trot. Radiography, real time beta-mode ultrasonography and gamma-scintigraphy of the caudal thigh for the presence of chip fractures, sequestrum formation and, or, abscessation were inconclusive. Radiographic examination of the chest revealed multifocal, nodular cannon ball-like opacities throughout the entire lung fields from which a diagnosis of a primary soft tissue tumour with metastasis to the thorax was made. An anaplastic sar...
Radiologic evaluation of the horse relevant to purchase. Adequate radiographic evaluation of the horse relevant to purchase examination requires the successful integration of technique, interpretation, and reporting. A thorough knowledge of lameness and disease can be masked by incorrect interpretation resulting from poor-quality films or an incomplete examination. Thus, care must be taken to produce an adequate number of high-quality films on which to base a report, which allows you to describe changes that are present. This information, coupled with your physical examination, other laboratory data, and the knowledge of the expressed use of the hor...
Can a pelvic fracture in a horse be detected by probe scintigraphy? Pelvic fracture is a relatively common spontaneous fracture in thoroughbred racehorses. Its diagnosis can be difficult, and radiography in the acute phase carries the risks associated with anaesthesia and recumbency. This paper describes the use of a hand-held probe for point counting after the injection of technetium-99m in the investigation of four cases of pelvic fracture. The level of increased uptake of radioactivity was lower (40 to 61 per cent increase) than for distal limb bone fractures.
Equine arch vessel anomaly associated with coarctation of the aorta. Angiography in a 30-year-old man revealed the unique combination of aortic coarctation and an unusual arch anomaly. Proximal to the coarctation, a single arch vessel trifurcated into the brachiocephalic, left common carotid and left subclavian arteries. This anomalous arch vessel is a normal equine variant.
Examination of the upper and lower respiratory tract relevant to purchase. The intent and extent of the respiratory tract examination relevant to purchase are dictated by numerous factors, including historical information, signs suggestive of respiratory tract abnormalities, intended use of the horse, and economic considerations. Following a thorough and systematic examination of the horse at rest, evaluation during and following exercise may be warranted. The physical examination should include evaluation of regional symmetry of the head, neck, and thorax; evaluation of nasal airflow and patency; palpation of the nasal septum, larynx, and trachea; examination for su...