CT myelography of the thoraco-lumbar spine in 8 dogs with degenerative myelopathy (original) (raw)
Related papers
Imaging Diagnosis-CT Myelography in a Dog with Intramedullary Intervertebral Disc Herniation
Veterinary Radiology & Ultrasound, 2011
A 5-year-old Chihuahua was examined for peracute pain and paraparesis. Neuroanatomic localization was consistent with a symmetric T3-L3 myelopathy. Computed tomography (CT) of the T9-L5 vertebrae was normal. Myelography disclosed attenuation of the subarachnoid space from T11 to L1, consistent with spinal cord swelling. CT following the myelogram disclosed a focal area of intramedullary iodinated contrast medium at T13-L1. At surgery, intervertebral disc material was removed from the spinal cord. Based on the findings in this patient, intramedullary disc herniation should be considered a cause for focal intramedullary contrast medium accumulation. r
Veterinary Radiology & Ultrasound, 2006
Eighteen Doberman pinscher dogs with clinical signs of cervical spondylomyelopathy (wobbler syndrome) underwent cervical myelography and magnetic resonance (MR) imaging. Cervical myelography was performed using iohexol, followed by lateral and ventrodorsal radiographs. Traction myelography was performed using a cervical harness exerting 9 kg of linear traction. MR imaging was performed in sagittal, transverse, and dorsal planes using a 1.5 T magnet with the spine in neutral and traction positions. Three reviewers independently evaluated the myelographic and MR images to determine the most extensive lesion and whether the lesion was static or dynamic. All reviewers agreed with the location of the most extensive lesion on MR images (100%), while the agreement using myelography was 83%. The myelogram and MR imaging findings agreed in the identification of the affected site in 13-16 dogs depending on the reviewer. MR imaging provided additional information on lesion location because it allowed direct examination of the spinal cord diameter and parenchyma. Spinal cord signal changes were seen in 10 dogs. Depending on the reviewer, two to four dogs had their lesions classified as dynamic on myelography but static on MR images. Myelography markedly underscored the severity of the spinal cord compression in two dogs, and failed to identify the cause of the signs in another. The results of this study indicated that, although myelography can identify the location of the lesion in most patients, MR imaging appears to be more accurate in predicting the site, severity, and nature of the spinal cord compression.
Veterinary Radiology & Ultrasound, 2010
Forty-six dogs with either cervical (C1-C5 or C6-T2) or thoracolumbar (T3-L3) acute myelopathy underwent prospective conventional computed tomography (CT), angiographic CT, myelography, and CT myelography. Findings were confirmed at either surgery or necropsy. Seventy-eight percent of lesions were extradural, 11% were extradural with an intramedullary abnormality, 7% were intramedullary, 2% were intradural-extramedullary, and 2% had nerve root compression without spinal cord compression. Intervertebral disc herniation was the most frequent abnormality regardless of signalment or neurolocalization. Twenty-one of 23 Hansen type I disc extrusions but none of the Hansen type II disc protrusions were mineralized. Two chondrodystrophic dogs had acute myelopathy attributable to extradural hemorrhage and subarachnoid cyst. CT myelography had the highest interobserver agreement, was the most sensitive technique for identification of compression, demonstrating lesions in 8% of dogs interpreted as normal from myelography and enabling localization and lateralization in 8% of lesions incompletely localized on myelography due to concurrent spinal cord swelling. None of the imaging techniques evaluated permitted definitive diagnosis of spinal cord infarction or meningomyelitis but myelography and CT myelography did rule out a surgical lesion in those cases. While conventional CT was adequate for the diagnosis and localization of mineralized Hansen type I disc extrusions in chondrodystrophic breeds, if no lesion was identified, plegia was present due to concurrent extradural compression and spinal cord swelling, or the dog was nonchondrodystrophic, CT myelography was often necessary for correct diagnosis.
Epidemiological aspects of myelography in dogs: 61 cases (2003–2012)
Semina: Ciências Agrárias, 2014
Myelography is a radiological contrast examination technique frequently used in the diagnosis of vertebral spine and spinal cord disorders. The procedure involves inserting a needle with subsequent injection of contrast medium, which delimits the spinal cord. The main indication is suspected spinal injuries not visualized on plain radiographs. Myelography is effective in the identification of the location of the lesion but is contraindicated in patients with infectious diseases or who have recently experienced trauma. Advantages of myelography are cost effectiveness in both the examination procedure and maintenance of equipment, and delivery of quality images, compared with other imaging methods in dogs. Disadvantages include a relatively long examination procedure, the need for general anesthesia, and the risk of seizures or death. The aim of this study was to characterize a population of dogs undergoing myelography according to the following factors: severity of injury, breed, age, sex, reproductive status, diet, weight, previous illnesses, vertebral region evaluated, lesion location in spinal cord or meninges, cause of radiographic signs, and possible complications. The database was created from information in medical records, and included 61 dogs with suspected disorders of the vertebral spine, spinal cord, and/or meninges that underwent myelography at the Unidade Hospitalar para Animais de Companhia of Pontifícia Universidade Católica do Paraná from January 2003 through December 2012. The results indicate that the most common degree of injury severity was Grade 2 (39.34% of the patients). The most prevalent breeds were mixed breed dogs (22.58%) and the dachshund (18.03%). Ages with higher frequency were 6 and 10 years (average, 7.6 years). According to sex and reproductive status, intact male (42.62%) and female (36.06%) dogs were most affected. The commercial (50.82%) and mixed (44.26%) diets were the most common diets. The body weight between 6 and 15 kg (37.70%) was the most significant. Most of the patients showed no previous diseases (73.77%). The thoracolumbar region was the most evaluated (47.22%). Most injuries were extramedullary (62.30%), and the most common cause was intervertebral disc disease (52.38%). The complications of myelography were not significant. It can be seen that the data in our environment tend to be similar to those of the national literature, but international literature is currently focusing on more sensitive tests such as CT and MRI.
Computed Tomography Myelographic Findings in Dogs with Cervical Spondylomyelopathy
Veterinary Radiology & Ultrasound, 2011
Computed tomography (CT) myelography is used occasionally in the diagnosis of cervical spondylomyelopathy, but the type of lesion found in large-versus giant-breed dogs using this modality has not been characterized. Our purpose was to report the frequency of compressive lesions in large-and giant-breed dogs with cervical spondylomyelopathy and imaged using CT myelography. Fifty-eight dogs were retrospectively studied, 23 large-breed and 35 giant-breed dogs. Multiple sites of compression were found in 12 large-breed dogs (52.2%) compared to 30 (85.8%) giant-breed dogs. The main site of compression was at C5-6 and C6-7 in both large-breed (91.3%) and giant-breed (72.4%) dogs. The main cause and direction of compression was disc-associated and ventral in 19 (82.6%) of the large-breed dogs while osseous changes were the primary cause of compression in 27 (77.2%) of the giant-breed dogs, with most compressions being lateral (51.4%), followed by dorsolateral (14.2%). Osseous compression was observed at C7-T1 in eight giant-breed dogs (22.8%), and at T1-T2 or T2 only in five dogs (14.3%). Four of 23 large-breed dogs (17.4%), and seven (20%) of 35 giant-breed dogs had spinal cord atrophy. Therefore, giant-breed dogs often have multiple compressions, usually caused by osseous changes causing lateralized compressions. In large-breed dogs most compressions are disc-associated and located ventrally. Considering the number of giant-breed dogs with compressions at C7-T1, T1-2, and T2, it is important to include the cranial thoracic region when imaging dogs suspected of having cervical spondylomyelopathy.
DEGENERATIVE MYELOPATHY IN DOGS
One of the chronic progressive disorders of the spinal cord in dogs is the degenerative myelopathy (DM). The most predisposed age in dog is 5 to 14 years, while rarely noted in younger, there is no gender predisposition. This disorder most commonly appears in dogs of the German shepherd breed, but it can appear in other breeds too. The main changes about this disease are degeneration of the myelin, especially in the thoracic-lumbar segments of the spinal cord and the dorsal nerve roots. The progression of the disease is slow and can last months to years. Undoubtedly, diagnosis is made by examinations of the CSF and establishing elevated level of protein segments. Key words: dog, degenerative myelopathy, CSF
Veterinary Surgery, 2011
To compare the sensitivity of computed tomography (CT) and myelography to a reference standard of CT myelography for determining localization of Type I intervertebral disc extrusions in dogs. Prospective blinded comparative study. Dogs with acute onset myelopathy because of suspected disc extrusions (n = 30). Dogs had CT, myelography, and CT myelography to diagnose disc extrusions. Sensitivity of CT and myelography was compared to CT myelography for lateral, longitudinal, and combined localization. Confidence in the assessment of each imaging study was scored by 3 reviewers. Sensitivity of CT for lateral, longitudinal, and combined localization was 94%, 91%, and 81%, respectively, and was 64%, 74%, and 53%, respectively for myelography. Sensitivity of all 3 categories of localization was significantly different between modalities (P < .0001, P = .0031, P < .0001). Significant differences in the sensitivity of lateral and combined localization were found between confidence scores for myelography (P < .0001, P < .0001). Significant differences in the sensitivity of lateral, longitudinal, and combined localization were found between confidence scores for CT (P = .011, P = .013, P = .027). Poor sensitivity was obtained for both modalities except when imaging studies were assigned the highest confidence score. CT is a more sensitive imaging technique than myelography for localizing disc extrusions when compared to a reference standard of CT myelography. Both modalities yielded high sensitivity with the highest confidence score and poor sensitivity for all other confidence scores.
Veterinary Radiology <html_ent glyph="@amp;" ascii="&"/> Ultrasound, 2003
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.
CT Findings of Thoracolumbar Spine Lesions in Dogs
In veterinary medicine, computed tomography (CT) is one of the most commonly used methods for imaging the spine because it provides a detailed examination of the spinal cord and surrounding tissues. The aim of this study was to assess thoracolumbar lesions in a number of dogs studied during the year 2011. There were retrospectively evaluated CT studies from 30 dogs of different breeds (mean age= 6.23 years) presented at the Interdepartmental Center of Radiology in the period January -December 2011, with suspected thoracolumbar vertebral or spinal cord lesions. The CT studies were performed without contrast medium in 27 patients, with contrast medium in subarachnoid space (CT-myelography) in two dogs, and in two patients before and after i.v. administration of contrast medium (Iopamidol 370mgl/ml). In one dog both intravenous and subarachnoid administration of contrast medium were used. There were found 46 disc herniations, 10 degenerative spondylopathies, 5 vertebral malformations, ...