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.
Use of gastrotomy to relieve esophageal obstruction in a horse. Esophageal obstruction of 1 week's duration in a gelding was diagnosed by contrast radiography and esophagoscopy. A food bolus was found at the junction of the caudal thoracic portion of the esophagus and the cardia. A gastrotomy was performed through a cranial abdominal incision and a phytobezoar was manually broken down and removed. The gelding was started on complete pellet food and water on the fifth day after surgery. The horse remained clinically normal more than 1 year after surgery.
Assessment of an immunoturbidimetric method for measuring equine serum haptoglobin concentrations. Serum haptoglobin was measured by immunoturbidity in Thoroughbreds stabled in three Newmarket yards for nine months. The mean serum haptoglobin value for horses housed in Stable 1 was 1.43 +/- 0.68 g/litre, similar to values in grazing adult ponies. The mean monthly haptoglobin values remained constant. For horses in Stable 2 there was an increase in serum haptoglobin values in June and July whereas, in Stable 3, the increases early in the training season were associated with an increase in serum viral titres. In equine serum, haptoglobin values estimated in g/litre by immunoturbidimetry were ...
Proximal suspensory desmitis: clinical, ultrasonographic and radiographic features. Clinical, ultrasonographic and radiographic features of proximal suspensory desmitis in the forelimb and the hindlimb are described. Acute cases may present with slight, localised, oedematous swelling, heat, distension of the medial palmar (plantar) vein and/or pain, whereas chronic cases or those rested immediately after onset of lameness usually have no detectable clinical signs suggestive of the source of pain. In these cases local analgesia is required to identify pain in the proximal metacarpal (metatarsal) region. Transverse ultrasonographic images of the suspensory ligament usually yiel...
[Soft tissue lesions of the equine carpus: roentgenological and echographic studies]. Common soft tissue disorders of the equine carpus are fluctuating or firm soft tissue swellings, wounds and draining tracts. Survey radiography may show the size, position and origin of the swellings and reveals soft tissue calcification, accumulation of air and radiopaque foreign material. Contrast radiography enables accurate visualization of the size, shape, position and origin of fluctuating soft tissue swellings, demonstrates abnormal intersynovial communication and allows precise demonstration of the extent of puncture wounds and draining tracts. Ultrasonography allows differentiation be...
Anatomical validation of two-dimensional echocardiography in the horse. This study was performed on 15 horses to validate the cardiac anatomy as imaged with two dimensional echocardiography (2DE) and to determine the accuracy of intracardiac measurements. 2DE images were recorded in five horses in life with a Diasonics DRF100 ultrasound system and a 3.5 MHz transducer in different tomographic planes. After slaughter, the hearts were fixed in 10 per cent formalin. To compare in vivo and in vitro results, the specimens were suspended in a water-filled tank and 2DE images were made using the same transducer positions as in life. In vitro 2DE and autopsy measurements ...
An investigation of the second heart sound in the normal horse. The second heart sound was evaluated in conscious, normal horses using intracardiac and external sound detection devices and echocardiography. The second heart sound (S2) in the normal horse is single or split by a narrow interval, not usually detected by external phonocardiographic evaluation. Splitting of S2 was classified as normal (aortic [A2] preceding pulmonic [P2] components) in 66.7 per cent and reversed (P2 preceding A2) in 33.3 per cent of the horses studied. Normal splitting appears to result from lower impedance of the pulmonary vasculature delaying the onset of P2. Reverse splitti...
Problem wounds of the horse. Three clinical cases are presented to illustrate some of the problems that may complicate the treatment of wounds in horses. The three examples are a lower limb laceration, a chronic draining chest wound, and complications associated with a fiberglass cast. The use of ancillary diagnostic aids such as arthrocentesis, diagnostic nerve blocks, radiographs, and ultrasonography are indicated to assess change to deeper structures.
Transendoscopic Nd:YAG laser surgery for treatment of epiglottal entrapment and dorsal displacement of the soft palate in the horse. Transendoscopic neodymium:yttrium-aluminum-garnet (Nd:YAG) laser was used to treat 12 standing horses with epiglottic entrapment (EE) or dorsal displacement of the soft palate (DDSP), or both. In four horses, transendoscopic laser staphylectomy was performed. The most common presenting complaints were respiratory stridor, cough, and exercise intolerance. Ten horses with EE healed without epiglottic complications; in one horse, partial adhesion of the aryepiglottic fold to one side of the epiglottis was corrected surgically through a laryngotomy incision. One horse with DDSP had no further sign...
Atelectasis causes gas exchange impairment in the anaesthetised horse. The anatomical basis of gas exchange impairment in the anaesthetised horse was studied by computerised tomography (CT; three shetland ponies) and morphological analysis (one pony and three horses). By means of CT, densities were seen in dependent lung regions early during anaesthesia, both with spontaneous breathing and with mechanical ventilation. The densities remained for some time where they had initially been created when the animal was turned from dorsal to sternal recumbency. Deep insufflation of the lungs reduced the dense area. Gas exchange was impaired roughly in proportion to the de...
[Radiographic diagnosis of abdominal diseases in foals and ponys. II. Pathologic findings in 60 cases]. A diagnostic approach based on clinical and radiographic examinations for evaluation of young foals and small ponies with acute abdominal discomfort is presented. Standing right to left lateral abdominal radiographs were taken of 54 foals and 6 ponies using a previously described technique. Interpretation of the radiographs was in conjunction with all clinical and laboratory findings and patient management. Using this approach, the site and cause of acute abdominal discomfort could be diagnosed accurately in 55 of 60 (91%) patients as confirmed by clinical, surgical or necropsy findings. Typic...
[Sonographic diagnosis of early pregnancy in horses, cattle, sheep, goats, swine, dogs and cats. Standard values and limitations]. Ultrasonography allows early and reliable pregnancy detection in several domestic animals. Transrectal sonography can be recommended in horses and cattle, transrectal or transcutaneous procedures in sheep, goats and pigs while transcutaneous ultrasound scanning is appropriate in dogs and cats. Three periods of time can be distinguished in the diagnosis of early pregnancy by ultrasound: the earliest phase, where signs of pregnancy can be found in some cases, but accuracy of diagnosis is very low; the succeeding period, where reliable diagnosis is possible, but results are often difficult to ach...
Ultrasonographic findings in horses with cholelithiasis: eight cases (1985-1987). Cholelithiasis and/or obstructive biliary tract disease was diagnosed ultrasonographically in 8 horses, 5 to 15 years old. Ultrasonographic findings revealed greater than normal amount of hepatic parenchyma in the right side of the abdomen in 8 horses and in the left side in 3 horses. The echogenicity of the liver was greater than normal, and thick distended bile ducts were seen in all horses. Choleliths were imaged ultrasonographically in 6 horses. Subsequently, postmortem findings in 6 horses revealed periportal and intralobular fibrosis, moderate bile duct dilatation, proliferation, and cho...
[X-ray diagnosis of abdominal diseases in foals and ponies. I. Technics and normal findings]. Clinical examination of foals and small ponies with abdominal disorders is limited by the inability to perform rectal palpation. In these patients, radiographic evaluation of the abdomen may contribute to the clinical diagnosis and may help to localize the site of abdominal diseases. The technique for lateral standing survey and contrast radiography of the abdomen in foals and the normal radiographic anatomy are described.
Pleuroscopic diagnosis of disseminated hemangiosarcoma in a horse. A 7-year-old Thoroughbred mare was examined because of persistent bilateral epistaxis and respiratory distress. Evidence of bilateral pleural effusion was found during physical examination, and a large amount of serosanguineous fluid was drained from the right side of the thorax. Cytologic examination and bacteriologic culture of the transtracheal aspirate and pleural fluid did not yield evidence of sepsis. A coagulation profile was unremarkable. Radiographic and echographic changes were seen in the lung parenchyma. Pleuroscopy, with the horse standing, revealed numerous dark nodules on the pl...
Effect of intestinal resection on two juvenile horses with granulomatous enteritis. Two horses were presented with lethargy, weight loss, anorexia, and swelling of the limbs and ventral body wall. One horse, a 12-month-old American Paso Fino colt, also had acute abdominal pain. The other horse, a seven-month-old Tennessee Walking Horse (TWH) filly passed diarrheic stools during the initial examination. Each horse had low serum protein, neutropenia, and a normal packed cell volume (3.2 g/dl, 1300 cells/ul, and 38%, respectively, for the colt, and 2.4 g/dl, 696 cells/ul, and 44%, respectively for the filly). After intravenously administering plasma, the colt's PCV dropped to 23...
Pulse oximetry in horses. The clinical usefulness of two pulse oximeters was evaluated at two probe sites in nine anesthetized horses. The hemoglobin saturation determined by the pulse oximeters (SaOx) was compared with the hemoglobin saturation calculated from the measured arterial oxygen tension (SaO2). The mean and standard deviation (SD) were calculated from the differences in saturation measurements, over the saturation range of 80% to 100%, for each oximeter used at the tongue probe site and for one oximeter used at the ear. The oximeter results tended to underestimate the SaO2 with mean differences of -3.7% on t...
Fractures of the accessory carpal bone in the horse. The clinical signs and radiographic appearance of 19 cases of fracture of the accessory carpal bone of horses are described. In 17 cases the fractures were in the frontal plane and occurred palmar to the groove on the lateral aspect of the bone. In six cases radiographs taken six months to three years after the fracture occurred showed no evidence of bony union; nevertheless, these and five other horses for which follow-up information was available for up to seven years all became sound, and seven of them returned to competitive activity.
Radiology in racetrack practice. This article focuses on the principles involved in making radiographs of equine limbs; understanding radiographic anatomy, including normal variations; and principles of radiographic interpretation. The influence of pathogenesis of disease on the radiographic image is considered. Diseases associated with racing as well as the developing racehorse are discussed.
[Ovarian structure and function in the mare from the clinical viewpoint with special regard to ultrasonography]. Ultrasonography is a good means of monitoring follicular development in the mare and allows objective observation and measurement of follicular growth as well as identification of corpora lutea and hematoma in the ovary. The significance of ultrasonography in this field lies in the specific anatomical structure of the mare's ovary and the different phenomena preceding and accompanying ovulation, which are described in this paper. The last part deals with the handling and use of ultrasonography.
Changes in accessory sex glands of stallions after sexual preparation and ejaculation. Ultrasonographic images of the accessory sex glands of 8 stallions were recorded immediately prior to sexual preparation, immediately after sexual preparation, and immediately after ejaculation. Relative size changes, determined by measurements of ultrasonograms of accessory sex gland, were contrasted. Length and width of the bulbourethral glands increased significantly (P less than 0.05) after sexual preparation and decreased significantly (P less than 0.05) after ejaculation. The increase in bulbourethral gland volume following sexual preparation was correlated significantly (P less than 0.0...
Correlation between radiographic and arthroscopic findings in the equine carpus. The radiographic and arthroscopic findings in 150 carpal joints in 114 lame horses were compared. Chip, slab, or sagittal fractures were identified in 130 (87%) joints. In 101 (78%) of these there was good agreement between radiographic and arthroscopic findings on the number and position of fractures. In 23 (18%) joints, chip fractures additional to those seen radiographically were found arthroscopically. In one joint a large chip fracture from the craniolateral aspect of the distal radius was identified only by arthroscopy, while in 6 joints fractures were identified only by radiography. Obs...
Ultrasound as an aid to diagnosis of granulosa cell tumour in the mare. The ultrasonic appearance of seven cases of granulosa cell tumour is described, and compared with an ovarian haematoma and an ovarian serous cystadenoma. The granulosa cell tumours varied from being uniformly dense to having one or several large fluid filled cysts. Some tumours resembled the haematoma or cystadenoma and also, in some aspects, normal ovarian structures such as corpora haemorrhagica or follicles in early pregnancy. There was no typical ultrasonographic appearance of the granulosa cell tumours which enabled definitive diagnosis. However, ultrasound may be a diagnostic aid when us...
Arthrography of the equine shoulder joint. Techniques and normal radiographic anatomy for positive and double contrast shoulder arthrography in horses were evaluated. General anaesthesia was used for most radiographic projections of the shoulder. The mediolateral projection provided the most information during arthrography, although the supinated mediolateral view occasionally allowed better definition of the cartilage surfaces on the medial aspects of the humeral head. The craniocaudal mediolateral oblique and caudocranial projections provided limited additional information. Water soluble non-ionic contrast agents, such as metrizamide...
Local anesthetics and nuclear medical bone images of the equine fore limb. The effects of two local anesthetic agents on the diagnostic quality of nuclear medical bone images (NMBIs) of distal parts of the equine fore limb were investigated. Local effects on bone uptake of technetium 99m methylene diphosphonate (99mTc-MDP) 4 and 24 hours after perineural and intraarticular injection of mepivacaine hydrochloride and bupivacaine hydrochloride were evaluated in the carpal and metacarpophalangeal regions of 12 horses and ponies. Neither mepivacaine hydrochloride nor bupivacaine hydrochloride significantly altered the diagnostic quality of the NMBIs. The injection and sub...
Diagnostic ultrasonography for evaluation of cryptorchidism in horses. The location and size of 11 retained testes were accurately determined ultrasonographically. There was 100% correlation between the location of the testis determined by ultrasound vs that determined by surgery. Testicular size determined presurgically in all cases closely approximated the actual size obtained by gross measurement of the excised testis. The cryptorchid testicular echotexture was less dense than that of the normal descended testicles, but was easily identified. Ultrasonographic evaluations were completed by use of an ultrasound base unit with attached 5-MHz transrectal transduce...
Investigations of the horse conceptus via magnetic resonance imaging (MRI) and nitroxide spin labels as contrast agents. Results are presented which illustrate the usefulness of Magnetic Resonance Imaging as applied to the study of living embryos. Nitroxide spin labels were employed as contrast agents to study the structure and properties of the embryos. These spin labels offer the additional advantage that they may potentially be bound to biologically important molecules thereby imparting the ability to produce contrast in the MR images to these new molecules. The horse conceptus was chosen over other embryos due to its large size. Whereas the embryos of cattle and swine are sub-millimetre in size, the horse co...
In vitro ultrasonographic appearance of the normal and verminous equine aorta, cranial mesenteric artery, and its branches. Ninety-one equine aortic and cranial mesenteric arterial segments were evaluated ultrasonographically in a water bath. On the basis of pathologic evidence of verminous arteritis, arterial segments were classified into 4 categories, and the ultrasonographic characteristics of each group were evaluated. Normal arteries (class 1) were ultrasonographically characterized by a smooth luminal surface layer and uniform wall thickness and echogenicity. Arteries with only histopathologic evidence of verminous arteritis (class 2) were ultrasonographically characterized by a smooth luminal surface layer, ...