首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 187 毫秒
1.
2.
3.
OBJECTIVE: To test the effects of computed tomography (CT) image plane and window settings on diagnostic certainty for CT characteristics associated with dysplastic elbow joints (elbow joint dysplasia) in dogs and to provide optimal display guidelines for these CT characteristics. SAMPLE POPULATION: CT images of 50 dysplastic elbow joints from 49 lame dogs and 10 elbow joints from 5 sound dogs. PROCEDURES: CT image data were obtained in transverse, sagittal, and dorsal planes. Each plane was examined by use of 3 Hounsfield unit (HU) window settings. Two veterinary radiologists independently evaluated sets of CT images for evidence of 7 CT characteristics. Effect of elbow joint status, image plane, and window settings on diagnostic certainty for these CT characteristics was tested by use of a visual analogue scale. RESULTS: Diagnostic certainty for abnormalities of the medial coronoid process (MCP) and radial incisure was highest in the transverse plane, subchondral defects or sclerosis of the trochlea humeri was highest in the dorsal plane, and joint incongruity was highest in the sagittal plane. Certainty for hypoattenuating subchondral defects or fissures was highest at 2,500 or 3,500 HUs, whereas certainty for subchondral sclerosis was highest at 1,500 HUs and lowest at 3,500 HUs. CONCLUSIONS AND CLINICAL RELEVANCE: Diagnostic certainty for CT characteristics of elbow joint dysplasia in dogs was affected by image display variables. Diagnostic certainty for altered subchondral bone density was primarily influenced by window settings, whereas structural MCP abnormalities and joint incongruity were influenced most by image plane.  相似文献   

4.
5.
The objective of this study was to provide a detailed multiplanar computed tomographic (CT) anatomic reference for the bovine tarsus. The tarsal regions from twelve healthy adult cow cadavers were scanned in both soft and bone windows via a 16‐slice multidetector CT scanner. Tarsi were frozen at ?20o C and sectioned to 10‐mm‐thick slices in transverse, dorsal and sagittal planes respecting the imaging protocol. The frozen sections were cleaned and then photographed. Anatomic structures were identified, labelled and compared with the corresponding CT images. The sagittal plane was indispensable for evaluation of bone contours, the dorsal plane was valuable in examination of the collateral ligaments, and both were beneficial for assessment of the tarsal joint articulations. CT images allowed excellent delineation between the cortex and medulla of bones, and the trabecular structure was clearly depicted. The tarsal soft tissues showed variable shades of grey, and the synovial fluid was the lowest attenuated structure. This study provided full assessment of the clinically relevant anatomic structures of the bovine tarsal joint. This technique may be of value when results from other diagnostic imaging techniques are indecisive. Images presented in this study should serve as a basic CT reference and assist in the interpretation of various bovine tarsal pathology.  相似文献   

6.
The aim of the present study was to evaluate to what extent the distal tibia and the trochlear ridges of the talus can be examined with ultrasound (US) in the dog and to establish a protocol for an optimal US examination of these ridges. Six hind limbs of deceased adult mixed-breed dogs were used. In two limbs, needles were placed using US guidance on the trochlea of the talus, just dorsal to and plantar to the distal tibia: one with the tarsal joint in extension and one with the joint in flexion. Then mediolateral (ML) radiographs of both joints were made with the needle in place to determine the percentage of the trochlear ridge of the talus that can be seen using US imaging. An US examination of the tarsal joint was performed on the four other limbs using microconvex (8 MHz) and linear (12 MHz) transducers (Logiq 7) and compound imaging. A three-step protocol was performed including a dorsal approach with the limb extended and the linear transducer (step I), a plantar approach with the limb flexed and the linear transducer (step II), and a plantar approach with the limb flexed and the microconvex transducer (step III). After the US examination, the four limbs were frozen and sectioned, two in a transverse and two in a sagittal plane. Bony structures on the US images were matched with the corresponding anatomic sections. The distal tibia and both trochlear ridges of the talus were easily recognized on the US images using the proposed protocol. When combining the dorsal and plantar approaches, it was possible to visualize up to 75% of the trochlear ridges of the talus in the dog.  相似文献   

7.
Objective To investigate whether rostral extension of the hind limbs increases the cranio‐caudal dorsal interlaminar distance between the seventh lumbar vertebra and the sacral bone (LS distance) in sternally recumbent anesthetized dogs. Study design Prospective clinical study. Animals Eighteen dogs (eight neutered males, three intact males, six spayed females, one intact female) of various breeds, weighing 4–34 kg and ranging in age from 1 to 13 years. Methods Each dog was grouped by size: small (≤10 kg), medium (15–20 kg) or large (≥25 kg). Each dog was anesthetized and positioned in sternal recumbency. Computed tomography (CT) of the lumbosacral area was performed with the hind limbs resting on the stifle and the feet extended posteriorly, and then with the hind limbs extended rostrally. LS distance, craniocaudal dorsal interlaminar distance between sixth and seventh lumbar vertebra (L6–L7 distance), length of L7 vertebral body and lumbosacral angle (LS angle) were measured on a reconstructed mid‐sagittal CT image from the two hind limb positions. The measurements from the two hind limb positions for the whole dog population and by size were compared using Student’s T tests. Diagnostic interpretation of the CT images was performed. Results The length of L7 was taken as the reference value as it was not affected by hind limb position. LS distance, L6–L7 distance and LS angle were significantly higher when the hind limbs were extended rostrally in all three size groups. The CT images of ten dogs showed clinically undetected osteoarthrosis of the ileo‐ and lumbosacral area. Conclusions and clinical relevance Rostral extension of the hind limbs significantly increases LS and L6–L7 distance and LS angle even in dogs with clinically undetected osteoarthrosis of the ileo‐ and lumbosacral area, and may enhance the ease of lumbosacral epidural injection in sternally recumbent anesthetized dogs.  相似文献   

8.
Reasons for performing study: The equine temporomandibular joint (TMJ) and its surrounding structures can be difficult to investigate in cases with a clinical problem related to the region. Little previous attention has been given either to a computed tomographic (CT) imaging protocol for the joint or an interpretation of the structures displayed in CT images of the normal joint. Objectives: To provide a CT atlas of the normal cross‐sectional anatomy of the equine TMJ using frozen and plastinated sections as anatomical reference. Methods: Eight TMJs from 4 immature pure‐bred Spanish horses were examined by helical CT. Scans were processed with a detailed algorithm to enhance bony and soft tissue. Transverse CT images were reformatted into sagittal and dorsal planes. Transverse, sagittal and dorsal cryosections were then obtained, photographed and plastinated. Relevant anatomic structures were identified in the CT images and corresponding anatomical sections. Results: In the CT images, a bone window provided excellent bone detail, however, the soft tissue components of the TMJ were not as well visualised using a soft tissue window. The articular cartilage was observed as a hyperattenuating stripe over the low attenuated subchondral bone and good delineation was obtained between cortex and medulla. The tympanic and petrous part of the temporal bone (middle and inner ear) and the temporohyoid joint were seen in close proximity to the TMJ. Conclusions: Helical CT provided excellent images of the TMJ bone components to characterise the CT anatomy of the normal joint. Potential relevance: Detailed information is provided that may be used as a reference by equine veterinarians for the CT investigation of the equine TMJ and serve to assist them in the diagnosis of disorders of the TMJ and related structures (middle and inner ear). The study was performed at an immature stage and further studies of mature individuals are required in order to confirm that the clinical interpretation is not affected by changes occurring with age.  相似文献   

9.
OBJECTIVE: To describe anatomy of the orbits as revealed by computed tomography (CT) in different scan planes, determine the most useful scan plane for imaging the eye, optic nerve, and extraocular muscles, and compare image quality of direct CT images with reconstructed images obtained from 2-mm-thick and 5-mm-thick transverse images. ANIMALS: 9 dogs with no ocular abnormalities. PROCEDURE: In 3 dogs, CT was combined with cisternography to facilitate imaging of the optic nerve and determine the scan plane that allowed optimum imaging of the optic nerve in a single image. In 6 dogs, CT images were made in transverse, dorsal oblique, and sagittal oblique scan directions. Dorsal and sagittal reconstructions were made from transverse images. RESULTS: In all dogs, scanning in different planes enabled identification of ocular structures, optic nerves, and orbital adnexa, as well as identification of the confines of the orbit. Imaging of optic nerve and extraocular muscles was optimal on dorsal oblique scans at an angle of 43 to 45 degrees to the skull base and on sagittal oblique images at an angle of 59 to 61 degrees to the midline of the skull. CONCLUSIONS AND CLINICAL RELEVANCE: All scan directions provided detailed images of orbital structures. Transverse images were convenient for survey examination, and dorsal oblique and sagittal oblique images were superior for imaging optic nerves and extraocular muscles. Image quality of reconstructed images obtained from the 2-mm-thick transverse images was superior to that obtained from the 5-mm-thick images. Optimum quality was achieved with direct multiplanar imaging.  相似文献   

10.
11.
12.
Margaret A.  Blaik  DVM  R. Reid  Hanson  DVM  Steven A.  Kincaid  DVM  MS  PhD  John T.  Hathcock  DVM  MS  Judith A.  Hudson  DVM  PhD  Debra K.  Baird  DVM  PhD 《Veterinary radiology & ultrasound》2000,41(2):131-141
The objective of this study was to define the normal gross anatomic appearance of the adult equine tarsus on a low-field magnetic resonance (MR) image. Six radiographically normal, adult, equine tarsal cadavers were utilized. Using a scanner with a 0.064 Tesla magnet, images were acquired in the sagittal, transverse and dorsal planes for T1-weighted and the sagittal plane for T2-weighted imaging sequences. Anatomic structures on the MR images were identified and compared with cryosections of the imaged limbs. Optimal image planes were identified for the evaluation of articular cartilage, subchondral bone, flexor and extensor tendons, tarsal ligaments, and synovial structures. MR images provide a thorough evaluation of the anatomic relationships of the structures of the equine tarsus.  相似文献   

13.
OBJECTIVES: To assess the accuracy of reconstructed computed tomography for imaging canine elbow joint spaces. METHODS: Computed tomography scans of eight cadaveric elbows were obtained and reconstructed computed tomography images were formatted in the dorsal and sagittal planes. Humeroradial and humeroulnar joint space measurements were obtained from these images. Intra-observer and inter-observer variations in joint space measurements were assessed, as was the effect of specimen positioning (inter-image variation). After freezing, four elbows were sectioned in the dorsal plane and four in the sagittal plane. In addition to visual comparison of the frozen sections with reconstructed computed tomography images, joint space measurements were obtained from frozen sections and compared with those from reconstructed computed tomography images. Variation was assessed using statistical calculations and graphical techniques. RESULTS: Both inter-image and intra-observer analyses revealed good agreement and low variation between data sets. Inter-observer correlation was only moderate, though variation was low. Visually, the reconstructed computed tomography images accurately reflected the frozen section anatomy. Agreement between frozen section and reconstructed computed tomography joint space measurements was good, with minimal variation. CLINICAL SIGNIFICANCE: These results indicate that reconstructed computed tomography is capable of accurately imaging elbow joint spaces and precise joint space measurements can be obtained. Reconstructed computed tomography may be useful for determining joint space measurements and detecting elbow incongruencies in dogs with elbow dysplasia.  相似文献   

14.
15.
This study has been carried out to determine the effect of neutral position, hyperextension and hyperflexion of the tarsal joint on the tibial nerve, motor action potential latency and tarsal canal compartment pressure in dogs with the aid of electrophysiological and anatomical methods. Totally twenty healthy mongrel dogs were used. Latency of motor nerve action potential (MNAPL) studies of tibial nerve via surface stimulating and needle recording electrodes was performed on right hind limbs of all the dogs. The compartment pressures of the tarsal canal with the pressure transducer were determined from both limbs from ten of the dogs. In one dog, tarsal regions of both left and right limbs were demonstrated using magnetic resonance imaging (MRI). Two dogs were euthanatized and tarsal regions of the dogs were sectioned for correlative anatomy. Nerve conduction studies showed that the MNAP latency of the tibial nerve were 3.55 +/- 0.097 ms, 3.76 +/- 0.087 ms and 3.39 +/- 0.097 ms in neutral, hyperextension and hyperflexion positions, respectively. Hyperflexion of the tarsal joint caused prolongation of the MNAP latency of the tibial nerve with the highest pressure value being determined in tarsal canal. From the anatomical viewpoint, the distance between the flexor hallucis longus muscle and the superficial digital muscle was the shortest during hyperflexion and the plantar branch of saphenous artery, lateral and medial plantar nerves located more laterally in cadaver and MR imaging sections. As a result of this study, it is thought that tarsal region diseases as well as long time splint in the hyperflexion position as applied in the Ehmer sling can affect the compartment pressure and nerve tension because of occupying in the tarsal canal. Raising pressure and nerve stretching in the tarsal canal compartment could cause deficiencies in the conduction velocity of the tibial nerve. This might be a result of tarsal tunnel syndrome in the dog. Clinicians could consider this syndrome in cases of tarsal region diseases as well as application of long time splint in hyperflexion of tarsal joints in dogs.  相似文献   

16.
OBJECTIVE: To test the hypotheses that kinematic data of the sagittal motion of canine hind limbs during walking obtained with a 2-dimensional (2-D) system correlate well with those obtained with a 3-dimensional (3-D) system and that the data obtained with the 2-D system are repeatable. ANIMALS: 6 adult dogs with no evidence of lameness. PROCEDURES: Hind limb motions of 6 walking dogs were recorded via 2-D video and 3-D optoelectric systems simultaneously. Five valid trials were digitized, and 5 data sets (2-D 60 Hz, 3-D 180 Hz, 3-D sagittal 180 Hz, 3-D 60 Hz, and 3-D sagittal 60 Hz) of a complete gait cycle were created for each dog. In sagittal data sets, 3-D data were reduced to exclude coordinates for mediolateral orientation. Temporospatial parameters; angles of hip, stifle, and tarsal joints; and coefficients of variation of angular measurements of each dog were calculated for each data set. Accuracy of the 2-D analysis was determined by calculating mean absolute differences and estimating agreement between the 2-D and 3-D 180-Hz data sets. RESULTS: Values of joint angles and angular excursions measured with the 2-D system were repeatable and agreed with respective values obtained with the 3-D system. Reduction of the sampling rate had a greater impact on values of kinematic variables obtained with the 3-D system than did elimination of data on mediolateral orientation. CONCLUSIONS AND CLINICAL RELEVANCE: Kinematic analysis using a 2-D video system provided accurate and repeatable data of the sagittal angular motion of canine hind limbs during walking.  相似文献   

17.
Magnetic resonance (MR) images of the normal eye and orbit of the dog and cat were acquired. T1-weighted, proton-density, and T2-weighed images were obtained in the oblique dorsal, straight sagittal, and oblique sagittal planes. Signal intensity for the various orbital structures differed among the three resonance techniques. T1-weighted images provided the greatest contrast of the retrobulbar structures. T-1 weighted images also had the highest signal to noise ratio, thereby providing the best anatomic detail. Anatomic components of the globe, retrobulbar structures and ocular adnexa were easily seen in all MR sections. The oblique dorsal and oblique sagittal planes were superior for evaluating the optic nerve in its entirety.  相似文献   

18.
OBJECTIVE: To quantify the effects of trotting velocity on joint angular excursions, net joint moments, and powers across the hind limb joints in Greyhounds. ANIMALS: 5 healthy Greyhounds with no history of lameness of the hind limbs. PROCEDURES: Small reflective markers were applied to the skin over the joints of the hind limbs, and a 4-camera kinematic system was used to record positional data at 200 Hz in tandem with force platform data while the dogs trotted on a runway at slow, medium, and fast velocities. Breed-specific morphometric data were combined with kinematic and force data in an inverse-dynamics solution for net joint moments and powers at the hip, stifle, tarsal, and metatarsophalangeal joints. RESULTS: Angle, moment, and power patterns at the various joints were conserved among the 3 velocities. With increasing velocity, moments and powers at the tarsal, stifle, and hip joints during the stance phase were increased in amplitude, whereas amplitudes during the swing phase were not. The main contributors to increased velocity were the hip extensors and stifle flexors during the early part of the stance phase and the tarsal extensors during the late part of the stance phase. CONCLUSIONS AND CLINICAL RELEVANCE: Increases in trotting velocity in Greyhounds do not alter the basic patterns of work and power for various joints of the hind limbs, but local burst amplitudes during the stance phase increase incrementally.  相似文献   

19.
OBJECTIVE: To correlate anatomic features of the equine tarsus identified in plastinated sections with images obtained via magnetic resonance imaging (MRI). ANIMALS: 4 horses. PROCEDURE: MRI (1.5-Tesla magnet) of the tarsus was performed on the pelvic limbs of 4 clinically normal horses following euthanasia. After imaging, tarsocrural joint spaces and vasculature were injected with colored latex. Sagittal and transverse sections of the tarsi were plastinated to facilitate interpretation of MR images. RESULTS: Relevant anatomic structures were identified and labeled on the plastinated tissue slices and corresponding MR images. Results indicated high correlations between MRI findings and those of plastinated sections. CONCLUSIONS AND CLINICAL RELEVANCE: The data obtained provided certain reference standards for normal anatomic structure sizes and positions in the equine tarsus. This information may aid future physiologic or clinical studies of this joint.  相似文献   

20.
A 16-year-old, Quarter Horse mare was presented for a 3/5 right hind lameness associated with osteoarthritis of the talocalcaneal joint (TCLJ). Positron emission tomography (PET) and computed tomography (CT) demonstrated marked increased uptake of 18F-sodium fluoride and bone remodeling at the medial facet of the TCLJ, respectively. Under general anesthesia 2 cortical screws (4.5 and 5.5 mm) were placed in neutral fashion via an arthrotomy from dorsomedial to plantaromedial through the medial facet of the TCLJ followed by copious lavage of the tarsocrural joint. Eight weeks after surgery, observable effusion of the tarsocrural joint was present and lameness had worsened. Radiographic examination revealed a fragmented medial malleolus of the tibia, likely secondary to repetitive trauma of the screw heads during tarsal flexion. Repeated CT showed partial fusion of the TCLJ. Both screws were removed and the tarsocrural joint was thoroughly lavaged arthroscopically. At a 20-month recheck the lameness had not improved, and ultrasound examination revealed severe thickening of the TCLJ capsule. Recheck examination 48 mo after surgery showed complete fusion of the TCLJ and resolution of the lameness.Key clinical message:Diagnosis of osteoarthritis of the TCLJ is challenging. Management by arthrodesis using a dorsomedial approach can result in fragmentation of the medial malleolus, with secondary synovitis and capsulitis of the tarsocrural joint.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号