巨噬细胞活性MRI对多发性硬化大鼠模型中枢神经系统病灶诊断价值的初步研究

目的 探讨巨噬细胞活性成像(MAI)对多发性硬化(MS)模型大鼠脑和脊髓病灶的诊断价值.方法 20只正常Lewis大鼠用数字表法随机分成实验组15只,对照组5只.应用髓鞘少突胶质细胞糖蛋白多肽35-55(MOG35-55)致敏实验组大鼠制备MS动物模型实验性自身免疫性脑脊髓炎(EAE),大鼠首次急性发病后第3天行MR检查.分别对大鼠脑和脊髓行T2WI、T1WI和Gd-DTPA增强T1WI的三维容积扫描.经大鼠尾静脉注入超微超顺磁性氧化铁(USPIO)24 h后行USPIO增强T2WI(即MAI).利用工作站专业软件获得大鼠脑和脊髓冠状面、横断面和矢状面的重组图像,并与常规图像进行比较.结果 成功建立MOG35-55-EAE模型大鼠15只.MOG35-55-EAE大鼠急性发病期相关的中枢神经系统病灶多数分布在脑内(58/63),少数位于脊髓(5/63).常规MRI上病灶表现为T2WI高信号、T1WI低信号,部分出现Gd-DTPA强化.在MAI图像上病灶呈低信号,部分USPIO强化病灶在T2WI上呈等信号,病灶的USPIO强化与Gd-DTPA强化表现不完全一致.T2WI(14/15)和MAI(13/15)对MOG35-55-EAE大鼠急性期病灶的敏感度高,两者联合对病灶的检出率高达100%(15/15),增强T1WI的敏感度相对较低(7/15).对照组大鼠MAI未见异常.结论 MAI弥补传统MR检查技术的不足,能监测EAE的炎症反应,与常规T2WI联合能提高MOG35-55-EAE大鼠病灶的检出率;Gd-DTPA增强能显示EAE血脑屏障破坏的早期活动性病灶,MAI与之联合成像对EAE病灶的诊断和监测有互补作用.     

超微超顺磁性氧化铁和钆对比剂增强兔动脉硬化斑块之比较

目的：比较超微超顺磁性氧化铁（USPIO）和钆对比剂在磁共振图像上增强动脉粥样硬化斑块的异同。方法：20只新西兰大白兔高脂喂养8周,存活18只,分为对照组和实验组,每组各9只。使用磁共振在心电门控下对两组兔主动脉斑块进行检测,再给对照组注射钆对比剂,实验组注射USPIO对比剂,并分别于注射后即时、24、36和48 h进行扫描。扫描序列为二维时间飞跃法、快速自旋回波T1WI、脂肪抑制的快速自旋回波序列T1WI和快速自旋回波序列T2WI。比较各组兔主动脉硬化斑块内增强前后以及增强后不同时期的脂肪抑制T1WI和T2WI,对比噪声比（CNR）值变化差异。将两组动物处死后取出胸主动脉进行大体普鲁士蓝染色和切片显微镜观察。结果：对照组主动脉硬化斑块注射钆对比剂后T1WI显著强化,CNR值明显上升,24 h后回归注射前状态;T2WICNR值轻度下降,24 h后回归正常。实验组硬化斑块注射USPIO后T1WI显著强化,CNR值明显上升,24 h后有所下降,但明显高于注射前,48 h和72 h后CNR值持续上升;T2WI注射后信号显著降低,24 h后CNR值有所上升,但仍然低于注射前,48 h和72 h CNR值持续下降。实验组兔胸主动脉和切片普鲁士蓝染色阳性,对照组显示阴性。结论：相对于钆对比剂,超顺磁性、超长时间的血浆半衰期以及能够被巨噬细胞特异性吞噬的特性,使得常规剂量的USPIO可以同时引起强化组织信号在T1WI及T2WI上显而易见的变化,并且能够保持长时间的持续强化。     

大鼠急性期局灶性脑缺血后炎性反应的超微超顺磁性氧化铁增强MRI研究

目的:通过超微超顺磁性氧化铁微粒(USPIO)观察大鼠急性期局灶性脑缺血后炎症反应.方法:48只大鼠随机分成假手术组及模型组,每组各24只,进行右侧大脑中动脉栓塞造模.造模成功后,立即于大鼠尾静脉注射USPIO对比剂.两组均按造模后MR扫描时间点(6h、12h、24h、36h、48h、72h)平均分成6亚组行MR扫描,结束后即刻取脑行HE染色观察细胞坏死、普鲁士蓝染色观察铁微粒、免疫组化染色观察吞噬细胞.结果:6h模型亚组于MRI图像上梗死灶未见明显强化.12～72h模型亚组梗死灶于T2WI及T2W快速场回波(T2W-FFE)图像上呈负性强化,于T1WI图像上呈正性强化.除72h亚组的T2W-FFE序列外(t=0.728,P=0.478),模型组与假手术组的6h、12h、24h、36h、48h、72h各亚组的各序列上的病灶信号强度比值均见明显差异(P＜0.01).普鲁士蓝染色示12～72h模型组梗死灶铁微粒沉积,免疫组化染色(CD68)显示病灶区吞噬细胞增生.结论:USPIO可作为大鼠急性期脑缺血后炎症反应活体监测的新型MRI对比剂.     

USPIO增强MRI检测兔动脉粥样硬化斑块的实验研究

目的:探讨USPIO增强MRI检测兔动脉粥样硬化(AS)斑块的可行性及价值.方法:健康雄性新西兰大白兔30只,随机分为实验组20只,对照组10只.实验组采用球囊导管损伤主动脉内膜结合高脂饮食的方法建立兔动脉粥样硬化模型,对照组不做干预.观察USPIO增强前后AS斑块MRI信号表现,并与病理检查结果行对照研究.结果:12例兔AS模型成功建立,扫描范围内共发现普鲁士蓝染色阳性斑块67个,USPIO增强前后信号明显改变者共53个.USPIO增强T_2WI及T_2~*WI表现为斑块中央信号减低,其负性强化峰值出现在注射对比剂后96h.USPIO增强3D-TOF序列表现为管壁点状充盈缺损.病理检查发现,氧化铁颗粒主要沉积在内膜下、泡沫细胞中以及泡沫细胞融合崩解的粥样坏死物中.结论:USPIO增强MRI能检出并反映兔动脉粥样硬化斑块成分,有望用于对AS病变诊断及斑块稳定性的评估.     

脑实质海绵状血管瘤的MRI诊断

目的:探讨脑实质内海绵状血管瘤的MRI表现,以及对病理分型的MRI诊断价值.材料和方法:32例MRI平扫.18例行Gd-DTPA增强扫描,所有病例均经手术病理证实.并采用x2检验对病理分型与MR/表现进行分析.结果:32例共32个病灶.24例T1WI和T2WI均表现为高低混杂信号,呈网格状或桑葚样、结节状;5例TIWI呈团块状或完全高信号;T2WI等信号或低信号,3例T1WI等信号或低信号,T2WI稍高信号.23例T2WI显示病灶边缘呈完整低信号环.18例增强扫描中,3例基本无增强,7例轻度增强,8例点状或不规则增强.病理表现分为两型: Ⅰ型血管壁仅有菲薄的胶原纤维和内皮细胞,18个;Ⅱ型血管壁较厚,有薄层平滑肌,14个.Ⅰ型与Ⅱ型脑内海绵状血管瘤MRI表现没有统计学差异.结论:网格状或桑葚样、结节状高低混杂信号并伴有T2WI周围低信号环是CA的MRI的特征性表现,MRI表现与病理分型无关.     

兔动脉粥样硬化斑块:USPIO增强MR与Gd-DTPA增强MR对比实验研究

目的 在MR连续观察下,采用自制超小超顺磁性氧化铁(ultrasmall superparamagnetic iron oxide,US-PIO),与钆喷酸葡胺(Gd-DTPA)对比,分别对动脉粥样硬化(AS)兔行增强MR检查,旨在探讨USPIO增强MR对AS兔的价值.材料与方法35只雄性新西兰大白兔随机分为两组,25只给予高脂饮食诱导动脉粥样硬化,10只给予正常饮食作为对照组.所有扫描均在1.5 T磁共振扫描仪上进行,采用Cardiac线圈.扫描序列包括:T1WISE,T1WI SE脂肪抑制,T2WI FSE,T2*WI GRE.所有动物于喂养10周时测血清总胆固醇量,并进行平扫及USPIO增强24 h扫描,1周后行Gd-DTPA增强扫描,完成Gd-DTPA增强扫描当天处死不同喂养阶段模型兔及同期对照组正常兔,整个过程每2周重复一次.USPIO使用剂量为0.05 mmolFe/kg体重,Gd-DTPA使用剂量为0.25 mmol/kg体重.MR所见与病理相对照.结果 喂养10周时模型兔血清总胆固醇值明显高于正常组(P＜0.05),且所有模型兔大体标本均发生肉眼可见动脉粥样硬化样改变,除5只模型兔喂养中途死亡,其余兔均完成全程扫描.病理证实斑块内巨噬细胞吞噬USPIO.USPIO增强MR较Gd-DTPA增强能更好识别斑块内各种成分.结论 US-PIO增强MR对识别斑块成分具有独特价值,并能反映斑块内炎性浸润,因此对判断斑块易损性优于Gd-DTPA增强MR.     

脑梗死大鼠脑内移植超顺磁性氧化铁颗粒标记神经干细胞后的MR示踪研究

目的探讨超顺磁性氧化铁颗粒（SP10）标记的胎鼠神经干细胞（NSCs）在脑梗死模型大鼠脑内移植后，MR示踪观察的可行性。方法大鼠脑梗死模型24只，按随机数字表法分为3组：第1组大鼠同侧尾状核移植SP10和5-溴脱氧尿核苷（BrdU）双标记的NSCs；第2组对侧尾状核移植双标记的NSCs；第3组对侧尾状核移植未标记的NSCs。移植后1、3、5、7周后进行MR示踪观察，选择T2WI和梯度回波（GRE）序列，成像后相应时间点每组处死2只大鼠，取脑组织冰冻切片后进行普鲁士蓝染色及BrdU染色。结果移植后1周MRI显示：移植标记细胞组在注射点处可见类圆形低信号影，未标记细胞组注射点未见异常信号影；3周后，第1组梗死皮层下可见线状低信号影；移植5周后，第2组沿胼胝体走行可见扇形低信号影，尖端指向病灶。GRE序列显示标记细胞较清晰，而T2WI显示梗死病灶和大鼠脑正常结构较清晰。相应时间点相应部位普鲁士蓝染色及BrdU染色可见阳性细胞，与MRI结果相符。结论超顺磁性氧化铁颗粒和BrdU双标记的神经干细胞移植至大鼠脑内后可迁移到病灶区；MR成像能够在活体内连续示踪观察神经干细胞的迁移及分布情况。     

额叶低分化型滑膜肉瘤1例

该文报道了1例脑外(颅内)低分化型滑膜肉瘤患者。女, 30岁, CT平扫示右额叶囊实性肿块伴出血及占位效应。MRI平扫示病灶T1WI呈等-低信号, T2WI呈等-高信号, 液体衰减反转恢复序列(FLAIR)呈稍高-高信号;病灶内见小片状T1WI稍高信号及T2WI、FLAIR低信号区;增强扫描病灶呈不均匀明显强化;扩散张量成像彩色编码各向异性分数图示病灶周围脑白质神经纤维束缺失、中断;MR波谱成像示病灶实性部分胆碱/N-乙酰基天冬氨酸比值为3.83。最终病理诊断为低分化型滑膜肉瘤。     

原发性透明细胞型肝癌的CT和MRI诊断

目的 探讨原发性透明细胞型肝癌的影像表现,评价CT和MRI对该病的诊断价值.方法 回顾性分析19例经手术病理证实的原发性透明细胞型肝癌的CT和MRI表现.13例行CT平扫和动态增强扫描,8例行MR T1WI、T2WI和动态增强扫描.结果 CT平扫13例病灶均为低密度,其中9例病灶内部见不规则的更低密度影.增强后动脉期所有病灶均有强化表现,9例病灶不均匀强化,病灶中心有无强化的低密度区.门静脉期11例病灶呈相对低密度,2例呈等密度.3例可见环形强化的包膜.MR T1WI上5例病灶为低信号,3例为稍高信号.T2WI上5例病灶为混杂高信号,3例为等、低信号.MRI增强动脉期所有病灶均有显著强化.门静脉期和延迟期7例病灶为相对低信号,1例为等信号.2例病灶见环形强化的包膜.结论 CT和MRI可显示原发性透明细胞型肝癌的特征性表现,有助于提高该病的诊断准确性.     

脑内海绵状血管瘤影像诊断

目的：探讨脑内海绵状血管瘤的CT、MRI影像表现特点及诊断价值。方法：回顾性分析28例脑内海绵状血管瘤的影像资料,经CT检查18例,6例增强扫描,MR检查28例,10例增强扫描,11例经手术病理证实,3例做伽马刀治疗,14例随诊证实。结果：脑内海绵状血管瘤CT平扫表现为稍高或混杂密度影,边界清晰,病灶内可见单发或多发点状或斑片状钙化,少数可表现为血肿密度,增强扫描轻度不均匀强化或无强化。MR典型表现为T2WI及T1WI高低不均匀信号,呈＂爆米花＂样,周边可见低信号环,部分病灶为T2WI中央高、周边低信号,T1WI略低信号,边界模糊;T2WI为高信号,T1WI中央高、周边低信号;少数病灶表现为T2WI、T1WI均为高信号且信号均匀。DWI呈中间混有高信号的不均匀黑色低信号或均匀黑色低信号且较T1WI及T2WI范围加大,增强扫描表现为不均匀强化或无明显强化。结论：脑内海绵状血管瘤以MRI表现更典型,MRI检查T2WI及DWI序列是诊断及随访脑内海绵状血管瘤的最佳方法。     

桥本脑病的MRI特点

目的 探讨桥本脑病(HE)的MRI特点及其机制,以提高诊断及鉴别诊断能力.方法 回顾性分析5例临床诊断为HE患者的临床和MRI资料.5例患者均行头颅常规MR扫描,并对其中常规MRI表现异常的3例患者行DWI、MRA和增强扫描.观察病变的分布和信号特点,测量病变处和对侧无病变区组织的ADC值.并通过分析2例有连续临床和MRI资料的患者,推测其机制.结果 5例患者中有3例发现脑内异常改变,3例均表现为深部白质内斑点样异常信号,T1WI、DWI呈等信号,T2WI、液体衰减反转恢复(FLAIR)序列呈高信号,同时伴脑内其他部位多发斑片状病变,灰、白质均受累,主要累及基底节核团、海马和扣带回,发病初期T1WI呈等、低信号,T2WI、FLAIR、DWI呈高信号,病变区ADC值[(0.449±0.092)×10-3 mm2/s]较对侧无病灶区[(0.838±0.062)×10 -3 mm2/s]均明显降低.所有患者均无MRA异常改变和强化表现.对2例经糖皮质激素治疗症状缓解的患者连续追踪,1例MRI表现为病灶明显缩小,T1WI呈高信号,T2WI、FLAIR呈等、高信号,DWI呈低信号,ADC值明显升高;另1例病灶完全消失.结论 桥本脑病的MRI表现具有一定特点,可以作为HE诊断、鉴别诊断和疗效判断的手段之一,并可能成为活体研究HE病理机制的有效方法.     

Histochemical detection of ultrasmall superparamagnetic iron oxide (USPIO) contrast medium uptake in experimental brain ischemia.

Recently, macrophage infiltration in different central nervous system (CNS) pathologies has been visualized with ultrasmall particles of iron oxide (USPIO) as a new cell-specific contrast medium for MRI. However, validation of these findings at the histological level has been hampered by the fact that the in situ detection of iron uptake by conventional Prussian blue staining is not sensitive enough to detect low amounts of iron in the brain. Here, an improved method for the histochemical detection of USPIO uptake in ischemic brain lesions is reported. The procedure relies on the sequential enhancement of Prussian blue staining by diaminobenzidine and silver/gold impregnation. After photothrombotic cortical brain infarction, this method allowed sensitive in situ detection of iron-laden macrophages which matched both macrophage immunostaining and USPIO-induced signal alterations in high-resolution 7 T MRI. This staining method provides a basis for correlative histological assessment of USPIO-enhanced MRI in a broad spectrum of CNS pathologies.     

MR imaging of relapsing multiple sclerosis patients using ultra-small-particle iron oxide and compared with gadolinium

BACKGROUND AND PURPOSE: Inflammatory multiple sclerosis (MS) lesions are characterized by microglia activation and infiltration of T cells, B cells, and macrophages across the blood-brain barrier (BBB). In the experimental autoimmune encephalomyelitis (EAE) rat model of MS, previous MR imaging investigations with a new contrast agent ultra-small-particle iron oxide (USPIO) that accumulates in phagocytic cells revealed in vivo the presence of macrophage brain infiltration. The goal of this study was to characterize MS lesions with the use of this contrast agent. METHODS: A prospective MR imaging study of 10 patients with MS in acute relapses was achieved by using USPIO and gadolinium. RESULTS: Twenty-four hours after USPIO injection, 33 acute MS lesions in 9 patients showed USPIO uptake. Lesions were seen as high signal intensities on T1-weighted images and low signal intensities on T2-weighted images. Gadolinium enhancement was seen in 31 of these lesions in 7 patients. These 7 patients presented 24 gadolinium-enhanced lesions that did not enhance with USPIO. Two patients showed USPIO-enhanced lesions but no gadolinium-enhanced lesions. CONCLUSION: Taken together with earlier findings obtained in experimental models or in human stroke, the visualization of macrophage activity in vivo with USPIO characterize a distinct cellular and inflammatory event of the dynamic process of MS lesion formation. The macrophage activity information obtained with USPIO is distinct and complementary to the increased BBB permeability seen with gadolinium.     

In vivo assessment of experimental neonatal excitotoxic brain lesion with USPIO-enhanced MR imaging

Purpose:

To assess the feasibility of magnetic resonance imaging (MRI) enhanced with ultrasmall superparamagnetic particles of iron oxide (USPIO) for assessing excitotoxic brain lesions in an experimental model of neonatal periventricular white matter (PWM) lesions.

Materials and methods:

Brain lesions were induced by intracerebral injection of ibotenate in 14 newborn rats. Pre- and post-USPIO T2-weighted MRI was performed in seven of them (group A) and in five control newborns (group C). In seven newborns with induced cerebral lesions, USPIO-enhanced MRI was not performed (group B). We compared the signal intensity of the lesion to the contralateral unaffected brain (lesion-to-brain contrast, LBC) and the lesion signal-to-noise ratio (SNR) before and after USPIO injection. MR imaging was correlated with histology.

Results:

USPIO injection significantly (P?<?0.05) decreased LBC and SNR of brain lesion but induced no changes in normal controls. The densities of macrophages and iron-laden cells were higher on the lesion side than on the contralateral side (P?<?0.05). Neither lesion size nor the surrounding macrophage infiltrate was significantly different between groups A and B.

Conclusion:

Post-USPIO T2-weighted MRI demonstrated negative enhancement of neonatal excitotoxic brain lesion. USPIO injection does not appear to exacerbate brain lesions.     

Comparison of ultrasmall particles of iron oxide (USPIO)-enhanced T2-weighted, conventional T2-weighted, and gadolinium-enhanced T1-weighted MR images in rats with experimental autoimmune encephalomyelitis

BACKGROUND AND PURPOSE: Ultrasmall particles of iron oxide (USPIO) constitute a contrast agent that accumulates in cells from the mononuclear phagocytic system. In the CNS they may accumulate in phagocytic cells such as macrophages. The goal of this study was to compare USPIO-enhanced MR images with conventional T2-weighted images and gadolinium-enhanced T1-weighted images in a model of experimental autoimmune encephalomyelitis (EAE). METHODS: Nine rats with EAE and four control rats were imaged at 4.7 T and 1.5 T with conventional T1- and T2-weighted sequences, gadolinium-enhanced T1-weighted sequences, and T2-weighted sequences obtained 24 hours after intravenous injection of a USPIO contrast agent, AMI-227. Histologic examination was performed with hematoxylin-eosin stain, Perls' stain for iron, and ED1 immunohistochemistry for macrophages. RESULTS: USPIO-enhanced images showed a high sensitivity (8/9) for detecting EAE lesions, whereas poor sensitivity was obtained with T2-weighted images (1/9) and gadolinium-enhanced T1-weighted images (0/9). All the MR findings in the control rats were negative. Histologic examination revealed the presence of macrophages at the site where abnormalities were seen on USPIO-enhanced images. CONCLUSION: The high sensitivity of USPIO for macrophage activity relative to other imaging techniques is explained by the histologic findings of numerous perivascular cell infiltrates, including macrophages, in EAE. This work supports the possibility of intracellular USPIO transport to the CNS by monocytes/macrophages, which may have future implications for imaging of human inflammatory diseases.     

联合MRI常规与弥散成像判断多发性硬化斑块的病理基础

目的：研究MRI常规与弥散成像（DWI，DTI）联合应用，在判定多发性硬化斑块病理基础中的价值。材料和方法：对14例脑部多发性硬化病例进行联合MRI常规及弥散加权（DWI）、弥散张量成像（DTI）。其中1例为继发进展型（SP型），13例为好转－复发型（RR型）。首次发作期（急性斑块）成像者5例，缓解期（慢性斑块）成像者9例。分析常规MRI T1WI、T2WI及DWI、DTI成像后所获得的ADC图、FA图上的信号改变，量化分析DTI成像中的平均D值及各向异性指数AI值。结果：急性与慢性MS斑块MRI表现明显不同。急性MS斑块较大，斑块内信号不均匀，大致可以分为两部分：中心为数毫米至2cm不等的圆形或卵圆形异常信号影，呈T1WI低、T2WI高信号，推测病理为脱髓鞘或轴索丢失。周围为片状不规则形T1WI略低、T2WI略高信号影，考虑为水肿。发作MS斑块DWI可呈现高信号，e指数ADC图亦可呈现高信号，但范围后者明显小于前者。斑块中心平均D值升高、AI值明显下降，周围ADC值亦升高，但不如前者明显，AI值无明显改变，支持常规MRI关于斑块病理的推测。慢性MS斑块较小，多呈小片状或宽条状分布于侧脑室旁，T1WI呈略低信号、T2WI高信号。DWI呈近等信号、e指数ADC图呈等或略低信号。斑块平均D值不同程度升高，AI值下降，提示为脱髓鞘或轴索丢失，而无水肿存在。结论：联合MRI常规与弥散成像可以判断多发性硬化斑块的病理，从而进一步加深了对MS斑块病理的认识。     

脑多发性结核瘤的MRI诊断

目的：分析脑内多发性结核瘤的MRI表现。方法：回顾性分析11例经手术、病理或临床随访证实为脑多发性结核瘤的MRI表现。MRI采用T1flair、FrfseT2WI、T2flair及Gd-DTPA增强T1WI检查。结果：病灶绝大多数位于灰白质交界区及基底节区,未成熟结核结节呈长T1长T2信号,灶周水肿明显,结节状强化;成熟结核结节呈典型“环靶征”,灶周水肿较轻,环形强化。T2flair和增强扫描病灶显示较佳。结论：脑多发性结核瘤是颅内结核的一种特殊表现,MRI表现具有特征性。     

颅内原发淋巴瘤的MRI诊断和鉴别诊断

目的 分析颅内原发淋巴瘤的MRI表现，提高诊断及鉴别诊断的能力。方法对6例经病理证实的颅内原发淋巴瘤的常规MRI资料回顾性分析其病灶大小、分布、信号特点及强化特征。结果MRI显示4例为单发，2例为多发，共9个病灶，其中位于大脑半球深部4个，灰白质交界区5个，累及胼胝体2个。影像学形态多为类圆形团块或结节，边界较清晰，占位效应及瘤周水肿较轻。T2WI呈等或略低信号，T2WI为等或略高信号。增强后病灶呈团块状或结节状显著强化。结论颅内原发淋巴瘤MRI信号及强化形式具有一定特征，将影像学征象与临床资料相结合综合分析有助于提高诊断准确率。     

不同病理类型局灶性皮质发育不良的MRI特征

目的 总结局灶性皮质发育不良(FCD)的MRI特征性表现,探讨不同病理类型FCD各自的特异性MRI征象.方法 回顾性分析经病理证实的44例FCD患者的MRI表现.将44例患者根据病理检查结果分为FCD Ⅰ型和Ⅱ型,观察以下MRI征象在两种类型中的出现情况:(1)局灶性皮层增厚;(2)灰、白质分界不清;(3)液体衰减反转恢复(FLAIR)序列和(或)T2WI上白质内向脑室方向延伸的锥形异常增高信号;(4)脑叶发育不全;(5)FLAIR上灰质信号强度增高;(6)T2WI上灰质信号强度增高;(7)FLAIR上皮层下白质信号强度增高;(8)T2WI上皮层下白质信号强度增高;(9)T1WI上皮层下白质信号强度减低.2组间的比较采用χ2检验及校正χ2检验.结果 44例FCD患者中FCD Ⅰ型30例,FCDⅡ型14例.共32例患者MRI表现异常,灰、白质分界不清为最常见征象(23例).其中FCD Ⅰ型患者中MRI表现异常者21例,特征性表现为脑叶发育不全11例,FCDⅡ型脑叶发育不全0例,两种类型间差异有统计学意义(连续性校正χ2=5.0286,P=0.0249).FCDⅡ型患者中MRI表现异常者11例,特征性表现为局灶性皮层增厚10例,FCD Ⅰ型为11例(χ2=4.6234,P=0.0315);FLAIR上白质信号增高9例,FCD Ⅰ型为7例(χ2=6.9180,P=0.0085);白质内向脑室方向延伸的锥形异常增高信号4例,FCD Ⅰ型为0例(连续性校正χ2=6.2883,P=0.0122);差异均有统计学意义.其他征象两种类型间差异无统计学意义.结论 不同病理类型FCD的MRI表现各有特点,了解这些特点有助于不同病理类型FCD的早期诊断和术前评估.