脊髓栓塞缺血损伤MRI表现与病理对照的实验研究

目的探索犬脊髓栓塞缺血损伤与MRI表现的关系.材料与方法利用明胶海绵、碘油对犬胸7～9肋间动脉进行栓塞,以生理盐水作对照,术后12、24小时、3天用1.0T磁共振仪,脊柱表面线圈,SE序列对脊髓损伤部位进行矢状面、横断面扫描,并与病理运动、功能分级进行对照.结果对照组、明胶海绵组脊髓MRI无改变,MRI能显示灰质白质及周围结构;碘油组单侧、双侧损伤的节段呈长T1长T2改变,与病理改变及功能分级一致.结论MRI能早期反映脊髓栓塞缺血损害的病理变化,与术后的运动功能密切相关,是判断预后的良好指标.     

选择性椎体供血动脉栓塞的动物实验研究

目的 通过对实验犬进行选择性椎体供血动脉栓塞的研究，旨在建立椎体急性缺血模型以及探讨影响栓塞结果的因素，为临床更好地实施脊柱肿瘤术前动脉栓塞提供理论依据。方法 用明胶海绵对12只实验犬分别行单节段和多节段选择性腰动脉造影和栓塞，栓塞后1－7d内观察后肢功能情况、靶节段椎体、脊髓MRI表现和病理改变。结果 栓塞单节段（双侧）或多节段腰动脉者均引起椎体不同程度的缺血、坏死改变。栓塞单根腰动脉者，不管靶动脉是否发出根髓动脉其靶椎体未见明显变化和未发生瘫痪；栓塞多节段腰动脉者有1只犬发生不全。在栓塞单节段以上腰动脉的脊柱节段水平可背部肌肉发生不同程度的缺血坏死表现。结论 （1）选择性动脉栓塞可用于椎体急性缺血模型的制作，为椎体缺血性病变的实验性诊断和治疗研究提供可能。（2）单节段动脉栓塞难于使整个椎体缺血坏死。（3）多节段动脉栓塞时有可能引起并发症，特别是栓塞范围内存在根髓动脉时。（4）在作选择性脊柱动脉检塞时，必要时应行保护性栓塞。     

肋间血管神经束移位脊髓内治疗截瘫(附16例报告)

目的：探讨肋间血管神经束移位脊髓内治疗截瘫的效果。方法：取脊髓损伤平面上之肋间血管神经柬埋于硬脊膜内，观察其支配肌力、感觉功能情况。结果：16例中，经此手术后下肢肌力明显恢复，可带支架扶双拐站立行走，大小使功能有改善，从A级或B级提高到D级4例；有8例本体感觉恢复，大小便功能有改善，从A组提高到B级、C级；另2例从A级提高到B级，无效2例。结论：将肋间血管神经束埋于硬膜内治疗截瘫有一定效果，手术简单，尤其对陈旧性脊髓损伤来说，其效果还是比较乐观的。     

支气管动脉栓塞术并发症分析

目的　研究支气管动脉栓塞术并发症及其相关因素。方法　 1 61例患者 ,大咯血 2 6例 ,支气管肺癌 1 35例。行选择性支气管动脉插管造影确认病变血供 ,分别在支气管动脉干或支气管动脉分支超选择插管下行栓塞术或栓塞化疗术 ,栓塞物质为明胶海绵颗粒、PVA和碘油。结果　并发症发生率 6 .2 % ,包括脊髓缺血 (1 .2 2 % )、肋间动脉缺血 (3 .7% )、肺动脉栓塞 (1 .2 % )。脊髓缺血和肋间动脉缺血均发生在支气管动脉主干栓塞者。脊髓缺血见于PVA组和碘油组 ,肺动脉栓塞见于碘油组 ,而肋间动脉缺血在各栓塞物质组均有发生。结论　支气管动脉栓塞术宜谨慎施行 ,使用同轴导管技术超选择性插管值得推荐 ,明胶海绵颗粒是相对安全的栓塞物质     

儿童脊髓节细胞胶质瘤一例

病例资料 患者,男,5岁,外院脊髓MRI检查:Th6-L3椎管内占位,脊髓空洞.患者患病以来大小便正常,体力下降.查体:左下肢肌力4级,右下肢肌力2级,肌张力低,双侧髋关节外翻畸形,双下肢肌肉萎缩.躯干感觉障碍平面约在Th10椎体水平.我院MRI示脊髓呈梭形增粗,C2-Th6段脊髓内见串珠样长T1、长T2信号,Th6-L3段脊髓见梭形等T1、混杂T2信号(图1、2).注射Gd-DTPA行增强扫描,Th6-L3段脊髓内病灶明显强化,长约14.3 cm,C2-Th6段脊髓内病灶未见强化(图3).     

不同序列磁共振成像诊断脊柱损伤的价值研究

目的：探讨不同序列磁共振成像在脊柱损伤诊断中的应用价值。方法：选择急性脊柱外伤56例,均采用T1WI、T2WI、STIR、DWI及FLAIR等序列进行MRI检查,比较不同序列对椎体和脊髓损伤的诊断价值。结果：STIR显示损伤椎体内片状高信号113枚;T1WI示椎体内条状、片状低信号92枚;T2WI示椎体内条状、片状高信号87枚;DWI示椎体内片状高信号62枚、条状高信号23枚、等信号28枚;FLAIR示椎体变扁或楔形变72枚。脊髓损伤25例（25处病灶,其中颈段18处,胸段3处,圆锥4处）,;所有脊髓损伤STIR、T2WI、DWI呈斑片状或点状高信号,边缘模糊;T1WI示局部低信号12例,其中低信号内斑点状略高信号2例;FLAIR显示局部略高信号14例;所有序列均未见脊髓断裂病例。椎体骨折ADC值为（1.72±0.21）×10-3 mm2/s,正常椎体为（0.25±0.02）×10-3 mm2/s;脊髓损伤ADC值为（0.50±0.03）×10-3 mm2/s,正常脊髓为（1.04±0.08）×10-3 mm2/s。对于椎体骨折的诊断,STIR非常显著优于DWI、T1WI、T2WI及FLAIR（P〈0.01）;对于脊髓损伤的诊断,T2WI、STIR、DWI非常显著优于FLAIR及T1WI（P〈0.01）。结论：STIR可作为急性脊柱损伤的首选扫描序列,DWI可作为重要辅助序列,FLAIR不宜作为常规扫描序列。     

支气管动脉内灌注化疗药物并发脊髓损伤的初步探讨

作者对３７例肺癌患者进行了１２５次支气管动脉造影和动脉内灌注化疗药物（顺铂、丝裂霉素、５－氟脲嘧啶），其中１例在灌注的同时加用５ｍｌ碘苯酯经乳化后进行支气管动脉栓塞。共发生３例脊髓损伤，１例在支气管动脉栓塞后即出现截瘫，另两例为术后第３～４ｄ出现右下肢麻木无力及小便困难，继而出现两下肢瘫痪及大小便失禁。症状出现后用激素、神经营养药及对症处理后均有好转。作者对并发脊髓损伤的原因、预防措施及治疗作了初步探讨。     

后路脊髓减压加硬化剂椎体内注射治疗脊椎骨血管瘤并发截瘫4例

我科自1987年开始应用后路脊髓减压加硬化剂椎体内注射治疗脊椎骨血管瘤并发截瘫4例,经观察效果良好,现报告如下。 1 临床资料 本组4例均为全脊椎骨血管瘤。年龄21～53岁,平均39.7岁。病变位于T_9 1例,T_(11) 2例,L_1 1例,均为单个脊椎受累。双下肢全瘫1例,双下肢不全瘫(肌力3级以下)3例。双下肢全瘫者大小便失禁。瘫痪时间19～37d。     

MR扩散加权成像对脊柱单纯性与病理性骨折的鉴别诊断

目的：探讨磁共振扩散加权成像（DWI）在脊椎单纯性与病理性骨折中的鉴别诊断价值。方法：43例共79个压缩性骨折椎体行MRI平扫和弥散加权成像检查。单纯性骨折23例共34个椎体,病理性骨折20例共45个椎体。分析病变椎体与正常椎体DWI信号特点,测定ADC值,分析单纯性骨折组、病理性骨折组及正常对照组之间ADC值差异。结果：单纯性压缩性骨折的ADC值为（2.39±0.37）×10-3mm2/s,病理性压缩性骨折的ADC值为（1.47±0.42）×10-3mm2/s,正常对照组的ADC值为（0.32±0.11）×10-3mm2/s,各组之间均具有显著性差异（P〈0.05）。结论：DWI及ADC值测定对单纯性骨折与病理性骨折具有重要鉴别诊断意义。     

犬大脑中动脉近端栓塞建立类腔隙性脑梗死模型的研究

目的研究介入法血栓栓塞犬大脑中动脉（MCA）建立脑梗死模型的可行性、稳定性及急性期在磁共振扩散加权成像（DWI）上的演变过程,并探讨该模型的发生及其可能的发病机制。 方法成年健康毕格犬6只,插管至左侧颈内动脉后采用1条直径约1.7 mm、长5 mm的白色血栓栓塞,栓塞成功后30 min～6 h内每30 min使用DWI序列连续扫描观察梗死病灶急性期的演变过程。栓塞后24 h、7天复查血管造影、MR扫描及神经功能评分,记录梗死灶的出现时间、位置及大小,分别比较6 h DWI病灶、24 h和7天的T2加权像上病灶的体积,并比较24 h与7天的神经功能评分。7天后处死动物取脑组织行病理检查。 结果所有犬皆为左侧MCA的近端栓塞,DWI在栓塞后(1.24±0.51)h可以在基底节、脑白质区显示单一或数个异常信号病灶,6 h DWI病灶的直径为(6.90±2.08)mm。共有9个病灶在三个时间点都可以显示,病灶的大小均<10 mm;栓塞后6 h DWI,24 h T2WI以及7 d T2WI病灶体积分别为(168.39±138.11)mm3、(186.88±161.54)mm3和(165.89±135.30)mm3,三者之间差异无明显统计学意义（P=0.0531）。7 d时动物均存活,24 h和7 d的神经功能评分分别为4.50±1.38和2.33±0.82（P=0.0009）。病理学检查证实为基底节梗死最常见,其次为脑白质区。 结论介入单栓子栓塞法可以成功建立犬MCA近端栓塞的类腔隙性脑梗死模型,DWI能够在早期检测到小的脑缺血病灶。犬拥有丰富的颅内外血管吻合,近端大血管栓塞可形成类腔隙性脑梗死的病灶,因此栓塞可能是腔隙性脑梗死的病因之一。     

Temporal evolution of spinal cord infarction in an in vivo experimental study of canine models characterized by diffusion-weighted imaging

PURPOSE: To determine the temporal evolution of diffusion abnormalities of in vivo experimental spinal cord infarction. MATERIALS AND METHODS: Guided by a digital subtract angiography (DSA) monitor, an agent of 1:1 match of lipiodol and diatrizoate meglumine was injected into bilateral T9-11 intercostal arteries of six dogs to embolize the spinal branches of intercostal arteries and establish the canine spinal cord infarction models. The progression of experimental spinal cord infarction was followed by dynamic MRI, including diffusion-weighted imaging (DWI) on a 1.5 Tesla MR system from one hour to 168 hours postembolization. Apparent diffusion coefficient (ADC) values were calculated and analyzed. At the end of the MRI experiments, the spinal cords of the animals were fixed for histology. RESULTS: A total of six experimental models were successfully established. In all cases, DWI images showed slight hyperintensity within one hour postembolization, whereas only four cases presented slight hyperintensity on T2-weighted images. ADC values of spinal cord infarction lesions decreased rapidly at early stage (several hours to 24 hours) and then increased gradually. CONCLUSION: The temporal evolution of diffusion abnormality of experimental spinal cord infarction may help us better understand various DWI signals in the process of spinal cord infarction.     

扩散加权成像在脊髓急性外伤中的应用

目的　研究扩散加权成像(DWI)在脊髓急性外伤中的应用价值。方法　急性脊髓外伤18例,在72h内行常规MRI和DWI(Philips1. 5TMR仪),其中2例行单次激发DWI(ssh DWI),16例行多次激发DWI(msh DWI)。结果　2例行ssh DWI者,均显示为脊髓病灶局部明显高信号,但图像质量较差,无法行表观扩散系数(ADC)值测量。其余16例均行msh DWI,图像质量明显改善,按照损伤程度和DWI表现不同分为3型: (1)水肿型:本组10例,损伤病灶呈不同程度DWI高信号,损伤部较正常部ADC值有明显减低(t=7. 515,P<0. 01),但本组急性期( 72h)内ADC值在24h内(4例)和25~48h(5例)两组间差异无统计学意义(t=0. 844,P>0. 05); (2)混合型: 4例,病灶混合出血与水肿,DWI呈混杂高信号; (3)出血型: 2例,病灶以出血为主,DWI呈低信号,相应T2WI呈不均匀高信号,T1WI低信号。结论　DWI为脊髓外伤的超早期诊断、帮助判断脊髓传导功能的完整性和脊髓压迫损伤的程度,以及是否合并出血等提供了新的客观手段,值得进一步临床研究和应用。     

Diffusion-weighted MR imaging (DWI) in spinal cord ischemia

Introduction Spinal cord infarction is a rare clinical diagnosis characterized by a sudden onset of paralysis, bowel and bladder dysfunction, and loss of pain and temperature perception, with preservation of proprioception and vibration sense. Magnetic resonance imaging (MRI) usually demonstrates intramedullary hyperintensity on T2-weighted MR images with cord enlargement. However, in approximately 45% of patients, MR shows no abnormality. Diffusion-weighted MR imaging (DWI) has been widely used for the evaluation of a variety of brain disorders, especially for acute stroke. Preliminary data suggest that DWI has the potential to be useful in the early detection of spinal infarction.Methods We performed DWI, using navigated, interleaved, multishot echo planar imaging (IEPI), in a series of six patients with a clinical suspicion of acute spinal cord ischemia.Results In all patients, high signal was observed on isotropic DWI images with low ADC values (0.23 and 0.86×10⁻³ cm²/s), indicative of restricted diffusion.Conclusion We analyzed the imaging findings from conventional MR sequences and diffusion-weighted MR sequences in six patients with spinal cord infarction, compared the findings with those in published series, and discuss the value of DWI in spinal cord ischemia based on current experience. Although the number of patients with described DWI findings totals only 23, the results of previously published studies and those of our study suggest that DWI has the potential to be a useful and feasible technique for the detection of spinal infarction.     

脊髓前动脉损伤致脊髓缺血性损伤模型的MRI评价

目的：研究经脊髓前动脉损伤，致脊髓缺血性损伤模型的高场强MRI信号表现特征。方法：选用12只家犬经颈前手术入路，切断脊髓前动脉，经高场强MRI扫描，对照病理分析脊髓前动脉损伤后脊髓的MRI信号变化特征。结果：脊髓前动脉损伤后脊髓MRI表现出异常T2WI高信号，且出现在脊髓前动脉损伤节段的前2／3，多表现为一例受累及或偏向一例。结论：MRI能确定脊髓缺血性损伤的部位及信号特征。     

无骨折脱位型颈髓损伤的MRI分析

目的 :探讨无骨折脱位型颈髓损伤的发生机理、好发部位及MRI特点。材料和方法 :回顾性分析 43例无骨折脱位型颈髓损伤的MRI表现。结果 :共发现脊髓异常MR信号 46处 ,多位于C4-6水平 ,异常信号T1WI为低信号、等信号或高信号 ;T2WI为信号均匀或不均匀的高信号。结论 :MRI能显示脊髓损伤的范围和病理改变 ,明确脊髓损伤处有无突出椎间盘的持续性压迫。是无骨折脱位型颈髓损伤最好的检查方法     

Percutaneous translumbar spinal cord compression injury in a dog model that uses angioplasty balloons: MR imaging and histopathologic findings

BACKGROUND AND PURPOSE: Previous animal models for spinal cord injury required laminectomy and exposure of the spinal cord to create direct trauma, compromising imaging by both surgical artifact and the nature of the production of the injury. Our purpose was to study a model that uses percutaneous intraspinal navigation with an angioplasty balloon, providing a controlled degree of spinal cord compression and allowing improved MR imaging of spinal cord injury. METHODS: Nine mongrel dogs were studied. MR images were obtained of six dogs after technique development in three dogs. Angioplasty balloons measuring 7 or 4 mm in diameter and 2 cm in length were placed in the midthoracic subarachnoid space. Imaging was performed by using a 1.5-T MR imaging unit before and after balloon inflation. The balloon was inflated within 5 seconds and deflated after 30 minutes. T1- and T2-weighted and contrast-enhanced images were acquired. Spinal cords were submitted for pathologic examination. RESULTS: All four animals with 7-mm balloons experienced hemorrhage, and three had axonal injury revealed by histopathologic examination. One of two animals with 4-mm balloons experienced no injury, and one had axonal injury without hemorrhage. Regional parenchymal enhancement was seen in two of the animals with 7-mm balloons. CONCLUSION: This percutaneous spinal cord injury model results in a graduating degree of injury. It differs from previous techniques by avoiding surgical exposure and the associated artifacts, yet it offers histopathologic findings similar to those of human spinal cord injury. The canine spinal cord is amenable to MR imaging with clinical imaging units. Further evaluations with various durations of compression and various balloon sizes are warranted.     

MR扩散加权成像评价膀胱癌经动脉灌注化疗及栓塞术后疗效的价值

目的探讨MR扩散加权成像(DWI)在膀胱癌经髂内动脉灌注化疗及栓塞术后疗效评价中的作用。资料与方法对经病理证实的28例膀胱移行上皮细胞癌患者于介入术前后行MR DWI。在GE Signa Excite HD 1.5TMR扫描仪上,先取多个扩散敏感梯度因子(b值)分别为300 s/mm2、500 s/mm2、800 s/mm2、1000 s/mm2、1200 s/mm2、1500 s/mm2,利用固定参数组合的自旋回波-回波平面成像(SE-EPI)序列对28例经动脉灌注化疗及栓塞术的膀胱癌肿块分别于术前24～48 h、术后7～10天各进行一次多b值的DWI。经分析比较后选取合适的b值为1200s/mm2,测量出每例膀胱癌不同监测时间点的肿瘤平均表观扩散系数(ADC)值,对两组结果进行比较。结果 28例膀胱肿瘤治疗前平均ADC值(1.15±0.12)×10-3mm2/s,介入治疗后肿瘤平均ADC值(1.36±0.15)×10-3mm2/s,治疗后肿瘤平均ADC值升高,P值<0.05,差异具有统计学意义。结论初步研究表明,对膀胱肿瘤的ADC值进行动态测定,可以评价膀胱癌介入治疗后早期病理学反应。     

Line scan diffusion weighted imaging (LSDI) on 0.2 Tesla MRI of the normal cervical cord in vivo: preliminary study

Diffusion weighted imaging(DWI) has been widely performed in the brain. However, DWI of the spinal cord is rarely performed because of technical and physiologic problems. Line scan diffusion weighted imaging(LSDI) is spin-echo based and relatively insensitive to susceptibility artifacts. We calculated the apparent diffusion coefficient(ADC) values of the normal cervical spinal cord by LSDI on a 0.2 Tesla MR imager and compared the ADC values with those from 1.5 Tesla MRI previously reported in the literature. The ADC values were adequate, and LSDI on 0.2 Tesla MRI is expected to become a useful tool for clinical application.     

硬脊膜动静脉瘘的MRI和DSA影像学特点及栓塞治疗

目的 探讨硬脊膜动静脉瘘的MRI和DSA影像学特点及血管内栓塞治疗方法。方法 12例硬脊膜动静脉瘘患者均行MRI和脊髓血管造影检查,4例行栓塞治疗。分析其MRI和血管造影表现。结果 12例硬脊膜动静脉瘘中,MRI屉示脊髓内弥漫性长T2信号影11例,脊髓斑片状强化2例,脊髓背侧异常血管影6例。脊髓血管造影均能显示其瘘口和引流静脉,并反映其病变范围、供血状况及特征。4例行栓塞治疗患者其临床症状均有改善。结论 脊髓血管造影是诊断硬脊膜动静脉瘘的主要确诊方法。MRI对确定诊断具有重要作用。血管内栓塞是一种有效的治疗方法。     

Multishot diffusion-weighted MR imaging features in acute trauma of spinal cord

Objectives

To analyse diffusion-weighted MRI of acute spinal cord trauma and evaluate its diagnostic value.

Methods

Conventional MRI and multishot, navigator-corrected DWI were performed in 20 patients with acute spinal cord trauma using 1.5-T MR within 72 h after the onset of trauma.

Results

Twenty cases were classified into four categories according to the characteristics of DWI: (1) Oedema type: ten cases presented with variable hyperintense areas within the spinal cord. There were significant differences in the apparent diffusion coefficients (ADCs) between lesions and unaffected regions (t?=?-7.621, P?<?0.01). ADC values of lesions were markedly lower than those of normal areas. (2) Mixed type: six cases showed heterogeneously hyperintense areas due to a mixture of haemorrhage and oedema. (3) Haemorrhage type: two cases showed lesions as marked hypointensity due to intramedullary haemorrhage. (4) Compressed type (by epidural haemorrhage): one of the two cases showed an area of mild hyperintensity in the markedly compressed cord due to epidural haematoma.

Conclusions

Muti-shot DWI of the spinal cord can help visualise and evaluate the injured spinal cord in the early stage, especially in distinguishing the cytotoxic oedema from vasogenic oedema. It can assist in detecting intramedullary haemorrhage and may have a potential role in the evaluation of compressed spinal cord.

Key Points

? Multishot, navigator-corrected diffusion-weighted MRI is helpful when evaluating spinal cord injury (SCI). ? Four types of SCI may be classified according to the DWI characteristics. ? DWI differentiates cytotoxic from vasogenic oedema, thereby determining the centre of SCI. ? DWI can assist in detecting intramedullary haemorrhage. ? DWI can help evaluate the degree of compressed spinal cord.