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1.
The magnetic resonance (MR) imaging findings in 22 dogs and two cats with confirmed paraspinal infection of the thoracolumbar spine were characterized. These findings included extensive T2-hyperintense areas (24/24), abscessation (20/24), mild inherent T1-hyperintensity of muscle and abscesses (18/24), and postcontrast enhancement (24/24). Changes involved the vertebral canal in four patients. The longus coli muscles were affected in one cat. Thoracolumbar changes in the remaining 23 patients involved the iliopsoas and epaxial muscles in 23/23 and 19/23 patients, respectively. Iliopsoas muscle abscessation was unilateral in 12/23, and bilateral in 6/24 patients. Abscessation involved both epaxial and iliopsoas muscles in 2/23 patients and the epaxial muscles alone in one patient. A contrast-enhancing sinus tract within the deep thoracolumbar fascia was present in 10/23 patients. Lumbar vertebrae periosteal reactions were identified in 19/23 patients on MR images compared with 15/17 patients with radiography. A focal area of signal void suspected to represent foreign material was seen in 5/23 patients but foreign material was actually found in only two of these five. There was no recurrence of clinical signs following MR imaging and revision surgery. MR imaging permits the severity and extent of changes associated with paraspinal infection to be characterized and allows the location, number and any communication of sinus tracts to be documented.  相似文献   

2.
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   

3.
Inflammatory myopathies are the result of infiltration of inflammatory cells into striated muscle, with or without an association with an underlying cause. Two broad classifications are IIMs and secondary inflammatory myopathies associated with other diseases. Standard diagnostic criteria for inflammatory myopathy include the presence of weakness or loss of specific muscle group function, an increase in CK, EMG changes associated with muscle membrane instability, and histologic evidence of inflammation. Not all these criteria, however, must be present. Fresh-frozen biopsy from two proximal muscles is recommended for biopsy confirmation. IIM can either focally affect head or neck muscles or be more diffuse. MMM is an immune-mediated disease characterized by a humoral antibody produced against the unique type IIM and type I variant mvofibers of masticatory muscles of dogs, which causes inflammation and loss of function of the muscles of mastication. Idiopathic polymyositis can affect focal muscle groups (extraocular, laryngeal) or present as multifocal or diffuse involvement of skeletal muscle in the cat and dog. Familial canine DM is an inflammatory disease of the striated muscle, skin, and vasculature in young Collies, Shetland Sheepdogs (Shelties), and, rarely, Collie-crossbred dogs. Immunosuppressive therapy is the key to successful treatment. Protozoal parasitic myopathies are the most common cause of clinically relevant secondary inflammatory myopathies. The degree of systemic involvement is often the limiting factor to successful treatment. Early recognition of the clinical signs for proper diagnostic testing and institution of appropriate therapy can result in a rewarding outcome in treating inflammatory myopathies in the cat and dog.  相似文献   

4.
The purpose of this study was to describe the appearance of the femoral head of normal, young, small breed dogs, and dogs with avascular necrosis using low-field (0.3 T) magnetic resonance (MR) imaging. Images of the femoral heads were obtained in the dorsal plane, and included T1-weighted spin-echo, T2-weighted fast spin-echo, fast spin echo-inversion recovery, and fluid attenuated inversion recovery pulse sequences. MR imaging features of the asymptomatic femoral heads and necks included uniform high signal intensity compared with muscle on T1- and T2-weighted images. There was either uniform enhancement or no enhancement on postcontrast T1-weighted images. The MR imaging findings of dogs affected with avascular necrosis differed from those of asymptomatic dogs. Typically, the affected dogs had inhomogeneous intermediate to low-signal intensity within the femoral head and neck compared with muscle on T1-weighted images, inhomogeneous enhancement of the femoral head and/or neck on postcontrast T1-weighted images, and inhomogeneous low- to high- signal intensity within the femoral head and neck on T2-weighted images.  相似文献   

5.
To describe the signs that may be associated with intracranial inflammatory conditions, magnetic resonance (MR) images of 25 dogs that had inflammatory cerebrospinal fluid (CSF) were mixed with those of a control group of 40 dogs that had CSF negative for inflammatory disease and reviewed without knowledge of the clinical signs or diagnosis. CSF was considered inflammatory if the protein level was > 0.25 g/l and the white cell count was > 5 mm(-3). Abnormalities were found by MR imaging in 19 (76%) dogs with inflammatory CSF. Two dogs had focal lesions, 10 had multifocal lesions, and seven had diffuse lesions. Lesions affected all divisions of the brain. Mass effect was identified in seven (28%) dogs, including one that had a choroid plexus carcinoma. Lesions were hyperintense in T2-weighted images in 18 dogs and hypointense in T1-weighted images in six dogs. Multifocal or diffuse intraaxial lesions that were hyperintense in T2-weighted images were observed in 17 (68%) dogs with inflammatory CSF. Administration of gadolinium resulted in enhancement of intraaxial lesions in nine (36%) dogs and enhancement of meninges in seven (28%) dogs. Six (24%) dogs with inflammatory CSF had images interpreted as normal.  相似文献   

6.
Magnetic resonance (MR) images were acquired in five dogs and one cat with ocular and orbital disease. MR images were obtained in the dorsal or oblique dorsal, and oblique sagittal planes. Pathologic changes identified in MR images included inflammatory lesions, cystic structures, and neoplasms. All abnormalities were readily apparent in TI-weighted images. MR findings in affected animals were often similar in signal intensity, location, and growth pattern to those found in people with comparable diseases. Although no MR changes were considered pathognomonic for a given disease, MR imaging provided detailed information on the homogeneity, extent and invasiveness of the lesions.  相似文献   

7.
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   

8.
Spinal epidural empyema is defined an accumulation of purulent material in the epidural space of the vertebral canal. Spinal epidural empyema should be considered as a differential diagnosis in dogs with pyrexia, spinal pain, and rapidly progressing myelopathy. Magnetic resonance (MR) imaging is the imaging test of choice in humans. Here, we describe the MR imaging features of five dogs with confirmed spinal epidural empyema. The epidural lesions appeared as high or mixed signal masses in T2-weighted (T2W) images. Increased signal within the spinal cord gray matter at the site of the lesion was detected in T2W images in all dogs. Two patterns of enhancement were detected on postcontrast T1-weighted (T1W) images. Mild to moderate peripheral enhancement was seen in three dogs and a diffuse pattern of enhancement was seen in one. Discospondylitis was identified in three dogs on T1W postcontrast images. Decompressive spinal surgery was performed in all dogs. Bacteria isolated from the abnormal epidural tissue were Enterobacter cloacae, coagulase-positive Staphylococci, Pasteurella multocida, and Escherichia coli. In one dog bacteria were not isolated. These MR imaging features, along with appropriate clinical signs, can allow prompt diagnosis and appropriate treatment planning.  相似文献   

9.
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10.
Pelvic limb lameness that was localized clinically to the lateral gastrocnemius head was observed in dogs without history of trauma. The aim of this retrospective study was to describe magnetic resonance imaging (MRI) findings of this condition. Nine dogs were identified, eight Border Collies and one Australian Shepherd. They all had chronic pelvic limb lameness; no signs of joint effusion or instability were present. In MR images there was high signal intensity in the lateral head of the gastrocnemius muscle around the sesamoid bone in T2‐weighted, T2*‐weighted, and STIR images and an iso‐ to mildly hyperintense signal in T1‐weighted images with marked contrast enhancement. The abnormal signal intensity most likely represents a myotendinous strain. The breed affiliation to Border Collies is striking, and a relation to biomechanical forces or motion pattern may be possible. Except for the dog with the most extensive lesion all dogs had an excellent outcome.  相似文献   

11.
Signal changes within the bone marrow adjacent to osteoarthritic joints are commonly seen on magnetic resonance (MR) images in humans and in dogs. The histological nature of these lesions is poorly known. In this study, we describe the MR imaging of bone marrow lesions adjacent to the stifle joints of dogs with experimental osteoarthritis over 13 months. Histology of the proximal tibia at the end of the study was compared with the last MR imaging findings. In five adult dogs, the left cranial cruciate ligament was transected. Post-operatively, MR imaging was performed at 1, 2, 3, 4, 6, 8, and 13 months. Dogs were euthanised after 13 months and histological specimen of the proximal tibia were evaluated. Bone marrow edema like MR imaging signal changes were seen in every MR examination of all dogs in one or more locations of the proximal tibia and the distal femur. Lesions varied in size and location throughout the whole study with the exception of constantly seen lesions in the epiphyseal and metaphyseal region at the level of the tibial eminence. On histology, hematopoiesis and myxomatous transformation of the bone marrow and/or intertrabecular fibrosis without signs of bone marrow edema were consistent findings in the areas corresponding to the MR imaging signal changes. We conclude that within the bone marrow, zones of increased signal intensity on fat suppressed MR images do not necessarily represent edema but can be due to cellular infiltration. Contrary to humans, hematopoiesis is seen in bone marrow edema-like lesions in this canine model of osteoarthritis.  相似文献   

12.
Reversible magnetic resonance (MR) imaging lesions have been described in humans following seizures. This condition has not yet been reported in animals. This paper describes reversible abnormalities identified in 3 dogs using MR imaging that was performed initially within 14 days of the last seizure and follow-up imaging that was performed after 10 to 16 weeks of anticonvulsant therapy. All three dogs had lesions in the piriform/temporal lobes, characterized by varying degrees of hyperintensity on T2-weighted images and hypointensity on T1-weighted images. In one dog, contrast enhancement was evident. On reevaluation, partial resolution occurred in all 3 dogs. In a fourth animal with an olfactory meningioma, similar appearing lesions in the temporal cortex and right and left piriform lobes were identified after seizure activity. A surgical biopsy of the temporal cortex and hippocampus was performed and edema, neovascularization, reactive astrocytosis, and acute neuronal necrosis were evident. These histologic findings are similar to those reported in humans with seizures. Recognizing the potential occurrence of reversible abnormalities in MR images is important in developing a diagnostic and therapeutic plan in canine patients with seizures. Repeat imaging after seizure control may help differentiate between seizure-induced changes and primary multifocal parenchymal abnormalities.  相似文献   

13.
Objective— To report diagnosis and treatment of bilateral iliopsoas muscle contracture in a dog with spinous process impingement. Study design— Case report. Animals— German Shepherd dog. Methods— A dog with chronic progressive lameness, flexion contracture of the coxofemoral joints, severe pain, and decreased femoral reflexes had severe spondylosis bridging the vertebral bodies from L1 to L4 and enlarged dorsal spinous processes from T8 to L6 with impingement and bony proliferation. Ultrasonographic and magnetic resonance imaging (MRI) findings were consistent with fibrosis, mineralization, and atrophy of the iliopsoas muscles bilaterally which was treated by staged tenectomy of the insertions of the iliopsoas muscles. Results— Because of severe perivascular fibrosis, the femoral vessels required ligation. Bilateral iliopsoas muscle tenectomy improved gait and provided pain relief. Histologic findings were consistent with fibrotic myopathy. Conclusions— Slow progression of severe clinical signs observed bilaterally in this dog differs from previous reports of iliopsoas myopathy. Findings were similar to the fibrotic myopathy of the gracilis or semitendinosus muscles described in dogs. Clinical Relevance— Iliopsoas muscle abnormalities should be considered in dogs with limited hip extension and pain. MRI is useful for diagnosing muscle fibrosis. Iliopsoas tenectomy may improve clinical function in dogs with fibrotic myopathy.  相似文献   

14.
A retrospective study was performed on 200 randomly selected cases of inflammatory myopathy in dogs from diagnostic muscle biopsies received at the Comparative Neuromuscular Laboratory, University of California, San Diego. The most common clinical signs in dogs diagnosed with an inflammatory myopathy were generalized weakness, stilted gait, dysphagia, masticatory or generalized muscle atrophy, inability to open the jaw, megaesophagus, and dysphonia. Myalgia was rarely described. Age of onset ranged from 0.25 to 14 years. Genders were equally represented. Breed distribution approximated the 2002 American Kennel Club registration statistics (r = .85) with the notable exception of Boxers and Newfoundlands. From the results of muscle biopsies, clinical signs, and presence or absence of antibodies against type 2M fibers, dogs were classified as a generalized inflammatory myopathy (gIM)--including immune-mediated polymyositis; infectious and preneoplastic myositis; and, rarely, dermatomyositislike or overlap syndromes or unclassified myositis-or a focal inflammatory myopathy (flM)--including masticatory muscle and extraocular myositis. Average creatine kinase (CK) and aspartate aminotransferase (AST) concentrations in gIMs were significantly higher than those with fIMs (P < .05). Neoplasia developed in 12 of 200 dogs within 12 months of diagnosis of polymyositis, with lymphoma diagnosed in 6 of 32 Boxers. Inflammatory myopathy was associated with antibody titers against infectious diseases in 38 dogs. Neospora caninum and Hepatozoon americanum cysts were found in tissues of 2 dogs not serologically tested. Antibodies against an unidentified sarcolemmal antigen were found in 9 of 19 Newfoundlands with polymyositis. The spectrum of canine inflammatory myopathies can be broad, with infectious etiologies relatively common, and can include preneoplastic and uncharacterized syndromes.  相似文献   

15.
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   

16.
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17.
The sensitivity of low‐field magnetic resonance (MR) T2* images for predicting the presence of meniscal lesions was determined in 12 dogs with naturally‐occurring cranial cruciate ligament rupture and three control dogs, using histopathology as the reference standard. Previously published grading systems were used to grade the severity of meniscal lesions on MR images, gross inspection and histopathology. Focal areas of increased signal intensity were detected in 11/12 symptomatic dogs and 3/3 control dogs. Lesions mimicking meniscal tears (pseudotears) were identified at junctions between meniscal margins and adjacent connective tissue in control dogs and dogs with naturally occurring disease. Histopathologic lesions were present in all menisci of both symptomatic and control dogs, including the menisci from two affected dogs that appeared grossly normal but were removed and submitted based on MR imaging findings. Histopathologic lesions identified included hyaline cartilage metaplasia and changes in the amount of ground substance and cellularity. The sensitivity of MR imaging for detecting the presence of meniscal histopathologic lesions was 90% in symptomatic dogs and 91% in control dogs. However, agreement between severity scores for the different tests was poor. Low‐field MR imaging is a sensitive test for predicting the presence but not severity of meniscal histopathologic lesions in dogs with naturally‐occurring cranial cruciate ligament rupture. Findings also supported previous studies indicating that histopathologic lesions can be present in dogs with grossly normal menisci. An improved grading system for comparing MR images and histopathologic severity of meniscal lesions in dogs is needed.  相似文献   

18.
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.  相似文献   

19.
Animals with a portosystemic shunt (PSS) often have neurologic abnormalities. Diagnostic imaging, including brain magnetic resonance (MR) imaging, is not performed routinely in these animals. In this study, brain MR images were obtained in 13 dogs and three cats with a PSS, and in 15 dogs and five cats that were neurologically normal and used as controls. All animals with a PSS had widened sulci. In addition, 10 out of 13 dogs with a PSS and one out of three cats with a PSS had hyperintense focal areas in the lentiform nuclei on T1-weighted (T1W) images, which did not enhance after intravenous gadolinium. Following surgical correction of the PSS, MR imaging examinations were repeated in one dog and one cat. The hyperintensity of the lentiform nuclei had decreased. This study indicates that MR imaging findings of widened sulci and hyperintensity of the lentiform nuclei on T1W images may be found in dogs and cats with a PSS.  相似文献   

20.
Magnetic resonance (MR) imaging characteristics of intracranial granular cell tumors (GCTs) have been previously reported in three dogs. The goal of this retrospective study was to examine a larger number of dogs and determine whether distinctive MR characteristics of intracranial GCTs could be identified. Six dogs with histologically confirmed intracranial GCTs and MR imaging were included. Tumor location, size, mass effect, T1‐ and T2‐weighted signal intensity, and peritumoral edema MR characteristics were recorded. In all dogs, GCTs appeared as well‐defined, extra‐axial masses with a plaque‐form, sessile distribution involving the meninges. All tumors were located along the convexity of the cerebrum, the falx cerebri, or the ventral floor of the cranial vault. All tumors were mildly hyperintense on T1‐weighted images, and iso‐ to hyperintense on T2‐weighted images. A moderate‐to‐severe degree of peritumoral edema and mass effect were evident in all dogs. Findings indicated that, while several MR imaging characteristics were consistently identified in canine cerebral GCTs, none of these characteristics were unique or distinctive for this tumor type alone.  相似文献   

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