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1.
The caudal lumbar and lumbosacral spine of 13 dogs with pain or neurologic deficits were evaluated using magnetic resonance imaging (MRI). Spin echo T1, proton density, and T2 weighted and gradient echo T2* imaging sequences were utilized. MRI permitted direct, multiplanar, tomographic visualization of the spine facilitating evaluation of all components of degenerative caudal lumbar and lumbosacral stenosis. Abnormalities detected included intervertebral disc degeneration, intervertebral disc protrusion involving both the vertebral canal and intervertebral foramina, articular process osteophytosis, articular process fracture, nerve root impingement by spondylosis deformans, and the presence of low signal material within the vertebral canal of 2 dogs with recurrent pain following previous spinal surgery. In all 7 dogs treated surgically, MRI findings were consistent with surgical findings.  相似文献   

2.
Recognition of disc degeneration in vivo is important in the investigation of the pathophysiology of intervertebral disc disease as well as the assessment of patients. The purpose of this study was to compare low-field magnetic resonance imaging and histopathologic findings of disc degeneration in the canine caudal lumbar spine. A simple four-stage classification system for disc degeneration is proposed. Most common signs of disc degeneration in magnetic resonance imaging included nuclear clefts, decreased signal intensity of the nucleus pulposus and tears of the annulus fibrosus, or disc herniations. The association between magnetic resonance images and histopathologic findings was highly significant. A sensitivity of 100% and specificity of 79% for magnetic resonance imaging was calculated using histopathology as the gold standard.  相似文献   

3.
为明确不同类型的椎间盘疝出疾病的磁共振影像(MRI)特点,本文对7例犬椎间盘疝出病例的诊治过程进行总结,通过一般检查、神经学检查和MRI扫描,诊断为椎间盘疝出。其中有3例为椎间盘突出,2例为椎间盘脱出,2例为椎间盘膨出。主要的MRI表现为椎间盘退变,T2加权像上的椎间盘信号降低,脊髓、硬膜囊不同程度的受压和变形。这些结果表明MRI扫描可对椎间盘组织是否发生退变以及椎间突出的程度进行准确判断,在犬椎间盘疝出的诊断与治疗中有极高的应用价值。  相似文献   

4.
The cervical spine of 27 dogs with cervical pain or cervical myelopathy was evaluated using magnetic resonance imaging (MRI). Spin echo T1, T2, and post-contrast T1 weighted imaging sequences were obtained with a 0.5 Tesla magnet in 5 dogs and a 1.5 Tesla magnet in the remaining 22 dogs. MRI provided for visualization of the entire cervical spine including the vertebral bodies, intervertebral discs, vertebral canal, and spinal cord. Disorders noted included intervertebral disc degeneration and/or protrusion (12 dogs), intradural extramedullary mass lesions (3 dogs), intradural and extradural nerve root tumors (3 dogs), hydromyelia/syringomyelia (1 dog), intramedullary ring enhancing lesions (1 dog), extradural synovial cysts (1 dog), and extradural compressive lesions (3 dogs). The MRI findings were consistent with surgical findings in 18 dogs that underwent surgery. Magnetic resonance imaging provided a safe, useful non-invasive method of evaluating the cervical spinal cord.  相似文献   

5.
Understanding the normal course and optimizing visualization of the canine peripheral nerves of the lumbar plexus, in particular the sciatic and the femoral nerves, is essential when interpreting images of patients with suspected peripheral neuropathies such as inflammatory or neoplastic conditions. The purpose of this prospective, anatomic study was to describe the magnetic resonance imaging (MRI) anatomy of the normal canine femoral and sciatic nerves and to define the sequences in which the nerves are best depicted. A preliminary postmortem cadaver study was performed to determine optimal sequences and imaging protocol. In a second step the optimized technique was implemented on 10 healthy Beagle dogs, included in the study. The applied protocol included the following sequences: T1‐weighted, T2‐weighted, T2‐Spectral Attenuated Inversion Recovery, T1‐weighted postcontrast and T1‐Spectral Presaturated Inversion Recovery postcontrast. All sequences had satisfactory signal‐to‐noise ratio and contrast resolution in all patients. The sciatic and femoral nerves were seen in all images. They were symmetric and of homogeneous signal intensity, being iso‐ to mildly hyperintense to muscle on T2‐weighted, mildly hyperintense in T2‐Spectral Attenuated Inversion Recovery, and iso‐ to mildly hypointense in T1‐weighted images. No evidence of contrast enhancement in T1‐weighted and T1‐Spectral Presaturated Inversion Recovery postcontrast sequences was observed. The anatomic landmarks helpful to identify the course of the femoral and sciatic nerves are described in detail. This study may be used as an anatomical reference, depicting the normal canine femoral and sciatic nerves at 3 Tesla MRI.  相似文献   

6.
The cervical spine of 21 dogs with clinical signs of cervical stenotic myelopathy was evaluated using magnetic resonance (MR) imaging. Spin echo T1, T2 and gradient echo T2 weighted images were obtained with a 1.5 Tesla magnet in 12 dogs and a 1.0 Tesla magnet in 9 dogs. Sagittal or parasagittal T1W and T2W images were helpful in determining the presence of spinal cord compression or degenerative disease of the articular processes. Transverse T1W and T2W images were the most useful for the identification of dorsolateral spinal cord compression secondary to soft tissue and ligament hypertrophy, as well as synovial cysts, associated with the articular processes. The MR imaging findings were consistent with the surgical findings in all 14 dogs that underwent surgery. Magnetic resonance imaging provided a safe, non-invasive method of evaluating the cervical spine in dogs suspected of having cervical stenotic myelopathy. Veterinary  相似文献   

7.
German shepherd dogs are overrepresented in the group of dogs with cauda equina compression syndrome due to degenerative lumbosacral stenosis. A congenital predisposition for early degeneration of the lumbosacral intervertebral disc has been suspected. Our aims were to assess the morphologic appearance of the lumbosacral intervertebral disc and the lumbosacral junction in healthy German shepherd dogs compared to other breeds and to evaluate for an early onset of degenerative changes. The lumbosacral spine of 110 clinically sound German shepherd dogs and 47 healthy dogs of other large breeds was examined using magnetic resonance (MR) imaging. The degeneration of every intervertebral disc was graded using an established classification system. Signal intensity of the entire lumbosacral disc and the nucleus pulposus was determined independently. Lumbosacral malalignment was assessed according to a previously described method. The findings for the German shepherd dogs were compared to those of the other breeds. Although most dogs were younger than 18 months at the date of examination, significantly higher grades of degeneration were detected for the lumbosacral intervertebral disc of German shepherd dogs (P < 0.003). Degeneration of the lumbosacral intervertebral disc was independent from findings in the other lumbar discs. We conclude that the German shepherd dog has a predisposition for degenerative changes in the lumbosacral intervertebral disc.  相似文献   

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9.
Cranial thoracic intervertebral disc herniations have been reported to be rare in dogs due to the presence of the intercapital ligament, however some studies have proposed they may not be uncommon in German Shepherd dogs. The purpose of this retrospective study was to compare cranial thoracic intervertebral disc herniations in German Shepherd dogs and other large breed dogs (control group). Medical records at the Ontario Veterinary College were searched for German Shepherd dogs and other large breed dogs that had magnetic resonance imaging studies including the T1‐T9 region. For each dog and each disc space from T1‐T9, three variables (compression, disc degeneration, and herniation) were recorded and graded based on review of sagittal T2‐weighted images. Twenty‐three German Shepherd dogs and 47 other large breed dogs met inclusion criteria. The German Shepherd dog group had higher scores than the control group for compression (P = 0.0099) and herniation (P < 0.001), but not disc degeneration (P = 0.97). In the German Shepherd dog group, intervertebral discs T2‐T3 and T4‐T5 had an increased risk for compression and T3‐T4 had an increased risk for compression and herniation. Findings from this study indicated that German Shepherd dogs may be more likely than other large breed dogs to have spinal cord compression due to cranial thoracic disc herniations. Imaging of the cranial thoracic spine, including T2‐T3, is recommended for German Shepherd dogs with T3‐L3 neurological signs.  相似文献   

10.
A 4-year-old neutered female terrier-cross was evaluated for an acute onset of paraplegia. Utilizing magnetic resonance (MR) imaging, the cause of the neurologic deficits was determined to be a lumbar intervertebral disc extrusion. The MR study additionally demonstrated parenchymal hyperintensity on T2-weighted images and similarly located diffuse hypointensity on gradient echo images, cranial and caudal to the compressive extradural lesion. Hemorrhagic myelomalacia was suspected based on these MR characteristics, which was subsequently confirmed surgically and histopathologically.  相似文献   

11.
OBJECTIVE: To determine the association between the 3-dimensional (3-D) motion pattern of the caudal lumbar and lumbosacral portions of the canine vertebral column and the morphology of vertebrae, facet joints, and intervertebral disks. SAMPLE POPULATION: Vertebral columns of 9 German Shepherd Dogs and 16 dogs of other breeds with similar body weights and body conditions. PROCEDURE: Different morphometric parameters of the vertebral column were assessed by computed tomography (CT) and magnetic resonance imaging. Anatomic conformation and the 3-D motion pattern were compared, and correlation coefficients were calculated. RESULTS: Total range of motion for flexion and extension was mainly associated with the facet joint angle, the facet joint angle difference between levels of the vertebral column in the transverse plane on CT images, disk height, and lever arm length. CONCLUSIONS AND CLINICAL RELEVANCE: Motion is a complex process that is influenced by the entire 3-D conformation of the lumbar portion of the vertebral column. In vivo dynamic measurements of the 3-D motion pattern of the lumbar and lumbosacral portions of the vertebral column will be necessary to further assess biomechanics that could lead to disk degeneration in dogs.  相似文献   

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13.
The T2*‐weighted gradient recalled echo sequence is a sensitive means to detect blood degradation products. While not a routine sequence in magnetic resonance imaging of the spine in small animals, it can provide additional valuable information in select cases. The goal of this retrospective, cross‐sectional study was to describe findings when acquiring this sequence during magnetic resonance imaging examination of the spine in small animals. The University of Tennessee's veterinary radiology database was searched for dogs and cats that underwent magnetic resonance imaging for suspect spinal disease in which a T2*‐weighted gradient recalled echo sequence was acquired and susceptibility artifact was identified. The following information was recorded: signalment, clinical signs, location and appearance of susceptibility artifact, and final diagnosis. Thirty‐nine cases were included in the study. Extradural susceptibility artifacts were observed in cases of intervertebral disc herniation with or without associated hemorrhage (n = 28), extradural hemorrhage associated with spinal trauma (n = 2), hemophilia (n = 1), and in a cystic extradural mass (n = 1). Remaining lesions displaying susceptibility artifact were intramedullary and included presumptive acute noncompressive nucleus pulposus extrusion (n = 2), hematoma (n = 1), hemangiosarcoma metastasis (n = 1), intramedullary disc extrusion (n = 1), presumptive meningomyelitis (n = 1), and a mass of undetermined etiology (n = 1). Inclusion of a T2*‐weighted gradient recalled echo sequence may be helpful in spinal magnetic resonance imaging when standard imaging sequences are ambiguous or intramedullary lesions are observed.  相似文献   

14.
Three dogs with multilobular osteochondrosarcoma of the skull were evaluated using magnetic resonance (MR) imaging. Spin echo T1, T2, proton weighted and post contrast T1W images were obtained with a 1.5 Tesla magnet. The MR imaging findings were similar in all three dogs with mixed signal intensities in the T1W, T2W and proton weighted images and fairly large areas of contrast enhancement in the post contrast T1W images. The extent of brain and soft tissue involvement were well delineated and provided useful information concerning surgical planning. MR imaging provided a useful method of evaluating dogs with skull tumors.  相似文献   

15.
Various magnetic resonance (MR) imaging techniques have been used to assess lumbar spinal abnormalities in people. Four, young adult, clinically normal dogs were used to compare images of the spinal cord acquired using conventional spin-echo and rapid acquisition relaxation-enhanced (RARE), commonly called fast spin-echo (FSE), magnetic resonance imaging techniques. Lateral myelograms were made as an anatomic control. The T2-weighted FSE technique was characterized by better image quality than the T2-weighted conventional spin-echo technique. The short acquisition time with the FSE technique allowed increases in the matrix size and number of excitations, thus improving resolution and signal-to-noise ratio. In canine lumbar spinal MR imaging, use of a FSE technique is recommended to reduce the overall time for imaging and to improve image quality.  相似文献   

16.
OBJECTIVE: To compare morphologic and morphometric features of the cervical vertebral column and spinal cord of Doberman Pinschers with and without clinical signs of cervical spondylomyelopathy (CSM; wobbler syndrome) detected via magnetic resonance imaging (MRI). ANIMALS: 16 clinically normal and 16 CSM-affected Doberman Pinschers. PROCEDURES: For each dog, MRI of the cervical vertebral column (in neutral and traction positions) was performed. Morphologically, MRI abnormalities were classified according to a spinal cord compression scale. Foraminal stenosis and intervertebral disk degeneration and protrusion were also recorded. Morphometric measurements of the vertebral canal and spinal cord were obtained in sagittal and transverse MRI planes. RESULTS: 4 of 16 clinically normal and 15 of 16 CSM-affected dogs had spinal cord compression. Twelve clinically normal and all CSM-affected dogs had disk degeneration. Foraminal stenosis was detected in 11 clinically normal and 14 CSM-affected dogs. Vertebral canal and spinal cord areas were consistently smaller in CSM-affected dogs, compared with clinically normal dogs. In neutral and traction positions, the intervertebral disks of CSM-affected dogs were wider than those of clinically normal dogs but the amount of disk distraction was similar between groups. CONCLUSIONS AND CLINICAL RELEVANCE: The incidence of intervertebral disk degeneration and foraminal stenosis in clinically normal Doberman Pinschers was high; cervical spinal cord compression may be present without concurrent clinical signs. A combination of static factors (ie, a relatively stenotic vertebral canal and wider intervertebral disks) distinguished CSM-affected dogs from clinically normal dogs and appears to be a key feature in the pathogenesis of CSM.  相似文献   

17.
BackgroundMultifidus muscle stiffness decreases in patients with lumbar intervertebral disk herniation; however, age-related changes in humans have not been reported.ObjectivesThe reliability of ultrasound shear wave elastography in dogs, and changes in the shear elastic modulus of the thoracolumbar multifidus muscle with aging in dogs, were investigated.MethodsTwelve beagle dogs were divided into 2 groups based on the age of onset of intervertebral disk herniation: young (aged not exceeding 2 years; 1.3 ± 0.6 years old, n = 5) and adult (4.9 ± 1.2 years old, n = 7). The shear elastic modulus of the multifidus muscle, from the thirteenth thoracic spine to the fourth lumbar spine, was measured using ultrasound shear wave elastography. The length, cross-sectional area and muscle to fat ratio of the multifidus muscle, and the grade of intervertebral disk degeneration, were assessed using radiographic and magnetic resonance imaging examinations.ResultsThe length and cross-sectional area of the multifidus muscle increased caudally. In the young group, the shear elastic modulus of the multifidus muscle of the thirteenth thoracic spine was less than that of the third lumbar spine. In the adult group, the shear elastic modulus of the multifidus muscle of first and third lumbar spine was lower than that of the same site in the young group.ConclusionsUltrasound can be used to measure shear wave elastography of the thoracolumbar multifidus in dogs. If the multifidus muscle stiffness decreases, we should consider age-related change.  相似文献   

18.
The purpose of this study was to describe the appearance of normal bone marrow in seven adult dogs using low-field (0.3 T) magnetic resonance (MR) imaging. The areas imaged included the lumbar spine, pelvis, and femur. T1-weighted, fast spin-echo T2-weighted, and short tau (T1) inversion recovery (STIR) sequences were obtained at all locations. Histopathology was performed on sections from the sixth lumbar vertebral body, the wing of the ilium, and the femur (head and neck, mid-diaphysis, and condyle) for evaluation of cellularity and fat content. The lumbar spine and pelvic marrow MR images were similar in all dogs. The lumbar vertebral bone marrow was uniform, intermediate signal intensity, and isointense to muscle on all sequences. There was variation between dogs in the bone marrow distribution with MR imaging of the femur. In the proximal and mid-diaphysis of the femur there was patchy high-signal intensity on T1- and T2-weighted images, and hypointense foci on the STIR images. The distal femoral metaphysis had a variable pattern ranging from intermediate-to-high signal on T1- and T2-weighted images and intermediate-to-low signal on STIR images. The femoral condyles were uniformly high signal on T1- and T2-weighted images and hypointense on STIR images. Histopathologically there was a normal variation in the bone marrow cellularity. The marrow was normocellular (25–75% cellularity) for all sites examined except the femoral condyles, which were hypocellular (<25% cellularity).  相似文献   

19.
The canine meninges are not visible as discrete structures in noncontrast magnetic resonance (MR) images, and are incompletely visualized in T1‐weighted, postgadolinium images, reportedly appearing as short, thin curvilinear segments with minimal enhancement. Subtraction imaging facilitates detection of enhancement of tissues, hence may increase the conspicuity of meninges. The aim of the present study was to describe qualitatively the appearance of canine meninges in subtraction MR images obtained using a dynamic technique. Images were reviewed of 10 consecutive dogs that had dynamic pre‐ and postgadolinium T1W imaging of the brain that was interpreted as normal, and had normal cerebrospinal fluid. Image‐anatomic correlation was facilitated by dissection and histologic examination of two canine cadavers. Meningeal enhancement was relatively inconspicuous in postgadolinium T1‐weighted images, but was clearly visible in subtraction images of all dogs. Enhancement was visible as faint, small‐rounded foci compatible with vessels seen end on within the sulci, a series of larger rounded foci compatible with vessels of variable caliber on the dorsal aspect of the cerebral cortex, and a continuous thin zone of moderate enhancement around the brain. Superimposition of color‐encoded subtraction images on pregadolinium T1‐ and T2‐weighted images facilitated localization of the origin of enhancement, which appeared to be predominantly dural, with relatively few leptomeningeal structures visible. Dynamic subtraction MR imaging should be considered for inclusion in clinical brain MR protocols because of the possibility that its use may increase sensitivity for lesions affecting the meninges.  相似文献   

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