Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic tool used in veterinary medicine to obtain detailed images of the internal structures of horses. It utilizes strong magnetic fields and radio waves to create cross-sectional images, allowing for the examination of soft tissues, bones, and joints without the need for radiation. MRI is particularly useful for diagnosing conditions in areas that are challenging to assess with other imaging modalities, such as the hoof, distal limb, and head. This page compiles peer-reviewed research studies and scholarly articles that explore the application, techniques, and advancements in MRI technology for equine diagnostics, as well as its role in improving the understanding of equine anatomy and pathology.
Branch MV, Murray RC, Dyson SJ, Goodship AE.Osteoarthritis (OA) is a common cause of distal tarsal pain, but disease development is poorly understood. Awareness of normal tarsal structure and function is important in order to understand the pathogenesis of OA. Thickening of the subchondral bone (SCB) plate has been related to the development of OA, but SCB plate patterns in the equine tarsus have not been documented. Objective: There is a repeatable pattern of SCB thickness across the distal tarsal joints, and specifically that thickness would be greatest dorsally and laterally. Methods: Twenty cadaver tarsi were collected from mature h...
Dyson SJ, Murray R, Schramme MC.The diagnosis of foot-related lameness often remains elusive and it can be difficult to offer rational treatment, or to predict outcome. Objective: To describe the spectrum of injuries of the foot identified using magnetic resonance imaging (MRI), to determine their relative prevalence among MRI diagnoses and to establish the long-term results of treatment. Methods: The MR images of horses examined from January 2001--December 2003 were reviewed. Horses were selected for MRI if the pain causing lameness was localised to the foot using perineural analgesia but any clinical, radiological or ultra...
Zubrod CJ, Farnsworth KD, Tucker RL, Ragle CA.We describe the clinical, imaging, and necropsy findings of two horses with severe injury of the collateral ligaments of the distal interphalangeal (DIP) joint diagnosed using magnetic resonance (MR) imaging. In MR images it was possible to examine the collateral ligaments of the DIP joint from the origin at the middle phalanx to the insertion on the distal phalanx. Both horses in this report had abnormal high signal intensity within the collateral ligaments of the DIP joint, and one horse had abnormal high signal intensity within the bone of the distal phalanx on short tau inversion recovery ...
McKnight AL, Manduca A, Felmlee JP, Rossman PJ, McGee KP, Ehman RL.Magnetic resonance imaging (MRI) of the distal extremities of the standing, sedated horse would be desirable if diagnostic quality images could be obtained. With the availability of extremity and special purpose magnet designs on the market, a system to safely accommodate the standing horse may gain increasing popularity. This paper considers the issue of motion that will need to be addressed to achieve successful, diagnostic quality images. The motion of the carpus and tarsus of five standing, sedated horses was quantified. The obtained motion records were then used to induce motion in cadave...
Hevesi A, Stanek Ch, Garamvolgyi R, Petrasi Z, Bogner P, Repa I.Magnetic resonance imaging (MRI) was tested for evaluation of the soft tissue structures of the equine digit in 16 limbs, derived from three adult warmblood horses and two newborn warmblood foals. The following measuring sequences were used in sagittal, transversal and coronal planes: spin echo, gradient echo, inversion recovery. The images were made with a 1.5 Tesla Siemens scanner in a CP-Helmholtz circular coil. To compare the visualization of the same tissue structures in adult and in newborn cases the limbs were imaged with the routinely used MRI sequences that are used for mature tissues...
Busoni V, Snaps F, Trenteseaux J, Dondelinger RF.The purpose of this study was to describe the normal magnetic resonance (MR) imaging characteristics of the palmar structures of the equine podotrochlear apparatus by means of retrospective evaluation of MR imaging studies of 16 cadaver limbs. The articular aspect of the distal sesamoid bone was not evaluated in this study. Equine digits were imaged with a human knee radiofrequency coil in a 1.5 T magnetic field, using spin echo (SE) T1-weighted, turbo spin echo proton density (TSE PD)-weighted with and without fat saturation (FS), and FS TSE T2-weighted sequences. The limbs were dissected aft...
Audigié F, Tapprest J, George C, Didierlaurent D, Foucher N, Faurie F, Houssin M, Denoix JM.The purpose of this paper was to correlate the magnetic resonance imaging (MRI) characteristics of a mature brain abscess in a horse with histopathologic alterations of brain tissue. Eight months after the onset of clinical signs, MRI of the brain of a 10-month-old filly was performed. A large space-occupying lesion in the right cerebral hemisphere was identified. This space-occupying lesion was delineated by a thick and well-defined capsule that was isointense to brain parenchyma on the T1-weighted images and with a markedly hypointense on the T2-weighted images. The identification of such a ...
Zubrod CJ, Schneider RK, Tucker RL.Four horses were examined because of chronic forelimb lameness. In all horses, the cause of the lameness was localized to the metacarpus by means of physical examination and diagnostic anesthesia, and radiography of the affected limb revealed a small exostosis of the second metacarpal bone. Magnetic resonance imaging revealed suspensory desmitis in the region of this exostosis in all 4 horses. In addition, an abnormal area of low signal intensity, suggestive of an adhesion, was seen between the exostosis and the suspensory ligament. In all horses, an adhesion between the suspensory ligament an...
Murray RC, Roberts BL, Schramme MC, Dyson SJ, Branch M.Injury of the distal aspect of the deep digital flexor tendon (DDFT) is a recognized cause of lameness, but diagnosis is difficult. This study aimed to improve understanding of DDFT morphology and pathology using retrospective evaluation of magnetic resonance (MR) images. We hypothesized that: (1) The distal aspect of the DDFT in normal horses would have a repeatable proximal/distal pattern and symmetry between limbs and between lobes; (2) DDFT dimensions would be related to bodyweight, navicular bone dimensions and hoof size; (3) this symmetry and pattern would be lost in DDFT injury; and (4)...
Dyson SJ, Murray R, Schramme M, Branch M.There have been no previously published case series of horses examined using either scintigraphy or MRI to diagnose collateral ligament injuries not detectable using ultrasonography or radiography, nor have other concurrent soft tissue lesions been described. Objective: To describe the clinical features of horses with desmitis of the collateral ligaments of the distal interphalangeal (DIP) joint and to evaluate the results of radiographic, ultrasonographic, scintigraphic and magnetic resonance imaging (MRI) examinations. Methods: Horses were examined between January 2001 and January 2003 and w...
Anastasiou A, Hall LD.Cramer-Rao theory and computer simulations were used to show that the errors involved in calculating the magnetization and relaxation parameters of a two-component system decrease with: (1) increasing SNR, (2) increasing number of echoes used in the fitting procedure, and (3) increasing ratio of the relaxation times of the two components, T(22)/T(21). Images of bi-compartmental phantoms of known T(2) values were acquired using an optimized imaging sequence, and an optimized fitting algorithm was used to calculate the T(2) values of the two components by fitting the resulting images to a bi-exp...
Zubrod CJ, Schneider RK, Tucker RL, Gavin PR, Ragle CA, Farnsworth KD.To assess the use of magnetic resonance (MR) imaging for identifying subchondral bone damage in the distal limbs of horses. Methods: Retrospective study. Methods: 11 horses. Methods: Medical records of horses with lameness and subsequent evidence of subchondral bone damage as determined by MR imaging were reviewed. Severity and duration of lameness, results of diagnostic local anesthesia and diagnostic testing, surgical and necropsy findings, and treatment were recorded. Outcome was determined by follow-up information obtained from the owner or referring veterinarian. Results: Lameness was loc...
Murray RC, Dyson SJ, Schramme MC, Branch M, Woods S.Chronic laminitis is a severe disease affecting the equine digit. It was hypothesized that magnetic resonance (MR) imaging would improve visualization of structures within the foot and pathology associated with chronic laminitis. This study aimed to describe the MR imaging findings in chronic laminitis, compare different pulse sequences for visualization of pathology, and to compare MR imaging with standard radiography. Twenty (10 forelimb, 10 hindlimb) cadaver limbs from 10 horses clinically diagnosed with chronic laminitis (group L) and 10 limbs without laminitis (group N) were used. Laterom...
Dyson S, Murray R, Schramme M, Branch M.The differential diagnosis of foot pain has long proved difficult and the use of magnetic resonance imaging (MRI) offers the opportunity to further the clinical understanding of the subject. Objective: To determine the incidence of deep digital flexor tendon (DDFT) injuries in a series of 75 horses with lameness associated with pain localised to the digit, with no significant detectable radiographic or ultrasonographic abnormalities, using MRI; and to describe a variety of lesion types and relate DDF tendonitis with anamnesis, clinical features, response to local analgesic techniques and nucle...
Nollet H, Van Ham L, Verschooten F, Vanderstraeten G, Deprez P.To determine the usefulness of magnetic motor-evoked potentials (MMEPs) for assessing the integrity of the cervical, thoracic, and thoracolumbar spinal cord in horses with bilateral hind limb ataxia. Methods: 9 horses and 1 donkey with bilateral hind limb ataxia of various degrees. Methods: The motor cortex was stimulated magnetically, and MMEPs were recorded bilaterally from the extensor carpi radialis and cranial tibial muscles. Results: In 5 horses and 1 donkey, MMEPs with normal onset latencies and peak-to-peak amplitude were recorded from the extensor carpi radialis muscles, whereas abnor...
Anastasiou A, Skioldebrand E, Ekman S, Hall LD.The distal row of carpal bones (C2, C3, and C4) from eight left intercarpal joints--four from Standardbred Trotters and four from Swedish Warmblood horses--were used to assess the potential of magnetic resonance (MR) imaging to detect cartilage and bone lesions. The joints used in the study were classified by macroscopic and radiographic examinations as having normal, mild, moderate, or severe articular cartilage lesions and bone sclerosis. Those classifications correlated well with the appearance of the MR images. Bone sclerosis in the MR images was observed as regions of decreased signal int...
Dyson S, Marks D.New information about foot anatomy, effects of local analgesia, and advances in diagnostic imaging (ultrasonography, nuclear scintigraphy, MRI, CT, and endoscopy) has opened the way for more specific diagnoses of lameness. New questions have been raised, however, and some older ideas are now in doubt. This article discusses some of these findings in the light of our own clinical experiences as they relate to diagnosis of the causes of foot pain.
Tapprest J, Audigie F, Radier C, Anglade MC, Voisin MC, Foucher N, Collobert-Laugier C, Mathieu D, Denoix JM.In humans, magnetic resonance (MR) imaging is the method of choice for the diagnosis of stress fractures. In this paper, bilateral stress fracture of the lateral condyle of the third metacarpal bone in a French trotter is described. Results of the radiographic, MR imaging, and histologic examinations are presented, with a focus on the MR signal abnormalities found. Based on this patient, the potential use of MR imaging for the diagnosis of stress fractures in horses is discussed.
Spoormakers TJ, Ensink JM, Goehring LS, Koeman JP, Ter Braake F, van der Vlugt-Meijer RH, van den Belt AJ.The occurrence of unexpectedly high numbers of horses with neurological signs during two outbreaks of strangles required prompt in-depth researching of these cases, including the exploration of magnetic resonance imaging (MRI) as a possible diagnostic technique. Objective: To describe the case series and assess the usefulness of MRI as an imaging modality for cases suspected of space-occupying lesions in the cerebral cavity. Methods: Four cases suspected of suffering from cerebral damage due to Streptococcus equi subsp. equi infection were examined clinically, pathologically, bacteriologically...
Dyson S, Murray R, Schramme M, Branch M.Foot pain is a common cause of equine lameness and there have been significant limitations of the methods available for the diagnosis of the causes of foot pain (radiography, nuclear scintigraphy and ultrasonography). Until recently, magnetic resonance imaging (MRI) in the horse has been limited to examination of cadaver limbs. Objective: Our purpose was to 1) describe MRI of the foot in live horses, 2) describe MRI findings in horses with foot pain in which a definitive diagnosis could not be established by alternative means and 3) correlate MRI findings with other methods of clinical investi...
Ferrell EA, Gavin PR, Tucker RL, Sellon DC, Hines MT.Magnetic resonance (MR) imaging was used as a neurodiagnostic modality in the assessment of 12 horses with neurologic disease localized cranial to the foramen magnum. This retrospective study included a mixed population of horse breeds and consisted of three foals and nine adult horses. MR sequences of the head and central nervous system of each horse were acquired. Routine MR sequences included transverse T1 weighted (T1wt), T2 weighted (T2wt), and proton density images. Additional imaging sequences were obtained on a patient-dependent basis. Eight neurologic related diseases were diagnosed. ...
Walker AM, Sellon DC, Cornelisse CJ, Hines MT, Ragle CA, Cohen N, Schott HC.A retrospective study of the medical records of 33 horses was performed to determine the clinical and diagnostic abnormalities associated with temporohyoid osteoarthropathy. Data collected from medical records included signalment, presenting complaints, history, physical examination findings, laboratory data, results of diagnostic imaging studies, and treatments. Follow-up information was obtained from a review of case records; by telephone conversation with the owner, veterinarian, or trainer; or by both methods. Of 33 horses with temporohyoid osteoarthropathy, 29 presented with facial nerve ...
Busoni V, Snaps F.Ten normal equine isolated limbs were imaged using a knee coil in a 1.5 Tesla magnetic field, with short echo time sequences (TE < 15 ms). Magnetic resonance imaging was performed on each isolated limb in different positions, with and without extension of the metacarpophalangeal joint. Deep digital flexor tendon orientation ranged from 20 to 60 degrees in relation to the static magnetic field. Increased intratendinous signal intensity was observed when the angle between the deep digital flexor tendon and the constant magnetic field approached 55 degrees ("magic angle"). The increa...
Kasashima Y, Kuwano A, Katayama Y, Taura Y, Yoshihara T.Six live horses with various stages of acute to chronic superficial digital flexor (SDF) tendinitis were examined using magnetic resonance imaging (MRI). In each case, MRI findings were compared to the corresponding ultrasonographic (USD) and histologic findings, to establish the usefulness of MRI. In the acute cases, lesions characterized by hemorrhage were well defined as high signal intensity on MRI and hypoechoic regions on USD. Chronic tendon fibrosis was slightly hyperechoic and difficult to distinguish from the normal tendon tissue around the original injury by using USD. In contrast, M...
Nollet H, Deprez P, Van Ham L, Verschooten F, Vanderstraeten G.The aim of this study was to investigate the use of magnetic motor evoked potentials as an ancillary diagnostic test in horses with cervical cord lesions. Transcranial magnetic stimulation was performed in 12 ataxic horses and the results of the evoked responses were compared to those found in normal horses. The latency and peak-to-peak amplitude of the potentials in the 12 ataxic horses were significantly different from those measured in normal horses. The configuration of the abnormal potentials was also polyphasic. Normalisation of the evoked potentials occurred in none of the horses, prese...
Tomlinson JE, Sage AM, Turner TA, Feeney DA.To map the equine pelvis using ultrasonography, validated by use of computed tomography (CT), magnetic resonance imaging (MRI), and measurements of frozen cadaver slices. Methods: 6 ponies and 6 horses. Methods: Ultrasonographic examination of the pelvis was performed on 6 clinically normal ponies. Measurements were obtained for imaged structures. Computed tomography, MRI, and measurements of frozen sections were performed after death and used to verify measurements. Linear regression determined the degree of correlation between measurements obtained ultrasonographically and the other modaliti...
Arencibia A, Vazquez JM, Ramirez JA, Ramirez G, Vilar JM, Rivero MA, Alayon S, Gil F.The purpose of this investigation was to define the magnetic resonance (MR) imaging appearance of the brain and associated structures of the equine head. MR images were acquired in oblique dorsal (T2-weighted), sagittal (T1-weighted), and transverse planes (T2-weighted), using a magnet of 1.5 Tesla and a human body coil. Relevant anatomic structures were identified and labeled at each level. The resulting images provided excellent anatomic detail of the cranioencephalic structures. Annotated MR images from this study are intended as a reference for clinical imaging studies of the equine head, ...
Gray LC, Magdesian KG, Sturges BK, Madigan JE.A two-month-old Appaloosa colt developed neurological signs shortly after birth involving deficits affecting cranial nerves IV, VII, VIII, IX, X and XII, and possibly nerve VI. The most likely differential diagnoses were congenital anomalies, meningoencephalitides, trauma or nutritional causes. The foal was investigated by the analysis of cerebrospinal fluid (CSF), electromyelography (EMG), brain auditory evoked responses, magnetic resonance imaging (MRI), peripheral nerve biopsy, and Western blot analysis for the presence of intrathecal antibodies to Sarcocystis neurona, the causative agent o...
Sanders SG, Tucker RL, Bagley RS, Gavin PR.Magnetic resonance imaging (MR) was used to make a diagnosis of equine nigropallidal encephalomalacia in a horse. Equine nigropallidal encephalomalacia is a neurodegenerative disease that has many characteristics with Parkinson-like diseases in humans. Historically, horses were euthanized based on clinical signs and exposure to the toxic weed, yellow star thistle (Centaurea solstitialis). Previously, the disease has only been confirmed on necropsy. MR imaging can provide accurate and sensitive visualization of typical lesions seen in the brain of horses affected with equine nigropallidal encep...
Fairburn AJ, Sherlock CE, Mair TS.Radiography is a standard diagnostic test for horses with suspected fractures of the palmar/plantar processes (PP) of the distal phalanx, however published studies evaluating the diagnostic utility for radiography are currently lacking. The objectives of this retrospective, diagnostic case-control study were to determine the sensitivity of radiographs for the detection of PP fractures, and determine the diagnostic utility of the palmar/plantar oblique projections of the PP for the identification of PP fractures compared to standard radiographic series. The medical records of horses undergoing...
Louie EW, Streeter R, Story M, Scrivani PV, Barrett M, Mullen KR.A neonatal Dutch Warmblood colt was evaluated for inability to stand, incoordination and intention tremor. Despite partial improvement in clinical signs during the first 4 days of hospitalization, neurological deficits remained. Magnetic resonance imaging identified a unilateral infratentorial arachnoid cyst-like lesion with ipsilateral compression and displacement of the cerebellar hemisphere, absent corpus collosum, polymicrogyria, suspect leukoencephalopathy, and noncompressive occipitoatlantal malformation. Improvement in clinical signs during the first 6 months of life suggests that ho...
Gerlach K, Mader D, Delling U, Theuß T, Müller K, Offhaus J, Berner D.The aim of the present study was to verify the diagnostic validity of low-field magnetic-resonance-imaging (MRI) findings in septic diseases of the foot region following penetrating sole injuries caused by nails. Methods: MRI examinations were performed in 10 horses with injuries in the foot region. The diagnostic findings were validated by conventional methods (clinical, surgical, radiological, sonographic, and computed tomographic findings and/or post-mortem histological examination). Results: Navicular bone involvement was revealed most accurately, with a high degree of predictability, and ...
Madsen LM, Gutierrez-Nibeyro SD, Stewart MC, McCoy AM, Schaeffer DJ.To determine the stance duration and ground reaction forces (GRF) of horses with deep digital flexor (DDF) tendinopathy at the level of the foot and compare the stance duration and GRF to those of clinically sound horses. Unassigned: Prospective clinical study. Unassigned: Sixteen horses (seven horses with bilateral forelimb lameness, four horses with unilateral forelimb lameness, and five horses with no lameness). Unassigned: Analyses of kinetic variables were performed on both forelimbs from sound horses and horses diagnosed with chronic DDF tendinopathy. Stance duration and longitudinal and...
Trolinger-Meadows KD, Biedrzycki AH, He H, Werpy N.The use of magnetic resonance imaging (MRI) has led to increased clinical and research applications using 3D segmentation and reconstructed volumetric data in musculoskeletal imaging. Lesions of the deep digital flexor tendon (DDFT) are a common pathology in horses undergoing MRI. Three-dimensional MRI reconstruction performed for volumetric tendon analysis in horses has not previously been documented. The aim of this proof-of-concept study was to evaluate the 3D segmentation of horses undergoing repeated MRI at several time points and to perform an analysis of the segmented DDFTs across time....
Warnock WR, Marsh CA, Hand DR.The purpose of this study was to report long-term outcome following arthroscopic debridement of articular cartilage lesions of the distal interphalangeal joint, diagnosed with high-field magnetic resonance imaging. Diagnosis was based on the results of diagnostic anesthesia, magnetic resonance imaging (MRI), and arthroscopy. Ten horses underwent arthroscopic evaluation for cartilage injury and received various intra-articular therapies after surgery. Three of ten horses had lesions that were surgically inaccessible. Four horses became sound and returned to their preoperative level of athletici...
Knecht S, Luechinger R, Boesiger P, Stüssi E.The mechanical property of articular cartilage determines to a great extent the functionality of diarthrodial joints. Consequently, the early detection of mechanical and, thus, functional changes of cartilage is crucial for preventive measures to maintain the mobility and the quality of life of individuals. An alternative to conventional mechanical testing is the inverse finite element approach, enabling non-destructive testing of the tissue. We evaluated a method for the assessment of the equilibrium material properties of the patellar cartilage based on magnetic resonance imaging during pate...
Gutierrez-Nibeyro SD, Werpy NM, White NA, McCutcheon J, Weng HY, Christopher JM.High- and low-field magnetic resonance (MR) imaging systems are available for clinical diagnosis of collateral desmopathy of the equine distal interphalangeal joint (DIJ). Knowledge of the normal appearance, size, shape,and signal variation of these ligaments on high- and low-field MR images is essential when assessing desmopathy detected by MR imaging. However, there are no descriptions of the normal features of DIJ collateral ligaments on images obtained with a standing low-field MR system. Low-field MR imaging characteristics of normal collateral ligaments of the DIJ of cadaver feet were co...
Urraca del Junco CI, Shaw DJ, Weaver MP, Schwarz T.Magnetic susceptibility artifacts as a result of metal debris from shoeing are a common problem in magnetic resonance imaging of the equine foot. Our purpose was to determine the suitability of radiography as a screening tool for the presence and location of metallic particles in the equine foot and to predict the size of the resultant magnetic susceptibility artifact. Radiography had 100% sensitivity for detection of metal particles > or = 1 mm diameter. Metal particles of known diameter were placed within the hoof wall of 22 cadaver feet and scanned with a low-field strength MR imaging un...
Branch MV, Murray RC, Dyson SJ, Goodship AE.Understanding of the development of pathology and source of pain in distal tarsal osteoarthritis is poorly understood. Magnetic resonance imaging is often used in the analysis of human osteoarthritis (OA) because it is sensitive to early changes. Objective: In association with distal tarsal joint (DTJ) pain, there will be an alteration in the characteristic subchondral bone (SCB) thickness pattern of horses with no history of pain when subjected to low-level exercise. Methods: Sixteen cadaver tarsal joints were collected from 9 mature horses with a history of tarsal pain and radiographic evide...
Easley JT, Brokken MT, Zubrod CJ, Morton AJ, Garrett KS, Holmes SP.Fourteen horses with septic arthritis underwent high-field (1.5 T) magnetic resonance imaging (MRI). Septic arthritis was diagnosed based on results from historical and clinical findings, synovial fluid analyses and culture, and radiographic, ultrasonographic, arthroscopic, and histopathologic findings. MR findings included diffuse hyperintensity within bone and extracapsular tissue on fat-suppressed images in 14/14 horses (100%), joint effusion, synovial proliferation, and capsular thickening in 13/14 horses (93%), bone sclerosis in 11/14 horses (79%), and evidence of cartilage and subchondra...
Wulster KB.This article discusses the basis of image formation of radiography, scintigraphy, PET, computed tomography (fan beam and cone beam), and magnetic resonance as it relates to imaging of musculoskeletal injury in the sport horse. The benefits and drawbacks of each modality are discussed with particular emphasis on sensitivity, specificity, and accuracy of identification of subchondral bone injury. Examples of straightforward as well as confounding lesions are provided, emphasizing the need for appropriate clinical workup and diagnostic analgesia, where appropriate.
Stewart HL, Kawcak CE, Inscoe CR, Puett C, Lee YZ, Lu J, Zhou OZ, Selberg KT.To describe the technique and assess the diagnostic potential and limitations of tomosynthesis for imaging of the metacarpophalangeal joint (MCPJ) of equine cadavers; compare the tomosynthesis appearance of pathological lesions with their conventional radiographic, CT, and MRI appearances; and evaluate all imaging findings with gross lesions of a given MCPJ. Methods: Distal portions of 4 forelimbs from 4 equine cadavers. Methods: The MCPJs underwent radiography, tomosynthesis (with a purpose-built benchtop unit), CT, and MRI; thereafter, MCPJs were disarticulated and evaluated for the presence...
Jenner F, Närväinen J, de Ruijter-Villani M, Stout TA, van Weeren PR, Brama P.Equine embryogenesis post implantation is not well studied, and only two-dimensional illustrations are available. A thorough appreciation of the complex three-dimensional relationship between tissues and organs and their development is, however, crucial for understanding physiological and pathological mechanisms. Objective: The goals were 2-fold: 1) to establish a freely accessible online atlas as a reference tool for the scientific and pedagogic communities; and 2) to create a framework for integration of data with known spatiotemporal distribution, such as gene expression or cell lineage. Me...
Olive J, Vila T, Serraud N.To compare navicular bone marrow lesion (BML) conspicuity in the feet of horses as determined via 2 fat-suppressed MRI techniques, including standard short tau inversion recovery (STIR) and inversion recovery gradient echo (IRGE). Methods: Feet (n = 150) of horses with lameness referable to the distal portion of the digit. Methods: STIR and IRGE sequences were obtained prospectively in all feet with a standing low-field equine MRI system. Presence of a BML was ascertained by identification of a characteristic combination of marrow alterations in T1-weighted, T2*-weighted, T2-weighted, and STIR...
Leaper DJ, Foster ME, Brennan SS, Davies PW.Magnetic fields have been considered for treating many ailments over man's history. There have been many anecdotal unsupported claims for successful treatment of soft tissue injury although reports have been more substantive in the orthopaedic field. The widespread clinical and veterinary use of a light self-adhesive magnetic foil in Europe prompted this trial of experimental wound healing. One hundred and sixty Sprague-Dawley rats had a linear 2.5 cm incision or a circular 1 cm skin defect made over the mid-dorsal spine. Equal numbers were randomised to receive either a magnetic foil or a dum...
Pekarkova M, Kircher PR, Konar M, Lang J, Tessier C.The purpose of the present study was to describe normal magnetic resonance (MR) imaging anatomy of the equine larynx and pharynx and to present the optimal protocol, sequences, and possible limitations of this examination technique. Using a 0.3 T unit, the laryngeal and pharyngeal regions was imaged in two horses. The protocol consisted of sagittal and transverse T2-weighted (T2w) fast spin echo, transverse T1-weighted (T1w) spin echo, and dorsal high-resolution T1w gradient echo (both pre- and postcontrast enhancement) sequences. Euthanasia was performed at the end of the imaging procedure. M...
Katzman SA, Spriet MP, Beck BR, Barrett MF, Hendrickson DA.A 6-year-old Quarter Horse gelding used for barrel racing was evaluated for acute onset of non-weight-bearing lameness of the left hind limb following strenuous exercise. Nuclear scintigraphic imaging revealed focal increased radiopharmaceutical uptake centrally within the left talus. Subsequent standard radiographic and ultrasonographic examinations of the tarsus failed to identify the cause of the increased radiopharmaceutical uptake; however, the lameness was definitively localized to the tarsocrural joint by intra-articular anesthesia. Subsequent MRI sequences of the left tarsus revealed a...
Thomas AL, Schramme MC, Lepage OM, Segard EM.An awareness of magnetic susceptibility artifacts is important for interpreting prepurchase and postoperative magnetic resonance imaging (MRI) studies in horses. These artifacts occur when a metallic or a paramagnetic substance creates a local magnetic field deformity. Aims of the current experimental study were to determine prevalence of these artifacts after arthroscopy in a sample of nonlame horses, and to describe effects of time and type of pulse sequence on low-field MRI signal intensity and detection of the artifacts. Ten, nonlame Standardbred horses were prospectively recruited. All ho...
Rice HC, Brokken MT, Hostnik ET, Bertone AL. The aim of this study was to evaluate the injection of a bone substitute material (BSM) into an impact lesion in the palmar condyle of the third metacarpal bone. Methods: This was an controlled study performed on six horses. Methods: Medial metacarpal condyles were exposed via arthrotomy and a compressive lesion created in anaesthetized horses using 80 psi (27.6 MPa) onto the articular surface ( = 12). Paired limbs were randomly selected as a control or for extra-articular injection of BSM towards the subchondral bone near the compressive lesion. Parameters of the surgical tech...
Testa B, Biggi M, Byrne CA, Bell A.Acquisition of magnetic resonance images of the equine limb is still sometimes conducted under general anaesthesia. Despite low-field systems allow the use of standard anaesthetic equipment, possible interferences of the extensive electronic componentry of advanced anaesthetic machines on image quality is unknown. This prospective, blinded, cadaver study investigated the effects of seven standardised conditions (Tafonius positioned as in clinical cases, Tafonius on the boundaries of the controlled area, anaesthetic monitoring only, Mallard anaesthetic machine, Bird ventilator, complete electro...
Adrian AM, Koene M, Roberts S, Doughty P, Bolas N, Kinns J, Brehm W, Gerlach K.The extent of fat suppression using short tau inversion recovery (STIR) imaging is variable between horses. Our aim was to determine if patient's age and/or hoof temperature have an influence on the T(1) relaxation time of bone marrow in the equine distal limb, thereby affecting the suppression of fat signal. Magnetic resonance imaging was conducted on standing horses and cadaver samples using a low-field magnet (0.27 T). The hoof temperature was measured at the lateral side of the coronary band. A modified inversion recovery fast spin-echo (IR-FSE) sequence was used to measure the signal inte...
Ravanetti P, Hamon M, Lechartier A, Zucca E.Surgical repair of unicortical fractures of the distal condyles of the third metacarpal/metatarsal bones (MCIII/MTIII) has been described. In the present case, a bioabsorbable screw was used to stabilize a unicortical fracture in the palmar aspect of the medial condyle of MCIII in a National Hunt Thoroughbred racehorse. The clinical, radiographic, and magnetic resonance imaging findings before and after surgery were recorded. Eighteen weeks after surgery, the lameness had resolved and the bone surrounding the fracture had recovered its normal architecture. One year after surgery, the horse was...
Oehler UM, Janzen EG, Betteridge K, Fyfe C, Towner RA, Savage N, Scodras J.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...
Ball AN, Hoaglund EL, Pool R, Barrett MF, Bass LD.Lameness remains a common cause of retirement in the equine athlete and among hobby enthusiasts. The distal limb is one of the most frequently imaged areas, and recent advances in diagnostic imaging capabilities help practicing veterinarians differentiate normal variants from informative pathology. Although acute, non-weight-bearing lameness is commonly associated with etiologies, such as fractures, abscesses, and laminitis, other uncommon differentials such as cystic lesions and neoplasia might also be considered. This report describes the characterization of a large, cystic lesion in the thi...
Martinelli MJ, Baker GJ, Clarkson RB, Eurell JC, Pijanowski GJ, Kuriashkin IV, Carragher BO.To expand our current knowledge and to establish limits of correlation between signal intensities of the magnetic resonance (MR) image and actual macroscopic and microscopic anatomic features of the imaged structures of the equine metacarpophalangeal joint (MCPJ). Methods: The right MCPJ was obtained from 4 adult horses that were euthanatized for reasons unrelated to the musculoskeletal system. Methods: The distal portion of the right forelimbs was collected from 4 equine cadavers. The bones were drilled to provide fixed reference points and examined by MR imaging. After imaging, the joints we...
Dimock AN, Spriet M.The effect of the chemical shift artifact, resulting from misregistration or phase cancellation at the interface between compact and trabecular bone, on apparent bone thickness was quantified in six isolated equine limbs. Sagittal T1-weighted spin echo (SE) and in-phase three-dimensional spoiled gradient echo (SPGR) images were acquired twice with a 1.5 T magnetic resonance (MR) unit, switching the frequency encoding direction between acquisitions. Out-of-phase SPGR images were also obtained. MR images with different frequency encoding directions were compared with each other and to radiograph...
Lempe-Troillet A, Ludewig E, Brehm W, Budras KD, Winter K, Edinger J.The object of this study was to describe previously defined soft tissue structures by using spin and gradient sequences in a 0.5 Tesla magnetic resonance system in order to improve the characterisation of tendon and ligaments at the plantar region of the equine tarsus and metatarsus while considering possible age-related variations. Methods: Cadaveric hindlimbs from twenty-two Warmblood horses with an age range from one month to twenty-five years were examined in spin and gradient echoes. The proximal suspensory ligament from six limbs was dissected to assign the signal intensities histologica...
Yorke EH, Judy CE, Saveraid TC, McGowan CP, Caldwell FJ.Distal border fragments of the navicular bone are increasingly being detected due to the improved capabilities of magnetic resonance imaging (MRI), but their clinical significance remains unclear. The purpose of this retrospective study was to describe the location, size, and frequency of fragments in a cohort of horses presented for MRI of the foot and to compare MRI findings with severity of lameness. Archived MRI studies and medical records were searched from March 2006 to June 2008. Horses were included if a distal border fragment of the navicular bone was visible in MRI scans. Confidence ...
