磁共振胰胆管成像对肝移植术后胆系的评价

背景:由于肝移植术后患者出现胆道并发症时,没有特征性体征,此种并发症很难发现。MRI特别是磁共振胰胆管成像是一种具有安全、准确、非侵袭性特点,可用于综合评估移植后肝脏功能和并发症的有效手段。目的:评估磁共振胰胆管成像对肝移植术后胆系的显示以及诊断胆管并发症的价值。设计:对比观察。单位:南方医科大学南方医院影像中心。对象:于2003-01/2005-01在南方医科大学南方医院影像中心接受影像学检查肝移植患者13例,均为男性,年龄40-58岁。术前临床诊断为原发性肝癌2例,重症肝硬化11例。10例行原位经典式肝移植,3例行背驮式原位肝移植术,所有胆管吻合方式为胆总管端-端吻合。移植后至首次MR检查时间15d-1年。所有患者对检测项目均知情同意。方法:13例原位肝移植患者术后均用磁共振快速自选回波序列及快速小角度激发梯度回波序列常规扫描、磁共振胰胆管成像、钆喷替酸葡甲胺动态增强检查,分析各序图像特点。主要观察指标:磁共振胰胆管成像对重建胆道和胆道并发症的显示。结果:3例患者胆管管径正常,吻合口无狭窄。1例厚层磁共振胰胆管成像胆管未显影。胆管扩张8例;胆管狭窄5例;胆总管结石2例;胆囊管残端黏液囊肿2例;T管拔管后胆漏1例;排斥反应2例。结论:磁共振胰胆管成像不仅可显示肝移植术后外科重建胆道的影像,而且可准确、快速诊断肝移植术后胆道并发症。     

磁共振成像在颅脑方面应用的初步报告(与X—CT比较)

磁共振成像(magnetic resonance imaging,MRI)用于临床以来,卓有成效的诊断价值得到了医学界的公认,特别是对颅脑疾病的诊断,可能占有较X-CT 或血管造影更重要的地位。我院从西德/瑞士BRUKER/SPECTROSPIN 公司引进一     

复发性脑膜瘤的MRI表现及病理特点研究

目的探讨复发性脑膜瘤的MRI表现及病理特点。资料与方法回顾性分析15例复发性脑膜瘤,对其MRI表现及病理特点进行研究。结果 MRI示复发瘤位于大脑镰旁4例、矢状窦旁1例、蝶骨嵴3例、鞍区3例、小脑幕2例、桥小脑角区1例、枕骨大孔区1例;颅内多发7例,形态不规则或分叶状12例,瘤内囊变坏死8例,脑膜尾征4例,瘤周水肿6例,1例发生C5椎体及椎旁软组织转移;瘤体T1WI为等或稍低信号,T2WI和T2FLAIR为略高信号,增强扫描多为明显的不均匀强化。病理证实:恶性13例,良性2例;连续复发7例;良性肿瘤全切术后,首次复发平均时间为3年,而恶性肿瘤为1.4年,连续复发者首次复发后平均每1～2年肿瘤再次复发;组织学类型改变5例,其中4例从低级别向高级别发展。结论复发性脑膜瘤有独特的MRI表现及病理特点,充分认识并确定其特征性改变,有助于提高诊断的准确率。     

基于Gd-EOB-DTPA增强MRI的评分系统在肝功能评估中的应用

目的 探讨功能性肝脏显像评分(FLIS)在评价乙型肝炎后肝硬化患者的肝功能情况中的应用价值。方法 搜集行钆塞酸二钠(Gd-EOB-DTPA)增强MRI扫描的乙型肝炎后肝硬化患者104例,分别比较MRI肝功能评分与实验室相关生化指标(血清总胆红素、人血白蛋白、血浆凝血酶原时间)、MRI肝功能评分与Child-Pugh功能评分、MRI肝功能分级与Child-Pugh功能分级的相关性。结果 MRI肝功能评分与血清总胆红素、人血白蛋白、血浆凝血酶原时间分别为中度负相关、中度正相关、中度负相关(r=-0.64、0.43、-0.47);MRI肝功能评分与Child-Pugh肝功能评分为中度负相关(r=-0.47);MRI肝功能分级与Child-Pugh肝功能分级具有较好的一致性(Kappa=0.47)。结论 FLIS能较好地反映乙型肝炎后肝硬化患者肝功能情况,有望为患者的随访监测及个体化治疗提供一个稳定、可靠的方法。     

钆布醇在腹部增强磁共振动脉血管成像中的应用价值:一项前瞻性、多中心研究

目的探究钆布醇增强磁共振血管成像(MRA)在腹部动脉血管扫描的应用价值。方法前瞻性纳入2014年12月至2015年12月期间行钆布醇增强MRA检查患者112例,由两名观察者对图像质量进行分析,对大中血管行主观评分和信号值测定,对小血管进行主观评分。采用Kappa检验对两名观察者的主观评分进行一致性分析。结果最终纳入112例患者,其中96例患者因体检行腹部MRA检查,16例患者因肝脏占位行腹部MRA检查。所有患者均未发现不良反应。112例钆布醇增强MRA图像中,有2例患者因呼吸伪影严重而影响血管显影。110例MRA图像清晰,能清晰显示大中血管和小血管的起源、走行。大中血管成像的主观评分为(21.22±1.93)分,对小血管成像的主观评分为(6.24±1.33)分。对感兴趣区大中血管的信号强度测量显示信号噪声比和对比信号噪声比率分别为1093.27±331.71和897.27±333.29。两名观察者对大中血管定性分析的一致性Kappa值为0.782,对小血管定性分析的一致性Kappa值为0.772。结论钆布醇增强MRA能清晰显示大中血管,还能良好显示部分小血管,在腹部动脉血管扫描中具有良好的应用价值。     

SWI对颅内肿瘤内出血的显示

目的探讨SWI对于颅内肿瘤内出血的显示。方法采用GESignaEXCITEⅡ3.0TMR对20例颅内占位扫描,序列有T2WI,T1FLAIR和SWI。对SWI原始扫描图像进行Funtool（adw4.3版）的SWI计算,对所得的数据行3DMIP最小密度投影重建,重建层厚20mm,间隔0mm。结果 7例胶质瘤常规序列发现胶质瘤出血1例,SWI显示出血6例,3例转移瘤常规序列发现胶质瘤出血1例,SWI显示出血3例,5例血管畸形在常规序列和SWI均显示有出血,5例脑膜瘤常规MR和SWI均没有显示出血。在常规MR显示有出血的病例,SWI显示的出血范围明显大于常规序列显示的范围。结论 SWI对于颅内占位性病变的出血显示比常规序列敏感。     

Rathke囊肿的影像诊断及误诊分析

目的研究Rathke囊肿的影像学表现。资料与方法回顾性分析经病理证实的13例Rathke囊肿的CT和MRI表现。结果 13例病变均同时位于鞍内及鞍上。5例诊断正确;5例误诊为垂体瘤;3例误诊为颅咽管瘤。结论 Rathke囊肿的CT和MRI表现具有一些特点:密度或信号多变但均匀、囊内结节、无强化或环状强化、较少钙化,为诊断提供有价值的鉴别依据。     

多层螺旋CT对肺类癌的诊断及鉴别诊断

目的：探讨多层螺旋CT（MSCT）对肺类癌的诊断和鉴别诊断的价值。方法：回顾性分析经病理证实的9例类癌患者的临床和MSCT资料。结果：9例中8例表现为边界清楚单发类圆形或不规则形肿块影,1例表现为右肺中叶不规则高密度影,边缘模糊,类似于大叶性肺炎。3例病灶密度均匀,4例可见浅分叶,1例可见深分叶,3例有细短毛刺,3例有胸膜凹陷征,4例可见钙化灶,3例有胸腔积液。8例肿块表现为＂冰山征＂（支气管腔外部分大于腔内部分）。增强扫描后5例中度以上（20~40 HU）强化,3例轻度（1~20 HU）强化,1例病灶内窄带状强化。本组病例均未见空洞、囊变、坏死。结论：肺类癌的MSCT的影像特点为肺内单发边缘清楚类圆形肿块,多为明显均匀强化,以及＂冰山征＂和/或特征性钙化。若见因支气管狭窄或闭塞导致的类似于大叶性肺炎的表现,应高度注意本病可能。     

新型MR对比剂长循环超顺磁氧化铁脂质体纳米微粒的体内外实验研究

目的 评价自制新型MR对比剂:长循环超顺磁性氧化铁(superparamagnetic iron oxide,SPIO)脂质体纳米微粒的药代动力学.方法 以加入SPIO为对照组,加入长循环SPIO脂质体纳米微粒为实验组.(1)巨噬细胞的体外吞噬实验:将巨噬细胞株RAW 264.7经复苏、培养,细胞达到80%～90%融合后,以每孔2.5×105个细胞接种于培养板,对照组和实验组细胞与不同浓度药物孵化后,分别测定细胞中Fe浓度和Fe染色情况,并用析因设计的方差分析对结果进行统计学处理.(2)小鼠体内药物分布实验:C57BL/6J雄性小鼠6只,每组2只,设为空白对照组、对照组、实验组,经尾静脉分别注射生理盐水、SPIO以及长循环SPIO脂质体后牺牲动物,经病理检查观察2组药物在体内的分布情况.(3)荷肺癌裸鼠MR成像实验:建立20只BALB/c裸鼠移植型肺癌模型,分为对照组和实验组,每组10只,分别经尾静脉注入SPIO和长循环SPIO脂质体纳米微粒后行MR扫描,测量增强前后2组实验动物各时间点肝脏和肿瘤ROI的信号强度,绘制信噪比(SNR)时间动态变化曲线,采用协方差分析比较2组动物肝脏及肿瘤增强12 h 后SNR差异有无统计学意义.(4)细胞毒性实验(噻唑蓝,MTT法):检查2种药物对人肝细胞株HL-7702细胞的毒性作用,用析因设计的方差分析对结果进行统计学处理.结果 (1)巨噬细胞的体外实验:析因分析结果表明,对照组细胞内Fe含量明显高于实验组,差异有统计学意义(F=296 839.9,P=0.000).普鲁士蓝染色显示对照组巨噬细胞染色较深,实验组巨噬细胞染色较浅.(2)小鼠体内药物分布实验:对照组肝、脾、肺、肾组织内蓝染颗粒多于实验组.(3)荷肺癌裸鼠MR成像实验:平扫对照组肝脏SNR为31.47±0.56,实验组为30.89±1.41;增强扫描12 h后对照组为17.00±0.96,实验组为22.29±0.73.平扫对照组肿瘤SNR为58.41±0.61,实验组为58.44±1.08;增强扫描12 h后对照组为58.50±0.63,实验组为52.47±1.18.经协方差分析表明增强12 h后对照组肝脏SNR显著低于实验组(F=167.022,P=0.000);而实验组肿瘤 SNR显著低于对照组(F=266.106,P=0.000).(4)细胞毒性实验:随着培养液中Fe浓度的增加,HL-7702细胞生存率均有下降趋势,但析因分析结果表明,实验组药物的细胞毒性较对照组低(F=2256.204,P=0.000).结论 长循环SPIO脂质体纳米微粒在体内外均有较好的抗巨噬系统吞噬功能,在体内实现了长循环,对非网状内皮系统的肿瘤也具有良好的T2负性被动靶向强化效果;同时还降低了SPIO对细胞的毒性作用.

Abstract：

Objective To evaluate pharmacodynamics of prepared long-circulating superparamagnetic iron oxide (SPIO) liposomes. Methods Control and experimental groups were established after adding SPIO or long-circulating SPIO liposomes as agents. (1)Macrophages experiment in vitro: the RAW 264.7 macrophage cell strains were recovered, cultured and seeded in the culture plate at a density of 2.5×105 cells/well until they reached 80%-90% confluence. The intracellular Fe uptake of control and experimental group cells were quantified by Ferrozine assay after incubation with different concentrations of drugs. Factorial design analysis of variance was used as statistics method. Prussian blue staining method was used to detect staining of experimental cells.(2)Drug biodistribution in mice: C57BL/6J(n=6) were classified into blank control group (n=2), control group(n=2) and experimental group(n=2).Saline, SPIO and long circulating SPIO were injected via the tail vein in the blank control group, control group and experimental group respectively. Then distribution of drugs in the body was observed by pathological examination.(3) MR imaging of tumor-bearing nude mice: 20 BALB/c nude mice bearing lung cancer models were established and classified into control group and experimental group. After administration of drugs, all animals underwent MR scanning. Signal intensities of livers and tumors were measured, SNR-time dynamic curves were drew. Covariance analysis was used to compare post-enhanced SNR at the 12th hour. (4)Cytotoxicity studies (MTT): cytotoxicity of both drugs on human liver cell line HL-7702 was studied, and statistically analyzed using factorial design analysis of variance. Results (1) Macrophages experiment in vitro: The nanoparticle uptake by macrophage cells evaluated by ferrozine assay showed the uptake of blank SPIO was higher than long-circulating SPIO liposomes. Compared with the blank control group, there was strong blue staining in the macrophages with Prussian staining in the control group and little blue staining in the experimental group. (2) Drug biodistribution in mice: for blue stained cells composed of iron particles, the amounts in the liver, spleen, lung, kidney of the control group were more than those in the experimental group. (3) MR imaging of tumor-bearing nude mice: the non-enhanced SNR of livers and tumors in the control group and experimental group were 31.47 ± 0.56, 30.89 ± 1.41, 58.41 ± 0.61, 58.44 ± 1.08, respectively. After injecting of contrast agents, SNR of livers and tumors in the control group and experimental group were 17.00 ± 0.96, 22.29 ± 0.73, 58.50 ± 0.63, 52.47 ± 1.18, respectively. The covariance analysis showed that SNR of the livers in the control group after 12 hours was significantly lower than the experimental group (F=167.022, P=0.000); while the SNR of the tumors in the experimental group was significantly lower than the control group (F=266.106, P=0.000).(4) Cytotoxicity of nanoparticles by MTT method: the viability of HL-7702 cells tend to decrease with the increase of Fe concentration. Cytotoxicity in the long-circulating SPIO liposomes was lower than the SPIO(F=2256.204,P=0.000). Conclusions Long-circulating SPIO liposomes we prepared reveal suitable sizes, even distribution, and good anti-macrophage ability in vitro and in vivo. They have long circulation characteristic and T2 negative enhancement effect in the transplanted lung cancers, while they still maintain low cytotoxicity.