Topic:Scintigraphy
Scintigraphy, also known as nuclear scintigraphy, is a diagnostic imaging technique used in equine medicine to assess bone and soft tissue abnormalities. This procedure involves the administration of a radiopharmaceutical agent that emits gamma rays, which are detected by a gamma camera to create detailed images of the horse's body. Scintigraphy is particularly useful for identifying areas of increased metabolic activity, often indicative of inflammation, infection, or injury. It is commonly employed in cases where lameness or other musculoskeletal issues are present, but the precise location or cause is not easily determined through other diagnostic methods. This page compiles peer-reviewed research studies and scholarly articles that explore the applications, methodology, and diagnostic value of scintigraphy in equine veterinary practice.
Validation of the 13C-octanoic acid breath test for measurement of equine gastric emptying rate of solids using radioscintigraphy. Disordered gastric motility may be a significant factor in the pathogenesis of many equine conditions. Although tests for liquid phase emptying rate have been validated in the horse, there are no effective tests for solid phase emptying measurement that can be performed routinely in the field. Objective: The objective of this study was the assessment of a novel stable isotope technique, the 13C-octane acid breath test (13C-OABT), for the measurement of gastric emptying of solid ingesta, by direct comparison with the optimum method of gastric scintigraphy. Methods: To facilitate dual measuremen...
Computed tomographic appearance of osteochondritis dissecans-like lesions of the proximal articular surface of the proximal phalanx in a horse. A 6-year-old Thoroughbred gelding presented with a left forelimb lameness. The results of lameness examination, radiography, nuclear scintigraphy, and computed tomography are presented. Based on the diagnostic imaging, subchondral fractures and osteochondritis dissecans lesions of the proximal articular surface of the proximal phalanx were diagnosed. A brief discussion of osteochondritis dissecans is presented.
[Diagnostic validity of palpation in horses with back problems]. There is a regularly high proportion of x-ray findings indicating a pathological deterioration of the equine vertebral column which do not correlate with the clinical symptoms. Therefore, palpation remains one of the most important clinical examination methods to determine whether or not a horse is suffering from back pain. The aim of this study was to check the validity of palpation results of horses with an assumed back problem. The palpation results of 167 horses were evaluated in retrospect: If the palpation proceeds under following conditions, positive palpation results agree with an prim...
Forelimb skeletal scintigraphy responses in previously untrained Thoroughbreds undergoing initial treadmill training. Scintigraphy has been used in numerous clinical settings to examine horses to determine the origin of lameness problems, but it has not been used previously to monitor prospectively the skeletal responses of a group of similarly-trained racehorses. Our hypothesis was that in naïve Thoroughbred (TB) racehorses, initial treadmill training induces increased radiopharmaceutical uptake in high-motion joints and in the dorsal third metacarpal bone (MC3). Eight previously-untrained TB racehorses underwent sequential skeletal scintigraphic examinations as they exercised daily for 9 weeks on an inclin...
Exercise-induced pulmonary perfusion redistribution in heaves. This study aimed to compare exercise-induced pulmonary perfusion redistribution in healthy vs. 'heavey' horses using scintigraphy, a minimally invasive technique. Six healthy (A) and 5 'heavey' horses in remission (B(I)) and during clinical signs of disease (B(II)) were investigated. Dimensions of the exercising pulmonary perfusion (QE) images were expressed in percent of the resting perfusion (QR) images. Computed QE to QR ratios (QE/QR) images enabled the definition of the region more perfused at exercise than at rest (R1). In all groups, exercise induced a major enlargement of the Q image b...
Quantitative detection of atropine-delayed gastric emptying in the horse by the 13C-octanoic acid breath test. The 13C-octanoic acid breath test has been correlated significantly to radioscintigraphy for measurement of gastric emptying indices in healthy horses. The objective of this study was to investigate the validity of the test for measurement of equine delayed gastric emptying, prior to its potential clinical application for this purpose. A model of atropine-induced gastroparesis was used. Gastric emptying rate was measured twice in 8 horses using concurrent radioscintigraphy and/or breath test after treatment i.v. with either atropine (0.035 mg/kg bwt) or saline in randomised order. Analysis of ...
The scintigraphic anatomy of the equine sacroiliac joint. The aim of this study was to describe the scintigraphic appearance and location of the sacroiliac joint (SI-joint) in dorsal and dorso 30 degree lateral views of the equine pelvis in a scintigram. The pelvis from 10 different horses was prepared by attaching plastic tubes along relevant margins of the bone and around the SI-joint. A radioactive solution was injected into the tubes, and scintigraphic images were acquired with a gamma camera. Five specific landmarks were identified on the left and right sides of the pelvis. There was no significant difference in the distance measurements between...
Subjective and quantitative scintigraphic assessment of the equine foot and its relationship with foot pain. It was hypothesised that in solar bone images of the front feet of clinically normal horses, or horses with lameness unrelated to the front feet, there would be less than a 10% difference in the ratio of uptake of radiopharmaceutical in either the region of the navicular bone, or the region of insertion of the deep digital flexor tendon (DDFT), compared to the peripheral regions of the distal phalanx. Nuclear scintigraphic examination of the front feet of 15 Grand Prix show jumping horses, all of which were free from detectable lameness, was performed using dorsal, lateral and solar images. Th...
Evaluation of acetaminophen absorption in horses with experimentally induced delayed gastric emptying. To evaluate the correlation between the half-time of liquid-phase gastric emptying (T50) determined by use of nuclear scintigraphy, using technetiumTc 99m pentetate, and absorption variables of orally administered acetaminophen in horses with experimentally delayed gastric emptying. Methods: 6 mature horses. Methods: Delayed gastric emptying was induced by IV injection of atropine sulfate. Twenty minutes later, acetaminophen and technetium Tc 99m pentetate were administered simultaneously via nasogastric tube. Serial lateral images of the stomach region were obtained, using a gamma camera. Pow...
Impingement of the dorsal spinous processes in two hundred and fifteen horses: case selection, surgical technique and results. The surgical treatment of impingement of dorsal spinous processes (DSPs) at 2 equine veterinary hospitals following a similar diagnostic and surgical protocol is described with special reference to the diagnosis and case selection. The diagnosis was made from clinical examination and results of radiography and diagnostic analgesia of the affected sites. Scintigraphy was also used as an aid to diagnosis at one hospital. Surgical treatment was generally recommended when conservative treatment, which included 3-9 months rest, intralesional corticosteroids and physiotherapy, had failed. The DSPs w...
Unusual osteochondral lesions of the talus in a horse. A 2-year-old Thoroughbred gelding was evaluated for a grade 3 out of 5 unilateral hind limb lameness. Flexion of the right hock and stifle joints (spavin test) exacerbated the lameness. Response to intra-articular and perineural anaesthesia isolated the source of lameness to the tarsocrural area, despite an absence of tarsocrural joint effusion. Routine radiographic examination of the hock did not reveal any significant abnormalities. Skeletal nuclear scintigraphic evaluation revealed a focal region of increased bone activity in the proximal medial trochlear ridge of the talus. Flexed laterome...
Factors influencing blood flow in the equine digit and their effect on uptake of 99m technetium methylene diphosphonate into bone. It was hypothesised that exercise may promote perfusion of the distal part of the limbs and enhance uptake of radiopharmaceutical into bone, but bandaging and lameness would have no effect. Two hundred and two horses undergoing routine nuclear scintigraphic examination for assessment of lameness or poor performance between November 1998 and November 1999 were assigned randomly to one of 4 groups: no bandages and no exercise (NB/NE); bandages and no exercise (B/NE); no bandages and exercise (NB/E); bandages and exercise (B/E). In the bandage groups, the distal forelimbs were bandaged for at lea...
Equine nuclear scintigraphy. Indications, uses, and techniques. The demand for advanced and correlative imaging methods in equine medicine is growing. Scintigraphy can provide unique information about the physiologic status of an animal that cannot be discerned by other imaging modalities.
Equine bone scintigraphic uptake patterns related to age, breed, and occupation. It is well known that skeletal scintigraphy is an imaging modality with high sensitivity but low specificity. Sites of IRU provide good evidence of increased bone turnover but not its specific cause. Results of lameness workups, blocks, and other imaging techniques are required to determine specific causes. Overinterpretation of causes of IRU is tempting, especially in assigning diagnoses to EIBR--adaptive or non-adaptive. Nevertheless, a quarter of a century's experience with equine skeletal scintigraphy has shown that certain patterns and locations can be fairly predictive of certain patholo...
Osteitis of the axial border of the proximal sesamoid bones in horses: eight cases (1993-1999). To determine clinical, radiographic, and scintigraphic abnormalities in and outcome of horses with septic or nonseptic osteitis of the axial border of the proximal sesamoid bones. Methods: Retrospective study. Methods: 8 horses. Methods: Data collected from medical records included signalment; history; horse use; severity and duration of lameness; results of perineural anesthesia, radiography, ultrasonography, and scintigraphy; and outcome following surgery. Results: Five horses did not have any evidence of sepsis; the other 3 had sepsis of the metacarpophalangeal or metatarsophalangeal joint ...
Comparison of radiography and scintigraphy in the diagnosis of dental disorders in the horse. Scintigraphy, with 99mTechnetium methylenediphosphonate (99mTc-MDP) and 99mTc-labelled leucocytes, was compared to radiography in the diagnosis of dental disease in the horse in a prospective case-controlled study, comprising 30 horses with clinical signs of dental disease and 30 control horses. In each case, right and left lateral, ventral and dorsal soft tissue and bone phase scintigraphic images were obtained after i.v. injection of 1 GBq/100 kg bwt 99mTc-MDP, using a gamma camera. The same views were acquired in 10 horses with clinical signs of dental disease and 12 control horses after in...
Diagnostic findings and prognosis following arthroscopic treatment of subtle osteochondral lesions in the shoulder joint of horses: 15 cases (1996-1999). To determine clinical, scintigraphic, radiographic, and arthroscopic findings and results of treatment in horses with lameness attributable to subtle osteochondral lesions of the shoulder joint. Methods: Retrospective study. Methods: 15 horses. Methods: Medical records were reviewed, and results of physical examination, scintigraphy, radiography, arthroscopy, and treatment were recorded. Results: Severity of lameness ranged from grade 1 to 4. Response to shoulder flexion or extension was variable. Twelve horses had a narrow upright foot. Intra-articular anesthesia of the shoulder joint localiz...
Clinical effects of exercise on subchondral bone of carpal and metacarpophalangeal joints in horses. To determine effects of treadmill exercise on subchondral bone of carpal and metacarpophalangeal joints of 2-year-old horses. Methods: 12 healthy 2-year-old horses. Methods: Horses were randomly assigned to the control (n = 6) or exercised (6) groups. Horses in the exercised group ran on a high-speed treadmill 5 d/wk for 6 months. Horses in the control group were hand walked for the same amount of time. Results of clinical, radiographic, nuclear scintigraphic, and computed tomographic examinations, and serum and synovial concentrations of biochemical markers of bone metabolism were compared be...
Effect of a static magnetic field on blood flow to the metacarpus in horses. To determine the effect of a static magnetic field on relative blood flow to the metacarpus of horses. Methods: Randomized controlled clinical trial. Methods: 6 healthy adult horses. Methods: Red blood cells were radiolabeled in vivo by administration of technetium Tc 99m (pyro- and trimeta-) phosphates, and scintigraphic images were obtained 30 minutes later. A magnetic wrap that emitted a static magnetic field was applied to 1 metacarpus and a control wrap was applied to the contralateral metacarpus. Forty-eight hours later, the wraps were removed, and scintigraphy was repeated. Relative per...
Scintigraphic detection of equine orthopedic infection using Tc-HMPAO labeled leukocytes in 14 horses. The aim of this study was to evaluate the diagnostic value of 99mTc-HMPAO leukocyte scintigraphy (LS) by means of a retrospective review of its use in 14 horses that were evaluated for orthopedic infection as a cause of lameness. A total of 17 LS exams were performed in 14 horses. LS studies were positive in 10 of 14 horses. A bacterial infection was confirmed with cytology or culture in 9 of 10 positive horses. Negative LS studies occurred in 4 of 14 horses. Necropsy confirmed the lack of infection in 2 of the 4 horses. Other clinical data and a favorable clinical outcome supported a negative...
Effects of a digital filter on detectability of a phantom lesion in a scintigram of the equine tarsus. The aim of this study was to examine the effects of a digital filter on the detectability of a phantom lesion in a scintigram of the equine tarsus. Lateral images containing 50, 100, 150, 500, or 1000 kcounts were acquired. A created phantom lesion of 0 (normal), 10, 15, 20, or 30% increased intensity relative to local background was placed in the centrodistal tarsal joint area in the images of different count levels. Duplicate images were filtered with a Metz filter. The complete set of filtered and unfiltered images totaling 180 images was projected as slides to a group of 9 observers. The s...
Sclerosis of the third carpal bone. A prospective study of its significance in a group of young standardbred trotters. To assess the significance of radiographic signs of sclerosis of the third carpal bone (C3) in young Standardbred trotters in relation to performance, lameness and bone turnover both carpi in 14 Standardbred trotters were radiographically and scintigraphically examined 6 times, from the beginning of speed training until the beginning of racing, between the mean ages of 20 and 42 months. At the end of the study 8 horses had raced in official qualifying races and 14 limbs in 11 horses had been diagnosed with carpal lameness. All horses but 2 developed sclerosis and all but one had increased bone...
Scintigraphic characterization of distal radial physeal closure in young Standardbred racehorses. A longitudinal scintigraphic and radiographic study of distal radial physeal activity in 14 Standardbred trotters was conducted to quantify and visually evaluate physeal uptake around the time of physeal closure. Initial intense 99mTc-HDP uptake was seen, followed by a rapid decrease of activity starting at a mean age of 20 months. Mean physeal to distal diaphyseal ROI and line profile ratios compared to ratios of mature horses decreased from 2.8 to 1.4 at the time of radiographic closure at 24-32 months. Ratios then gradually decreased until values of mature horses were reached at the end of ...
Differences in uterine position of reproductively normal mares and those with delayed uterine clearance detected by scintigraphy. The position of the uterus within the abdomen may affect a mare's ability to rapidly clear the uterine lumen of contamination. In this study, the position of the uterus was determined from left and right lateral flank scintigrams taken 1 and 2 h after intrauterine infusion of radiocolloid. Scintigraphy was performed during estrus in 44 mares, 24 were reproductively normal and 20 exhibited a delay in uterine clearance. Reproductively normal mares were nulliparous (n = 14) or pluriparous (n = 10), 3 to 21 yr of age, had no history of persistent uterine infections and cleared > 50% of a radioc...
Dynamics of prostaglandin secretion, intrauterine fluid and uterine clearance in reproductively normal mares and mares with delayed uterine clearance. Two experiments were performed to investigate relationships between oxytocin, prostaglandin release, uterine emptying and fluid accumulation in the uterus. In Experiment 1, the effect of oxytocin on the pattern of prostaglandin release during uterine clearance of radiocolloid was measured in 5 normal mares and 5 mares with delayed uterine clearance. Uterine clearance was measured during estrus by scintigraphy at 0, 60 and 120 min after colloid infusion. After the 120-min reading, 20 IU, i.v., oxytocin were given, and the amount of colloid cleared was measured at 135, 150 and 180 min. Plasma wa...
Comparison of nuclear scintigraphy and acetaminophen absorption as a means of studying gastric emptying in horses. To evaluate the correlation between halftime of liquid-phase gastric emptying (T50), determined with nuclear scintigraphy using technetium Tc 99m pentetate, and absorption variables of orally administered acetaminophen. Methods: 6 mature horses. Methods: Technetium Tc 99m pentetate (10 mCi) and acetaminophen (20 mg/kg of body weight) were administered simultaneously in 200 ml of water. Serial left and right lateral images of the stomach region were obtained with a gamma camera, and T50 determined separately for counts obtained from the left side, the right side and the geometric mean. Power ex...
Feasibility of scintigraphy in exercise-induced pulmonary haemorrhage detection and quantification: preliminary studies. We hypothesised that scintigraphic imaging of the lungs following injection of 99mTc labelled red blood cells (99mTc-RBC) in the exercising horse might enable exercise-induced pulmonary haemorrhage (EIPH) quantification. Ideally, to favour detection of bleeding, circulating 99mTc-RBC not involved in the haemorrhage should be removed from the circulation quickly. Altering RBC during labelling to stimulate splenic uptake of 99mTc-RBC may encourage this. In order to investigate this hypothesis, 99mTc-RBC distribution was followed for 1 h in 2 groups of horses. Group 1 was injected i.v., at rest, ...
Transport of spermatozoa in the reproductive tracts of mares. A scintigraphic method was developed to study sperm migration in the reproductive tracts of mares. Mares (n=5) and stallions (n=2) were used to test various steps of the procedure and three other mares and a stallion were used to study sperm transportation. A radiolabelling solution was prepared from 99mTc (Technetium-99m) and hexamethyl propylene amine oxime. The highest labelling of spermatozoa (57-72%) was obtained by incubation of the spermatozoa with the radiolabelling solution for 20 min at 20 degrees C. Radioactivity outside the spermatozoa was removed by centrifugation and by two subse...
Results of bone scintigraphy in racing standardbred horses: 64 cases (1992-1994). To document anatomic patterns of scintigraphic uptake and related orthopedic disease associated with racing activity in Standardbred horses. Methods: Retrospective study. Methods: 64 Standardbred horses evaluated for lameness. Methods: Medical records at the time of discharge were reviewed, and information regarding signalment; history; results of lameness examination, scintigraphy, and radiography; diagnosis; and treatment were obtained. Results: 274 areas of increased radiopharmaceutical uptake were identified. Scintigrams of 218 limbs (106 forelimbs, 112 hind limbs) were available for revie...