超顺磁性氧化铁增强MRI检测转移性淋巴结的实验研究

目的探讨超顺磁性氧化铁粒子(SPIO)增强MRI检测转移性淋巴结的价值。方法取新西兰兔12只,6只于后腿肌肉接种VX2癌细胞,用于建立肿瘤转移性淋巴结模型;6只作为正常对照组。皮下间隙注射SPIO(每肢10 μmol Fe),在注射前和注射后12 h行MRI扫描,序列包括自旋回波(SE )T1WI、SE T2WI和梯度回波(GRE)T2WI,并与病理结果对照。结果平扫时,正常淋巴结和VX2转移淋巴结在三个序列图像上均表现出相似的信号特点。在增强SE T1WI 上,两组淋巴结的信号强度均未见变化;在增强SE T2WI上,正常淋巴结的信号强度不均匀降低,VX2转移组淋巴结的信号强度未见明显变化;在增强GRE T2WI上,正常淋巴结的信号强度明显地均匀降低,而VX2转移组有4个淋巴结信号强度未见降低,2个淋巴结不均匀降低。结论SPIO增强MR成像可用于检测转移性淋巴结。     

实验性肝细胞癌SPIO增强MR成像序列的选择

目的评价不同SPIO增强MRI扫描序列在实验性肝细胞癌检查中的价值。方法建立80只大鼠肝细胞癌模型,大鼠分别于灌药后第16、18、20、21、22、23、24、25周行MRI扫描,先行SE—T1WI、FMPSPGR—T1WI、GRE—T2WI和FSE．PDWI、FSE—T2WI的MR／平扫检查,再采用相同序列和参数进行SPIO增强MR／检查,并选取兴趣区获取相关参数。结果SPIO增强后,肝组织信号在所有扫描序列上均降低,GRE—T2WI上肝组织的信号降低最显著,肝细胞癌的CNR最高,而FSE—PDWI上肝组织和肝细胞癌的SNR最高。结论GRE—T2WI、PDWI是实验性肝细胞癌SPIO增强MRI的较理想序列。     

超顺磁性氧化铁增强MRI检测转移性淋巴结的实验研究

目的：探讨超顺磁性氧化铁粒子（SPIO）增强MRI检测转移性淋巴结的价值。方法：取新西兰兔12只，6只于后腿肌肉接种VX2癌细胞，用于建立肿瘤转移性淋巴结模型；6只作为正常对照组。皮下间隙注射SPIO（每肢10μmol Fe），在注射前和注射后12h行MRI扫描，序列包括自旋回波（SE）T1WI、SE T2WI和梯度回波（GRE）T2WI，并与病理结果对照。结果：平扫时，正常淋巴结和VX2转移淋巴结在三个序列图像上均表现出相似的信号特点。在增强SE T1WI上，两组淋巴结的信号强度均未见变化；在增强SE T2WI上，正常淋巴结的信号强度不均匀降低，VX2转移组淋巴结的信号强度未见明显变化；在增强GRE T2WI上，正常淋巴结的信号强度明显地均匀降低，而VX2转移组有4个淋巴结信号强度未见降低，2个淋巴结不均匀降低。结论：SPIO增强MR成像可用于检测转移性淋巴结。     

垂体卒中的不同影像学表现

分析16例垂体卒中的X线、CT、MRI表现，对比它们诊断垂体卒中的特点。其中行X线检查4例；CT平扫 增强14例，2例仅做平扫；MR平扫 增强10例，6例仅做平扫。结果X线检查呈蝶鞍扩大3例，双鞍底1例。CT检查中，1例平扫表现为偏心性斑片状高密度影，增强后余部均匀强化；3例平扫呈斑片状高密度影，增强后无强化区面积大于平扫所见高密度区；10例呈均匀密度，增强后呈环形强化；2例未做增强者，1例见局限性低密度区。1例见一液平。MRI检查中，1例T1WI等信号环绕中央高信号，T2WI低信号；7例T1WI、T2WI均高信号；5例T1WI低信号，T2WI高信号；1例见1个有液平的囊性病灶；2例高低混杂信号。临床表现有2例无突发史。提示MR可明确辨别瘤体的占位情况，估计亚急性出血的新旧程度，MR增强并无补充诊断意义。     

颅内软骨瘤7例MR分析

目的探讨颅内软骨瘤的MR特征以提高其诊断水平。方法回顾性分析7例经病理证实的颅内软骨瘤的MR表现。结果 7例肿瘤中,位于鞍区3例,前颅窝底2例,大脑镰旁及颞部各1例。MR检查示:肿瘤在T1WI上呈不均匀等低信号,其中1例夹杂片状高信号,在T2WI中呈以片带状高信号为主的混杂信号;1例高信号区呈囊泡状改变,其钙化部分6例在T1WI及T2WI中均为低信号影;1例在T1WI中为高信号,在T2WI中为等低信号影;注射Gd-DTPA增强扫描,5例瘤周呈花环状强化,2例周缘强化不明显,瘤内呈斑片状不均匀轻度强化,所有病例边界清晰,均未见瘤周水肿及瘤内出血。结论颅内软骨瘤好发于颅底及大脑镰区,钙化多见,具有延迟强化特点,确诊依靠病理检查。     

Gd-DTPA和HSA-Gd-DTPA应用于MR淋巴造影的对比研究

目的 对两种不同造影剂Gd-DTPA和HAS-Gd-DTPA在MRI淋巴造影中的价值进行对比性研究.方法 健康新西兰兔12只,完全随机法分成Gd-DTPA组(A组)和HAS-Gd-DTPA组(B组).仰卧位固定兔子,轴位和矢状位扫描双侧腘窝淋巴结.平扫序列包括T1WI(TR/TE=539/14 ms),脂肪抑制T1WI(T1WI FS,TR/TE=539/14 ms),T2WI(TR/TE=2234/85 ms).增强扫描:平扫后双侧后肢趾蹼间隙各注射0.2 ml 0.5 mmol Gd·L-1 Gd-DTPA和HAS-Gd-DTPA,A组于给药后第10 min、30 min和60 min行T1WI和T1WIFS扫描,B组于给药后第30 min、1 h、3 h行T1WI和T1WI FS扫描.相关参数与平扫时相同.测量增强前后两组淋巴结的信号强度并计算其强化率(E).结果 (1)经趾蹼间隙给药后,Gd-DTPA很快吸收入血循环,胫前静脉显影,尿液明显强化,淋巴结不均匀强化,而HAS-Gd-DTPA不进入血循环,淋巴管和淋巴结明显、均匀的强化.(2)A组淋巴结的强化率低于B组的强化率,且随时间的延长逐渐降低,而B组的E值逐渐增大.结论 相比Gd-DTPA,大分子量造影剂HAS-Gd-DTPA更适合于间隙给药法MRI淋巴造影的研究.     

垂体脓肿的MRI诊断及鉴别诊断

目的探讨垂体脓肿的MRI诊断与鉴别诊断和临床特点。方法回顾性分析6例经手术病理证实的垂体脓肿的MRI表现,所有患者术前均行MR平扫和增强。结果6例均表现为垂体腺增大,向鞍上突出;5例MR平扫T1WI呈低信号,1例呈等信号;4例T2WI呈脑脊液样高信号,2例呈稍高信号;MR增强扫描均呈环形强化,且环壁薄而均匀,部分环壁稍厚。结论平扫T1WI呈低或等信号、T2WI呈脑脊液样高信号或稍高信号及增强呈环形强化是垂体脓肿的主要MR表现。     

1.5T MR腕关节平扫增强在痛风患者中的诊断效果及影像学特点研究

目的 研究1.5T MR 腕关节平扫增强在痛风患者中的诊断效果及影像学特点。方法 选取2018年2月～2019年2月我院收治的痛风性腕关节炎患者10 例,14 个腕关节。对所有患者的14 个腕关节都进行CT 检查及1.5T MR 检查。结果 1.5T MR 检值织肿胀及关节积液方面的病变检出情况显著多于CT 检查（P＜0.05）。14 个腕关节全部表现出软组织肿胀及滑膜增厚,T1WI 上表现出略微的低信号或等信号,T2WI 上表现出略微的高信号或等信号;9 个腕关节表现出骨质破坏侵蚀,T1WI 上表现为弧形低信号,T2WI 上表现为略微的高信号或者等信号（不均匀）;9 个腕关节表现出骨髓水肿,T1WI 上表现出略低的信号,T2WI 上和PDWI上表现为高信号;13 个关节显示形成痛风石,单发性5 个,多发性8 个,共检查出痛风石27 个,在T1WI 上表现为略微的低信号或等信号,T2WI 上和PDWI 上表现出低混杂信号及低信号;12 个腕关节表现出关节积液,T2WI 上和PDWI 上都表现出高信号。结论 痛风性腕关节炎在1.5T MR 当中表现多种多样,MR 可以将炎症反应、滑膜厚度及软组织情况显示出来,对痛风性腕关节炎具有较高的诊断价值。     

Gal-BSA-SPIO制备及兔VX2肝癌模型与人肝脏ASG受体的MRI研究

目的 尝试合成肝脏靶向对比剂乳糖基白蛋白超顺磁氧化铁(Gal-BSA-SPIO),探讨Gal-BSA-SPIO对肝癌的检出及其诊断价值.材料和方法采用还原胺法合成Gal-BSA.Gal-BSA与SPIO混合后超声振荡.建立20只兔的、VX2肝癌模型,随机分为SPIO组和Gal-BSA-SPIO组,行MR平扫及增强.测定肝脏及肿瘤的T2值.对13例人肝脏标本(肝癌6例、肝硬化4例、正常肝组织3例)Gal-BSA-SPIO孵育后,Perl's染色,观察去唾液酸糖蛋白(ASG)受体分布.统计学方法:对增强前后各组的T2值进行t检验.结果 Gal-BSA-SPIO平均粒径34.4 nm.20只兔VX2肿瘤直径3～12 nm,T1WI肝实质呈中等信号,肿瘤呈低信号,T2WI肝实质低信号,病灶为略高信号;GRE T2*WI肝实质中等信号,肿瘤略高信号.增强扫描,SPIO组T2WI肝实质信号轻中度下降,与肿瘤对比提高;Gal-BSA-SPIO组T2WI肝实质信号显著下降,肿瘤呈明亮的"灯泡征".正常肝脏的SPIO组和Gal-BSA-SPIO组增强后T2值明显下降,与增强前有显著性差异.肿瘤的SPIO组和Gal-BSA-SPIO组增强后T2值无明显下降,与增强前无显著性差异.组织学检查SPIO组,Kupffer细胞内见蓝染的铁颗粒;Gal-BSA-SPIO组.肝细胞内见较多的蓝染的铁颗粒,两组的肿瘤内未见蓝染的铁颗粒.Gal-BSA-SPIO孵育后,正常肝组织可见大量蓝染色,肝硬化及癌旁肝硬化组织均可见蓝染色;肝细胞癌罕见蓝染色.结论 Gal-BSA-SPIO可以与肝细胞膜的ASG受体可特异性结合,通过受体介导的特异性对肝脏产生负向增强作用,明显提高肿瘤对比噪声比.     

Wernicke脑病的MRI评价

目的探讨Wernicke脑病的MRI表现特点。方法回顾性分析经临床证实的6例Wernicke脑病的MRI病例资料,所有病例行MR平扫,2例行增强扫描。结果 5例对称分布于第三、四脑室、中脑导水管、双侧丘脑周围斑片状异常信号,2例穹隆柱、乳头、视交叉及白质异常信号,T1WI序列5例为低信号,T2WI序列5例呈高信号,FLAIR序列5例呈高信号,1例DWI呈高信号,2例增强后病灶有强化。1例MR无阳性发现。结论 Wernicke脑病的MRI的表现具有一定特征,MRI可作为Wernicke脑病的首选检查方法     

Differentiation of white and red thrombus with magnetic resonance imaging: a phantom study

Background  An early identification of the composition of arterial thrombus may have diagnostic, therapeutic, and prognostic implications. The variation of magnetic resonance (MR) signal intensity between white and red thrombi, especially in the susceptibility sensitive MR sequence, remains unknown. Our research was to evaluate the feasibility of MRI in differentiating of white and red thrombi with a phantom study.

Methods  A total of 12 red and 12 white thrombi were prepared with the venous blood. Examination of the phantom was completed using a 3.0T MR unit, including fluid attenuated inversion recovery (FLAIR) T1, T2-weighted imaging (T2WI), FLAIR T2, T2* gradient echo (T2*GRE) imaging, and susceptibility weighted angiography sequences (SWAN). MR signal intensity patterns of the thrombi were objectively classified as hyperintensity, isointensity and hypointensity, compared with the background agar. The volume of thrombus was calculated and correlated with its signal intensity.

Results  For white thrombi, 11/12 clots showed hyperintensity and 1/12 showed isointensity in FLAIR T1 images. In T2WI, 6/12 clots showed hyperintensity, 3/12 isointensity, and 3/12 hypointensity. In FLAIR T2, 8/12 clots showed hyperintensity and 4/12 showed isointensity. In T2*GRE, 3/12 clots showed hyperintensity and the remaining 9/12 clots showed isointensity. In SWAN, 5/12 clots demonstrated hyperintensity and 7/12 isointensity. For the red thrombus, 12/12 clots demonstrated hyperintensity in FLAIR T1, T2WI, and FLAIR T2 sequences. In T2*GRE and SWAN sequences, 3/12 clots displayed hypointensity and the remaining 9/12 clots showed slight hyperintensity. Thrombi with hypointensity displayed in T2*GRE and SWAN sequences were significantly larger than those with hyperintensity.

Conclusions  Differentiation of white and red thrombi with conventional MR sequence is unreliable, because both kinds of thrombi do not possess unique signal intensity features in these sequences. Red thrombus may or may not show hypointensity in the susceptibility sensitive MR sequences, depending on its size and time course.

     

钙化性脑膜瘤的CT和MRI诊断

目的:探讨钙化性脑膜瘤的CT和MRI表现.方法:回顾性分析经本院手术病理证实的36例钙化性脑膜瘤患者的CT和MRI表现,全部病例均行CT和MRI平扫及增强扫描.结果:36例钙化性脑膜瘤CT表现为高密度的团块状钙化,骨窗上密度不均,无强化,19例周围见低密度的水肿区,17例未见明显的水肿区,5例脑膜瘤与颅骨内板间可见线状低密度影;而MRI表现T1WI 脑膜瘤信号主要为等信号和略低信号,T2WI 脑膜瘤信号主要为等信号、略高信号、略低信号,16例边缘区可见厚环状或小斑片状的低信号影,增强扫描T1WI肿瘤可见明显强化,9例可见脑膜尾征.结论:CT与MRI相结合能更全面观察钙化性脑膜瘤的特征,对提高诊断的正确性有重要意义.     

Rathke囊肿的CT和MRI诊断

回顾性分析经手术与病理证实的19例Rathke囊肿的CT及MRI资料。CT平扫发现4例为低密度,1例为等密度,14例为高密度。MRI平扫发现病变1例位于鞍内,18例位于鞍内并向鞍上延伸。病变呈圆形、椭圆形或哑铃形,T1低信号、T2高信号有6例;T1高信号、T2等信号有5例;T1等信号、T2高信号有4例;T1等信号、T2等信号有3例;T1高信号、T2高信号有1例。19例MRI增强扫描,均未见明显强化。Rathke囊肿囊液密度和信号变化多样,但结合临床和影像学表现对其中多数病例可做出正确诊断。     

脑内海绵状血管瘤的MRI表现及弥散成像的诊断价值

目的 探讨脑内海绵状血管瘤的MRI表现及磁共振弥散成像（DWI）的诊断价值。方法 回顾性分析45例经病理证实的脑内海绵状血管瘤患者的MRI资料，重点分析DWI信号特征及其对病灶的显示能力。结果 45例共捡出47个病灶，34个病灶T，WI和T1WI均呈网状高、低混合信号，8个病灶T，WI1T，WI均呈高信号，4个病灶T1WI、T1WI均呈低信号，1个病灶T1WI呈等信号、T1WI呈稍低信号，46个病灶（占97．87％）T1WI灶周具有“铁环征”：DWI显示的病灶范围包括瘤体及灶周舍铁血黄素区域，敏感性较高、可提高病灶的显示率。结论 MRI是诊断脑内海绵状血管瘤的首选方法，常规SE序列与弥散成像相结合，能更准确、全面地提供诊断信息。     

SPIO-enhanced magnetic resonance imaging for differentiating metastatic from hyperplastic lymph nodes： A study in rabbits

To investigate the potential of superparamagnetic iron oxide particles (SPIO) in MR imaging for the differentiation between hyperplastic and metastatic lymph node. Methods: Animal models of malignant lymph node metastasis were established in 6 New-Zealand rabbits by a unilateral intra-muscular injection of VX2 carcinoma cells,and models of hyperplastic lymph nodes were induced in another 6 rabbits by a unilateral intra-muscular injection of egg yolk emulsion. MR images of the lymph nodes were obtained before and 12 h after interstitial injection of SPIO. Image results were analyzed and compared with pathological findings. Results: On unenhanced images, the signal intensity of hyperplastic and metastatic lymph nodes did not differ significantly. After administration of SPIO, the signal intensity of beth hyperplastic and metastatic lymph nodes remained unchanged on T1-weighted SE images. On T2-weighted SE ima-ges, the signal intensity of hyperplastic lymph nodes decreased heterogeneously, while that of all metastatic ones re-mained unchanged. On T2-weighted GRE images, the signal intensity of hyperplastic lymph nodes decreased signifi-cantly and homogeneously, while that of 4 metastatic ones remained unchanged and that of the rest 2 decreased hetero-geneously. Conclusion: SPIO-enhanced MR imaging may enable the differentiation between the hyperplastic and meta-static lymph nodes.     

Magnetic resonance imaging enhanced by superparamagnetic iron oxide particles in detecting lymph node metastasis of tumors: an experimental study]

OBJECTIVE: To investigate the value of superparamagnetic iron oxide particles (SPIO) in magnetic resonance (MR) imaging for detecting lymph node metastasis of tumors. METHODS: Twelve New Zealand rabbits were used in this study, 6 of which received unilateral intra-muscular inoculation of VX2 carcinoma cells to induce lymph node metastasis of the tumor, and the other 6 served as normal control group. MR images of the lymph nodes of the rabbits were obtained before and 12 h after subcutaneous injection of SPIO, followed by image analysis in correlation with pathological examinations. RESULTS: On plain MR images, normal and metastatic lymph nodes showed similar signal characteristics. After administration of SPIO, the signal intensity of both normal lymph nodes and metastatic ones remained unchanged in spin echo (SE) T1-weighted images. On SE T2-weighted images, the signal intensity of normal lymph nodes significantly decreased heterogeneously, while that of all metastatic lymph nodes remained unchanged. In gradient recalled echo (GRE) T2-weighted images, the signal intensity of normal lymph nodes decreased significantly and homogeneously, while that of 4 rabbits in metastasis group remained unchanged, with the signal intensity in the other 2 rabbits decreased heterogeneously. CONCLUSION: SPIO-enhanced MR imaging can be applied to detect lymph node metastasis of the tumors.     

骨梗死的影像学诊断

目的探讨骨梗死的影像学特征。方法对13例经临床及病理证实的骨梗死患者行X线、CT及MRI检查，分析其影像学表现，并将骨梗死分为急性期、亚急性期和慢性期，总结其影像学特征。结果骨梗死急性期X线、CT表现为干骺端骨质疏松，MRT1WI骨梗死灶中央部分呈等至高信号，T2WI呈高信号，T1WI骨梗死灶边缘呈环形低信号，T2WI呈环形高信号；亚急性期X线、CT表现为小的虫噬样改变，伴有斑点状钙化，MRT1WI骨梗死灶呈等或低信号，T2WI呈等或稍高信号，T1WI骨梗死灶边缘呈环形低信号，T2WI呈环形高信号；慢性期X线、CT表现为不规则状、蜿蜒状骨质硬化，MRT1WI和T2WI均呈低信号。结论MRI是诊断骨梗死急性期的最有效方法，在急性和亚急性期，MRI优于X线和CT，在慢性期，X线、CT和MRI均具有特征性表现。     

肝脏局灶性结节增生的MRI诊断

目的 分析和研究肝脏局灶性结节增生(FNH)的MRI表现及诊断价值。方法 回顾性分析24例30个经手术病理证实的FNH的平扫及动态增强扫描图像。24例中有4例又行肝特异性造影剂检查，包括2例锰福地匹三钠(Mn-DPDP)和2例超顺磁性氧化铁(SPIO))增强扫描。结果 22例为单发FNH，2例为多发。大小为1．0～6．0cm。24个病灶在T1WI上呈典型的等或略低信号，4个呈低信号，2个为略高信号。25个病灶在T2WI呈典型的等或略高信号，5个呈高信号。29个病灶的实质部分在动脉期明显强化，在门脉期和延迟期呈等或略高信号。1个病灶的实质部分在动脉元强化，而在延迟期变成等信号。2个病灶在延迟期出现增强的假包膜。21个病灶MRI平扫和动态增强扫描显示瘢痕，9个均未显示。瘢痕为T1WI低信号或等信号，T2WI高信号，增强后延迟强化，4个病灶动态增强扫描动脉期显示供血动脉影。使用Mn-DPDP后病灶为等或略高信号。使用SPIO后，病灶呈等信号。结论 多数FNH有典型MRI征象，综合使用平扫和动态增强扫描是正确诊断的关键。肝特异性造影剂对FNH的诊断有帮助。     

EXPERIMENTAL STUDY OF INFLAMMATORY AND METASTATIC LYMPH NODES WITH DIFFUSION WEIGHTED IMAGING ON ANIMAL MODEL： COMPARISON WITH CONVENTIONAL METHODS

Objective To investigate the feasibility of magnetic resonance （MR） diffusion weighted imaging （DWI） in discriminating inflammatory from VX2 carcinoma metastatic lymph nodes in rabbit model.
Methods Twenty New Zealand white rabbits were randomly divided into 2 groups. Complete Freund＇s adjuvant was injected into the bilateral dorsal footpads to set up ipsilateral lymphadenitis model （n = 10）, and the other 10 rabbits received a subcutaneous implantation of VX2 tumor cell suspension （1.5×10^7 cells/mL） in both thighs to set up metastatic lymph node model. MR imaging scan covering the popliteal fossa and lilac fossa including short time inversion recovery echo-planar imaging DWI （STIR-EPI-DWI）, Tl-weighted imaging （T1WI） and T2-weighted imaging （T2WI） was performed 2 weeks after injection. T2WI signal intensity （SI）, DWI SI, long/short axial ratio （LSR） and apparent diffusion coefficient （ADC） values of the lymph nodes were evaluated in all cases. Right after MR imaging scan, popliteal and iliac fossa lymph nodes were collected for hematoxylin-eosin staining.
Results Totally 33 lymph nodes larger than 5 turn, including 22 inflammatory and 11 metastatic ones, were successfully isolated and taken into pathological analysis. LSR showed no significant difference between the inflammatory and malignant lymph nodes （P 〉 0.05）. Both benign and malignant lymph nodes appeared iso-intense on TlWI and hyperintense on both T2WI and DWI images with an even lower TlWI and higher T2WI SI core at the hilum. Both T2WI and DWI SI showed no significant difference between two pathological groups （P 〉 0.01） in popliteal fossa. The mean ADC value of inflammatory nodes [（1.199±0.281） ×10^-3 mm^2/s] was significantly higher than that of metastatic nodes [（0.858 ± 0.090） ×10^-3 mm^2/s, P 〈 0.01]. On ADC map, a high ADC value central area could be seen in most of the lymph nodes no matter benign or malignant. ADC value gave out the largest area under curve （AUCADC =