扩散加权成像联合钆塞酸二钠增强MRI在肝转移瘤诊断中的研究进展

早期检出肝脏转移瘤对选择合适的治疗方案和提高病人术后生存率有较大价值。扩散加权成像主要反映活体组织中水分子的布朗运动,在肝脏局灶性病变的检出和定性方面显示出较大优势,尤其是在肝脏微小转移瘤的检出方面;而钆塞酸二钠(Gd-EOB-DTPA)增强MRI是一种既能进行肝脏动态增强扫描又能提供肝脏特异性信息的影像检查方法,在肝脏转移瘤检出方面的价值和准确性均较高。就DWI联合Gd-EOB-DTPA增强MRI在肝脏转移瘤检出中的研究进展予以综述。     

肝脏乏血供病变的Gd-EOB-DTPA MRI表现

由于肝脏乏血供病变的常规影像表现相似,故术前对病变的良恶性鉴别诊断有一定困难。MRI是肝脏病变诊断最有价值的成像方法,利用非特异性细胞外对比剂钆塞酸二钠（Gd-EOB-DTPA）在肝胆期可以被肝细胞特异性摄取的特点,能够提高病变的检出率和诊断准确性。就多种肝脏乏血供良恶性病变的病生理特点及Gd-EOB-DTPA的MR影像征象予以综述。     

MRI for characterization of primary tumors in the non-cirrhotic liver: Added value of Gd-EOB-DTPA enhanced hepatospecific phase

Purpose

To evaluate the added value of hepatospecific phase in Gd-EOB-DTPA enhanced magnetic resonance imaging (MRI) in patients with primary tumors in non-cirrhotic liver.

Methods

Twenty-nine patients (median, 39 years; range, 18–81 years; 11 male) underwent preoperative Gd-EOB-DTPA enhanced MRI including hepatospecific phase after 10 and 20 min of contrast injection at four institutions in Europe, North America and New Zealand. Images were evaluated by three different readers (R1–R3) who characterized liver tumors with and without consultation of the hepatospecific phase images. Confidence in diagnosis was scored on a visual analog scale from 1 to 10. Histopathology (adenoma, n = 5; focal nodular hyperplasia, n = 11 and hepatocellular carcinoma, n = 13) in all patients served as the standard of reference. Differences were evaluated using the McNemar and Wilcoxon signed rank test.

Results

Without hepatospecific phase images available, 22 (76%), 19 (66%) and 19 (66%) of 29 tumors were characterized correctly by the three readers respectively. Mean confidence in diagnosis was 6.1, 5.7 and 5.8. With the hepatospecific phase included, characterization of liver tumors did not change significantly with 21 (72%), 23 (79%) and 19 (66%) of 29 tumors diagnosed correctly (p > 0.05). According confidence ratings increased to 6.3, 6.5 and 7.7, respectively. Increase in diagnostic confidence was significant for R2 and R3 (p < 0.05) and independent of reader's experience.

Conclusion

The additional hepatospecific phase in Gd-EOB-DTPA enhanced MRI did not significantly increase diagnostic accuracy in characterization of primary tumors in the non-cirrhotic liver. However, 2/3 readers showed a significant increase in diagnostic confidence after consultation of the hepatospecific phase.     

Care Bolus技术在肝癌Gd-EOB-DTPA MRI动态增强中的应用

目的：探讨Carebolus技术在肝癌Gd—EOB-DTPAMR动态增强肝脏动脉期扫描中的价值。方法：纳入本院2012年3月-12月行Gd—EOH_DTPA动态MR增强的72例患者,分为A、B两组,A组行Carebolus技术动态扫描,B组行定时延时动脉期扫描,分析Gd—EOB-DTPA增强后患者胸主动脉下段、腹腔干信号强度、门静脉和肝癌病灶强化情况,采用独立样本t检验,独立样本的Wilcoxon符号秩和检验及KruskalWallisH统计两组问的差别。结果：A、B两组Gd—EOB-DTPA增强后胸主动脉下段信号强度分别为15．5±7．8和21．3±11．3,腹腔干信号强度分别为22．5±8．2和31．0±14．0,两组间差异均有统计学意义（P=0．0065,P=0．0015）。A、B两组动脉期门静脉无强化率分别为53％和4％,差异有统计学意义（P=0．000）。A、B两组动脉期肝癌病灶最优强化率分别为79％和46％,差异有统计学意义（P=0．005）。结论：Carebolus技术对肝癌病灶动脉增强特点的显示明显优于常用的动脉延时扫描技术。Carebolus技术可作为常规扫描技术用于肝癌Gd-E013-DTPAMR动态增强肝脏动脉期扫描。     

钆塞酸二钠增强MRI对不典型肝细胞癌和肝内胆管细胞癌的鉴别诊断价值

目的 探讨钆塞酸二钠（Gd-EOB-DTPA） 增强 MRI对最大径≤3 cm的不典型肝细胞癌（HCC）及肝内胆管细胞癌（ICC）的鉴别诊断价值。 方法 回顾性纳入经病理证实的最大径≤3 cm的不典型HCC 26例[男17例,女9例,平均年龄（56.9±11.3）岁;HCC组]及ICC 21例[男16例,女5例,平均年龄（58.2±11.6）岁;ICC组]的临床及影像资料。评估2种肿瘤平扫及Gd-EOB-DTPA动态增强MRI上影像特征,包括肿瘤最大径、病灶边缘、病灶包膜、伴远端胆管扩张情况、病灶信号是否均匀、瘤体ADC值、动脉期强化特征、瘤周血流灌注是否异常、动态强化方式及肝胆期信号特征。采用t检验及χ ²检验分析2组的临床特征和常规平扫序列、增强MRI表现的差异,采用多因素Logistic回归分析鉴别两者的预测因素。2名影像医师对2种肿瘤的平扫及增强影像诊断结果的一致性分析采用kappa检验。 结果 HCC组病人相比ICC组多有肝炎及肝硬化病史,血清肿瘤标志物甲胎蛋白（AFP）高于ICC组,而ICC组的糖类抗原199（CA-199）水平更高;常规平扫序列MRI上HCC组病灶常有包膜,而ICC组常伴远端胆管扩张且ADC值更高;增强后ICC组更多表现为动脉期边缘强化、中央逐渐强化,更易出现肝胆期靶征改变（均P<0.05）。多因素Logistic回归分析显示增强动脉期边缘强化及肝胆期靶征为鉴别诊断HCC和ICC的重要预测征象。2名影像医师诊断一致性良好（κ=0.837,P<0.001)。 结论 Gd-EOB-DTPA 增强MRI肝胆期靶征和动脉期边缘强化对最大径≤3 cm的不典型HCC及ICC有重要鉴别诊断价值,可为治疗方案提供参考。     

Impact of liver cirrhosis on liver enhancement at Gd-EOB-DTPA enhanced MRI at 3 Tesla

Purpose

The purpose of this study was to assess differences in enhancement effects of liver parenchyma between normal and cirrhotic livers on dynamic, Gd-EOB-DTPA enhanced MRI at 3 T.

Materials and methods

93 patients with normal (n = 54) and cirrhotic liver (n = 39; Child–Pugh class A, n = 18; B, n = 16; C, n = 5) underwent contrast-enhanced MRI with liver specific contrast media at 3 T. T1-weighted volume interpolated breath hold examination (VIBE) sequences with fat suppression were acquired before contrast injection, in the arterial phase (AP), in the late arterial phase (LAP), in the portal venous phase (PVP), and in the hepatobiliary phase (HBP) after 20 min. The relative enhancement (RE) of the signal intensity of the liver parenchyma was calculated for all phases.

Results

Mean RE was significantly different among all evaluated groups in the hepatobiliary phase and with increasing severity of liver cirrhosis, a decreasing, but still significant reduction of RE could be shown. Phase depending changes of RE for each group were observed. In case of non-cirrhotic liver or Child–Pugh Score A cirrhosis mean RE showed a significant increase between AP, LAP, PVP and HBP. For Child–Pugh B + C cirrhosis RE increased until PVP, however, there was no change in case of B cirrhosis (p = 0.501) and significantly reduced in case of C cirrhosis (p = 0.043) during HBP.

Conclusion

RE of liver parenchyma is negatively affected by increased severity of liver cirrhosis, therefore diagnostic value of HBP could be limited in case of Child Pugh B + C cirrhosis.     

Detection of colorectal hepatic metastases using MnDPDP MR imaging and diffusion-weighted imaging (DWI) alone and in combination

To compare the diagnostic accuracy of MnDPDP MR imaging and diffusion-weighted imaging (DWI), alone and in combination, for detecting colorectal liver metastases in patients with suspected metastatic disease. Thirty-three consecutive patients with suspected colorectal liver metastases underwent MR imaging. Three image sets (MnDPDP, DWI and combined MnDPDP and DWI) were reviewed independently by two observers. Lesions were scored on a five-point scale for malignancy and the areas (Az) under the receiver operating characteristic curves were calculated for each observer and image set. The sensitivity and specificity for lesion detection were calculated for each image set and compared. There were 83 metastases, 49 cysts and 1 haemangioma. Using the combined set resulted in the highest diagnostic accuracy for both observers (Az = 0.94 and 0.96), with improved averaged sensitivity of lesion detection compared with the DWI set (p = 0.01), and a trend towards improved sensitivity compared with the MnDPDP set (p = 0.06). There was no difference in the averaged specificity using any of the three image sets (p > 0.5). Combination of MnDPDP MR imaging and DWI resulted in the highest diagnostic accuracy and can increase sensitivity without loss in specificity.     

Gd-EOB-DTPA enhanced MR imaging: Evaluation of biliary and renal excretion in normal and cirrhotic livers

Objective

The purpose of this study was to assess the difference in the activity of biliary and renal excretion between normal and cirrhotic livers on contrast-enhanced MR imaging obtained with gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA).

Methods

A total of 78 patients with cirrhotic liver (n = 44) and with normal liver (n = 34) underwent multi-phase Gd-EOB-DTPA enhanced MR imaging (arterial, portal, equilibrium, and three hepatobiliary phases (10, 15 and 20 min HP), respectively), and these contrast-enhanced images were qualitatively and quantitatively evaluated for the differences of the biliary and renal excretion between normal and cirrhotic livers.

Results

The timing of biliary excretion of contrast agents in the cirrhotic liver was significantly slower than that in the normal liver (P < 0.001). The degree of contrast enhancement in the common bile duct in the normal liver was significantly better than that in the cirrhotic liver (P = 0.003). Contrast agents were demonstrated in the duodenum at 20 min HP in 8/44 (18%) cirrhotic liver while they were seen in 15/34 (44%) normal liver (P = 0.013). The enhancement effects of renal medulla and portal vein at 20 min HP in the cirrhotic liver were significantly higher than those of normal liver (P = 0.043 and P < 0.001, respectively).

Conclusion

Biliary excretion of Gd-EOB-DPTA was impaired in cirrhotic livers in comparison with normal livers while renal excretion of Gd-EOB-DPTA was increased.     

联合SWI与DWI在急性脑弥漫性轴索损伤中的应用价值

目的：评价联合磁敏感成像（SWI）与扩散加权成像（DWI）在急性期脑弥漫性轴索损伤中的应用价值。方法：32例脑弥漫性轴索损伤急性期患者,所有患者行常规MRI序列、DWI及SWI序列全脑扫描。结果：共检出病灶313个,T1WI 78个,T2WI 207个,FLAIR 292个,DWI 286个,SWI 297个。SWI显示245个病灶内分布斑片状、点状出血灶,其它序列共显示43个内分布出血灶。SWI、DWI病灶检出率高于常规T2WI（χ2=82.465,χ2=59.584;P〈0.01）,SWI、FLAIR及DWI病灶检出率无明显差异（χ2=3.052;P〉0.05）。结论：联合SWI与DWI有利于提高急性脑弥漫性轴索损伤的检出率,有助于准确评价病变的严重程度,SWI与DWI应作为急性脑弥漫性轴索损伤的常规扫描序列组合。     

High-dose gadolinium-enhanced MRI for diagnosis of meningeal metastases

We compared high-dose (0.3 mmol/kg) and standard-dose (0.1 mmol/kg) gadolinium-enhanced MRI for diagnosis of meningeal metastases in 12 patients with suspected meningeal metastases. They were imaged with both standard-dose and high-dose gadolinium. All patients with abnormal meningeal enhancement underwent at least one lumbar puncture for cerebrospinal fluid (CSF) cytology, while patients with normal meningeal enhancement were followed clinically. All patients with negative CSF cytology also were followed clinically. A single observer reviewed all the images, with specific attention to the enhancement pattern of the meninges. Abnormal leptomeningeal enhancement was present in three cases, and abnormal pachymeningeal enhancement in three other patients. All of these patients had abnormal CSF analyses. In two of the three cases of abnormal leptomeningeal enhancement the disease was more evident on high-dose than on standard-dose imaging; in one case the abnormal enhancement was visible only on high-dose imaging. In one of the three cases with abnormal pachymeningeal enhancement, the disease was evident prospectively only with high-dose imaging. Received: 5 June 1997 Accepted: 12 June 1997     

钆塞酸二钠增强MRI特征对肝细胞癌微血管侵犯的预测价值

目的 探讨术前钆塞酸二钠增强MRI特征预测肝细胞癌（HCC）微血管侵犯（MVI）的价值。 方法 回顾性分析83例经手术病理确诊的HCC病人的术前影像及临床资料,其中男75例,女8例,平均（57.6±11.4）岁。所有病人均进行了MRI平扫和增强检查,分析其常规MRI征象和肝胆期征象。根据术后病理结果将病人分为MVI阳性组30例及MVI阴性组53例。采用t检验或χ²检验比较2组间临床和影像特征的差异,将差异有统计学意义的特征纳入多因素Logistic回归分析,获得独立危险因素后分别建立单独预测模型及联合预测模型,采用受试者操作特征曲线评估不同模型的预测效能,计算其曲线下面积（AUC）,并采用DeLong检验比较不同模型预测MVI的AUC。 结果 与MVI阴性组相比,MVI阳性组的肝胆期肿瘤最大径、瘤周晕征、肿瘤边缘分型中的单结节外突/多结节融合型占比均更高,肿瘤信号强度比值较低;常规MRI征象中包膜不完整性、瘤周强化的占比更高;AFP水平大于MVI阴性组（均P<0.05）。多因素Logistic回归分析显示肝胆期的肿瘤最大径、瘤周晕征和单结节外突/多结节融合型均为HCC MVI的独立危险因素（OR值分别为1.424、26.998、6.144,均P<0.05）,肿瘤最大径越大、瘤周晕征阳性及单结节外突/多结节融合型表现的病人发生MVI的风险越高。联合预测模型、肿瘤最大径模型、单结节外突/多结节融合型模型和瘤周晕征模型预测MVI的AUC分别为0.926、0.803、0.792、0.823。联合模型预测MVI的敏感度、特异度和AUC值均最高,且AUC值分别高于肿瘤最大径模型、单结节外突/多结节融合型模型和瘤周晕征模型（均P<0.05）。 结论 钆塞酸二钠增强MRI上肿瘤最大径、单结节外突/多结节融合型和肝胆期瘤周晕征是预测MVI的独立危险因素,且三者联合预测效能更高。     

MRI肝胆特异性对比剂Gd-EOB-DTPA对小肝细胞癌的诊断研究进展

肝细胞癌(HCC)是常见的原发性肝脏恶性肿瘤,全球的发病率逐年增长。HCC的早期发现与及时治疗是提高病人预后及生存率的关键。钆塞酸二钠(Gd-EOB-DTPA)是一种新型的MRI肝胆特异性对比剂,不仅具有普通细胞外间隙对比剂的功能,还可被肝细胞特异性摄取,进而提供肝胆期信息。Gd-EOB-DTPA增强MRI对HCC的诊断价值优于常规细胞外间隙对比剂增强MRI。就Gd-EOB-DTPA增强MRI在小HCC诊断及鉴别诊断中的应用现状进行综述。     

Comparison of three different injection methods for arterial phase of Gd-EOB-DTPA enhanced MR imaging of the liver

Objective

To compare three different injection methods for optimizing hepatic arterial phase of gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) enhanced MR imaging.

Methods

Arterial phase images were obtained after the injection of contrast agent at a rate of 3 mL/s with diluted Gd-EOB-DTPA (dilution method) in 27 patients, 3 mL/s with undiluted Gd-EOB-DTPA (3 mL method) in 26 patients and 1 mL/s with undiluted Gd-EOB-DTPA (1 mL method) in 28 patients. In the quantitative evaluation, signal-to-phantom ratios (SPR) of the liver parenchyma, pancreas, renal cortex, portal vein and aorta were evaluated. In the qualitative evaluation, the seven items for image quality of hepatic arterial phase were assessed, and the total score of all items in each subject was calculated.

Results

The score of enhancement of abdominal aorta and total score of seven items in 1 mL method were significantly higher than those in 3 mL method. The SPR of the liver parenchyma in 3 mL method was significantly higher than that in 1 mL method, suggesting substantial hepatic inflow from portal venous return.

Conclusion

For the optimal arterial phase imaging, injection rate of 1 mL/s with undiluted Gd-EOB-DTPA is convenient and preferable, compared with other two methods, based on our qualitative analysis.     

钆塞酸二钠和钆喷酸葡胺肝脏多期动态增强呼吸伪影对比研究

目的:比较静脉注射钆塞酸二钠(Gd-EOB-DTPA)和钆喷酸葡胺(Gd-DTPA)的动脉期呼吸伪影,寻求减少Gd-EOB-DTPA动脉期呼吸伪影的可能方案.方法:搜集在1年内行Gd-EOB-DTPA和Gd-DTPA磁共振动态增强扫描的患者75例,由两位有经验的磁共振医师采用盲法对两种对比剂扫描方案的动脉期、门脉期及延迟期图像采用5分法评分,以≤3分定义为中重度伪影.两种对比剂扫描方案的呼吸伪影比较采用Wilcoxon秩和检验和配对卡方检验.结果:Gd-EOB-DTPA组发生动脉晚期呼吸伪影的比例明显高于Gd-DTPA组(分别为49.3％和6.7％,Z=-5.058,P＜0.001),其中中重度伪影的比例亦明显高于Gd-DTPA(分别为33.33％和2.67％,x2=21.04,P＜0.001);而Gd-EOB-DT-PA组动脉早期出现呼吸伪影和中重度呼吸伪影的比例与Gd-DTPA组差异无统计学意义(Z=-1.513,P=0.130;x2=0.25,P=0.625).结论:静脉注射Gd-EOB-DTPA较Gd-DTPA更易引起动脉期伪影,减少单期屏气时间和采用动脉期监测技术可能提高Gd-EOB-DTPA动脉期采集的图像质量.     

韦尼克脑病的MRI表现及DWI对临床预后的评价

目的:探讨韦尼克脑病(Wernicke’s encephalopathy,WE)的MRI表现及弥散加权成像(DWI)在临床预后及治疗中的价值。方法:对10例经临床证实的WE患者的MRI资料进行分析,同时DWI检查,8例行MRI复查并对治疗前后病灶表观弥散系数(ADC)值进行比较。结果:5例患者均出现双侧丘脑、第三脑室及导水管周围广泛对称性异常信号累及,乳头体、被盖及四脑室底部异常信号各1例。上述病变呈稍长T1稍长T2信号改变,FLAIR序列呈高信号。DWI显示10例病灶区呈高/稍高信号,5例患者治疗前ADC值减低,其中3例经治疗后复查ADC值升高;另外5例患者病灶区治疗前ADC值无明显下降,治疗后ADC值均升高,患者预后均较好。结论:WE脑病具有典型的MRI表现,DWI对临床诊断及预后评价具有重要意义。     

磁共振扩散加权成像在乳腺病变诊断中的应用

目的：探讨单纯磁共振扩散加权成像对诊断乳腺病变的临床应用价值。方法：对临床拟诊为乳腺肿块的37例患者行磁共振扩散加权成像检查,并获得病理证实,其中良性病灶18个,恶性病灶19个。描记扩散图像上病变的兴趣区,由软件计算获得表观扩散系数（ADC）值。对获取数据进行统计分析,采用t检验对良性和恶性病变的ADC值进行比较。结果：12例良性病变在DWI上呈等信号或高信号,但ADC值升高或下降不明显,6例良性病变DWI上呈高信号,ADC值明显下降;19例恶性肿瘤DWI上呈高信号,ADC值明显下降。良性病变组ADC值为（1.474±0.441）×10^-3mm^2/s,恶性病变组ADC值为（1.082±0.160）×10^-3mm^2/s,两者间差异有显著性意义（P=0.002）。结论：MR扩散加权成像ADC值测量在乳腺病变定性诊断中有一定的辅助诊断价值。     

肝VX-2 瘤模型MR扩散成像的实验研究

目的探讨肝VX-2瘤模型MR扩散成像特征.方法新西兰大白兔35只,采用块种植的方法,一期预实验皮下种植14只,肝内种植6只;二期肝内种植12只,另3只做正常对照.对包括二期肝内种植在内的15个肿瘤于种植前后行定期扩散加权成像(DWI) 与MR检查.以表观扩散系数(ADC)值等为指标进行统计分析.结果 (1)一期预实验,皮下种植成功率29%(4/14),肝内种植成功率33%(2/6);二期肝内种植成功率83%(10/12).(2)VX-2瘤在DWI上呈高信号,边缘清楚.正常组与VX-2瘤实验组b值为100和300 s/mm2时ADC值分别为(2.57±0.26)mm2/s、(1.73±0.31)mm2/s、(1.87±0.25)mm2/s与(1.57±0.23)mm2/s(F=43.26,P<0.001).随b值增大,病灶信号降低;ADC图上病灶呈低信号;不同b值之间病灶ADC值差异有统计学意义(P<0.05);b=100 s/mm2病灶与正常肝脏之间ADC值差异有统计学意义(P<0.01).(3)VX-2瘤发展迅速,易发生肺、肝、纵隔等处转移.结论 DWI在反映肝VX-2瘤内部水分子运动、发现与追踪病灶进展等方面有重要价值.     

磁共振扩散加权成像对于颅内表皮样囊肿的诊断价值

目的:探讨磁共振扩散加权成像(DWI)对于颅内表皮样囊肿的诊断价值。方法:回顾性分析11例经手术病理证实的颅内表皮样囊肿术前常规MRI和DWI的信号特征。结果:11例均为单发;7例表现为囊状均匀性长T1长T2信号,4例病灶信号不均匀,以长T1长T2信号为主,其内混杂少许等T1等T2信号;5例行增强扫描均未见异常强化;所有病灶在DWI上均表现为明显高信号,边界清楚,ADC图表现为中等信号。结论:DWI对于颅内表皮样囊肿的诊断及鉴别诊断具有重要价值,应作为首选检查与常规扫描同时应用。     

MRI扩散加权成像表观弥散系数对肝脏转移瘤的诊断价值

目的 评价表观弥散系数(apparent diffusion coefficient,ADC)在不同组织来源的肝脏转移瘤的诊断价值.方法 回顾性分析45例经1.5T MRI检查的肝脏转移瘤患者的扩散加权图像,采用单因素方差分析276处肝脏转移瘤的ADC值,比较不同肿瘤组间的差异性.结果 来源于胃直肠癌、肝癌、乳腺癌的肝脏转移瘤的平均ADC值间的差异无统计学意义.来源于肺癌的肝脏转移瘤的平均ADC值低于其他来源的肝脏转移瘤,差异有统计学意义(P＜0.05).来源于胰腺癌的肝脏转移瘤的平均ADC值高于其他来源的肝脏转移瘤,差异有统计学意义(P＜0.05).结论 ADC值在肺癌和胰腺癌来源的肝脏转移瘤的诊断中有一定的价值.