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.
Bulnes F, Argüelles D, Buzón A, García-Álamo K, Rodríguez-Gómez IM, Hernández E, Mozos E.This case report details a long-term follow-up of a hoof melanoma with dermo-epidermal activity (resembling Spreading Superficial Melanoma (SSM)) in a bay horse with a history of a right front hoof keratoma. Melanomas involving the horse's foot are seldom reported and usually diagnosed as anaplastic melanomas based on signalment and post-mortem examination. The clinical-pathological characteristics of the foot melanoma in this bay horse are consistent with SSM-like described in humans, which is considered an intermediate malignant tumour attending their biological behaviour. However, a definit...
Stutsel M, Jordan L, Smith C, Lee WY, Symonds N, Bell R, Young A.Foot-related lameness is common in Standardbred and Thoroughbred racehorses. Magnetic resonance imaging (MRI) provides information on both the soft tissue and osseous structures of the distal extremity. The aim of this study was to determine whether abnormalities identified on distal limb MRI differed between these two racehorse populations. Methods: The records of Standardbred and Thoroughbred racehorse distal extremity MRI examinations conducted at Camden Equine Centre and Ballarat Veterinary Practice between 2013 and 2023 were retrieved. Horses were included if pain causing lameness had bee...
Fugazzola MC, De Ruijter M, Veraa S, Plomp S, van Buul W, Hermsen G, van Weeren R.The objective of this study was to evaluate a non-resorbable implant for the focal repair of chondral defects in eight adult horses with 12-month follow-up. The bi-layered construct composed of a polycarbonate-urethane-urea biomaterial which was printed in 3D fashion onto a bone anchor was implanted into surgically created osteochondral defects into the femoropatellar joints of eight horses. The analysis of post-mortem outcomes were compared to defects treated with microfracture in the same animal on the contralateral femoropatellar jointfemoropatellar joint. The overall macroscopic scoring af...
Ross C, White JM, Hibner-Szaltys M, Stephenson RS, Withers JM, Marcatili M.To describe the surgical technique for removal of hoof wall masses in horses under standing sedation (SS) and local anesthesia (LA), and to report complications and long-term outcome following surgery. Methods: Observational retrospective study. Methods: Client-owned horses (n = 30). Methods: Horses undergoing keratoma removal under SS and LA in a single equine hospital between August 2016 and July 2023 were included in the study. Signalment, affected foot, history of lameness and/or foot abscesses, degree of lameness on admission, imaging findings (radiography and magnetic resonance imagi...
Becker R, Haenssgen K, Precht C, Khoma OZ, Hlushchuk R, Koch C, Kaessmeyer S, de Preux M.Equine trigeminal-mediated headshaking is a painful neuropathic disorder comparable to trigeminal neuralgia in humans. The selective destruction of pain fibers within the trigeminal ganglion, called rhizotomy, is the surgical treatment of choice for idiopathic trigeminal neuralgia refractory to medical treatment in humans. The human trigeminal ganglion is enclosed by a dural recess called the Meckel's or trigeminal cave, in which the ganglion is surrounded by a cerebrospinal fluid (CSF)-filled subarachnoid space. During glycerol rhizotomy, glycerol is percutaneously injected in this CSF-filled...
Stedman JM, Lutter JD, Hallman C, Laverty S, Richard H, Santschi EM.High-field MRI of the equine stifle provides high-resolution information about soft tissues that is useful in the diagnosis of stifle lameness. The aim of this prospective anatomic study was to describe the appearance, position, size, and shape of the equine femorotibial ligaments, meniscal ligaments, and menisci using 3 Tesla MRI under extended, extended-loaded, and flexed conditions. Additionally, histologic examination of the collateral and cruciate ligaments (CLs) of a single stifle was performed to compare with MRI images. In extension, mild variations in MRI signal intensity were apparen...
Byrne CA, Voute LC, Marshall JF.Agreement between experienced observers for assessment of pathology and assessment confidence are poorly documented for magnetic resonance imaging (MRI) of the equine foot. Objective: To report interobserver agreement for pathology assessment and observer confidence for key anatomical structures of the equine foot during MRI. Methods: Exploratory clinical study. Methods: Ten experienced observers (diploma or associate level) assessed 15 equine foot MRI studies acquired from clinical databases of 3 MRI systems. Observers graded pathology in seven key anatomical structures (Grade 1: no pathology...
Behroozi M, Graïc JM, Gerussi T.Diffusion-weighted Imaging (DWI) is an effective and state-of-the-art neuroimaging method that non-invasively reveals the microstructure and connectivity of tissues. Recently, novel applications of the DWI technique in studying large brains through imaging enabled researchers to gain insights into the complex neural architecture in different species such as those of (e.g., horses and rhinos), (e.g., bovids, swines, and cetaceans), and (e.g., felids, canids, and pinnipeds). Classical tract-tracing methods are usually considered unsuitable for ethical and practical reasons, in large animals...
Schiavo S, Beccati F, Pokora R, Lin ST, Milmine RC, Bak L, Peter VG, Murray RC.Pain localised to the metacarpophalangeal (MCP) and metatarsophalangeal (MTP) region represents a frequent cause of lameness in sport horses, and standing magnetic resonance imaging (MRI) of these regions is increasingly being acquired. This multicentre retrospective study describes the ranges of abnormalities identified on standing MRI of the MCP/MTP region and compares patterns of abnormalities between forelimbs, hindlimbs and different sports disciplines. In total, 341 MRI reports were reviewed. Subchondral bone plate irregularities, condylar and proximal phalanx pathologies were frequently...
Scharf A, Cheng TY, Urion R, Hostnik E.The objective of this study was to optimize an MRI-based diffusion tensor imaging (DTI) protocol for imaging the plantar nerves at the level of the tarsus in normal equine limbs. Methods: 12 pelvic cadaver limbs from horses without evidence of proximal suspensory pathology were imaged with a 3T MRI system. Methods: For diffusion-weighted imaging, b values of 600, 800, and 1,000 s/mm2 were tested. Data were processed with DSI Studio. Cross-sectional areas of the medial and lateral plantar nerve along the plantar tarsus were recorded. The length and number of fiber tracts, signal-to-noise ratio,...
van Veggel ECS, Vanderperren K, Selberg KT, Bergman HJ, Hoogelander B.This study evaluates the change in an MRI of the proximal metacarpal region in a group of sport horses that returned to work. This retrospective analysis evaluated 18 limbs represented by 17 horses. Results: The hyperintense signal within the dorsal collagenous part of the proximal suspensory ligament (PSL) on T1W/T2*W GRE sequences decreased or stayed the same in the majority of cases. The hyperintense STIR signal within the dorsal collagenous part of the PSL resolved in the majority of the patients, and the third metacarpal bone (McIII) hyperintense STIR signal resolved in all patients. The ...
Faulkner JE, Joostens Z, Broeckx BJG, Hauspie S, Mariën T, Vanderperren K.Sagittal groove disease of the proximal phalanx in equine athletes is commonly considered a bone stress injury. Repetitive hyperextension of the fetlock under high load is thought to contribute to its development. Concurrent changes are often reported in the dorsal sagittal ridge of the third metacarpus/metatarsus (MC3/MT3). Objective: To describe the spectrum of associated osseous abnormalities that are present in the fetlock in a large group of horses diagnosed with sagittal groove disease on low-field magnetic resonance imaging (MRI). Methods: Retrospective, cross-sectional. Methods: MRI im...
Reis IL, Lopes B, Sousa P, Sousa AC, Rêma A, Caseiro AR, Briote I, Rocha AM, Pereira JP, Mendonça CM, Santos JM, Lamas L, Atayde LM, Alvites RD....Here, we describe a case of a 5-year-old show-jumping stallion presented with severe lameness, swelling, and pain on palpation of the left metacarpophalangeal joint (MCj). Diagnostic imaging revealed full and partial-thickness articular defects over the lateral condyle of the third metacarpus (MC3) and the dorsolateral aspect of the first phalanx (P1). After the lesion's arthroscopic curettage, the patient was subjected to an innovative regenerative treatment consisting of two intra-articular injections of equine synovial membrane mesenchymal stem/stromal cells (eSM-MSCs) combined with umbilic...
Nessler JN, Delarocque J, Kloock T, Twele L, Neudeck S, Meyerhoff N, Riese F, Cavalleri JV, Tipold A, Feige K, Niebuhr T.To determine whether sensory nerve conduction stimulus threshold measurements of the infraorbital nerve are able to differentiate horses with idiopathic trigeminal-mediated headshaking (i-TMHS) from healthy horses and from horses with secondary trigeminal-mediated headshaking (s-TMHS). In a prospective trial, headshaking horses were examined using a standardized diagnostic protocol, including advanced diagnostics such as computed tomography and 3-Tesla-magnetic resonance imaging (MRI), to differentiate s-TMHS from i-TMHS. Clinically healthy horses served as controls. Within this process, patie...
Nagy A, Dyson S.There is a limited description of magnetic resonance imaging (MRI) and no information on computed tomographic (CT) findings in the fetlock of non-lame, non-racing sports horses. This study aimed to document comparative CT, MRI and radiographic findings in the metacarpophalangeal joints of showjumpers in full work. Clinical and gait assessments, low-field MRI, fan-beam CT and radiographic examinations of both metacarpophalangeal joints were performed on 31 showjumpers. Images were analysed descriptively. In most limbs (53/62, 85.5%), there were CT and MRI changes consistent with densification i...
Hewitt-Dedman CL, Kershaw LE, Schwarz T, Del-Pozo J, Duncan J, Daniel CR, Cillán-García E, Pressanto MC, Taylor SE.Magnetic resonance spectroscopy (MRS) has been used to investigate metabolic changes within human bone. It may be possible to use MRS to investigate bone metabolism and fracture risk in the distal third metacarpal/tarsal bone (MC/MTIII) in racehorses. Objective: To determine the feasibility of using MRS as a quantitative imaging technique in equine bone by using the H spectra for the MC/MTIII to calculate fat content (FC). Methods: Observational cross-sectional study. Methods: Limbs from Thoroughbred racehorses were collected from horses that died or were subjected to euthanasia on racecourses...
Myhre MG, Azeem A, Barrett M.Medical records from 2009 to 2021 from a private equine referral hospital in Rochester, NH, USA were analysed for cases that underwent general anaesthesia for low-field MRI of the distal limb. These were used to determine peri-anaesthetic morbidity and mortality. Unassigned: Two hundred and forty-three anaesthetic episodes were recorded in horses undergoing low-field MRI. The peri-anaesthetic complication rate prior to discharge was 6.2% (15/243). No patients experienced a fatal complication. Ninety two of the 243 patients had multiple sites imaged, 90/243 received pre-anaesthetic dantrolene, ...
Faulkner JE, Joostens Z, Broeckx BJG, Hauspie S, Mariën T, Vanderperren K.Injuries of the sagittal groove of the proximal phalanx (P1) in equine athletes are considered to predominantly occur due to chronic bone stress overload. Objective: To describe the range of abnormalities that is present in the sagittal groove in a large group of horses diagnosed with sagittal groove disease (SGD) on low-field MRI. Methods: Retrospective, cross-sectional. Methods: Medical records were searched to identify initial MRI images of horses diagnosed with SGD and these were blindly evaluated using a semi-quantitative grading scheme and novel SGD MRI classification system reflecting p...
Kim CS, Reisbig NA, Carmalt JL.Disorders of the equine temporomandibular joint (TMJ) cause clinical problems and detailed investigations of this joint are becoming more common. Specialist radiographic projections have the potential to highlight osseous abnormalities; however, the ability to assess the intra-articular soft tissue structures is currently limited to computed tomography (with, or without contrast enhancement) or magnetic resonance imaging. Both modalities are expensive and not readily accessible. Unassigned: To develop a technique of contrast arthrography of both compartments of the equine TMJ in cadavers and t...
Vullo C, Gugliandolo E, Biondi V, Biffarella M, Catone G, Tambella AM.The aim of this study was to determine the most appropriate sedation protocol for a standing magnetic resonance imaging (MRI) examination in horses, comparing continuous rate infusions (CRIs) of detomidine and romifidine combined with a single bolus of morphine. Sixteen horses referred for standing low-field open-magnet MRI were randomly assigned to one of two sedation protocols. The horses were premedicated with 0.03 mg/kg of intramuscular acepromazine, and those animals belonging to Group D received an intravenous (IV) loading dose of detomidine (0.01 mg/kg) 30 min later, while those of Grou...
de Preux M, Precht C, Guevar J, Graubner C, Thenhaus-Schnabel S, Buser L, Lukes A, Koch C.A 16-year-old warmblood mare was referred with a progressive history of behavioral changes and left-sided blindness. Following neuroanatomical localization to the forebrain, magnetic resonance imaging of the head revealed a well-delineated, 4.5 cm in diameter, round pituitary mass causing marked compression of the midbrain and optic chiasm. Euthanasia was recommended but declined by the owners. Veterinary specialists and a human neurosurgeon collaboratively prepared for surgical case management. A novel navigated transmandibular lateral transsphenoidal approach was developed to access the re...
Avila-Sanchez P, Pliego-Zermeño JA, Barron-Cervantes NM, Chan C.Pancreatic trauma is one of the least observed diagnoses in the emergency room, much less in pediatric emergencies. Any cause of direct abdominal blunt trauma can cause it. With only a few cases presented in the literature, horse accidents have been associated with this complication, but it has been never seen in literature as a case where the horse-riding saddle is the one causing the pancreatic trauma, until now. Emphasizing the importance of an early diagnosis is the key point, but more importantly, to highlight that the correct diagnostic approach will grant the opportunity for a lesion in...
Kutara K, Kadekaru S, Hisaeda K, Sugimoto K, Ono T, Inoue Y, Nakamura S, Yoshitake R, Ohzawa E, Goto A, Iwata E, Shibano K, Une Y, Kitagawa H.The necropsy of a 2-day-old Noma horse that died of weakness showed an enlarged cardiac base and a narrow cardiac apex, suggesting cardiac malformation. The excised heart underwent imaging to investigate its luminal structure. On three-dimensional magnetic resonance imaging, the right atrium and right ventricle were discontinuous. The right atrium communicated with the left atrium and the left ventricle communicated with the right ventricle. The lumen narrowed near the pulmonary artery valve. Since the same findings were observed on gross examination, the foal was diagnosed with tricuspid atre...
Germonpré J, Vandekerckhove LMJ, Raes E, Chiers K, Jans L, Vanderperren K.In this proof-of-concept study, the post-mortem feasibility of dual-energy computed tomography (DECT) in the detection of bone edema-like lesions in the equine foot is described in agreement with the gold standard imaging technique, which is magnetic resonance imaging (MRI). Unassigned: A total of five equine cadaver feet were studied, of which two were pathological and three were within normal limits and served as references. A low-field MRI of each foot was performed, followed by a DECT acquisition. Multiplanar reformations of DECT virtual non-calcium images were compared with MRI for the de...
Giorio ME, Graham RJ, Berner D, O'Neill HD, Bladon BM.Focal hyperintense lesions within the navicular bursa emanating from the dorsal border of the deep digital flexor tendon (DDFT) can be recognised on T1-weighted magnetic resonance images (MRI) and have been attributed to lameness in horses. Removal of these lesions, also referred to as synovial masses, by navicular bursoscopy is currently recommended. Objective: To investigate the correlation between MRI and navicular bursoscopic findings. It is hypothesised that the prognosis following surgery is proportional to the size of the DDFT lesion. Methods: Retrospective analysis of clinical records....
Ratcliffe TOC, Robinson P, Rosanowski SM.To evaluate and compare the prognosis for Thoroughbred racehorses to return to galloping and racing with injuries to the palmaroproximal metacarpus diagnosed with MRI. Methods: 29 flat racing Thoroughbreds at the Hong Kong Jockey Club that underwent MRI between 2014 and 2022. Methods: Clinical, radiographic, ultrasonographic, and MRI reports were collected from veterinary clinical records, and these were combined with training and racing data. Horses were categorized on the basis of MRI diagnosis: (1) proximal suspensory ligament (PSL) involvement only, (2) PSL and concurrent proximal third me...
Faulkner JE, Joostens Z, Broeckx BJG, Hauspie S, Mariën T, Vanderperren K.Evolution of magnetic resonance imaging (MRI) findings in horses with sagittal groove disease (SGD) of the proximal phalanx is relatively sparsely described. This retrospective, descriptive, longitudinal study describes the findings of sequential low-field MRI fetlock examinations in horses with SGD of the proximal phalanx using a classification system. Twenty-nine horses were included, predominantly warmbloods used for show jumping (79%). For 29 limbs re-examined during the initial rehabilitation period, classification remained constant (n = 18), increased (n = 2), decreased (n = 7), and fluc...
Seidler A, Aßmann A, Torgerson PR, Sánchez-Andrade JS, Bischofberger A.The objective of this study was to compare articular cartilage thickness observed in the different 2D and 3D sequences to the cartilage thickness of the equine stifle in cadavers to determine the accuracy of each sequence. The study was conducted as a blinded laboratory study using seven equine stifle specimens. The 2D (T2W TSE) and 3D (3D VIEW T2W HR, T2 3D mFFE, T1W VISTA SPAIR, 3D PDW SPAIR) 3-tesla MRI sequences of each stifle were obtained. Cartilage thickness was measured at 30 locations on MRI and on gross pathology. Thickness measurements were compared using a Bland-Altman plot and pos...
Morgan JM, Aceto H, Manzi T, Davidson EJ.Complications are a practical consideration for elective magnetic resonance imaging (MRI) studies performed under general anaesthesia but relatively little is known about their distribution and risk factors. Objective: To describe the incidence of complications associated with MRI performed under general anaesthesia at a large referral facility and evaluate potential risk factors for these complications. Methods: Retrospective case-control study. Methods: Patient information and details of the MRI procedure were collected retrospectively from medical records of all horses that had undergone an...
Lin ST, Bolas NM, Peter VG, Pokora R, Patrick H, Foote AK, Sargan DR, Murray RC.Palmar/plantar osteochondral disease (POD) of the metacarpal/tarsal condyles is a common pathological finding in racehorses. Objective: To compare diagnoses, imaging details, and measurements of POD lesions between cone-beam computed tomography CT (CBCT), fan-beam CT (FBCT), and low-field magnetic resonance imaging (MRI) using macroscopic pathology as a gold standard. Methods: Cross-sectional study. Methods: Thirty-five cadaver limbs from 10 horses underwent CBCT, FBCT, MRI, and macroscopic examination. CT and MR images were examined for presence of POD, imaging details of POD, and measurement...
Olive J, D'Anjou MA, Girard C, Laverty S, Theoret CL.Marginal osteophytes represent a well known component of osteoarthritis in man and animals. Conversely, central subchondral osteophytes (COs), which are commonly present in human knees with osteoarthritis, have not been reported in horses. Objective: To describe and compare computed radiography (CR), single-slice computed tomography (CT), 1.5 Tesla magnetic resonance imaging (MRI), and histological features of COs in equine metacarpophalangeal joints with macroscopic evidence of naturally-occurring osteoarthritis. Methods: MRI sequences (sagittal spoiled gradient recalled echo [SPGR] with fat ...
Kraft SL, Gavin P.This article discusses how cross-sectional imaging methods such as computed tomography and magnetic resonance imaging can provide unique and diagnostically important information in situations where radiography or diagnostic ultrasound have been unrewarding.
Radiography and ultrasonography are the most used techniques in veterinary clinical practice, due to organizational, managerial and, mostly, economic reasons. However, in the last decades, Computed tomography (CT), Magnetic Resonance Imaging (MRI) and, to a lesser extent, Nuclear Medicine (MN) are increasingly used. As we said in the previous article, all the Diagnostic Imaging techniques are actually "indispensable" in Veterinary Medicine, where many patients do not show any symptoms.This second part describes Computed Tomography (CT), Magnetic Resonance (MRI) and Nuclear Medicine techniques ...
Dyson S, Murray R.To improve understanding of the interrelationships between injuries of the podotrochlear apparatus and deep digital flexor tendon (DDFT). Objective: There is a difference in frequency of different types of lesions at different anatomical sites of the DDFT. Lesions of the collateral sesamoidean ligament (CSL), distal sesamoidean impar ligament (DSIL), distal interphalangeal (DIP) joint and navicular bursa are seen in association with lesions of the navicular bone. Methods: The magnetic resonance (MR) images of 264 horses with unilateral or bilateral foot pain were analysed and graded. Descripti...
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...
O'Brien T, Baker TA, Brounts SH, Sample SJ, Markel MD, Scollay MC, Marquis P, Muir P.To compare digital radiography (DR), computed tomography (CT), and magnetic resonance imaging (MRI) for detection of pathology of the distal aspect of the third metacarpal bone (MC3) and to assess whether arthrography would improve detection of articular cartilage or subchondral bone cracking. Methods: Cross-sectional study. Methods: Limb specimens from 17 Thoroughbred horses after catastrophic injury and 4 age-matched control horses. Methods: Standard DR, CT, and MRI images of the metacarpophalangeal joint were acquired before and after iohexol injection. Pathologic features detected with ima...
Kajabi AW, Casula V, Sarin JK, Ketola JH, Nykänen O, Te Moller NCR, Mancini IAD, Visser J, Brommer H, René van Weeren P, Malda J, Töyräs J....Chondral lesions lead to degenerative changes in the surrounding cartilage tissue, increasing the risk of developing post-traumatic osteoarthritis (PTOA). This study aimed to investigate the feasibility of quantitative magnetic resonance imaging (qMRI) for evaluation of articular cartilage in PTOA. Articular explants containing surgically induced and repaired chondral lesions were obtained from the stifle joints of seven Shetland ponies (14 samples). Three age-matched nonoperated ponies served as controls (six samples). The samples were imaged at 9.4 T. The measured qMRI parameters included ...
Radunsky D, Blumenfeld-Katzir T, Volovyk O, Tal A, Barazany D, Tsarfaty G, Ben-Eliezer N.Multi-echo spin-echo (MESE) protocol is the most effective tool for mapping T relaxation in vivo. Still, MESE extensive use of radiofrequency pulses causes magnetization transfer (MT)-related bias of the water signal, instigated by the presence of macromolecules (MMP). Here, we analyze the effects of MT on MESE signal, alongside their impact on quantitative T measurements. Study used 3 models: in vitro urea phantom, ex vivo horse brain, and in vivo human brain. MT ratio (MTR) was measured between single-SE and MESE protocols under different scan settings including varying echo train lengths, n...
Bertoni L, Jacquet-Guibon S, Branly T, Legendre F, Desancé M, Mespoulhes C, Melin M, Hartmann DJ, Schmutz A, Denoix JM, Galéra P, Demoor M....Osteoarthritis is a common cause of pain and economic loss in both humans and horses. The horse is recognized as a suitable model for human osteoarthritis, because the thickness, structure, and mechanical properties of equine articular cartilage are highly comparable to those of humans. Although a number of equine experimental osteoarthritis models have been described in the literature, these cases generally involve the induction of osteoarthritis in just one joint of each animal. This approach necessitates the involvement of large numbers of horses to obtain reliable data and thus limits the ...
Arencibia A, Vázquez JM, Jaber R, Gil F, Ramírez JA, Rivero M, González N, Wisner ER.The purpose of this investigation was to define the magnetic resonance imaging anatomy of the rostral part of the equine head. 10 mm-thick, T1-weighted images of two isolated equine cadaver heads were obtained using a 1.5 Tesla magnet and a body coil. MR images were compared to corresponding frozen cross-sections of the cadaver head. Relevant anatomic structures were identified and labeled at each level. The resulting images provided excellent anatomic detail of the oral and nasal cavities, paranasal sinuses and associated structures. Annotated MR images from this study are intended as a refer...
Murata D, Ishikawa S, Sunaga T, Saito Y, Sogawa T, Nakayama K, Hobo S, Hatazoe T.Medical interventions for subchondral bone cysts in horses have been extensively studied. This study investigated the regeneration of articular cartilage and subchondral bone with scaffold-free three-dimensional (3D) constructs of equine synovial membrane-derived mesenchymal stem cells (SM-MSCs) isolated from three ponies and expanded until over 1.0 × 10 cells at passage 2 (P2). Results: SM-MSCs were strongly positive for CD11a/CD18, CD44, and major histocompatibility complex (MHC) class I; moderately positive for CD90, CD105, and MHC class II; and negative for CD34 and CD45 on flow cytom...
Hontoir F, Nisolle JF, Meurisse H, Simon V, Tallier M, Vanderstricht R, Antoine N, Piret J, Clegg P, Vandeweerd JM.Articular cartilage defects are prevalent in metacarpo/metatarsophalangeal (MCP/MTP) joints of horses. The aim of this study was to determine and compare the sensitivity and specificity of 3-Tesla magnetic resonance imaging (3-T MRI) and computed tomography arthrography (CTA) to identify structural cartilage defects in the equine MCP/MTP joint. Forty distal cadaver limbs were imaged by CTA (after injection of contrast medium) and by 3-T MRI using specific sequences, namely, dual-echo in the steady-state (DESS), and sampling perfection with application-optimised contrast using different flip-an...
King JN, Zubrod CJ, Schneider RK, Sampson SN, Roberts G.Two hundred and thirty-two horses with lameness localized to the metacarpo(tarso)phalangeal (MCP/MTP) region without a radiographic diagnosis were evaluated. All horses had high-field magnetic resonance (MR) imaging of the MCP/MTP region performed for the lame limb and the contralateral limb for comparison. There were 46 horses that had bilateral abnormalities in the forelimbs; 27 of these horses were not lame in the contralateral limb at the time of examination. Bilateral hind limb abnormalities were observed in 37 horses; 22 horses were not lame in the contralateral limb. Soft tissue abnorma...
Zhu X, Suarez-Jimenez B, Zilcha-Mano S, Lazarov A, Arnon S, Lowell AL, Bergman M, Ryba M, Hamilton AJ, Hamilton JF, Turner JB, Markowitz JC....While effective treatments for posttraumatic stress disorder (PTSD) exist, many individuals, including military personnel and veterans fail to respond to them. Equine-assisted therapy (EAT), a novel PTSD treatment, may complement existing PTSD interventions. This study employs longitudinal neuro-imaging, including structural magnetic resonance imaging (sMRI), resting state-fMRI (rs-fMRI), and diffusion tensor imaging (DTI), to determine mechanisms and predictors of EAT outcomes for PTSD. Nineteen veterans with PTSD completed eight weekly group sessions of EAT undergoing multimodal MRI assessme...
Kang KD, Jung TW, Park IH, Han DH.Internet gaming disorder (IGD) has been suggested to be a mental health disorder. Attachment and emotional status in IGD patients are important for understanding the etiology and progression of IGD because both parameters are considered to be associated with the affective network. Equine-assisted activities and therapies (EAAT) have been reported to improve emotional status and attachment in subjects. We hypothesized that EAAT would improve attachment in IGD adolescents with insecure attachment issues and increase functional connectivity (FC) within the affective network. Methods: Subjects com...
Murray RC, Mair TS, Sherlock CE, Blunden AS.Eleven limbs taken postmortem from 10 lame horses were examined by MRI in a low-field 0.27T system designed for standing horses and a high-field 1.5T system used to examine anaesthetised horses. Nine limbs were examined in the foot/pastern region and two in the fetlock region, and the results were compared with gross pathological examinations and histological examinations of selected tissues. The appearance of normal tissues was similar between the two systems, but the anatomical arrangement of the structures was different due to differences in positioning, and a magic angle artefact was obser...
Porter EG, Werpy NM.This article addresses the clinical application of magnetic resonance imaging (MRI) and computed tomography (CT) as applied to the standing equine patient. This discussion includes the logistics, advantages, disadvantages, and limitations of imaging a standing horse. In addition, a brief review is given of the physics of these modalities as applied in clinical practice, and the currently available hardware and software required by these techniques for image acquisition and artifact reduction. The appropriate selection of clinical cases for standing MRI and CT is reviewed, focusing on cases tha...
Schmidt MJ, Knemeyer C, Heinsen H.In this study, the morphology of the horse brain (Equus caballus) is decribed in detail using high field MRI. The study includes sagittal, dorsal, and transverse T2-weighted images at 0.25 mm resolution at 3 Tesla and 3D models of the brain presenting the external morphology of the brain. Representative gallocyanin stained histological slides of the same brain are presented. The images represent a useful tool for MR image interpretation in horses and may serve as a starting point for further research aiming at in vivo analysis in this species.
Murray RC, Blunden TS, Schramme MC, Dyson SJ.Magnetic resonance (MR) imaging is increasingly used in the diagnosis of equine foot pain, but improved understanding of how MR images represent tissue-level changes in the equine foot is required. We hypothesized that alterations in signal intensity and tissue contour would represent changes in tissue structure detected using histologic evaluation. The study objectives were to determine the significance of MR signal alterations in feet from horses with and without lameness, by comparison with histopathologic changes. Fifty-one cadaver feet from horses with a history of lameness improved by pa...
Bischofberger AS, Konar M, Ohlerth S, Geyer H, Lang J, Ueltschi G, Lischer CJ.The diagnosis of lameness caused by proximal metacarpal and metatarsal pain can be challenging. Magnetic resonance imaging (MRI) offers the possibility for further diagnosis but there have been no studies on the normal MRI appearance of the origin of the suspensory ligament (OSL) in conjunction with ultrasonography and histology. Objective: To describe the MRI appearance of the OSL in fore- and hindlimbs of sound horses and compare it to the ultrasonographic and histological appearance. The findings can be used as reference values to recognise pathology in the OSL. Methods: The OSL in the fore...
Blunden A, Murray R, Dyson S.Lameness associated with lesions of the deep digital flexor tendon (DDFT) in the digit is now recognised as an important cause of lameness, but there is currently limited information about the pathological nature of the lesions. Objective: To compare: signal intensity changes on magnetic resonance images with histopathology; and histopathological changes in the DDFT from horses with no history of foot-related lameness (Group C) and horses with lesions of the DDFT confirmed using magnetic resonance imaging (MRI) (Group D). Methods: Transverse sections of the DDFT were harvested from 3 sites in ...
Seminati E, Nardello F, Zamparo P, Ardigò LP, Faccioli N, Minetti AE.We hypothesized that, as occurring in cars, body structural asymmetries could generate asymmetry in the kinematics/dynamics of locomotion, ending up in a higher metabolic cost of transport, i.e. more 'fuel' needed to travel a given distance. Previous studies found the asymmetries in horses' body negatively correlated with galloping performance. In this investigation, we analyzed anatomical differences between the left and right lower limbs as a whole by performing 3D cross-correlation of Magnetic Resonance Images of 19 male runners, clustered as Untrained Runners, Occasional Runners and Skille...
Couppé C, Svensson RB, Sødring-Elbrønd V, Hansen P, Kjaer M, Magnusson SP.Magnetic resonance imaging (MRI) has commonly been applied to determine tendon cross-sectional area (CSA) and length either to measure structural changes or to normalize mechanical measurements to stress and strain. The ability to reproduce CSA measurements on MRI images has been reported, but the accuracy in relation to actual tendon dimensions has never been investigated. The purpose of this study was to compare tendon CSA measured by MRI with that measured in vitro with the mould casting technique. The knee of a horse was MRI-scanned with 1.5 and 3 tesla, and two examiners measured the pate...
Tranquille CA, Parkin TD, Murray RC.Lateral condylar (LC) fractures of the third metacarpus (McIII) are a common reason for euthanasia in racehorses, and may be the result of repetitive overloading or cumulative pathological change. Magnetic resonance imaging (MRI) allows monitoring of bone and cartilage to detect pathological and adaptive changes that may be precursors of fracture. Objective: To describe bone and cartilage MRI features in the distal condyles of McIII of Thoroughbred racehorses, with and without condylar fracture. Objective: 1) A greater degree of bone and cartilage adaptation or pathology will be seen in fractu...
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 ...
Gonzalez LM, Schramme MC, Robertson ID, Thrall DE, Redding RW.Lameness originating from the metacarpo(tarso)phalangeal (MP) joint has a significant effect on the use and athletic competitiveness of a horse. The identification of the cause of lameness originating from the MP joint can be challenging, given the limitations of radiography, ultrasonography, and nuclear scintigraphy. Our purpose was to describe the injury types and incidence in magnetic resonance imaging (MRI) studies from 40 horses with lameness attributable to the MP joint region where it was not possible to reach a clinically plausible diagnosis using other imaging modalities. Horses were ...
Spriet M, Espinosa-Mur P, Cissell DD, Phillips KL, Arino-Estrada G, Beylin D, Stepanov P, Katzman SA, Galuppo LD, Garcia-Nolen T, Murphy B, Stover SM.Early and accurate detection of stress remodelling in racehorses is of utmost importance to prevent catastrophic injuries. Current imaging techniques have limitations in assessing early changes predisposing to catastrophic breakdowns. Positron emission tomography (PET) using F-sodium fluoride ( F-NaF) is a sensitive method for the detection of early bone turnover and may improve early recognition of subtle injuries. Objective: To validate the clinical use of F-NaF PET in Thoroughbred racehorses, to assess the value of PET in the detection of bone lesions and to compare PET results with findi...
Johnson PJ, Janvier V, Luh WM, FitzMaurice M, Southard T, Barry EF.There is growing interest in the horse for behavioral, neuroanatomic and neuroscientific research due to its large and complex brain, cognitive abilities and long lifespan making it neurologically interesting and a potential large animal model for several neuropsychological diseases. Magnetic resonance imaging (MRI) is a powerful neuroscientific research tool that can be performed , with adapted equine facilities, or in the research setting. The brain atlas is a fundamental resource for neuroimaging research, and have been created for a multitude animal models, however, none currently exist f...
Gold SJ, Werpy NM, Gutierrez-Nibeyro SD.Sagittal groove injuries of the proximal phalanx are an important cause of lameness in performance horses. The purpose of this retrospective case series study was to describe standing low-field magnetic resonance imaging (MRI) characteristics of these injuries in a group of Warmblood horses. Horses with an MRI diagnosis of sagittal groove injuries involving the proximal phalanx and that had follow-up MRI and clinical outcome information were included. Findings from clinical examinations, diagnostic tests, and other imaging modalities were recorded. All MRI studies were retrieved for re-evaluat...
Hyun GJ, Jung TW, Park JH, Kang KD, Kim SM, Son YD, Cheong JH, Kim BN, Han DH.Equine-assisted activity and training (EAAT) is thought to improve body balance and clinical symptoms in children with attention deficit hyperactivity disorder (ADHD). The study hypostheses were that EAAT would improve the clinical symptoms and gait balance in children with ADHD and that these improvements would be associated with increased brain connectivity within the balance circuit. Methods: A total of 12 children with ADHD and 12 age- and sex-matched healthy control children were recruited. EAAT consisted of three training sessions, each 70 minutes long, once a week for 4 weeks. Brain fun...
