大鼠种植型肝癌的超顺磁性的氧化铁磁共振增强实验研究

目的 研究正常大鼠的超顺磁性氧化铁（ＳＰＩＯ）剂量梯度－肝脏信号曲线、大鼠种植地癌ＳＰＩＯ增强前后的对比噪声比和检出率。方法 第１组：７２只正常ＳＤ大鼠随机分成１８个样本组,平扫后以０、２、５……２８０ｕｍｏｌＦｅ／ｋｇ１８个ＳＰＩＯ剂量分别做增强扫描,做剂量梯度－肝脏信号曲线。第２组：３８只种植型肝癌模型鼠,共计生成４３个肿瘤,行平扫及ＳＰＩＯ增强扫描,分析肿瘤磁共振强化特点;测量增强前后Ｔ１及     

超顺磁性氧化铁在大鼠诱癌模型磁共振诊断与鉴别诊断中的作用

目的研究超顺磁性氧化铁(SPIO)在大鼠诱癌模型的磁共振成像中对增生性结节与肝癌的鉴别作用，以及SPIO增强前后对各型肝癌的检出率。材料与方法42只诱发型肝癌模型鼠在肝硬化多发增生性结节基础上，共计生成379个肝癌，行平扫及SPIO增强扫描，分析增生性结节与肝癌的不同强化方式，并与病理对照统计平扫与增强扫描各型肝癌的检出率。结果增生性结节在SPIO增强扫描T2WI上信号明显降低，而肝癌的信号无明显改变；肝癌SPIO增强扫描T2WI检出率与病理接近，而平扫T2WI检出率与病理相差显著，其中平扫微癌与小癌的漏检率分别达32．9％与12．9％。结论SPIO是一种有效的检测肝癌的磁共振对比剂，不仅能提高小肝癌的检出率而且对增生性结节与肝癌的鉴别提供帮助。     

大鼠肝硬化肝癌SPIO增强MRI表现与Kupffer细胞的关系

目的：建立二乙基亚硝胺（DENA）诱导的大鼠肝硬化肝细胞癌（HCC）模型,探讨超顺磁性氧化铁（SPIO）增强MRI上肝硬化肝癌信号改变与肝Kupffer细胞（KCs）之间的关系。方法：22只大鼠肝硬化肝癌模型,其中6只为单纯性肝硬化,16只为肝硬化肝癌,对照组为10只清洁级Wistar雄性大白鼠,均行SPIO增强前后T1WI和T2WI扫描,并行病理检查（HE染色及普鲁士蓝染色）,分析肝脏Kupffer细胞数量与SPIO增强后信号之间的关系。结果：普鲁士兰染色切片上肝硬化组织内蓝染Kupffer细胞数量略减少,蓝色颗粒不均匀;高分化肝癌中Kupffer细胞减少,低分化肝癌Kupffer细胞显著减少甚至消失。肝癌与正常肝实质、硬化肝组织相比,Kupffer细胞数量减少,差异有显著性意义（P〈0．001）;正常肝实质与肝硬化组织内Kupffer细胞数量的差异无显著性意义（P＝0．088）。SPIO增强T2WI上,正常肝实质、肝硬化组织信号强度（SI）较增强前明显下降,信号强度下降百分比（PSIL）分别为42％和38％,两组间差异无统计学意义（P＝0．409）;肝癌信号强度较增强前无明显下降,PSIL为12％,明显低于正常肝实质和肝硬化组织（P〈0．001）;SPIO增强后肝癌对比噪声比（CNR）较增强前显著提高（P＝0．002）。SPIO增强T1WI上。正常肝实质及硬化肝组织PSIL分别为15％和6％,而肝癌的信号强度较增强前升高9％,部分小病灶呈不均匀轻度强化,肝癌CNR较增强前明显降低（P〈0．001）。SPIO增强T2WI上,肝组织PSIL与Kupffer细胞数量呈曲线趋势,随着组织内Kupffer细胞数量的增多病灶信号强度下降程度越明显,曲线估计3次模型决定系数R^2为0．920,有显著性意义（P〈0．001）。结论：SPIO增强T2WI上肝脏信号强度改变与Kupffer细胞数量及其吞噬功能有相关性,随着Kupffer细胞增多PSIL呈升高趋势。SPIO增强MRI不?     

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。     

超顺磁性氧化铁增强MRI诊断肝脏局灶性结节增生

目的 评价超顺磁性氧化铁（SPIO）对肝脏局灶性结节增生（FNH）的诊断价值。资料与方法 回顾性分析7例7个肝脏FNH的平扫、动态增强及SPIO增强MRI资料。结果 病灶在T1WI上呈相对低至等信号，T2WI上呈等至相对高信号，6个病灶可见中心瘢痕。动态增强扫描6个病灶以快速慢出方式强化。SPIO增强扫描6个病灶实质部分信号明显降低，5个中心瘢痕显示更清晰。结论 SPIO增强扫描进一步从组织成分方面为FNH诊断提供依据。     

胎鼠神经干细胞超顺磁性氧化铁颗粒标记移植后MRI研究

目的:探讨超顺磁性氧化铁颗粒(SPIO)标记神经干细胞的方法,以及标记细胞正常大鼠脑内移植后MR成像的方法学研究。方法:多聚左旋赖氨酸介导的SPIO标记胎鼠神经干细胞,进行台盼兰染色和普鲁士兰染色分别检测标记细胞的存活率和标记率。选取SD大鼠15只,简单随机法分为3组:第1组于大鼠右侧尾状核移植未标记的NSCs,第2组于大鼠右侧尾状核移植标记的NSCs,第3组右侧尾状核移植游离的SPIO颗粒,移植后第1、4、8周进行MRI。8周后处死大鼠,行组织切片普鲁士兰染色。结果:体外标记的神经干细胞普鲁士兰染色发现铁颗粒聚集于细胞浆内,标记率为100%;标记细胞与未标记细胞的台盼兰染色结果无显著差异。移植后MRI,第1组注射点未见低信号影;第2组注射点T2WI及GRE序列均可见类圆形低信号影;第3组大鼠注射后1周注射点可见低信号影,4周后低信号影变淡且边缘变模糊,8周后低信号影T2WI已不明显。与T2WI序列比较,GRE序列显示标记细胞更清晰,但显示范围较扩散。脑组织切片的普鲁士兰染色显示,第1组大鼠脑组织切片未见异常蓝染细胞,第2组注射点可见蓝染细胞,第3组注射点可见稍许散在蓝色颗粒状物质。结论:多聚左旋赖氨酸介导下SPIO可用于标记神经干细胞,标记细胞移植后MRI可以无创性观察移植神经干细胞的位置及分布情况。     

超顺磁性氧化铁微粒在分子影像学中的研究现状

超顺磁性氧化铁（SPIO）微粒作为磁共振分子对比剂可以提供足够的T2^＊效应，能在分子微克水平被检测到，不同大小的SPIO微粒通过不同的转染介质能够标记不同的靶细胞、靶分子或靶基因，不仅可以观察活体内解剖结构的变化，还可以了解生理和分子水平的改变。就SPIO作为磁共振分子影像对比剂的应用和研究现状进行综述。     

超顺磁性氧化铁的研究现状及其在肝增强磁共振成像的临床应？…

本文综述了超顺磁性氧化铁作为磁共夺对比剂的研究现状及其在肝磁共振成像中的临床应用前景。重点就目前常见的几种超顺磁性氧化铁的理化性质、摄入机制、磁化特性、毒副作用及临床应用现状等方面进行了讨论。     

超顺磁性氧化铁微粒在分子影像学中的研究现状

超顺磁性氧化铁(SPIO)微粒作为磁共振分子对比剂可以提供足够的T2*效应,能在分子微克水平被检测到,不同大小的SPIO微粒通过不同的转染介质能够标记不同的靶细胞、靶分子或靶基因,不仅可以观察活体内解剖结构的变化,还可以了解生理和分子水平的改变.就SPIO作为磁共振分子影像对比剂的应用和研究现状进行综述.     

口服超顺磁性氧化铁在MRCP中的应用

目的：研究超顺磁性氧化铁(SPIO)作为胃肠道阴性对比剂在改善磁共根胰胆管成像(MRCP)质量的应用。方法：30例受检者口服2mmol/Fe／1的SPIO液100m1后进行TSE MRCP检查，采用西门子1．5T MRI扫描机，服药前后常规行单层和多层扫描，原始图像经工作站处理后，采用最大信号强度投影技术重建获得新图像。结果：口服SPIO溶液可以完全抑制胃及十二指肠内液体信号，排除其干扰，使MRCP时胰胆管显影更加清晰。结论：口服SPIO，行MRCP检查，能抑制胃肠道内液体信号，使胰胆管显影更加清晰，特别是在TSEMRCP成像时效果更佳。     

Hepatocellular carcinoma with marginal superparamagnetic iron oxide uptake on T2*-weighted magnetic resonance imaging: histopathologic correlation

Purpose

To evaluate the characteristics of hepatocellular carcinomas (HCCs) with marginal superparamagnetic iron oxide (SPIO) uptake on T2*-weighted MRI.

Materials and methods

The study group consisted of 73 patients with 83 surgically resected HCCs. Preoperative SPIO-enhanced MRI studies were retrospectively reviewed. Marginal SPIO uptake was considered positive if a rim-like or band-like low intensity area was present on SPIO-enhanced T2*-weighted images. The prevalence of marginal SPIO uptake was evaluated. Pathological specimens with hematoxylin and eosin staining and immunohistochemical staining of CD68 were reviewed in HCCs with marginal SPIO uptake and 33 HCCs without marginal SPIO uptake (control group).

Results

Ten of 83 (12%) HCCs showed marginal SPIO uptake. All HCCs were hypervascular, and only one nodule showed a nodule-in-nodule appearance on imaging findings. The pathology specimens suggested possible causes of marginal SPIO uptake, including marginal macrophage infiltration in moderately or poorly differentiated HCC (n = 4), residual normal hepatic tissue at the marginal area of confluent multinodular or single nodular with extranodular growth type HCC (n = 3), and a well-differentiated HCC component in nodule-in-nodule type HCC (n = 3). Marginal macrophage infiltration was not seen in the control group.

Conclusion

SPIO-enhanced MRI may be able to demonstrate marginal macrophage infiltration in HCC.     

乙肝肝硬化背景小肝癌CT与MRI强化特征的比较研究

目的 比较乙肝肝硬化背景小肝癌(SHCC)CT与MRI的强化特征.方法 87例乙肝肝硬化SHCC患者共计91个病灶均行CT和MRI动态增强扫描,分别测量病灶平扫及增强各期CT值和MRI信号强度值,计算增强后CT与MRI各期相对强化率和病灶-肝脏对比率,绘制时间-密度/信号强度曲线并分型,观察记录病灶CT与MRI动脉期强化方式及假包膜的显示情况,分析比较乙肝肝硬化背景SHCC CT与MRI的强化特征.结果 MRI动脉期及平衡期SHCC相对强化率较CT高,差异有统计学意义(P＜0.05),CT与MRI门静脉期SHCC相对强化率差异无统计学意义(P＞0.05).MRI动脉期、门静脉期及平衡期SHCC病灶-肝脏对比率均较CT高,差异均有统计学意义(P＜0.05).CT与MRI SHCC时间-密度/信号强度曲线类型差异有统计学意义(P＜0.05),两两比较速升速降型及速升缓降型差异有统计学意义(P＜0.05),缓慢上升型及基本无强化型差异无统计学意义(P＞0.05).CT与MRI SHCC动脉期强化方式差异无统计学意义(P＞0.05).MRI动态增强SHCC假包膜显示率较CT高,差异有统计学意义(P＜0.05).结论 CT和MRI动态增强都能很好地反映SHCC相对肝实质的"陕进快出"的强化方式,MRI对显示SHCC动脉期快速强化的特征及假包膜较CT有优势,而CT更有利于观察SHCC强化"退出"的特点.     

MR动态增强扫描对结节型肝细胞癌的诊断价值

目的:探讨MR动态增强扫描对结节型肝细胞癌的诊断价值.方法:原发性结节型肝细胞癌24例,MRI平扫的基础上进行动态增强扫描,选取病灶感兴趣区,描出时间-信号强度曲线,进行分析.结果:16例时间-信号强度曲线为速升速降型,7例为速升缓降型;1例未见明显强化.结论:MR动态增强扫描能为结节型肝细胞癌的定性诊断提供重要依据.     

体外磁共振成像对神经干细胞标记后弛豫活性的实验研究

目的:研究超顺磁性氧化铁颗粒(SPIO)标记细胞后在细胞成像领域的应用价值。方法:SPIO与多聚赖氨酸(PLL)联合标记神经干细胞,使用4.7T磁共振对标记细胞进行T1WI、T2WI及T2*WI扫描,并测量标记细胞及未标记细胞的弛豫率R2和R2*。结果:①与未标记细胞相比,标记细胞于T1WI时信号强度平均上升24.06%,T2WI时信号强度平均下降50.66%,T2*WI时信号强度平均下降53.70%。②未标记细胞和标记细胞的T2分别为516 ms和77 ms,弛豫率R2分别为1.94/s及12.98/s;T2*分别为109 ms和22.9 ms,其弛豫率R2*分别为9.17/s及43.67/s。标记细胞的R2及R2*分别约增强了5倍及4倍。结论:SPIO能够有效的标记神经干细胞,明显提高标记细胞的R2及R2*,T2WI和T2*WI序列对显示标记细胞与未标记细胞间的信号差异较敏感。     

基于钆塞酸二钠增强MRI在LI-RADS v2018及LI-RADS v2017诊断肝细胞癌的对比研究

目的 探讨基于钆塞酸二钠(Gd-EOB-DTPA)增强MRI采用肝脏影像报告和数据系统2018版(LI-RADS v2018)诊断肝细胞癌(HCC)的效能,并与LI-RADS v2017进行对比研究.方法 回顾性分析2017年3月至2020年5月本院行Gd-EOB-DTPA增强MRI检查有病理结果的HCC高危患者.由三...     

肝细胞癌射频治疗后的磁共振表现

目的：评价MRI平扫及Gd-DTPA动态增强对射频治疗肝细胞癌疗效随访的价值。材料和方法：回顾性分析了55例RF术前及术后的MRI表现,并与活检及长期随访结果进行对照。结果：RF术前病灶在T1加权上多呈相对低信号、T2加权像上呈相对高信号,RF术后病灶转变成T1加权较高信号、T2加权均匀一致的等低信号,残存的癌结节表现为病灶周围包膜不规整或周边小结节并在动态增强时呈单峰型“快进快出”强化表现,活检提示癌灶残存。结论：MR平扫评价RF的疗效基本可靠,动态增强能进一步提高评价信心及准确率。RF术后定期MR随访具有重要意义。     

Usefulness of administration of SPIO prior to RF ablation for evaluation of the therapeutic effect: an experimental study using miniature pigs

Objectives

To evaluate the usefulness of administration of superparamagnetic iron oxide (SPIO) and magnetic resonance (MR) imaging for assessing the efficacy of radiofrequency (RF) liver ablation.

Material and methods

Using a protocol approved by the animal research committee of our university, nine RF liver ablations were performed in three miniature pigs. Six ablations were performed after administration of SPIO in two pigs (group A). Three ablations were performed in the other pig without administration of SPIO (group B). All pigs were sacrificed 4 days after the procedure. Harvested livers were scanned with a 1.5 T MR system before and after fixation with 10% buffered formalin, and MR images were precisely compared with histological specimens.

Results

There were no histological differences between the two groups. All ablated liver lesions showed coagulation necrosis at the external layer. There were no viable cells inside the coagulation necrosis. All ablated lesions had a hypointense rim on fast low angle shot (FLASH) images. The rims of group A were thicker than those of group B. The rims of group B corresponded histologically to congestion and hemorrhagic necrosis area. The rims of the group A corresponded to hemorrhagic necrosis and coagulation necrosis areas. In group A, the hypointense rim reflected necrotic Kupffer cells that took up SPIO before RF liver ablation.

Conclusion

Administration of SPIO made it possible to precisely evaluate ablated liver parenchyma by hypointense rim on FLASH images. This method is helpful for the evaluation of safety margin after RF ablation for liver tumors.     

肝癌氩氦刀冷冻治疗后MRI表现

目的　评价MRI平扫和动态增强对肝癌氩氦刀治疗后疗效随访的价值。资料与方法　回顾性分析 4 5例肝癌患者术后MRI表现并与AFP结果进行对照。结果　氩氦刀治疗后病灶变成T1WI较高信号 ,T2 WI等低信号。坏死灶无明显强化 ;残存癌灶或新发癌灶在动态增强时早期强化。小肝癌组 (<5cm)肿瘤完全坏死率 5 6 .7% ,大肝癌组 (≥ 5cm)肿瘤完全坏死率 2 0 %。小肝癌组的疗效优于大肝癌组 (χ2 =4 .0 6 ,P <0 .0 5 )。结论　MRI平扫和动态增强评价氩氦刀的疗效可靠、准确 ,氩氦刀术后定期MRI随访具有重要意义     

Diagnostic Performance of 2018 KLCA-NCC Practice Guideline for Hepatocellular Carcinoma on Gadoxetic Acid-Enhanced MRI in Patients with Chronic Hepatitis B or Cirrhosis: Comparison with LI-RADS Version 2018

ObjectiveTo evaluate the performance of the 2018 Korean Liver Cancer Association-National Cancer Center (KLCA-NCC) Practice Guidelines (hereafter, PG) for the diagnosis of hepatocellular carcinoma (HCC) using gadoxetic acid-enhanced MRI, compared to the Liver Imaging-Reporting and Data System (LI-RADS) version 2018 (hereafter, v2018).Materials and MethodsFrom January 2013 to October 2015, treatment-naïve hepatic lesions (≥ 1 cm) on gadoxetic acid-enhanced MRI in consecutive patients with chronic hepatitis B or cirrhosis were retrospectively evaluated. For each lesion, three radiologists independently analyzed the imaging features and classified the lesions into categories according to the 2018 KLCA-NCC PG and LI-RADS v2018. The imaging features and categories were determined by consensus. Generalized estimating equation (GEE) models were used to compare the per-lesion diagnostic performance of the 2018 KLCA-NCC PG and LI-RADS v2018 using the consensus data.ResultsIn total, 422 lesions (234 HCCs, 45 non-HCC malignancies, and 143 benign lesions) from 387 patients (79% male; mean age, 59 years) were included. In all lesions, the definite HCC (2018 KLCA-NCC PG) had a higher sensitivity and lower specificity than LR-5 (LI-RADS v2018) (87.2% [204/234] vs. 80.8% [189/234], p < 0.001; 86.2% [162/188] vs. 91.0% [171/188], p = 0.002). However, in lesions of size ≥ 2 cm, the definite HCC had a higher sensitivity than the LR-5 (86.8% [164/189] vs. 82.0 (155/189), p = 0.002) without a reduction in the specificity (80.0% [48/60] vs. 83.3% [50/60], p = 0.15). In all lesions, the sensitivity and specificity of the definite/probable HCC (2018 KLCA-NCC PG) and LR-5/4 did not differ significantly (89.7% [210/234] vs. 91.5% [214/234], p = 0.204; 83.5% [157/188] vs. 79.3% [149/188], p = 0.071).ConclusionFor the diagnosis of HCC of size ≥ 2 cm, the definite HCC (2018 KLCA-NCC PG) had a higher sensitivity than LR-5, without a reduction in specificity. The definite/probable HCC (2018 KLCA-NCC PG) had a similar sensitivity and specificity to that those of the LR-5/4.