Imaging techniques in horses encompass a range of diagnostic tools used to visualize the internal structures and systems of equine patients. These techniques assist in the diagnosis, monitoring, and treatment planning of various conditions affecting horses. Common imaging modalities include radiography (X-rays), ultrasonography, magnetic resonance imaging (MRI), and computed tomography (CT). Each technique offers unique advantages in terms of resolution, depth of penetration, and the type of tissues that can be examined. For instance, radiography is frequently used for assessing bone structures, while ultrasonography is often employed for soft tissue evaluation. MRI and CT provide detailed cross-sectional images, aiding in the assessment of complex anatomical regions. This page compiles peer-reviewed research studies and scholarly articles that explore the application, advancements, and comparative efficacy of imaging techniques in equine veterinary medicine.
Chalmers HJ, Cheetham J, Yeager AE, Ducharme NG.Nasopharyngeal and laryngeal evaluation is important when examining horses with upper airway signs for poor performance. Currently endoscopy is the most common method to evaluate the equine upper airway. Ultrasonography of the equine larynx has not previously been described. Using six cadaveric specimens and four standing horses, the ultrasonographic appearance of the equine larynx was established. A scanning technique, including useful acoustic windows and the normal ultrasonographic appearance at each site, is described. Ultrasound allowed visualization of portions of the hyoid apparatus, la...
Keys GJ, Berry DB, Pleasant RS, Jones JC, Freeman LE.To describe the vascular distribution pattern of contrast medium during intraosseous regional perfusion (IORP) of the distal portion of the equine forelimb. Methods: 13 cadaveric forelimbs from 12 horses without forelimb diseases. Methods: Serial lateromedial radiographic views were taken of the distal portion of 10 heparinized cadaveric forelimbs at 0, 1, 2, 6, 15, and 30 minutes during IORP of the third metacarpal bone (MCIII) by use of iodinated contrast medium and a tourniquet placed over the proximal portion of MCIII. Vascular regions of interest (ROI) were created for each radiograph. Re...
Weekes JS, Murray RC, Dyson SJ.In recent years, pain arising from the proximal metacarpal and metatarsal regions has become well recognized as a cause of lameness and various disease entities have been identified. However, our knowledge of normal patterns of radiopharmaceutical uptake is limited, making interpretation of images problematic. It is therefore important to characterize normal patterns of radiopharmaceutical uptake at specific sites to ensure valid interpretation of images in clinical cases with subtle lesions. The purpose of this study was to describe the pattern of radiopharmaceutical uptake in the proximal me...
Engeli E, Yeager AE, Erb HN, Haussler KK.The purpose of this study was to establish the normal percutaneous ultrasonographic appearance of anatomic structures within the equine sacroiliac region. Percutaneous ultrasonography was performed in a cranial-to-caudal direction in 10 normal adult live horses. The following structures were examined in detail: supraspinous ligament, lumbar and sacral spinous processes, thoracolumbar fascia and its caudal extension, tubera sacralia, ilial wings, dorsal and lateral portions of the dorsal sacroiliac ligaments, lateral part of the sacrum, and the lateral sacral crest. After ultrasonography, all a...
Ugryumova N, Gangnus SV, Matcher SJ.Polarization optical coherence tomography (PSOCT) is a powerful technique to nondestructively map the retardance and fast-axis orientation of birefringent biological tissues. Previous studies have concentrated on the case where the optic axis lies on the plane of the surface. We describe a method to determine the polar angle of the optic axis of a uniaxial birefringent tissue by making PSOCT measurements with a number of incident illumination directions. The method is validated on equine flexor tendon, yielding a variability of 4% for the true birefringence and 3% for the polar angle. We use t...
Ferrari M, Weller R, Pfau T, Payne RC, Wilson AM.The purpose of this work was to evaluate the accuracy and precision of a freehand three-dimensional (3-D) ultrasonography system in the determination of lesion volume in tendons. The accuracy and precision of a 3-D ultrasonography system was assessed by performing repeated measurements on a phantom of known volume. Volume measurements of tendon lesions performed with 3-D ultrasonography were compared with measurements based on a series of two-dimensional (2-D) ultrasound (US) scans and to direct measurements from dissections. A novel method for the creation of tendon lesions in vitro was devel...
Latorre R, Arencibia A, Gil F, Rivero M, Henry RW, Ramírez G, Váquez JM.To correlate anatomic features of the equine tarsus identified in plastinated sections with images obtained via magnetic resonance imaging (MRI). Methods: 4 horses. Methods: MRI (1.5-Tesla magnet) of the tarsus was performed on the pelvic limbs of 4 clinically normal horses following euthanasia. After imaging, tarsocrural joint spaces and vasculature were injected with colored latex. Sagittal and transverse sections of the tarsi were plastinated to facilitate interpretation of MR images. Results: Relevant anatomic structures were identified and labeled on the plastinated tissue slices and corr...
Sweers L, Carstens A.Two horses with discospondylitis are described with emphasis on the imaging modalities used and their contribution to the final diagnosis and outcome. Radiographic findings were vertebral endplate lysis with sclerosis in both horses, with additional vertebral subluxation and ventral spondylosis in one horse. Ultrasonographic findings included vertebral malalignment and obliteration of the intervertebral disc by spondylotic bone in one horse and irregular endplates, a widened disc space, a hypoechoic paravertebral abscess and hypoechoic, atrophic adjacent musculature with loss of linear fiber p...
Rodríguez MJ, Agut A, Gil F, Latorre R.The minute anatomy of the temporomandibular joint (TMJ) in horses is poorly documented in the literature. Objective: To examine in detail the anatomy of the normal equine TMJ and the relationship of the joint to adjacent structures. Methods: The anatomy of the TMJ was examined in 12 equidae using dissections, synovial and vascular injections and frozen and plastinated sections. Relevant structures were photographed. Results: Rostral and caudal compartments were identified in the dorsal and ventral synovial pouches of the TMJ. Lateral and caudal ligaments were identified and attachments of the ...
Lischer ChJ, Bischofberger AS, Fürst A, Lang J, Ueltschi G.Lameness in horses due to pain originating from the proximal metacarpal/metatarsal region remains a diagnostic challenge. In cases of obvious lameness the pain can be localised to this region by diagnostic anaesthesia. Because a variety of disorders can cause lameness in this region different imaging modalities including radiography, ultrasonography and scintigraphy should be used to arrive at an accurate diagnosis. Even though a precise anatomic-pathologic diagnosis can still be an enigma, because not only bone and joints, but also soft tissue structures including the proximal suspensory liga...
Abutarbush SM.To describe the use of ultrasonography to diagnose large colon volvulus (LCV) in horses. Methods: Descriptive report. Methods: 4 horses with clinical signs of abdominal pain. Methods: Each horse was administered analgesic agents for pain control and placed in stocks. Ultrasonographic evaluations were performed with a 3.5-MHz sector scanning transducer that was placed parallel to the long axis of the horse (longitudinal imaging) over an area of the left ventral aspect of the abdomen. The boundaries of the evaluated region included the ventral midline, 2 vertical lines at the level of the left 1...
Barakzai S, Tremaine H, Dixon P.To describe and analyze subjective and objective scintigraphic findings in horses with paranasal sinus disorders. Methods: Horses with suspected disorders of the paranasal sinuses or cheek teeth (n = 48) and control horses (n = 30). Methods: 99Technetium-methylenediphosphate (99Tc-MDP; 7500 MBq) was administered for scintigraphic examination of the skull. Abnormal patterns of increased radionuclide uptake (IRU) were identified and subjectively described. Scintigrams and radiographs were blindly assessed by 2 clinicians and the accuracy of the imaging modalities was compared. Objective analysis...
Steyn PF, Uhrig J.Bone scintigraphy is often used in horses because of its sensitivity and noninvasive nature. A 99mTc labeled radiopharmaceutical is injected at a dose of between 5.7 and 7.3GBq. Images are acquired immediately postinjection and 2-4h post. People are often in the room with the horse during the acquisition process. Objectives of this study were to (a) document the radiation exposure rates at different distances from various sites of the horse at varying times post injection and (b) study the usefulness of wearing lead aprons to reduce exposure rates to personnel. Radiation exposure rates were me...
Archer DC, Boswell JC, Voute LC, Clegg PD.Gamma scintigraphy is a well established imaging modality, which in equine practice is predominantly used in the investigation of lameness and suspected musculoskeletal problems. Whilst there is a growing literature on the indications for scintigraphy in the horse, there has been little emphasis so far on identifying the validity of scintigraphy as a diagnostic test. In particular, to what extent can the results of a scintigraphic examination be trusted? In this opinionated review the current indications for skeletal scintigraphy in the horse are considered and its validity as a diagnostic tes...
Archer DC, Cotton JC, Boswell JC.Gamma scintigraphy is an established imaging modality in the horse and is principally utilised to investigate skeletal disease using bone-seeking radiopharmaceuticals. However, depending on the radiopharmaceutical and imaging sequence, scintigraphy can be used to investigate disease in virtually any organ system. In this article the indications and validity of scintigraphy as a clinical diagnostic tool to investigate non-skeletal disease in the horse are reviewed. These indications include: investigation of dental disease, identification of inflammatory foci, vascular lesions, muscle and tendo...
Maulet BE, Mayhew IG, Jones E, Booth TM.Radiography is a very important aspect of equine stifle imaging. The precise radiographic anatomy of the soft tissue structures of the equine stifle has not been described previously. Objective: To describe the anatomical relationship between sites of attachment of soft tissue structures of the equine stifle and their locations on standard radiographic views. Methods: The sites of bony attachments of the tendons, ligaments and fibrous portion of the joint capsules of equine stifles were determined by gross dissection. These sites of attachment were transposed onto one set of bones deprived of ...
Verna M, Turner TA, Anderson KL.Nonfocused extracorporeal shock wave therapy (ESWT) treatment protocol is commonly used in veterinary practice. This study investigated the effects of four nonfocused ESWT treatments, given 2 weeks apart, on bone radiopharmaceutical uptake and radiographic and thermographic appearance in the metacarpal and metatarsal regions in six adult untrained horses. There were no measurable treatment effects determined by thermography (daily), scintigraphy (at 2-week intervals), and radiography (before study initiation and at study completion) between treated and control limbs. It was concluded that no g...
Doube M, Firth EC, Boyde A.Combined backscattered electron scanning electron microscopy (BSE SEM) and confocal scanning laser microscopy (CSLM) have been used to put tissue mineralization data into the context of soft tissue histology and fluorescent label information. Mineralization density (Dm) and linear accretion rate (LAR) are quantifiable parameters associated with mineralizing fronts within calcified tissues. Quantitative BSE (qBSE) may be used to determine Dm, while CSLM may be used to detect label fluorescence from which LAR is calculated. Eighteen-month old Thoroughbred horses received single calcein injection...
Solano M, Welcome J, Johnson K.Horses undergoing skeletal scintigraphy can have decreased radiopharmaceutical bone uptake in the limbs. This reduces the diagnostic value of the scan. The aim of the present study was to measure the changes in count density caused by vasodilatation and increased blood flow associated with intravenous injection of acepromazine during bone scintigraphy in normal horses. A three-phase bone scan was performed twice in 11 adult horses to study the effects of acepromazine on the count density of the resultant scintigrams. With acepromazine, there was a statistically significant mean difference of 1...
Bi X, Li G, Doty SB, Camacho NP.The orientation of collagen molecules is an important determinant of their functionality in connective tissues. The objective of the current study is to establish a method to determine the alignment of collagen molecules in histological sections of cartilage by polarized Fourier transform infrared imaging spectroscopy (FT-IRIS), a method based on molecular vibrations. Methods: Polarized FT-IRIS data obtained from highly oriented tendon collagen were utilized to calibrate the derived spectral parameters. The ratio of the integrated areas of the collagen amide I/II absorbances was used as an ind...
Gilger BC, Reeves KA, Salmon JH.To measure the ocular surface area, scleral thickness, and the aqueous and vitreous humor volumes in the canine and equine eye. Animals studied Fourteen canine and 16 equine cadaver eyes. Methods: Eyes were measured either fresh or following fixation in formalin. Ocular surface area was calculated using the fluid displacement method. Globes were hemisected and aqueous and vitreous humor were collected and quantitated. Scleral thickness was measured by digital caliper, by image projection, and by ultrasonic biomicroscopy (UBM). Results: Mean +/- standard deviation (SD) scleral surface areas in ...
Sepulveda MF, Perkins JD, Bowen IM, Marr CM.Doppler tissue imaging (DTI) is a novel noninvasive method by which myocardial velocity can be assessed directly and it allows regional, rather than global, cardiac function to be evaluated. Objective: That regional differences in myocardial velocities exist within the equine ventricle. Objective: To develop a repeatable examination technique for DTI in horses, describe DTI findings in various regions of the normal equine ventricle, compare colour (CDTI) and spectral (SDTI) techniques of DTI, and document regional differences in myocardial velocity. Methods: Five regions of the ventricles (rig...
Firth EC.Detecting changes in bone during growth, training, rest from competition (spelling), and disease in horses requires imaging techniques that have a high level of accuracy and precision. Currently, most imaging techniques used in horses do not possess such characteristics and are more suitable for detecting end-stage disease than subtle changes. Some are incapable of detecting changes in bone size. Non-planar techniques should be used for estimating or determining bone strength. This review outlines available imaging techniques and shows why cross-sectional procedures are required to accurately ...
Ineson AC, Rogers CW, Firth EC, Gee EK.To compare subjective and quantitative methods of assessing physeal swelling of the distal third metacarpal (Mc3) and metatarsal (Mt3) bones of Thoroughbred foals. Methods: The fetlocks of 16 Thoroughbred foals were filmed on five occasions over a period of 5 months and the video images were transferred to computer and digitised. The rate of change of each of the medial and lateral contours of the distal Mc3 and Mt3 bones was determined by calculating values for the second derivative of the contour. The degree of physeal swelling at the same site was subjectively assessed and allocated a grade...
Käfer-Karrer MJ, de Preux M, Van der Vekens E, Mattei LI, Kuhlmann J, Klopfenstein Bregger MD, Easley JT, Koch C.To describe the repair of a fractured cranial articular process (AP) of the sixth cervical vertebra (C6) with cortex screws placed in lag fashion using computer-assisted surgery. Methods: A 12-year-old Swiss Warmblood gelding. Methods: Case report. Methods: The gelding was presented with neck pain and ataxia after a fall. A fracture of the right cranial AP of C6 was identified on radiographs. The fracture was repaired by internal fixation with two 4.5 mm cortex screws of 58 and 48 mm length placed in lag fashion using computer-assisted surgery. Results: During general anesthesia, it was su...
Underberg BA, Kaessmeyer S, Schweizer D, Drews B, Van der Vekens E.The objective of this study was to establish a non-contrast enhanced MR angiography (NC-MRA) sequence for the equine foot (EF) using a post-mortem angiography model. Unassigned: Time-of-flight (TOF) sequences were tested using variable parameter settings and 3 slice orientations during vascular perfusion of frozen-thawed cadaver EF with paraffine oil. Transverse and dorsal orientations were planned perpendicular or parallel to the sublamellar vascular plexus at the dorsal aspect of P3, or approximately perpendicular to the coronary plexus. Visibility of the coronary plexus, sublamellar plexus,...
Nabenishi H, Tsuda T, Omoya Y, Ishii T.This study aimed to detect characteristic changes in the behavior and body surface temperature (BST) of pregnant mares before parturition using camera image analysis. A total of 53 pregnant Thoroughbred mares, which were individually stabled in box stalls, were included in this study. The mares were continuously monitored using a digital camera system comprising a thermal imaging camera and a visible camera. For the automatic determination of the x and y coordinates of each mare, the centroid of the mares was calculated using image processing software. Subsequently, trajectory analysis was per...
Maurer T, de Preux M, Precht C, Vidondo B, Koch C.To assess the accuracy of computer-assisted surgery (CAS) of equine cervical vertebrae using a purpose-built cervical frame (CF) for neck stabilization. Methods: Experimental cadaveric study. Methods: Six whole fresh equine cadavers. Methods: Cadavers were positioned in dorsal recumbency with the neck extended within the CF. A cone-beam computed tomography (CBCT)-based surgical navigation system with optical tracking was used. A ventral approach exposed cervical vertebrae C3-C5. In each cadaver, 12 drill corridors were prepared with the patient tracker on the CF (position CF), followed by 12 c...
Veitch KE, Szczykutowicz TP, Brounts SH, Ergun DL, Muir P, Loeber SJ.To evaluate the radiation dose to personnel locations during simulated head and limb scans with a novel equine standing CT (sCT) system. Methods: Measurements were made with the use of a helical fan beam sCT system (Equina; Asto CT Inc). Scatter radiation was measured in different positions in the sCT room to mimic the location of the control operator, horse handler, and lead rope handler during simulated equine head and limb imaging. Operator/handler dose was quantified at each location using entrance air kerma measured with a spherical ionization chamber and electrometer. Results: Radiation ...
Horne CR, Tufts S.Continual advancements in diagnostic imaging have allowed for more accurate and complete diagnoses of injuries in the performance horse. The use of several different imaging tools has further allowed the equine sports medicine clinician to more carefully direct treatment options, monitor response to therapy and guide rehabilitation recommendations. The advancements in diagnostic imaging and novel treatment options have led to the improvement in the overall prognosis of many injuries that affect the horse and their performance. The purpose of this section is to review the advancements made in d...
Bolz NM, Sánchez-Andrade JS, Torgerson PR, Bischofberger AS.The purpose of the study was to determine the diagnostic performance of computed tomographic arthrography (CTA) and 3-Tesla magnetic resonance imaging (MRI) for detecting artificial cartilage lesions in equine femorotibial and femoropatellar joints. Methods: A total of 79 cartilage defects were created arthroscopically in 15 cadaver stifles from adult horses in eight different locations. In addition, 68 sites served as negative controls. MRI and CTA (80-160 mL iodinated contrast media at 87.5 mg/mL per joint) studies were obtained and evaluated by a radiologist unaware of the lesion distributi...
Tithof PK, Rebhun WC, Dietze AE.A linear array 5 mHz ultrasonic scanner was used to diagnose aorto-iliac thrombosis in a 3 year old Standardbred gelding. There are no reports in the literature of utilization of ultrasonography for visualization of an aortic thrombus. The technique is fairly non-invasive, requiring only a rectal examination with a linear array probe. Arteriography is the only other method described for actual visualization of a thrombus. This procedure is technically difficult and highly invasive.