磁共振扩散加权成像对肝脏局灶病变的价值

目的:探讨磁共振扩散加权成像(diffusion weighted imaging,DWI)对肝脏局灶性病变诊断和鉴别诊断的价值.方法:原发性肝癌30例,肝血管瘤12例,肝囊肿13例,正常肝36例,行常规MRI检查加DWI,b值取500 s/mm~2和800 s/mm~2,利用MRI工作站软件Functool 2.6.6i,500 s/mm~2扫描的图像得到ADC图及eADC图,800 s/mm~2扫描的图像测出mADC,eADC及瘤肝ADC比值及瘤肝eADC比值等指标,利用SPSS12.0软件进行统计学处理.结果:mADC值正常肝(1.89±0.62 10.2 mm~2/s)低于肝囊肿与肝血管瘤(2.93±0.46 10~(-3)mm~2/s,2.26±0.45 10~(-3)mm~2/s,P<0.01,P<0.05)而高于原发性肝癌(1.43±0.52 10~(-3)mm~2/s,P<0.01);肝囊肿高于肝血管瘤(P<0.01)与原发性肝癌(P<0.01);肝血管瘤高于肝细胞癌(P<0.01).eADC值正常肝高于肝囊肿而低于肝血管瘤与原发性肝癌(0.1 55±0.07 vs 0.052±0.03,0.23±0.10,0.31±0.22,P<0.05,P<0.05,P<0.01);肝囊肿低于肝血管瘤(P<0.01)与原发性肝癌(P<0.01);肝血管瘤低于肝细胞癌(P<0.01).瘤肝ADC比值肝囊肿高于肝血管瘤与原发性肝癌(1.93±0.43 vs 1.43±0.44,0.95±0.45,均p0<.01);肝血管瘤高于原发性肝癌(P<0.01),瘤肝eADC比值在不同组间比较:肝囊肿低于肝血管瘤与原发性肝癌(1.00±0.57 vs 1.63±0.36,1.46±0.74,P<0.01,P<0.05);肝血管瘤高于原发性肝癌,但无显著性差异(P>0.05).结论:DWI有利于显示肝脏病变,综合运用mADC和eADC可进一步提高鉴别诊断的正确率.     

弥散加权成像和表观扩散系数在肝脏局灶性病变鉴别诊断中的研究

目的探讨分析弥散加权成像(diffusion-weighted imaging,DWI)和表观扩散系数(apparent diffusion coefficient,ADC)在肝脏局灶性病变鉴别诊断中的应用价值。 方法对2016年8月至2017年5月庆云县人民医院65例有肝脏内局灶性病变(focal liver lesion,FLL)的患者的DWI扫描(b＝50,400,800s/ mm²)进行回顾性分析。测量其中104个病灶(包括56个良性病变和48个恶性病变)实质部分的平均ADC值,避开内部坏死区。分别计算良性病变和恶性病变的特异度和敏感度。运用方差分析检测各类局灶性病变的组间差异。 结果恶性病变的平均ADC值为0.980×10^－3mm²/s,明显低于良性病变的平均ADC值(1.433×10^－3mm²/s),有统计学意义(P<0.05)。当ADC值为1.066×10^－3mm²/s时,恶性肿瘤的特性度和敏感度分别为86.6%和73.6%。在所有的病灶中,约39.5%的病灶平均ADC值低于1.0×10^－3mm²/s,这些病灶中恶性病变占90%。约20%的病灶平均ADC值大于1.5×10^－3mm²/s,他们中有9.5%的为恶性病变。 结论DWI的应用提高了磁共振对于肝脏良恶性病变鉴别的能力,尽管ADC值不能作为肝局灶性病变良恶性鉴别的特异性指标,但其可以作为一项鉴别良恶性性病变的重要参考数据。     

磁共振弥散加权成像联合LAVA技术诊断肝脏占位性病变的临床价值

目的探讨磁共振弥散加权成像(DWI)联合快速容积扫描(LAVA)技术诊断肝占位性病变的临床价值。方法采用DWI联合LAVA技术检查25例原发性肝癌、20例肝血管瘤和21例肝脏转移癌,比较各组DWI ADC值、信号增强比值(SER)、最大下降斜率(MSD)、正性增强积分(PEI)、最大上升斜率(MSI)和峰值(PV)等相关指标,比较诊断的准确性。结果肝血管瘤ADC值[(2.34±0.28)×10-3mm2/s]明显高于原发性肝癌[(1.27±0.25)×10-3mm2/s]和肝脏转移癌[(1.32±0.24)×10-3mm2/s,P0.05];肝血管瘤患者MSI(362.4±68.1)、PV(583.6±74.4)、MSD(97.6±42.8)和PEI(285.8±47.0)明显高于肝转移癌和原发性肝癌(P0.05),原发性肝癌患者MSI(285.2±78.7)、PV(496.8±72.2)、MSD(85.2±37.8)和PEI(234.9±72.4)明显高于肝转移癌[分别为(267.5±72.6)、(404.4±68.3)、(73.4±34.2)和(202.6±84.1),P0.05],而三组SER比较,无显著性差异(P0.05);原发性肝癌Ⅰ型曲线(68.0%)显著高于肝血管瘤(10.0%)和肝转移癌(0.0%,P0.05),肝脏转移癌Ⅱ型曲线(76.2%)高于原发性肝癌(20.0%)和肝血管瘤(20.0%)(P0.05),肝血管瘤Ⅲ型曲线(70.0%)高于肝转移癌(23.8%)和原发性肝癌(12.0%,P0.05);DWI联合LAVA增强扫描对各种肝占位性病变的诊断准确率(100.0%)均明显高于两单项检查(P0.05)。结论 DWI和LAVA联合检查可明显提高肝占位性病变的诊断正确率。     

3.0T磁共振弥散加权成像对肝硬化的诊断价值初步研究

目的 初步探讨磁共振弥散加权成像ADC值对肝硬化的诊断价值.方法 采用3.0T全身磁共振扫描系统对23例肝硬化患者、15例健康志愿者(对照组)行轴位弥散加权成像扫描,b值选用0、500、800、1000s/mm2,分别在肝脏右前叶、右后叶、左内叶测量各组的ADC值,进行统计学分析.结果 两组中肝脏左叶ADC值大于肝脏右叶的ADC值,且具有显著性差异;Z=-4.621 P=0.0001;右前叶ADC值略大于右后叶ADC值,两者之间未见显著性差异,Z=-1.552 P=0.06.b＝500、800、1000s/mm2时肝硬化组肝脏的ADC值均低于对照组肝脏的ADC值,且与对照组肝脏ADC值之间均有显著性差别.结论 3.0T磁共振弥散加权成像ADC值在诊断肝硬化引起弥漫肝实质损害中具有很大的临床价值.     

磁共振弥散加权成像及增强扫描对肝脏占位性病变的诊断价值

目的探讨磁共振弥散加权成像(MR DWI)结合增强扫描对肝脏占位性病变的诊断价值。方法回顾性研究56例肝脏占位性病变的MR DWI及增强表现,所有病变均经临床追踪或手术病理证实,包括肝细胞癌11例、胆管细胞癌8例,转移瘤9例、海绵状血管瘤13例、肝囊肿15例。结果肝细胞肝癌典型强化方式为快进快出,胆管细胞癌多为门脉期及延迟期轻度强化,转移瘤多呈环形强化,海绵状血管瘤多呈逐渐强化,少数较小病灶为动脉期强化,并持续至延迟期,肝囊肿无明显强化。在MR DWI上肝细胞肝癌、胆管细胞癌、转移瘤多为稍高信号,海绵状血管瘤为明显高信号,肝囊肿呈低信号。肝细胞肝癌、胆管细胞癌、转移瘤弥散系数(ADC)值差异无统计学意义(P>0.05),但明显低于血管瘤与肝囊肿囊内ADC值(P<0.05),肝囊肿ADC值明显高于其他各组(P<0.05)。结论 MRDWI在肝脏良恶性病变鉴别诊断中具有重要作用,结合增强扫描可提高诊断准确率。     

磁共振扩散加权成像在肝脏疾病中的应用

磁共振扩散加权成像是一种可反映活体内水分子扩散特征的功能成像方法,能间接反映细胞的密度和细胞膜的完整性及毛细血管灌注情况。介绍了该技术在肝脏病变中的主要应用,并重点介绍其在肝细胞癌、肝纤维化的分期及肿瘤疗效监测中的应用。指出这种无需注射对比剂的技术虽仍有不足,但随着软、硬件的发展,将有广阔的应用前景。     

磁共振功能弥散成像对肝脏早期弥漫性病变诊断价值的实验研究

目的探讨磁共振(MR)功能弥散成像(DWI)对早期肝脏弥漫性病变的诊断价值。方法用二乙基亚硝胺诱导大鼠肝脏病变,对其早期阶段(给药后1-14周)的弥漫性改变进行动态磁共振常规形态学成像(包括T1加权、T2加权和常规MR增强扫描)和DWI,并作组织学检查,与正常大鼠比较。结果两组大鼠肝脏的常规形态MR相比无明显差异,而DWI显示了实验组大鼠肝脏早期肝硬化的不均质性改变,表现为相应肝叶的片状信号增高。正常组各周间肝实质的表观弥散系数(ADC)值无明显差异;实验组自第5周ADC值开始下降。当悌度因子(b)为300 s/mm2时,正常组与实验组间以及实验组第10周与第1周和第9周间ADC值差异有统计学意义(P<0.05);当b=600 s/mm2和1 000 s/mm2时,自第6周正常组与实验组间以及实验组第6周与第1周和第5周间ADC值变化显示出明显差异(P<0.01)。病理组织学检查显示实验组1-4周大鼠肝脏的病理改变是以肝细胞肿胀为主,为肝炎阶段,5-8周则属于以肝实质内纤维组织增生为主的肝纤维化阶段,9-14周已进展为肝硬化阶段,实质内有许多纤维分割不完整或完整的增生性结节形成。结论MR功能弥散成像较形态结构影像能更早的反映肝脏弥漫性病变,动态ADC值的测定有助于肝脏早期弥漫性病变的诊断和病变进展的监测。     

磁共振弥散加权成像在肝脏病变中的应用进展

磁共振(MRI)弥散加权成像(DWI)是以图像显示分子微观运动的检查技术,为目前活体上测量水分子弥散运动与成像的惟一方法.其通过检测活体组织内水分子的微观弥散运动状态反映机体组织结构的生理、病理特点,对病理条件下活体内水分子的运动加以分析.现将DWI在肝脏病变诊断中的应用进展作一综述.     

磁共振弥散加权成像在肝硬化诊断中的应用

目的探讨磁共振弥散加权成像对肝硬化的诊断价值。方法采用GEHDx1．5TMRI扫描仪对100例临床诊断肝硬化患者（肝硬化组）及30名健康对照者（对照组）行轴位屏气弥散加权成像扫描（扩散敏感系数b值选用800mm^2／s）,比较2组表观弥散系数（apparent diffusion coefficient。ADC）值。结果对照组与肝硬化组肝脏ADC值分别为（1．842±0．173）和（1．380±0．137）×10^-3mm^2/s,后者低于前者,2组差异有统计学意义。结论肝硬化患者肝脏ADC值下降,磁共振弥散加权成像可望成为无创肝硬化诊断的手段之一。     

磁共振全身弥散加权成像在骨转移瘤诊断中的应用价值

目的探讨磁共振(MRI)全身弥散加权成像(WB-DWI)在骨转移瘤早期诊断中的应用价值。方法对经病理检查证实的41例恶性肿瘤患者行WB-DWI检查,对可疑病变部位行常规MRI或CT检查,将WB-DWI与常规MRI/CT检查结果进行比较,再结合活检病理检查、诊断性治疗及随访观察结果,评价WB-DWI显示骨转移瘤的准确性。结果 WB-DWI共诊断67处骨转移瘤,漏诊6处,其中颅骨2处、肩胛骨1处、胸骨1处、腰骶椎成骨型转移2处;误诊2处,均为椎体血管瘤;发现2例肋骨转移,常规CT和MRI漏诊。常规MRI/CT共诊断69处骨转移瘤,其中63处病灶与WB-DWI所见吻合。结论 WB-DWI在骨转移瘤早期诊断中具有较大的应用价值。     

磁共振扩散加权成像在胰腺囊性病变中的鉴别诊断价值

目的 评价磁共振扩散加权成像（DWI）在胰腺囊性病变中的鉴别诊断价值.方法 收集经临床和（或）病理证实的34例胰腺囊性病变,包括非肿瘤性病变的假性囊肿11例、单纯囊肿5例,肿瘤性病变的浆液性囊腺瘤6例、黏液性囊腺瘤10例、黏液性囊腺癌2例.34例均行常规MRI平扫及动态增强、DWI（b值0,600 s/mm2）扫描,记录病变DWI信号特点,测量病变及毗邻胰腺实质表观扩散系数（ADC）值,计算病变-胰腺实质ADC值比（ADCR）.采用受试者工作特征（ROC）曲线评价病灶ADC值及ADCR的诊断价值.结果 16例非肿瘤性囊性病变组中2例DWI上呈稍高信号,14例呈等信号,18例肿瘤性囊性病变组中17例呈高或稍高信号,l例呈等信号,两组差异具有统计学意义（P ＜0.001）.非肿瘤性、肿瘤性囊性病变的ADC值分别为（3.30 ±0.30）×10-3、（2.74±0.34）×10-3mm2/s;ADCR分别为1.85 ±0.20、1.31 ±0.21,差异均具有统计学意义（P值均＜0.001）.ADC值及ADCR诊断胰腺肿瘤性囊性病变的ROC曲线下面积分别为0.94±0.04、0.98±0.02.ADC值以3.105×10-3 mm2/s为阈值,诊断肿瘤性囊性病变的敏感性为81.3％,特异性为94.4％,ADCR值以1.525为阈值,诊断肿瘤性囊性病变的敏感性为100％,特异性为88.9％.结论 DWI在胰腺囊性病变的诊断与鉴别诊断中具有重要价值,可作为常规MRI的重要补充.     

磁共振扩散成像在诊断肝脏占位病变中的应用

量化分析肝脏占位性病变的磁共振扩散成像(DWI)的表面扩散系数(ADC值)的变化规律。对69个常见肝脏占位性病变病灶(肝血管瘤、肝囊肿、原发性肝癌、肝转移瘤)行磁共振扩散成像检查,计算病灶的ADC值。四种常见肝脏占位性病变病灶的ADC均值,肝血管瘤：(2．38±0．56)×10~(-3)mm~2/s肝囊肿：(2．47±0．71)×10~(-3)mm~2/s原发性肝癌：(1．23±0．14)×10~(-3)mm~2/s肝转移瘤：(1．44±0．46)×10~(-3)mm~2/s。综合量化分析病灶的ADC值的变化,能更准确的判断肝脏占位性病变的性质,为肝脏占位性病变的诊断及鉴别诊断提供更准确的结论。     

MR弥散加权成像在鉴别前列腺良恶性组织中的价值

目的研究前列腺良恶性病灶的磁共振表观弥散系数（apparent diffusion coefficienl,ADC）的差异。方法对健康对照27例、前列腺癌（PCa）患者25例行MR弥散加权成像（diffusion weighted imaging,DWI）。按B超引导穿刺活检操作医师在前列腺样图中标出的相应位置选出感兴趣区域（regions of interest,ROI）,分别对癌灶和正常前列腺组织的ADC值进行测定,比较其差异是否存在统计学意义。结果健康对照组的ADC平均值（1．73±0．16）×10^-3 mm^2／s;最低值（1．30±0．15）×10^-3mm^2/s;PCa组ADC平均值（0．81±0．12）×10^-3mm^2／s;最低值（0．58±0．10）×10^-3mm^2/s,分别通过t检验（P〈0．001）,两组间差异均存在统计学意义。结论ADC值能定量地反映前列腺组织信息,PCa病灶的ADC值明显低于正常组织。ADC值是鉴别前列腺良恶性病灶一个很有价值的可定量参数。     

Role of diffusion-weighted magnetic resonance imaging in the differential diagnosis of focal hepatic lesions

AIM: To evaluate the utility of diffusion-weighted imaging (DWI) in screening and differential diagnosis of benign and malignant focal hepatic lesions. METHODS: Magnetic resonance imaging (MRI) examinations were performed using the Signa Excite Xl Twin Speed 1.5T system (GE Healthcare, Milwaukee, WI, USA). Seventy patients who had undergone MRI of the liver [29 hepatocellular carcinomas (HCC), four cholangiocarcinomas, 34 metastatic liver cancers, 10 hemangiomas, and eight cysts] between April 2004 and August 2008 were retrospectively evaluated. Visualization of lesions, relative contrast ratio (RCR), and apparent diffusion coefficient (ADC) were compared between benign and malignant lesions on DWI. Superparamagnetic iron oxide (SPIO) was administered to 59 patients, and RCR was compared pre- and postadministration. RESULTS: DWI showed higher contrast between malignant lesions (especially in multiple small metastatic cancers) and surrounding liver parenchyma than did contrast-enhanced computed tomography. ADCs (mean ± SD × 10~(-3) mm~2/s) were significantly lower ( P < 0.05) in malignant lesions (HCC: 1.31 ± 0.28 and liver metastasis: 1.11 ± 0.22) and were significantly higher in benign lesions (hemangioma: 1.84 ± 0.37 and cyst: 2.61 ± 0.45) than in the surrounding hepatic tissues. RCR between malignant lesions and surrounding hepatic tissues significantly improved after SPIO administration, but RCRs in benign lesions were not improved. CONCLUSION: DWI is a simple and sensitive method for screening focal hepatic lesions and is useful for differential diagnosis.     

磁共振扩散加权成像评价肝硬化的应用价值

目的探讨肝硬化磁共振扩散加权成像（DW I）表观弥散系数（ADC）值变化与肝硬化程度之间的相关性。方法对54例肝硬化患者及48例正常肝脏行扩散加权成像,并测量ADC值,DW I序列所选用弥散敏感度（b值）分别为（0,400,600,800）s/mm2。在b1和b2（ADC1）、b1和b3（ADC2）及b1和b4（ADC3）计算肝脏ADC值。结果肝硬化平均ADC1、ADC2、ADC3均显著低于正常肝脏（P〈0.05）;Ch ild A、B、C各级肝硬化与正常肝脏相比,ADC值均明显降低（P〈0.05）;ADC值随肝硬化程度的加重而降低（P〈0.05）;各组ADC值随b值增大而降低（P〈0.05）;b值为600 s/mm2、800 s/mm2时,认为（1.30×10-3）s/mm2可能为正常肝脏与肝硬化的分界点,低于此值即可考虑为肝硬化。结论DW I-ADC值的测定可辅助临床诊断早期肝硬化并反映肝硬化的动态变化,是评价肝硬化的有价值的参考指标。     

New approaches to the investigation of focal hepatic lesions

In the past few years, tremendous advances have been made in the fields of magnetic resonance imaging, computed tomography and ultrasonography. These include the development of novel contrast agents and new approaches to image acquisition and processing. This review provides an overview of the state-of-the-art of imaging investigation of focal hepatic lesions and highlights some of the most exciting emerging technologies.     

Superparamagnetic iron oxide-enhanced MR imaging for focal hepatic lesions: a comparison with CT during arterioportography plus CT during hepatic arteriography

Background We aimed to evaluate the efficacy of a breath-hold superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging protocol for the detection of focal hepatic lesions, in comparison with a non-breath-hold SPIO-enhanced imaging protocol and computed tomography during arterioportography (CTAP) plus CT during hepatic arteriography (CTHA).Methods Findings of SPIO-enhanced MR imaging and CTAP/CTHA for 24 hepatic metastases in 17 patients and 29 HCCs in 21 patients were analyzed. All patients underwent breath-hold SPIO-enhanced MR imaging (1.5 tesla), breath-hold plus non-breath-hold SPIO-enhanced MR imaging, and CTAP plus CTHA prior to partial hepatectomy or laparoscopic ablation therapy. Histopathology for lesion characterization and intraoperative ultrasound for lesion detection were available for all patient. Breath-hold SPIO-enhanced MR imaging consisted of T2-weighted single-short fast spin echo (FSE), T2-weighted (T2W) FSE, T2*-weighted gradient echo (GRE), and T1-weighted GRE. For the non-breath-hold imaging protocol, respiratory-triggered, fat-suppressed T2W-FSE was added to the breath-hold MR imaging protocol. Double phase CTAP plus CTHA was performed on an angio-CT system. To compare the three imaging protocols, three radiologists performed blind film reading, and all data, on a hepatic segment-to-segment basis, were entered for alternative free-response receiver-operating characteristic (AFROC) analysis.Results ROC analysis showed that there was no significant difference in the area under the AFROC curve (A1) value for metastases and HCCs among the three protocols; the breath-hold SPIO-enhanced MR imaging protocol, non-breath-hold MR imaging protocol, and CTAP plus CTHA. The breath-hold SPIO-enhanced MR imaging protocol showed a sensitivity, specificity, and accuracy equivalent to the non-breath-hold MR imaging protocol and CTAP plus CTHA.Conclusions As a preoperative test, SPIO-enhanced MR imaging could have the potential to replace CTAP plus CTHA in a certain clinical setting.     

Ferucarbotran versus Gd-DTPA-enhanced MR imaging in the detection of focal hepatic lesions

AIM: To evaluate the efficacy of ferucarbotran-enhanced MR imaging in the detection of focal hepatic lesions compared to plain and Gd-DTPA-enhanced MR imaging. METHODS: Fifty-nine patients with suspected focal hepatic lesions were admitted to the study. Plain MR imaging (FSE T2WI with fat suppression and GRE T1WI sequences) and Gd-DTPA dynamic enhanced MR of the liver were initially performed followed by ferucarbotran- enhanced MR imaging 48 h later (including GRE T1WI, FSE T2WI with fat suppression, and GRE T2*WI sequences). Images were reviewed independently by three observers. Results were correlated with surgery and pathologic examination or reference examination, and sensitivity was statistically calculated for the different MR imaging sequences. RESULTS: Among all confirmed lesions (n = 133), ferucarbotran-enhanced MR imaging revealed 130 lesions on FSE T2WI with fat suppression, 115 lesions on dynamic T1WI GRE, and 127 lesions on GRE T2*WI. Pre-contrast MR imaging revealed only 84 lesions on GRE T1WI and 106 lesions on FSE T2WI with fat suppression, while Gd-DTPA dynamic enhanced GRE T1WI revealed 123 lesions. For 44 micro-lesions (< 1.0 cm) in all patients the detection rates were as follows: ferucarbotran-enhanced FSE T2WI with fat suppression, 93.2% (41/44); ferucarbotran-enhanced GRE T2*WI, 88.6% (39/44); Gd-DTPA dynamic-enhanced GRE T1WI, 79.5% (35/44); pre-contrast FSE T2WI with fat suppression, 54.5% (24/44); and pre-contrast GRE T1WI, 34.1% (15/44). In detecting micro-lesions, statistically significant difference was found for Ferucarbotran- enhanced FSE T2WI with fat suppression and GRE T2*WI sequences compared to the other sequences (P < 0.05).CONCLUSION: Ferucarbotran-enhanced FSE T2WI with fat suppression and GRE T2*WI sequences are superior in detecting micro-lesions (< 1 cm) in comparison with plain and Gd-DTPA dynamic-enhanced MR imaging.     

磁共振扩散加权成像对肝癌的诊断及鉴别诊断作用

目的:探讨磁共振扩散加权成像对肝癌诊断及鉴别诊断的作用.方法:选取肝脏占位性病变88例,其中原发性肝细胞癌28例,转移瘤15例,肝血管瘤33例,肝囊肿12例.应用不同的b值分别行轴位扩散加权成像扫描,在拟合出的ADC图上分别测出ADC值并进行统计分析.结果:随着b值或b值差的增大,肝脏占位病变的ADC值明显减小,而且波动范围减小,b值越大时越接近实际DC值.采用b值差为500时各组病变的ADC值作为肝脏占位病变的ADC平均值.肝囊肿(3.24±0.68)ADC值明显高于原发性肝癌(1.20±0.32)、血管瘤(2.01±0.53)和转移瘤(1.57±0.42)(P<0.01).血管瘤ADC值显著高于原发性肝癌(P<0.01)及转移瘤(P<0.05).转移瘤ADC值高于原发性肝癌,但无统计学意义(P>0.05).结论:ADC值的应用可大大提高MRI对肝癌的诊断和鉴别诊断能力.