1例犬死胎脑水肿及肺积水的核磁共振成像观察

小动物核磁共振成像(magnetic resonance imaging,MRI)技术是我国动物医学新兴的影像学检查方法。为了探究母犬产出足月死胎的原因,试验采用MRI技术对1只犬死胎进行了观察。结果表明:犬死胎脑部和肺部在T1WI序列成像为低信号,在T2WI序列成像为高信号,确认为脑水肿及肺积水,该影像为临床诊断提供了可借鉴的资料。     

犬急性水肿型胰腺炎MRI多序列扫描及增强扫描的影像特征

探究犬胰腺磁共振成像(magnetic resonance imaging, MRI)扫描序列总结归纳犬急性水肿型胰腺炎(acute edematous pancreatitis, AEP)的MRI影像表现。选用10只成年本地杂种犬为研究对象，手术经副胰管逆行注入牛磺胆酸钠与胰蛋白酶混合液建立犬急性水肿型胰腺炎模型，然后进行MRI扫描。MRI多序列扫描图像主观与客观分析结果显示，门控采集快速自旋回波T2加权成像(FSE-T2WI-TRIG)序列与门控采集脂肪抑制快速自旋回波T2加权成像(FSE-T2WI-FS-TRIG)序列评分较高，可作为犬胰腺首选MRI扫描序列，必要时可进行造影增强扫描。FSE-T2WI-TRIG、FSE-T2WI-FS-TRIG序列AEP表现为胰腺体积呈弥散性增大，外形不规则，胰腺实质T2WI信号呈不均匀增高，强度高于同层肝组织信号。胰腺与周围脂肪界限稍有不清，胰腺周围伴有渗出，呈条片状T2WI高信号。造影后胰腺实质不均匀强化，平均强化峰值时间为注射造影剂后60～90 s,存在明显延迟强化。研究结果表明，本研究筛选的MRI扫描序列可用于临床上犬AEP的检查，同时A...     

犬脑干脑炎的MRI诊断

1例犬脑干脑炎的病例MRI诊断。该犬临床症状表现为咳嗽,呕吐,无法正常行走,面神经反射减弱,眼球震颤。患犬有上呼吸道感染病史,血常规检查显示白细胞总数升高,中性粒细胞数升高,血液生化检查无明显异常。脑脊液检查见激活淋巴细胞,单核细胞增多,为淋巴细胞总数的50%。脑部MRI表现为脑桥均匀肿大,基底部出现不规则的高T2信号,边界模糊,侧脑室扩张,综合各项检查分析诊断为脑干脑炎。     

羊脑包虫病CT、MRI影像特征

本研究旨在观察羊脑包虫病CT、MRI的特征性影像学表现。选择3只表现出脑包虫病典型症状的新疆细毛羊进行神经学检查及血常规、血清生化检查。对其中2只羊头部进行CT和MRI扫查。最后进行病理剖检,观察病理解剖变化。动物神经学检查发现动物出现眼球震颤,双侧眼睑反射、角膜反射减弱,动物的翻正反应、双侧独轮车反应存在异常;血常规和血清生化检查结果无明显异常;CT影像可见颅内数量不等囊性低密度影,内部CT值与脑脊液相近,边界清晰,有占位效应,囊壁分布大量点状中等到高密度的原头节影像,其余脑组织未见明显异常密度影像。MRI影像可见颅内数量不等囊性病灶,T1WI低信号,T2WI高信号,与脑脊液信号相近,可见沿囊壁分布大量点状T1等信号,T2低信号的原头节影像,病灶周围未见明显异常信号。病理剖检可见充满澄清囊液的寄生虫包囊,内含有数量不等的原头节。寄生虫包囊位置与影像学检查结果一致。结果说明羊脑包虫病具有特征性的CT和MRI影像学表现,影像学诊断方法可准确定位寄生虫包囊数量和位置,显示病灶累及周围组织的情况,有助于手术治疗计划的制定。     

引起犬中枢神经兴奋的几种疾病的鉴别诊断

1犬瘟热、伪狂犬病和脑膜脑炎 犬瘟热、伪狂犬病和脑膜脑炎有着共同症状,如狂躁、痉挛、癫痫样发作,幼犬发病时大多有体温升高现象,易于混淆。但犬瘟热发展到病犬出现神经症状时,其前期早有许多典型症状,如双相热型、腹泻、粪便恶臭,呈红色水样,流脓性鼻涕和足枕间质增生等特点,一般多发生于幼犬和未经犬瘟热疫苗注射的犬。其与脑膜脑炎易于混淆,事实上,犬瘟热后期就表现为非化脓性脑膜脑炎,脑白质出现空泡。然而,脑膜脑炎可由多种原因引起,大多为细菌性因素,血液检查发现中性粒细胞增多。犬瘟热属病毒病,病犬血液中白细胞总数减少,患脑膜脑炎的犬脑脊液中蛋白质和细胞总数增多,并有病原微生物存在,而犬瘟热时犬脑脊液中蛋白质含量基本正常。患脑膜脑炎时,与病犬是否经犬瘟热等疫苗注射关系不大,脑膜脑炎常继发于感染和中毒,大多有原发病的典型症状,但一般不表现双相热型,更多的表现神经质,惊恐等。依此可将这两病进行区别。     

琯溪蜜柚砂囊粒化的无损检测

摘 要：柑橘砂囊粒化是柑果成熟期与采后贮藏期的常见生理性病害，严重影响果实品质。本文采用1.5 T 高场磁共振成像仪对采后贮藏30 d的琯溪蜜柚[Citrus grandis (L.) Osbeck]果实进行磁共振扫描检查，并以同层断面解剖图为对照，评估磁共振成像（MRI）应用于柑橘砂囊粒化症无损检测的有效性。结果表明， MRI检测中，T2WI能够显著区分果肉组织与海绵层组织的信号差异，其信号强度可代表果实组织相对含水量；T2WI信号在砂囊粒化部位强度显著降低，病变组织的失水特征清晰，与解剖结果一致。T2WI对砂囊粒化的确诊率100%，显著优于T1WI成像的识别率41.7%（χ2 = 5.76，P = 0.016）；T2WI和T1WI均能显示种籽照影，但T2WI对果肉组织影像的分辨率优于T1WI，因此MRI的T2WI分析可作为一种无损检测方法，对柚商品果实上市前砂囊粒化症发生程度以及种籽有无进行评估。     

磁共振成像(MRI)在犬颅脑损伤诊断中的应用

建立不同程度犬弥漫性颅脑损伤模型,研究磁共振成像(MRI)在犬不同程度颅脑损伤中的诊断价值,为犬临床影像学诊断提供参考。选取1岁龄比格犬18只随机分为对照组(3只)、颅脑损伤模型组15只(每组5只)。自制垂直落体打击模型装置,将100 g砝码分别从50,75,100 cm处落下打击颅骨开窗后的右侧额叶硬脑膜,造成不同程度的弥漫性颅脑损伤。使用MRI对犬头部进行T1WI、T2WI及液体衰减反转恢复序列(FLAIR)扫描,分析比较不同程度损伤影像表现、格拉斯哥昏迷评分(MGCS)及预后。结果显示,轻度颅脑损伤组MRI扫描表现为大脑皮质轻度水肿,MGCS预后良好;中度颅脑损伤组MRI扫描表现为大脑灰、白质中度水肿,中线轻微偏移,MGCS预后谨慎;重度颅脑损伤组MRI扫描表现为创伤部位大脑半球严重水肿、皮质血肿、脑室扩张、中线严重偏移,MGCS预后不良。结果表明,使用自制垂直落体打击模型能够模拟犬弥漫性颅脑损伤;MRI对犬颅脑损伤有十分重要的诊断价值;格拉斯哥昏迷评分对预后的评估具有重要作用。     

猫硬膜内髓外脊髓肿瘤的MRI诊断及手术治疗

介绍1例猫椎管内硬膜内肿瘤的诊断与治疗。患猫临床检查体温、呼吸、心率均正常;血常规、生化检查结果显示正常;头颈部MRI检查,在第2至第3颈椎之间硬膜内明显可见一占位性团块,SE序列T1加权像呈现稍高信号,FSE序列T2加权像呈现稍低信号,且前段脑脊液积聚,轴位T1加权像显示正常,脊髓被团块压迫出现变形;SE序列Gd-DTPA增强扫描可见该团块强化明显。综合各项检查结果诊断为硬膜内肿瘤,遂进行颈部背侧椎板切除手术,切除肿瘤,患猫术后恢复良好。肿瘤病理组织学检查显示为肉瘤。     

犬甲状腺功能减退症临床诊断与治疗

目的:明确犬甲状腺功能减退症临床诊断与治疗方法。方法:将本中心2018年1月至2019年7月接诊的18例患犬作为研究对象,明确犬甲状腺功能减退症临床诊断与治疗方法。结果:18例患犬经过临床治疗后,有10例患犬治疗效果明显,3例患犬病情好转后转院治疗,5例患犬主人放弃治疗。结论:利用临床诊断与皮肤检查、生化检查、内分泌检测以及血常规检查等手段可以有效的确诊犬甲状腺功能减退症,通过口服左旋甲状腺素钠并结合针对性治疗方法可以有效的控制犬甲状腺功能减退症。     

干细胞因子在3例犬急性脊髓神经系统疾病治疗中的应用和体会

犬神经系统疾病常表现为突发性、复杂性和难治性的特点,给临床诊断与治疗带来很多困难。磁共振成像(MRI)检查具备良好的软组织对比效果,为神经系统疾病诊断提高了准确性。本文介绍了3例患有神经系统疾病的患犬病例,结合临床症状和X线或MRI影像学检查结果确诊其为椎间盘疾病并继发急性脊髓神经损伤。患犬经常规治疗效果不明显,后通过静脉输注干细胞因子,1支/d,连用3 d治疗,迅速取得理想的康复效果。由本文患犬治疗结果得出,干细胞因子在修复神经损伤方面有一定疗效。     

Intracranial extension of retrobulbar blastomycosis (Blastomyces dermatitidis) in a dog

Blastomycosis (Blastomyces dermatitidis) is a fungal disease that is endemic in the southern United States. This case report illustrates the clinical, MRI and histopathologic findings in a dog with invasion of a retrobulbar blastomycotic lesion into the calvarium. A 5‐year‐old intact female Weimaraner was referred for a 2‐month history of change in behavior and recent onset of visual deficits. Magnetic resonance imaging (MRI) examination revealed a large (5.8 × 2.0 × 2.5 cm) mass extending from the left orbit through a circular defect in the left cranioventral aspect of the calvarium caudally to the level of the pituitary fossa and interthalamic adhesion. The mass was heterogeneously iso‐ to hypointense on T2‐W images, slightly hypointense on T1‐W images, did not attenuate on fluid attenuated inversion recovery (FLAIR) images, and did not show evidence of susceptibility artifact on T2*‐W gradient recalled echo (GRE) images. Vasogenic edema and associated mass effect were noted. The mass showed strong homogeneous contrast enhancement with well‐defined margins and had thickening of the adjacent meninges (dural tail sign). Based on MRI findings a malignant neoplastic process was considered most likely and the patient was placed on oral prednisone to decrease peri‐tumoral inflammation. The dog initially improved but was euthanized 3 weeks later for worsening clinical signs. Histopathologic assessment of the mass revealed marked pyogranulomatous optic neuritis with intralesional fungal yeasts consistent with blastomycosis (Blastomyces dermatitidis). To our knowledge this is the first report of invasion of a retrobulbar blastomycotic lesion into the calvarium in a dog.     

Hypophysitis,Panhypopituitarism, and Hypothalamitis in a Scottish Terrier Dog

A 6‐year old male neutered Scottish Terrier was referred with a 1 week history of progressive lethargy and anorexia. Neurological examination localized a lesion to the forebrain and hormonal testing showed panhypopituitarism. Magnetic resonance imaging (MRI) of the brain revealed a rounded, well‐defined, suprasellar central mass. The mass was slightly hyperintense to the cortical grey matter on T2‐weighted (T2W), hypointense on T1‐weighted (T1W) images and without T2* signal void. There was a central fusiform enhancement of the mass after contrast administration which raised the suspicion of a pituitary neoplasm. Rapid deterioration of the dog prevented further clinical investigations. Histopathologic examination revealed a lymphocytic panhypophysitis of unknown origin suspected autoimmune involving the hypothalamus (hypothalamitis). This is a unique case report of a dog presenting with inflammatory hypophysitis and hypothalamitis of suspected autoimmune origin with detailed clinical, MRI, histology and immunohistochemistry findings.     

Usefulness of MRI compared with CT for diagnosis of mesenteric lymphoma in a dog

We evaluated the usefulness of MRI and compared it with CT for diagnosis of mesenteric lymphoma in a dog. The results in the plain CT, dynamic CT and plain MR (T1WI and T2WI) images suggested that the mass was a large single nodular lesion with abundant blood perfusion. On enhanced MRI(T1WI) , the mass was depicted as a tumor with adhesion to the gut wall. Exploratory laparotomy confirmed the mass was consistent with the findings on enhanced MRI. We think that MRI might be a useful imaging tool for diagnosis of canine mesenteric lymphoma.     

Changes of magnetic resonance imaging on the brain in beagle dogs with aging

Age-associated changes of magnetic resonance imaging (MRI) on the brain were evaluated in 19 beagle dogs aged from 8-month- to 16-year-old. A significant correlation of the volume of lateral ventricle space was observed in the dogs with age advanced, however, no correlation was found between hippocampus size and the aging. The hypo-intensity areas on T2-weighted MRI were detected in globus pallidus and substantia nigra with a significant correlation of both intensity ratios to lateral ventricle with age advanced. These areas were coincided with the accumulation of iron in the slice of the brain with Perls' staining. In addition, hyper-intensity area, suggesting perivascular demyelination with fluid-filled space, was also observed in white matter surrounding the lateral ventricle on T2-weighted MRI. These results suggested that age-associated changes of T2-weighted MRI were developed in the dog brain, especially in globus pallidus, substantia nigra, and white matter surrounding lateral ventricle, like as those reported in the human brain.     

Correlation between fluorodeoxyglucose positron emission tomography and magnetic resonance imaging findings of non-suppurative meningoencephalitis in 5 dogs

This study characterized the [(18)F]2-deoxy-2-fluoro-D-glucose positron emission tomography (FDG-PET) findings of encephalitis in dogs and assessed the role of FDG-PET in the diagnosis of meningoencephalitis. The medical records, magnetic resonance (MR), and FDG-PET images of 3 dogs with necrotizing meningoencephalitis (NME), 1 dog with granulomatous meningoencephalitis (GME), and 1 dog with meningoencephalitis of unknown etiology (MUE) were reviewed. On the FDG-PET, glucose hypometabolism was identified in the dog with NME, whereas hypermetabolism was noted in the dog with GME. The T2-weighted images (WI) and fluid attenuated inversion recovery (FLAIR) images were characterized by hyperintensity, whereas the signal intensity of the lesions on the T1-WI images was variable. The metabolic changes on the brain FDG-PET corresponded well to the hyper- and hypointense lesions seen on the MR imaging. This type of tomography (FDG-PET) aided in the differentiation of different types of inflammatory meningoencephalitis when the metabolic data was combined with clinical and MR findings.     

Detection of Neospora caninum tachyzoites in cerebrospinal fluid of a dog following prednisone and cyclosporine therapy

Abstract: A 9‐year‐old female spayed Shetland Sheepdog was presented to the Kansas State University Veterinary Medical Teaching Hospital for evaluation following a 3‐week history of left rear limb lameness that had progressed to generalized ataxia. Multifocal or diffuse brain lesions were suspected based on physical examination findings. Cerebrospinal fluid (CSF) contained 52 nucleated cells/μL composed of mixed inflammatory cells. Treatment with prednisone and cyclosporine was initiated based on a presumptive diagnosis of granulomatous meningoencephalitis. Thirteen days later the dog was nonambulatory and mentally obtunded. Repeat CSF analysis revealed 298 nucleated cells/μL with 61% eosinophils. Rare protozoal tachyzoites consistent with Neospora caninum, Toxoplasma gondii, or Sarcocystis spp. were found extracellularly and within macrophages and an eosinophil. Despite cessation of prednisone and cyclosporine therapy and provision of supportive care, the dog died 6 days later. Examination of brain tissue sections revealed multifocally extensive, necrotizing, histiocytic, and lymphoplasmacytic meningoencephalitis with numerous protozoal zoites and cysts. Immunohistochemical analysis of brain tissue using a monoclonal antibody specific for N. caninum confirmed the diagnosis of neosporosis. Similar but less severe lesions were noted in the spinal cord, although organisms were not found. This case emphasizes the value of repeated CSF analysis when therapy is ineffective and the importance of excluding infectious causes of meningoencephalitis before commencement of immunosuppressive therapy.     

Accuracy of the withdrawal reflex for localization of the site of cervical disk herniation in dogs: 35 cases (2004-2007)

OBJECTIVE: To evaluate the accuracy of neurologic examination versus magnetic resonance imaging (MRI) in localization of cervical disk herniation and evaluate the usefulness of withdrawal reflex testing in dogs. DESIGN: Retrospective case series. ANIMALS: 35 client-owned dogs with a single-level cervical disk herniation as determined via MRI. PROCEDURES: 1 of 2 board-certified neurologists performed a complete neurologic examination in each dog. Clinical signs of a cervical lesion included evidence of neck pain and tetraparesis. The withdrawal reflex was used for neuroanatomic localization (C1-C5 or C6-T2). Agreement between results of neurologic and MRI examinations was determined. RESULTS: Agreement between neurologic and MRI diagnoses was 65.8%. In 11 dogs in which the lesion was clinically localized to the C6-T2 segment on the basis of a decreased withdrawal reflex in the forelimbs, MRI revealed an isolated C1-C5 disk lesion. In 1 dog, in which the lesion was suspected to be at the C1-C5 level, MRI revealed a C6-T2 lesion. Cranial cervical lesions were significantly associated with an incorrect neurologic diagnosis regarding site of the lesion. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that the withdrawal reflex in dogs with cervical disk herniation is not reliable for determining the affected site and that a decreased withdrawal reflex does not always indicate a lesion from C6 to T2.     

The use of magnetic resonance imaging in the diagnosis of neurological disease

Magnetic resonance imaging (MRI) data were correlated with clinical and cerebrospinal fluid (CSF) findings in one cat and two dogs with brain lesions. In all three cases, localization of the lesions, as determined clinically, was confirmed using MRI. Magnetic resonance imaging also helped us to define the full extent of the lesion(s) in each case. In one case, the lesion would have been diagnosed as purely inflammatory based on the abnormalities in the CSF. The MRI study, however, showed a homogeneous mass with circumferential changes characteristic of peritumoral edema or inflammation. In two cases, the MRI findings were confirmed at necropsy. An MRI study was also done on a normal dog, demonstrating the variable contrast and anatomical detail possible using this technique. We also discuss difficulties in identifying tumor type using MRI.