自然位与过屈位磁共振成像对平山病的诊断价值

目的:探讨颈椎自然位及过屈位磁共振成像对平山病的诊断价值.方法:对8例临床证实的平山病患者行颈椎自然位及过屈位磁共振平扫及增强扫描,所有患者均进行常规脑脊液检查、肌电图检查.结果:自然位MR扫描,8例均有C5～C7段脊髓轻度萎缩,前后径变短,过屈位扫描,7例患者可见颈髓前移,硬脊膜外腔增宽,1例患者可见硬膜外腔内流空血管影,7例在增强扫描中均可见不同程度的硬膜后间隙内异常强化影.结论:平山病患者在过屈位时颈髓及硬膜外腔的异常表现极具特征性,因此MRI过屈位平扫加增强扫描对平山病的诊断具有重要价值.     

平山病的MRI诊断

目的：探讨平山病（hirayama disease）的MR影像学表现,提高对该病的认识。方法通过查阅相关文献,回顾性分析2例临床已确诊的平山病MR自然位和过屈位影像表现,观察其低位颈髓的动态变化,并与健康自愿者的同条件扫描影像相比较,总结平山病的MR影像学表现。结果①自然位：曲线多有异常,下段颈髓萎缩,髓内可有异常信号,有失连接现象;②过屈位：所有患者均出现颈髓前移、变扁,硬脊膜后有月牙形、集簇状异常信号影;③2例患者强化检查示过屈位脊膜后异常信号影有强化;④志愿者自然位扫描显示颈椎曲度自然,颈髓粗细均匀,不存在失连接现象,过屈位脊膜后无异常信号影。结论MR颈椎检查特别是过屈位扫描能够显示出平山病的特征性影像学改变,对于平山病的早期诊断具有重大价值。     

平山病MRI诊断价值的初步研究

目的：探讨平山病的MRI表现及其诊断价值,加深对平山病的MRI表现及其可能的发病机制的认识。方法：回顾性分析5例经临床证实为平山病的MRI资料。所有患者均行颈椎常规仰卧位和屈颈位平扫及增强MRI检查。结果：常规仰卧位MPA显示5例患者中3例低位颈髓（C5-C7）萎缩,变扁平,髓内出现信号异常（主要位于灰质前角内）;屈颈位砌平扫5例均可见下段颈髓前移、变扁平加剧;4例硬脊膜外间隙增宽。增强MRI 3例患者可见增宽的硬膜外间隙内异常增粗并明显强化的静脉丛。结论：平山病的MRI表现有一定的特征性,屈颈位平扫及增强MRI对平山病的诊断有重要的价值。     

平山病的MRI诊断

目的:总结分析平山病的MRI表现,探讨MRI对平山病的诊断价值。方法:回顾性分析经临床及肌电图证实为平山病的11例患者的影像资料。结果:9例颈椎生理曲度变直或反弓;11例均有MRI上低位颈髓不同程度变扁、变细、萎缩,屈曲位均可见背侧硬脊膜向前移位、后硬脊膜外间隙增宽及弧形或梭形T2WI异常高信号。结论:平山病的MRI表现有一定的特征性,低位颈髓的局限性萎缩、细扁改变、屈曲位后硬脊膜外间隙T2WI高信号及流空信号对本病的诊断具有重要价值。     

平山病2例报告并文献复习

目的 探讨平山病的颈髓磁共振(MRI)表现及其诊断价值.方法 对2例平山病患者的临床、神经电生理、MRI影像学资料进行分析,并复习相关文献,总结平山病的颈髓MRI特点.结果 2例均为青年男性,主要表现为局限于手和前臂肌萎缩.肌电图均示神经源性损害.自然位MRI扫描,2例均有C4～C7段脊髓轻度萎缩,前后径变短.屈颈位MRI平扫2例均可见下段颈髓前移、变扁平加剧,硬脊膜外间隙增宽,其内可见蚓状异常血管流空信号.增强MRI2例均可见增宽的硬膜外间隙内异常增粗并明显强化的静脉丛.结论 平山病的MRI表现有一定的特征性,屈颈位平扫及增强MRI对平山病的诊断有重要的价值.     

不同体位颈椎MRI对平山病的影像诊断

目的 探讨平山病患者自然位和前屈位颈椎MRI表现及其诊断价值.资料与方法 对6例经临床确诊的平山病患者及6名正常自愿者均行颈椎自然位+前屈位+增强MRI,对比分析平山病患者低位颈髓的MRI表现.结果 自然位:6例患者颈椎生理曲度变直,低位颈髓变细;6名正常自愿者可见颈膨大(约脊髓C6～T2段).前屈位:6例患者低位颈髓变扁、萎缩,两种体位低位颈髓前后径差值与正常自愿者相比差异有统计学意义(P<0.05),另可见背侧硬膜囊后壁前移、硬膜外间隙增宽,内见迂曲、条形流空信号,增强后明显强化;正常自愿者低位颈髓较自然位略变细,背侧硬膜囊无前移、扩张,其内未见流空信号.结论 不同体位MRI均能显示平山病患者颈椎的异常表现,尤其是前屈位对平山病的诊断具有重要价值.     

改变颈椎屈曲角度对平山病特异性MRI征象的影响

目的 比较平山病患者颈椎不同屈曲角度MRI表现,研究颈椎屈曲角度对平山病MRI征象的影响.方法 20例临床确诊为平山病的患者,行颈椎中立位及屈曲位20°、25°、30°、35°、40°MR扫描,观察不同屈曲位MRI硬脊膜前移、硬膜外间隙增宽2个征象出现率.并测量硬膜外间隙最大矢状径(d)及同水平椎管矢状径(D),计算d/D用于定量分析上述2个征象.不同屈曲位各征象出现率的比较使用Fisher精确概率法.各组间d/D平均值比较使用重复测量资料方差分析,之后对任意两组间d/D平均值进行比较.结果 患者颈椎背侧硬脊膜前移及硬膜外间隙增宽征象出现率在屈曲角度20°时为70%(14/20),25°以上均为100%,20°与25°时特殊征象出现率差异有统计学意义(χ2=5.760,P=0.020).20°、25°、30°、35°、40°时,对应d/D值分别为0.51±0.06、0.54±0.08、0.57±0.09、0.61±0.09、0.59±0.07,差异有统计学意义(F=3.450,P=0.013),两两比较提示d/D平均值在屈曲35°时>20°和25°,在屈曲40°时>20°(P值均<0.05).结论 颈椎屈曲角度可以影响颈椎背侧硬脊膜前移及硬膜外间隙增宽的MRI征象.     

低颅压综合征的MRI表现(附5例报告)

目的 探讨低颅压综合征的MRI表现.资料与方法 回顾性分析5例低颅压综合征的影像学表现,其中1例行头颅CT平扫、头颅和脊柱MRI平扫及增强扫描、头颅MRV扫描,3例行头颅MRI平扫及增强扫描,1例行脊柱MRI平扫及增强扫描.结果 1例头颅CT扫描未见异常.4例头颅MRI扫描均显示硬脑膜弥漫性增厚并明显强化,1例出现脑下垂.1例头颅MRV显示上矢状窦、直窦、横窦扩张.2例脊柱MRI扫描显示硬脊膜广泛增厚并明显强化.结论 硬脑(脊)膜弥漫性增厚强化是低颅压综合征的特征性影像学表现,MRI增强扫描是诊断低颅压综合征的敏感影像学检查方法.     

平山病的MRI诊断

目的 探讨平山病低位颈髓在自然位和过屈位特殊的动态变化对诊断的价值。方法 对18例临床确诊为平山病的患者和31例正常对照者进行MR自然位和过屈位的矢状面和轴面扫描，测量C6椎体上缘颈髓前后径（APD）和横径（TD），观察其动态改变。结果 （1）自然位，平山病组表现有低位颈髓萎缩（病例组11例，对照组2例，X^2=14．76，P=0．000）和变扁平（病例组7例，对照组1例，X^2=8．15，P=0．004），差异有统计学意义。（2）过屈位，平山病组颈髓均前移后显著变扁，脊膜后有“月牙”形异常信号影。（3）自然位平山病组和对照组APD分别为（5．6±0．7）、（6．7±0．5）mm，过屈位APD分别为（4．3±0．8）、（6．0±0．5）mm，差异均有统计学意义（t值分别为-5．802、-8．952，P值均为0．000）。结论 平山病低位颈髓在正常位和过屈位存在特殊的动态变化，过屈位MRI可协助诊断。     

结核性脊髓脊膜炎的MRI诊断价值

目的：探讨MRI对结核性脊髓脊膜炎的诊断价值。方法：对21例结核性脊髓脊膜炎增强前后的MRI进行回顾性分析。结果：所有21例MRI平扫均可见脊膜受累,主要表现为脊膜不规则增厚,蛛网膜下腔狭窄或闭塞、分隔样改变、囊肿形成,神经根增厚;增强扫描表现为增厚的脊膜呈线状、斑块状、结节状和环状强化。本组21例中脊髓肿胀17例,脊髓空洞6例,髓内结核瘤5例。结论：MRI平扫和增强扫描可清晰显示结核性脊髓脊膜炎的病变部位和累及范围,可为临床治疗及判断预后提供影像学参考。     

屈颈MRI对青年性上肢远端肌萎缩症的诊断价值

目的评价屈颈MRI对青年性上肢远端肌萎缩症的诊断价值。方法男性患者5例，平均年龄21岁，临床表现为一侧或两侧上肢远端肌萎缩。对照组为健康志愿者，21岁男性8例。2组均行常规及屈颈颈椎MR平扫，矢状、轴面SET1WI、T2WI、液体衰减反转恢复（FLAIR）序列扫描。结果常规颈椎扫描：5例患者下段颈髓变细；屈颈位MR扫描：下颈段颈6以下脊髓前屈、变扁平，矢状径4～6mm，硬膜囊后壁前移，硬膜后间隙明显增宽，可见多发条状、迂曲流空信号影及软组织信号。对照组：常规扫描，下颈段脊髓（颈6～胸2）可见颈膨大，屈颈位脊髓略变细（6～7mm），硬膜囊后壁无前移，硬膜后间隙未见扩张血管影。结论屈颈MRI有助于显示下颈段脊髓及硬膜囊改变，结合临床资料可准确诊断青年性上肢远端肌萎缩症。     

Hirayama disease: MR diagnosis.

We report the MR findings in two cases of Hirayama disease, a kind of cervical myelopathy related to flexion movements of the neck. In flexion MR studies, we can see the striking and pathognomonic picture of anterior shifting of posterior dura at the lower cervical spinal canal. In nonflexion studies, we find that asymmetric cord atrophy, especially at the lower cervical cord, though subtle, is highly suggestive of Hirayama disease. When it is seen, a flexion MR study is warranted to prove this diagnosis.     

Magnetic resonance imaging in a juvenile type of distal and segmental muscular atrophy of the upper extremities

Eight patients with a juvenile type of distal and segmental muscular atrophy of the upper extremities (DSMA), a type of cervical flexion myelophathy, were evaluated using MR imaging. In the neutral position there was no spinal cord compression, but in flexion the spinal cord was displaced anteriorly and was compressed by the posterior surfaces or margins of the vertebrae and/or any herniated disks in all cases. In flexion, compression of the cord was exaggerated in seven patients by the anterior displacement of the posterior margin of the thecal sac, which was accompanied by dilated posterior internal vertebral veins. In patients suspected of having DSMA, MR images made in flexion are regarded essential for verifying the diagnosis. Correspondence to: K. Hasuo     

Hirayama flexion myelopathy: neutral-position MR imaging findings--importance of loss of attachment

PURPOSE: To investigate the sensitivity and specificity of various neutral-position magnetic resonance (MR) imaging findings in the diagnosis of Hirayama flexion myelopathy. MATERIALS AND METHODS: The neutral-position cervical MR images of 46 patients and 51 control subjects were evaluated for the following findings: localized lower cervical cord atrophy, asymmetric cord flattening, abnormal cervical curvature, loss of attachment (LOA) between the posterior dural sac and subjacent lamina, and noncompressed intramedullary high signal intensity on T2-weighted MR images. The difference in frequency of these findings between the control and patient groups was examined by means of the chi(2) test. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of these MR imaging findings in the diagnosis Hirayama disease were calculated. Multivariate analysis of these findings was also performed. RESULTS: There was a significant difference in the frequency of these MR imaging findings between the control and patient groups (all comparisons, P 相似文献   

Cervical degenerative disease at flexion-extension MR imaging: prediction criteria

PURPOSE: To determine if there are any neutral-position imaging criteria that can help predict functional cord impingement at flexion-extension cervical magnetic resonance (MR) imaging. MATERIALS AND METHODS: Sixty-two patients with cervical degenerative disease were evaluated with regard to the dynamic changes of canal stenosis at flexion-extension MR imaging. Functional cord impingement was considered if the cord was impinged or more impinged after neck flexion or extension. Selection criteria for neutral-position MR imaging, such as cervical curvature, canal space, degenerative stage, intramedullary high signal intensity on T2-weighted images, and resting instability, were evaluated for their ability to predict functional cord impingement at flexion-extension MR imaging (Fisher exact test, logistic regression analysis). RESULTS: MR images in 19 (31%) of 62 patients showed functional cord impingement at extension MR imaging compared with images in two (3%) patients at flexion MR imaging. Statistically significant differences were found for the criteria cervical degeneration stage (P <.001) and spinal canal space (P =.037) for predicting functional cord impingement at extension MR imaging. In contrast, no significant differences were found among selection criteria for flexion MR imaging. Probabilities of functional cord impingement at extension MR imaging were calculated with different combinations of degenerative stages and canal spaces. Probability could increase to 79% if the patient had both stabilization degeneration (disk protrusion or osteophytic formation with hypertrophy of the ligamentum flavum) and C7 canal space of 10 mm or less. CONCLUSION: None of the selection criteria evaluated in this study has the ability to predict functional cord impingement at flexion MR imaging; however, prediction of impingement at extension MR imaging can increase from 31% to 79% if proper criteria are selected.     

Pre- and postoperative MR imaging of the craniocervical junction in rheumatoid arthritis

Ten patients with severe chronic rheumatoid arthritis with atlantoaxial subluxation were examined with conventional radiography and MR imaging of the cervical spine before and at an average of 6 months after posterior occipitocervical fusion. Periodontoid pannus formation was revealed by MR preoperatively in nine patients, all with mobile horizontal atlantoaxial subluxation. Compression of the medulla and/or upper cervical cord, due to subluxation and periodontoid pannus bulging into the spinal canal, was seen in seven patients. After the stabilizing surgery the periodontoid pannus had decreased in size in all patients with preoperative pannus. This reduction in the pannus seems to be the result of the atlantoaxial immobility achieved by the posterior fusion. Postoperatively, three patients had some remaining compression of the medulla and/or cord secondary to immobile subluxation, while the pannus posterior to the odontoid process had disappeared. Artifacts from the surgical stainless steel fixation material were confined to the posterior part of the neck on short TR/short TE MR images and did not interfere with the evaluation of the periodontoid region and the anterior part of the medulla/cervical cord. We found that flexion and extension lateral radiographs, combined with sagittal short TR/short TE MR images in the neutral position, enable preoperative evaluation of patients with rheumatoid arthritis in the cervical spine. Postoperative MR should be performed only if there are residual or new symptoms.     

Classification system based on kinematic MR imaging in cervical spondylitic myelopathy.

BACKGROUND AND PURPOSEFunctional myelographic studies are often used to evaluate the dynamic changes of the cervical spinal canal during flexion and extension. The purposes of this study were to use kinematic MR imaging to assess the dynamic changes of the cervical spine in patients at different stages of degenerative disease and to describe a classification system based on static and dynamic factors in the pathogenesis of cervical spondylitic myelopathy.METHODSEighty-one patients with different stages (I-IV) of degenerative disease of the cervical spine were examined with MR imaging. In the neutral position (0 degrees) and at maximum flexion and extension, spinal stenosis was classified for each segment according to the following grading system: 0 = normal, 1 = partial obliteration of the anterior or posterior subarachnoid space, 2 = complete obliteration of the anterior or posterior subarachnoid space, and 3 = cervical cord compression or displacement.RESULTSAt flexion and extension, the prevalence of spinal stenosis and cervical cord impingement increased as the stage of degenerative disease progressed. With regard to a pincer effect (anterior and posterior cord impingement) and cord encroachment at multiple segments, statistically significant differences were observed at stages III and IV as compared with stages I and II. Significant increase in cord impingement was seen in 22 (27%) of 81 patients at extension, as compared with four (5%) of 81 patients at flexion.CONCLUSIONRegardless of the stage of degenerative disease and grade of spinal stenosis at the neutral position (0 degrees), cervical spinal motion may contribute to the development of cervical spondylitic myelopathy.