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1.
The authors encountered a dachshund dog, presenting vestibular disorder. On magnetic resonance (MR) imaging, a mass showing isointensity on the T1- and T2-weighted images and enhanced by contrast medium, was observed in the right cerebellum. In addition, the periphery of the mass showed isointensity on the T1-weighted image and hyperintensity on the T2-weighted image, suggesting sever oedema. Although the dog underwent surgery, it died. The mass was diagnosed pathologically as a granulomatous meningoencephalitis.  相似文献   

2.
F. Audigié  DVM  PhD    J. Tapprest  DVM  PhD    C. George  DVM    D. Didierlaurent  N. Foucher  F. Faurie  DVM    M. Houssin  DVM    J.-M. Denoix  DVM  PhD 《Veterinary radiology & ultrasound》2004,45(3):210-215
The purpose of this paper was to correlate the magnetic resonance imaging (MRI) characteristics of a mature brain abscess in a horse with histopathologic alterations of brain tissue. Eight months after the onset of clinical signs, MRI of the brain of a 10-month-old filly was performed. A large space-occupying lesion in the right cerebral hemisphere was identified. This space-occupying lesion was delineated by a thick and well-defined capsule that was isointense to brain parenchyma on the T1-weighted images and with a markedly hypointense on the T2-weighted images. The identification of such a capsule is highly diagnostic of a mature brain abscess. The lesion seen on MR images was confirmed at necropsy where a large abscess of the right hemisphere was observed. Streptococcus zooepidemicus and Pseudomonas aeruginosa were isolated from the abscess. Based on histopathologic examination, the signal characteristics of the capsule on T1-weighted and T2-weighted images were found to be due to the presence of numerous hemosiderin-laden macrophages. These results are in agreement with previous studies on human patients. This report confirms the value of MRI in the diagnosis of equine brain diseases.  相似文献   

3.
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   

4.
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5.
Karen M.  Vernau  DVM  Richard A.  Lecouteur  BVSc  PhD  Beverly K.  Sturges  DVM  Valerie  Samii  DVM  Robert J.  Higgins  BVSc  PnD  Philip D.  Koblik  DVM  MS  William  Vernau  BSc  BVMS  DVSc  PhD 《Veterinary radiology & ultrasound》2002,43(5):449-454
Clinical signs, magnetic resonance imaging (MRI) features, treatment, and outcome of two adult dogs with neurologic dysfunction resulting from hemorrhage into a quadrigeminal intracranial intra-arachnoid cyst are described. In dog 1, the cyst was hyperintense to cerebrospinal fluid (CSF) on T1-weighted MRI and hypointense to CSF on T2-weighted images. In dog 2, the cyst was isointense to CSF on T1- and T2-weighted images. Both dogs were treated with craniotomy and cyst fenestration. A large blood clot was removed from the lumen of the cyst in each dog. Dog 1 is clinically normal 3.5 years post-surgery and has a persistent cyst. Dog 2 had a good initial response to therapy but was euthanized 2.5 years post-operatively due to generalized seizures. The late onset of clinical signs in these dogs most likely resulted from hemorrhage into the cyst. Surgical fenestration and hematoma removal appear to provide a satisfactory treatment for adult dogs with an intracranial intra-arachnoid cyst and intracystic hemorrhage. Persistence of the cyst may occur in some dogs.  相似文献   

6.
A 14-year-old dog developed an acute onset of depression, disorientation, left hemiparesis, left hemianopia, left facial hypoesthesia, and a tendency to turn to the right. Based on these findings, a lesion affecting the right forebrain was suspected. Magnetic resonance imaging showed a mass within the right cerebral hemisphere resulting in compression of the right lateral ventricle and shifting the longitudinal fissure to the left. The lesion was hyperintense on T1-weighted images and hyperintense with focal regions of hypointensity on proton density-, and T2-weighted images, consistent with a subacute hemorrhage. At necropsy, there was a hematoma in the parietal portion of the right cerebral hemisphere. The hemorrhage was surrounded by numerous thin-walled veins, most likely a venous malformation. Magnetic resonance imaging of intracranial hemorrhage is reviewed.  相似文献   

7.
Janet S.  Muleya  BVM  MVM  Yasuho  Taura  DVM  Ph.D.  Munekazu  Nakaichi  DVM  PhD.  Sanenori  Nakama  DVM  Ph.D.  Akira  Takeuchi  DVM  Ph.D. 《Veterinary radiology & ultrasound》1997,38(6):444-447
The study was carried out to evaluate the applicability of magnetic resonance imaging (MRI) in detecting tumors in the abdomen of the dog. Abdominal ultrasound and MRI were performed on 8 dogs having a mass lesion on abdominal radiography. MR images were obtained in the transverse, sagittal and dorsal planes using T1- and T2-weighted spin echo pulse sequences. There was good visual correlation of the lesion site by MRI and ultrasonography (US).  相似文献   

8.
This article describes the discovery of a chronic cervical wooden foreign body ventral to the left transverse processes of the cranial cervical spine using magnetic resonance imaging (MRI) in a dog that presented with chronic neck pain and lameness. The dog did not exhibit dysphagia or chronic draining tracts, the most common signs of the presumed cause, that of a penetrating oropharyngeal foreign body. The foreign body itself was represented on MR images as an oval straight-edged core within an inflammatory tissue reaction. The wood was slightly hyperintense on T2- and isointense on T1-weighted images relative to muscle. Surrounding this was a more conspicuous contrast-enhancing reactive tissue rim that was hyperintense on all pulse sequences. Adjacent musculature also exhibited diffuse edema and contrast enhancement that extended around the left cervical vertebral transverse processes and local intervertebral nerve roots. The foreign body was found to be a wooden stick upon surgical removal. MRI is an excellent method for visualizing the inflammatory tissue reactions associated with soft-tissue foreign bodies because of its contrast resolution and depiction of anatomy in multiple imaging planes.  相似文献   

9.
Thoracolumbar spinal magnetic resonance imaging (MRI) examinations in dogs frequently include the region of the cisterna chyli within the field of view. It is important to be aware of the appearance and location of this structure to avoid confusing it for a pathologic periaortic lesion. MRI examinations of the thoracolumbar spine were reviewed in 30 dogs. The cisterna chyli was identified in 26 dogs and was most commonly located caudal to the diaphragmatic crura at the level of L4; afferent and efferent lymphatics were seen in all dogs. Transverse T2-weighted images were the most useful to locate the cisterna chyli. It was isointense to fluid on T2-weighted images and isointense to muscle on T1-weighted images. Mild contrast enhancement was seen in three dogs. The cisterna always wrapped around the aorta, but varied in shape, with the most common being the wide right dorsolateral ellipse. The thoracic duct was also visible in 30 dogs. MRI may have potential for noninvasive evaluation of the abdominal and thoracic lymphatic ducts in dogs.  相似文献   

10.
A nine-year-old, male, mongrel dog was unsteady after falling down a set of stairs. The dog exhibited a mildly abnormal gait 2 days after injury, and was not able to stand, with spasticity of the right limbs, 4 days after injury. MR imaging revealed a clearly demarcated mass on the top of the left lateral ventricle that showed mild hyperintensity on T1-weighted images and hyperintensity on T2-weighted images. The authors diagnosed the dog as having a traumatic intracerebral hematoma. This type of case, in which the clinical signs deteriorated due to edema associated with hematoma, is extremely rare.  相似文献   

11.
In humans affected with inflammatory myopathies, regions of altered signal intensity are found on magnetic resonance (MR) images of affected muscles. Although electromyography (EMG) is more practical for muscle disease evaluation, and a muscle biopsy is the only manner in which a definitive diagnosis can be made, MR imaging has proven useful if a specific anatomic localization is difficult to achieve. Three dogs with focal inflammatory myopathy diagnosed with the assistance of MR imaging are discussed and the findings are compared with those found in humans. MR images of the affected muscles in each dog were characterized by diffuse and poorly marginated abnormal signal on T1- and T2-weighted images. Marked enhancement was noted in these muscles after contrast medium administration. An inflammatory myopathy was confirmed histologically in all three dogs. A good association existed between the MR images and muscle inflammation identified histopathologically. MR imaging may be a useful adjunctive procedure for canine inflammatory myopathies.  相似文献   

12.
An 8-year-old Yorkshire terrier developed acute onset coma and seizure after cranial trauma. Intracranial hemorrhage was suspected from the clinical signs and history. Low-field magnetic resonance (MR) imaging revealed a round mass within the right cerebral hemisphere, compressing the right lateral ventricle and displacing the longitudinal fissure to the left. The lesion was hypointense on T1-weighted images and hyperintense on T2-weighted images, consistent with an acute hemorrhage. MR imaging was performed every 24 h for 6 days from 1 h after the injury, and then on day 14 of hospitalization. With time, the signal intensity changed to hyperintense on Ti-weighted images. On T2-weighted images the center of the mass changed to hypointense, and then to hyperintense with a hypointense rim. These changes of signal intensity were related to hemoglobin oxidation.  相似文献   

13.
Magnetic resonance imaging was performed in seven dogs with histopathologically-confirmed brain infarcts. The infarcts were non-hemorrhagic in four dogs and hemorrhagic in three dogs. Six dogs had single infarcts involving the cerebrum and one dog had multiple infarcts involving the cerebrum and brain stem. Non-hemorrhagic infarcts were typically wedge-shaped, hypointense on T1-weighted images, hyperintense on T2-weighted images, and did not enhance with gadolinium-DTPA. Hemorrhagic infarcts had mixed intensity on T1- and T2-weighted images, with variable patterns of enhancement.  相似文献   

14.
A two-year-old, castrated crossbred cat presented with loss of balance and anorexia. A mass of the caudal aspect of the cerebellum was revealed by magnetic resonance imaging (MRI). The mass was hypointense on T1-weighted images, iso- and hyperintense on T2-weighted images and was enhanced by intravenous gadolinium contrast medium. The MRI characteristics of this case were similar to those of medulloblastoma of the cerebellar vermis in humans. The authors were able to remove almost all of the tumour. The cat was discharged from hospital on day 22 after surgery, but died on day 45. The excised tissue was histologically diagnosed as medulloblastoma.  相似文献   

15.
A two-year-old, castrated crossbred cat presented with loss of balance and anorexia. A mass of the caudal aspect of the cerebellum was revealed by magnetic resonance imaging (MRI). The mass was hypointense on T1 -weighted images, iso- and hyperintense on T2-weighted images and was enhanced by intravenous gadolinium contrast medium. The MRI characteristics of this case were similar to those of medulloblastoma of the cerebellar vermis in humans. The authors were able to remove almost all of the tumour. The cat was discharged from hospital on day 22 after surgery, but died on day 45. The excised tissue was histologically diagnosed as medulloblastoma.  相似文献   

16.
A dog was referred for pancytopenia. Bone marrow biopsy showed hypocellular fatty marrow. Magnetic resonance imaging had a high signal on T1-weighted image in the metaphyseal region of the femur. We suggest that MRI could be a valuable supportive diagnostic method and introduce a strategy of treatment with cyclosporine and azathioprine in canine aplastic pancytopenia.  相似文献   

17.
Meningiomas are common intracranial masses in the dog, and surgical or radiation treatment of meningiomas depends on accurate identification and location. In this review of 13 patients with confirmed meningioma, low field magnetic resonance imaging characteristics of cranial vault meningiomas included increased signal intensity on T2-weighted images, decreased signal intensity on T1-weighted images, and marked contrast enhancement that was usually nonhomogeneous and well-defined. Mass effect and edema were usually present. Cyst formation and meningeal enhancement were also found in some patients. Low field magnetic resonance imaging characteristics of the meningiomas in these patients were similar to those magnetic resonance imaging findings reported in humans and the few reports pertaining to animals.  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.
A 6-year-old ShihTzu presented with tonic-clonic cluster seizure. T2-weighted magnetic resonance (MR) images showed bilateral diffuse hyperintense lesions at the cerebral cortex with enlarged sulci. Computed tomography revealed a portosystemic shunt (PSS) and azygos continuation. Based on the clinical signs, blood examinations and diagnostic images, the dog was diagnosed with hepatic encephalopathy secondary to PSS. The neurologic signs were gradually improved after medical therapy for hyperammonemia. This is the first report of hyperintensity of the cerebral cortex on T2-weighted MR images associated with acute hepatic encephalopathy in a dog.  相似文献   

20.
Magnetic resonance imaging was conducted on previously frozen left carpi from six normal dogs using a 1.5 Tesla magnet in combination with a transmit/receive wrist coil. Three-millimeter thick T1-weighted spin-echo images and 1-mm thick T2*-weighted gradient-recalled 3-D images were obtained in dorsal and sagittal planes. Carpi were embedded, sectioned, and stained. Anatomic structures on the histologic sections were correlated with the MR images. All of the carpal ligaments plus the radioulnar articular disc and the palmar fibrocartilage were identified on MR images. The accessorio-quartile ligament, which had not been well described previously in dogs, was also identified. It originated on the accessory carpal bone and inserted on the fourth carpal bone. The T2*-weighted gradient echo imaging technique provided better images than T1-weighted technique, largely because thinner slices were possible (1 mm vs. 3 mm), resulting in less volume averaging of thin ligaments with surrounding structures. Although MRI is currently the imaging modality of choice to identify ligamentous injury in humans, further studies are needed to determine if abnormalities can be detected in canine carpal ligaments using MRI.  相似文献   

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