磁共振ADC值联合血液生化学指标诊断肝纤维化的临床初探

目的探讨磁共振表观扩散系数(ADC)值联合血液生化学指标诊断肝纤维化的临床价值。资料与方法利用扩散成像技术检测41例慢性肝病患者磁共振ADC值(b=600s/mm2),同时测量透明质酸(HA)并计算肝纤维化诊断预测模型Forns和APRI指数。以肝纤维化病理分期作为金标准,应用受试者工作特征(ROC)曲线分析以上指标诊断肝纤维化的价值。用Logistic回归综合两指标信息,根据ROC曲线确定诊断界值,分析其诊断肝纤维化的价值。结果在判断S≥2肝纤维化时,ADC值、HA、Forns和APRI的曲线下面积(Az)分别为0.88、0.80、0.72和0.76;在判断S≥3肝纤维化时,Az分别为0.93、0.84、0.77和0.74。而在判断S≥2肝纤维化时ADC+HA、ADC+Forns和ADC+APRI两两联合诊断时的Az分别为0.93、0.93和0.92;在判断S≥3肝纤维化时,Az分别为0.96、0.95和0.94,且Logistic回归方法的诊断敏感性和特异性比单个指标诊断均有所提高。结论ADC值与血液生化学多指标联合建立Logistic回归模型,和单独检测相比诊断准确性提高,可供临床参考。     

钆塞酸二钠增强T1-mapping 成像和DWI对肝纤维化分期的评估价值

【摘要】目的：探讨钆塞酸二钠（Gd-EOB-DTPA）增强T1-mapping成像和DWI对肝纤维化分期的评估价值。方法：共99例被检者符合入组标准并纳入研究,其中对照组23例（健康志愿者,S0）,病例组76例。病例组中,慢性乙型肝炎肝纤维化S1期13例,S2期13例,S3期26例,S4期24例。采用Look-Locker序列于增强前及Gd-EOB-DTPA增强后20min（肝胆期）采集T1-mapping图像,并测量肝组织弛豫时间T1,同时计算肝胆期弛豫时间T1减低率（ΔT1）。进行DWI检查并测量肝脏ADC值。采用单因素方差分析比较不同组别ADC值、ΔT1及肝胆期弛豫时间T1（T1HBP）。应用ROC曲线分析ADC、T1HBP、ΔT1对肝纤维化≥S2期、≥S3期的诊断效能。采用Spearman相关分析评价各参数与肝纤维化分期的相关性。结果：S0组（对照组）的ADC、T1HBP、ΔT1分别为（1.57±0.16）×10-3mm2/s、( 239.08±20.63)ms、( 69.24±4.64)% ;S1组分别为( 1.44±0.12)×10-3mm2/s、(273.57±53.75)ms、( 64.27±9.94)% ;S2组分别为( 1.31±0.12)×10-3mm2/s、( 375.74±97.86)ms、(61.14±5.61)% ;S3组分别为( 1.18±0.09)×10-3mm2/s、( 561.59±56.55)ms、( 38.76±6.08)% ;S4组分别为( 1.03±0.08)×10-3mm2/s、( 564.69±68.62)ms、 ( 37.01±6.80)% 。S0、S1、S2、S3、S4组的ADC值、ΔT1 和T1HBP均具有统计学差异(P均＜0.05)。ADC值、ΔT1和T1HBP诊断肝纤维化≥S2期的曲线下面积（AUC）分别为0.903,0.987,0.984;诊断肝纤维化≥S3期的AUC分别是0.817,0.930,0.847。ADC值与肝纤维化分期呈负相关（r=－0.790,P=0.000）,T1HBP与肝纤维化分期呈正相关（r=0.822,P=0.000）,ΔT1与肝纤维化分期呈负相关（r=－0.832,P=0.000）。结论:Gd-EOB-DTPA增强T1-mapping成像和DWI对肝纤维化分期的评估具有一定的价值。     

瞬时弹性成像联合血清学标志物检测对肝纤维化的诊断效能分析

目的 血清学标志物联合检测对提高瞬时弹性成像技术(FibroScan)对肝纤维化诊断性能的影响.方法 选取慢性HBV感染患者313例,进行常规生化学检测、FibroScan检测及肝活检,绘制受试者工作特征(ROC)曲线,分析曲线下面积(AUROC),确定FibroScan、APRI、FIB-4诊断不同程度肝纤维化的界值...     

磁共振扩散加权成像联合Gd-EOB-DTPA定量分析肝纤维化

目的 探讨磁共振扩散加权成像(DWI)联合肝特异性对比剂Gd-EOB-DTPA评估肝纤维化的价值.方法 对79例慢性肝炎患者行DWI及Gd-EOB-DTPA肝胆期成像,分别测量及计算其表观扩散系数(ADC)和肝胆期相对强化值(RE).采用Logistic回归分析RE、ADC与肝纤维化病理分期的相关性.以肝纤维化S≥2和S≥3为阳性标准,分别对ADC组、RE组及ADC+ RE组行受试者工作特征曲线(ROC)分析,曲线下面积(AUC)两两分析采用Z检验.结果 经Logistic回归分析,RE、ADC均为S≥2和S≥3级肝纤维化的独立影响因素.在诊断S≥2时,ADC组AUC为0.861,以ADC=0.56×10-3 mm2/s为阈值,其敏感度为83.33％,特异度为85.71％;RE组AUC为0.771,以RE=1.03为阈值,其敏感度为86.67％,特异度为71.43％;ADC+RE组AUC为0.922,以Logit(P) =8.16为阈值,其敏感度为90.00％,特异度为91.84％.在诊断肝纤维化S≥3时,ADC组AUC为0.807,以ADC=0.53×10-3 mm2/s为阈值,其敏感度为86.96％,特异度为78.57％,;RE组AUC为0.748,以RE=0.89为阈值,其敏感度为78.26％,特异度为76.79％;ADC+ RE组AUC为0.906,以Logit(P)=8.73为阈值,其敏感度为82.61％,特异度为89.29％.除诊断S≥3时ADC组敏感度最高外,ADC+ RE组在诊断肝纤维化S≥2、S≥3时敏感度、特异度及AUC均较单一指标更高,且其AUC分别与ADC组(Zs2 =2.352、Zs3 =2.158)和RE组(Zs2 =2.465、Zs3=2.487)两两比较有统计学差异(P＜0.05).结论 ADC及RE均能用于量化评估肝纤维化,2个指标联合评估能明显提高判定效能.     

ADC值联合肝纤四项对肝纤维化分期的评估

目的 评价MRI扩散加权成像(DWI)联合肝纤四项对肝纤维化评价的准确性.方法 将弥漫性肝病行腹部MRI检查(包括DWI)的患者30例作为研究对象.依炎症活动度(G)、纤维化程度(S)分级,将患者分为G0S0期、G1(S1～S2)期、G2(S1～S3)期、G3(S2～S4)期和G4S4期,分析扩散敏感系数(b值)分别为600 s/mm2和800 s/mm2时,不同病理分期患者表观扩散系数(ADC)值的变化;同时检测患者血清中透明质酸(HA)、Ⅲ型前胶原(PCⅢ)、Ⅳ型胶原(C-Ⅳ)和层黏连蛋白(LN)的变化,结合ADC值进行分析.结果 随肝纤维化程度加重,ADC值依次降低;随ADC值的变化,血清肝纤四项指标水平也呈现不同的变化.结论 ADC值联合血清肝纤维化指标能够准确评估肝纤维化分期.     

3.0T MR弥散加权成像评价肝纤维化的临床应用

目的 探讨肝脏弥散加权成像ADC值评价肝纤维化程度的临床应用价值.方法 选取肝纤维化、肝硬化患者50例及正常人14例行肝脏常规MRI及DWI,依据纤维化程度分为6组:S0(14例)、S1(9例)、S2(14例)、S3(7例)、S4(3例)、肝硬化(17例).DWI采用4个b值(b=300,600,800,1000 s/mm2)成像,ADC分析软件进行图像后处理,获得平均ADC值.Spearman相关分析评价ADC值与肝纤维化程度的相关性.ROC曲线分析各b值条件下ADC值诊断S≥1、S≥2、 S≥3及肝硬化的效力.结果 肝脏ADC值与肝纤维化程度显著负相关(P＜0.001),4个b值条件下,ADC值在不同程度肝纤维化组间的差别均有统计学意义(P＜0.01).ROC分析结果显示各b值条件下,ADC值用来评价纤维化程度均有统计学意义(P＜0.05),诊断S≥3时的AUC相对最高;诊断同一程度纤维化时,以b取600 s/mm2时,AUC相对较高,但各b值下AUC的95%置信区间有交叉.b取600 s/mm2时,以ADC值≤1.489×10-3mm2/s为标准,诊断S≥1的灵敏度为84%,特异度为78.6%,准确性为84.4%;取1.453×10-3mm2/s为诊断界值,ADC诊断S≥2的 灵敏度为80.5%,特异度为73.9%,准确性 为83.5%;以ADC值≤1.414×10-3mm2/s为标准,诊断S≥3的灵敏度为81.5%,特异度为73%,准确性85.5%;以ADC值≤1.339×10-3mm2/s为标准,诊断肝硬化的灵敏度70.6%,特异度87.2%,准确性82.4%.结论 MR-DWI可以定量评价肝纤维化,有一定的临床应用价值.     

DWI和~1H-MRS在肝纤维化中的诊断价值

目的:探讨扩散加权成像(DWI)与氢质子波谱分析(1 H-MRS)在肝纤维化中的诊断价值。方法:使用腹腔注射CCl4溶液法诱导建立兔肝纤维化模型并进行DWI和1 H-MRS检查。DWI使用SE-EPI序列(b1=0s/mm2,b2=600s/mm2),1 H-MRS使用单体素点分辨波谱分析(PRESS)序列(TR 1500ms,TE 35ms),测量表观扩散系数(ADC)值及胆碱(Cho)和脂质(lipid)波峰下面积的比值(Cho/lipid)。以病理学肝纤维化分期为基础,将兔划分为无肝纤维化组(S0)、轻度-中度纤维化组(S1-S2)和重度纤维化及肝硬化组(S3-S4),比较不同组间ADC值和Cho/lipid变化规律。结果:随肝纤维化程度加重,ADC值依次降低(P<0.01),Cho/lipid依次升高(P<0.05);重度纤维化及肝硬化组与另两组ADC值及Cho/lipid差异均具有统计学意义(P均<0.05)。结论:DWI和1 H-MRS具备一定的定量肝纤维化及检测重度纤维化及肝硬化的能力。     

CT 对比剂对肾脏影响的 MRI 研究

目的：利用磁共振扩散加权成像(DWI)和横向弛豫时间值成像(T2 mapping)技术研究 CT对比剂对肾脏的影响。方法在3.0T 磁共振扫描仪上对13只健康雄性新西兰大白兔进行连续3 h 的 MRI 检查,检查序列包括 DWI 和 T2 mapping 序列。然后,将图像传输到工作站上进行后处理,得到肾脏皮质和外髓的横向弛豫时间(T2)值和表观扩散系数(ADC)值。结果肾脏外髓部分的 ADC 值在注射 CT 对比剂后的第20 min 时开始下降,并持续近3 h。肾脏皮质的 ADC 值在注射对比剂后的第20 min 时开始上升,并在第60 min 时结束。肾脏皮质和外髓的 T2值在基准值上下波动。结论注射对比剂后,肾脏实质内 T2值没有显著变化。但是皮质的 ADC 值显著上升,外髓的 ADC 值显著下降。CT 对比剂导致了肾脏细胞内外水含量的改变。     

MR扩散加权联合动态增强评估乙型病毒性肝炎肝纤维化分级的研究

目的探讨肝ADC值联合肝动脉灌注指数(HPI)诊断慢性乙型病毒性肝炎(CHB)肝纤维化分级的价值。方法前瞻性收集乙型肝炎病毒感染时间≥1年且准备行肝脏穿刺活检的69例CHB患者作为病例组,肝功能正常的健康体检者15例作为对照组。所有受试者均行上腹部DWI和动态增强(DCE)检查,分别测得肝ADC值和动脉灌注指数(HPI)值。病例组受试者行肝穿刺,并按照纤维化程度分为S0~S4级。采用单因素方差比较不同纤维化程度分级患者间肝脏ADC值、HPI值的差异,采用Spearman等级相关检验分析病例组肝脏纤维化程度与肝脏ADC值、HPI值的相关性,并采用ROC曲线分析肝脏ADC值和HPI值诊断肝纤维化的效能。结果病例组S0、S1、S2、S3及S4级分别有11、13、12、15及18例。对照组、S0级组、S1级组、S2级组、S3级组、S4级组患者的ADC值分别为(1.39±0.09)×10~(-3)、(1.39±0.08)×10~(-3)、(1.38±0.10)×10~(-3)、(1.20±0.06)×10~(-3)、(1.12±0.07)×10~(-3)、(1.01±0.07)×10~(-3)mm~2/s;HPI值分别为(0.23±0.04)、(0.23±0.03)、(0.26±0.03)、(0.29±0.03)、(0.36±0.07)、(0.41±0.05),各组间差异均有统计学意义(P均0.01)。病例组肝ADC值与肝脏纤维化程度呈高度负相关(r=-0.894,P0.01),HPI值与肝脏纤维化程度呈高度正相关(r=0.832,P0.01)。ADC值预测≥S1级、≥S2级、≥S3级、S4级肝纤维化的ROC下面积分别为0.893、0.991、0.966、0.952,HPI值预测上述分级肝纤维化的ROC下面积分别为0.924、0.928、0.943、0.905。结论肝ADC值较HPI值对肝纤维化程度区分有更高的诊断价值,二者联合应用可提升诊断效能。     

肝纤维化和肝硬化的MR扩散成像及与病理对照、CT灌注参数的相关性研究

目的利用扩散加权成像(DWI)检查技术测定肝纤维化和肝硬化患者表观扩散系数(ADC)值并与正常对照组及相应病理对照来反映肝纤维化程度,同时分析其与血流动力学指标的相关性。资料与方法分别对44例肝纤维化患者、49例肝硬化患者及46名正常对照者利用DWI(b=500s/mm2)技术进行ADC值测定,并与病理改变及CT灌注参数作对照研究。结果肝纤维化组、肝硬化组ADC值降低;对照组、S2、S3组ADC值逐渐降低;Child-PughA、B、C分级组中ADC值无差别;肝纤维化不同分级与Child-PughA、B、C分级组中S3组ADC值降低而ChildC组ADC升高;对照组及肝纤维化组ADC值均与CT灌注参数间无相关性;肝硬化组ADC值与CT灌注参数(BV、BF)正相关。结论b值为500s/mm2时可显示肝纤维化及肝硬化患者ADC值降低,肝硬化患者ADC值较肝纤维化患者ADC值升高与肝血流量增加有关。     

Diffusion-Weighted Imaging for Differentiation of Biliary Atresia and Grading of Hepatic Fibrosis in Infants with Cholestasis

ObjectiveTo determine whether the values of hepatic apparent diffusion coefficient (ADC) can differentiate biliary atresia (BA) from non-BA or be correlated with the grade of hepatic fibrosis in infants with cholestasis.Materials and MethodsThis retrospective cohort study included infants who received liver MRI examinations to evaluate cholestasis from July 2009 to October 2017. Liver ADC, ADC ratio of liver/spleen, aspartate aminotransferase to platelet ratio index (APRI), and spleen size were compared between the BA and non-BA groups. The diagnostic performances of all parameters for significant fibrosis (F3–4) were obtained by receiver-operating characteristics (ROCs) curve analysis.ResultsAltogether, 227 infants (98 males and 129 females, mean age = 57.2 ± 36.3 days) including 125 BA patients were analyzed. The absolute ADC difference between two reviewers was 0.10 mm²/s for both liver and spleen. Liver ADC value was specific (80.4%) and ADC ratio was sensitive (88.0%) for the diagnosis of BA with comparable performance. There were 33 patients with F0, 15 with F1, 71 with F2, 35 with F3, and 11 with F4. All four parameters of APRI (τ = 0.296), spleen size (τ = 0.312), liver ADC (τ = −0.206), and ADC ratio (τ = −0.288) showed significant correlation with fibrosis grade (all, p < 0.001). The cutoff values for significant fibrosis (F3–4) were 0.783 for APRI (area under the ROC curve [AUC], 0.721), 5.9 cm for spleen size (AUC, 0.719), 1.044 × 10⁻³ mm²/s for liver ADC (AUC, 0.673), and 1.22 for ADC ratio (AUC, 0.651).ConclusionLiver ADC values and ADC ratio of liver/spleen showed limited additional diagnostic performance for differentiating BA from non-BA and predicting significant hepatic fibrosis in infants with cholestasis.     

脾脏硬度对肝硬化食管静脉曲张的预测价值

目的评估脾脏硬度对肝硬化患者食管静脉曲张(EV)的预测价值。资料与方法回顾性分析80例慢性乙肝肝硬化患者的胃镜检查、Fibro Touch检查与血清学检查资料。以胃镜检查结果为“金标准”,将患者分为EV组和非EV组,比较两组患者肝脏硬度值(LSM)和脾脏硬度值(SSM);计算纤维化4项指标(FIB-4)、天冬氨酸氨基转移酶与血小板比率指数(APRI);探讨4项指标的相关性,并比较SSM、LSM单独及与血清学指标联合预测EV的价值。结果66例EV组患者LSM、SSM、APRI、FIB-4明显高于14例非EV组,差异均有统计学意义(P<0.05)。SSM与LSM、APRI、FIB-4均呈正相关(r=0.680、0.415、0.227,P<0.05)。Logistic回归分析结果显示,仅SSM是预测EV的影响因素(P=0.001)。LSM、SSM、FIB-4、APRI预测EV的受试者工作特征曲线下面积(AUC)分别为0.816、0.880、0.733、0.732。SSM的AUC显著大于FIB-4和APRI(P<0.05),但与LSM相比差异无统计学意义(P>0.05)。联合指标LSM+FIB-4、LSM+APRI、SSM+APRI、SSM+FIB-4预测EV的AUC分别为0.832、0.832、0.878、0.887。SSM+FIB-4联合诊断模型的AUC最高,显著高于单项血清学指标(P<0.05),但与LSM、SSM及其他联合指标比较差异无统计学意义(P>0.05)。结论应用Fibro Touch测量SSM可有效预测慢性乙肝肝硬化患者EV的存在,其预测价值与LSM相似。     

体素内不相干运动联合扩散峰度成像对乳腺癌HER-2表达的判断价值

目的 探讨体素内不相干运动成像(IVIM)联合扩散峰度成像(DKI)对乳腺癌HER-2表达状态的诊断价值.方法 选取本院经病理证实的乳腺癌患者201例,HER-2阳性组106例,HER-2阴性组95例,所有病例均行IVIM及DKI检查.分析两组间的临床病例资料和表观扩散系数(ADC)、真实扩散系数(D)、灌注相关扩散系...     

体素内不相干运动扩散加权成像在良性脑膜瘤中的初步研究

目的 探讨多b值体素内不相干运动扩散加权磁共振成像（introvoxel incoherent motion MR imaging,IVIM MRI）的单、双指数模型在良性脑膜瘤中的应用价值.方法 纳入22例手术病理证实为良性脑膜瘤并术前行常规MR序列及IVIM序列扫描的患者.多b值IVIM序列包括14个b值（0～1 000s/mm2）,所得IVIM序列原始数据经单、双指数模型处理,得到单、双指数模型衰减曲线,并生成对应参数图,测量肿瘤实质区及正常脑白质的单指数模型的扩散系数ADC值和双指数模型的扩散系数D值、灌注分数f值、灌注系数D＊值,采用配对样本t检验进行统计学分析.结果 单、双指数模型衰减曲线显示肿瘤实质区信号强度随b值的增大而衰减.肿瘤实质区ADC值、D值、D＊值、f值分别为（0.87±0.13）μm2/ms、（0.79±0.10）μm2/ms、（58.68±27.52）μm2/ms、（7.68±3.59）％;正常脑白质的ADC值、D值、D＊值、f值分别为（0.74±0.06）μm2/ms、（0.69±0.04）μm2/ms、（93.43±31.64）μm2/ms、（4.48±2.39）％.单指数模型中肿瘤实质区ADC值较正常脑白质ADC值两者比较差异有统计学意义（t=5.793,P＜0.05）;双指数模型中,肿瘤实质与正常脑白质D、f、D＊值分别进行比较,肿瘤实质的D、f值均较正常脑白质增高（t=4.384,P＜0.05和t=3.349,P＜0.05）;而肿瘤实质D＊值较正常脑白质D＊值减低（t=-3.559,P＜0.05）.肿瘤实质区单指数模型ADC值与双指数模型D值两者差异有统计学意义,且单指数ADC值显著较双指数模型D高（t=6.492,P＜0.05）.结论 基于棠规DWI序列的多b值IVIM双指数模型可以更准确地描述良性脑膜瘤的扩散信息,同时非侵入性地获得肿瘤灌注信息.     

Diagnosis of cirrhosis with intravoxel incoherent motion diffusion MRI and dynamic contrast‐enhanced MRI alone and in combination: Preliminary experience

Purpose:

To report our preliminary experience with the use of intravoxel incoherent motion (IVIM) diffusion‐weighted magnetic resonance imaging (DW‐MRI) and dynamic contrast‐enhanced (DCE)‐MRI alone and in combination for the diagnosis of liver cirrhosis.

Materials and Methods:

Thirty subjects (16 with noncirrhotic liver, 14 with cirrhosis) were prospectively assessed with IVIM DW‐MRI (n = 27) and DCE‐MRI (n = 20). IVIM parameters included perfusion fraction (PF), pseudodiffusion coefficient (D*), true diffusion coefficient (D), and apparent diffusion coefficient (ADC). Model‐free DCE‐MR parameters included time to peak (TTP), upslope, and initial area under the curve at 60 seconds (IAUC60). A dual input single compartmental perfusion model yielded arterial flow (Fa), portal venous flow (Fp), arterial fraction (ART), mean transit time (MTT), and distribution volume (DV). The diagnostic performances for diagnosis of cirrhosis were evaluated for each modality alone and in combination using logistic regression and receiver operating characteristic analyses. IVIM and DCE‐MR parameters were compared using a generalized estimating equations model.

Results:

PF, D*, D, and ADC values were significantly lower in cirrhosis (P = 0.0056–0.0377), whereas TTP, DV, and MTT were significantly increased in cirrhosis (P = 0.0006–0.0154). There was no correlation between IVIM‐ and DCE‐MRI parameters. The highest Az (areas under the curves) values were observed for ADC (0.808) and TTP‐DV (0.952 for each). The combination of ADC with DV and TTP provided 84.6% sensitivity and 100% specificity for diagnosis of cirrhosis.

Conclusion:

The combination of DW‐MRI and DCE‐MRI provides an accurate diagnosis of cirrhosis. J. Magn. Reson. Imaging 2010;31:589–600. © 2010 Wiley‐Liss, Inc.     

T1rho值对四氯化碳模型大鼠肝纤维化演变过程及严重程度的评估价值

目的探讨肝脏旋转坐标系下的自旋晶格弛豫时间(T1rho)值在四氯化碳(CCl4)建模大鼠肝纤维化进展及转归过程中的变化及对肝纤维化分期的价值。方法选取80只Sprague-Dawley大鼠采用随机数字表法分为3组,分别为CCl4组49只、恢复组20只、对照组11只,将大鼠分别标记行MRI基线扫描。CCl4组及恢复组大鼠经颈背部皮下注射CCl4进行建模,CCl4组于注药后4、6、8、10、12周末分别进行黑血T1rho扫描;恢复组大鼠于注药后4、6周末进行黑血T1rho扫描,第6周末扫描结束后停止注药,停止注药后1、2、4、6周末分别进行扫描;对照组于相同时间点注射等量玉米油,并于注射后第4、6、8、10、12周末分别进行黑血T1rho扫描。测量所有大鼠肝脏T1rho值,观察各组大鼠肝脏T1rho值随时间的变化。采用独立样本t检验比较各组大鼠相邻时间点肝脏T1rho值的差异。将实验鼠分为无肝纤维化组(S0)、轻度肝纤维化组(S1、2)及中重度肝纤维化组(S3、4),采用Kruskal-Wallis H检验分析3组间T1rho值间的差异,用受试者操作特征(ROC)曲线评估T1rho值对不同程度肝纤维化的诊断效能,采用Spearman检验评估T1rho值与肝纤维化严重程度的相关性。结果59只大鼠完成了整个实验,其中CCl4组28只、恢复组20只、对照组11只。CCl4组大鼠肝脏T1rho值随着注药时间的延长逐渐增加,8周末达到最大值,随后8~12周逐渐下降,除4周末与6周末、10周末与12周末大鼠肝脏的T1rho值差异无统计学意义(P值分别为0.112、0.487),其他相邻两个时间点大鼠肝脏T1rho值差异均有统计学意义(P均<0.05);恢复组大鼠肝脏T1rho值随着注药时间的延长逐渐上升,停止CCl4注射后肝脏T1rho值逐渐下降,相邻两个时间点大鼠肝脏T1rho值差异均有统计学意义(P均<0.05);对照组大鼠相邻时间点肝脏T1rho值差异均无统计学意义(P均>0.05)。无肝纤维化组(S0)、轻度肝纤维化组(S1、2)及中重度肝纤维化组(S3、4)大鼠分别为15、23、21只,T1rho值分别为[36.3(34.4,41.4)]、(47.2±8.4)、(48.8±9.0)ms,大鼠肝脏T1rho值随着肝纤维化程度的加重而加重,二者呈低度正相关(r=0.402,P=0.001);上述3组大鼠肝脏T1rho值间差异有统计学意义(P<0.01)。肝脏T1rho值鉴别无肝纤维化(S0)与有肝纤维化(S1~4)的ROC下面积为0.825(95%可信区间0.720~0.931),鉴别无或轻度肝纤维化(S0~2)与中重度肝纤维化(S3、4)的ROC下面积为0.668(95%可信区间0.540~0.796)。结论T1rho值对评估CCl4建模大鼠肝纤维化进展及转归有一定意义,对鉴别是否存在肝纤维化诊断价值中等,对鉴别轻度肝纤维化与中重度肝纤维化诊断价值较低。     

Chronic hepatitis: role of diffusion-weighted imaging and diffusion tensor imaging for the diagnosis of liver fibrosis and inflammation

PURPOSE: To determine the diagnostic performance of liver apparent diffusion coefficient (ADC) measured with conventional diffusion-weighted imaging (CDI) and diffusion tensor imaging (DTI) for the diagnosis of liver fibrosis and inflammation. MATERIALS AND METHODS: Breathhold single-shot echo-planar imaging CDI and DTI with b-values of 0 and 500 second/mm(2) was performed in 31 patients with chronic liver disease and 13 normal volunteers. Liver biopsy was performed in all patients with liver disease with a median delay of two days from MRI. Fibrosis and inflammation were scored on a 5-point scale (0-4). Liver ADCs obtained with CDI and DTI were compared between patients stratified by fibrosis stage and inflammation grade. Receiver operating characteristic (ROC) curve analyses were conducted to evaluate the utility of the ADC measures for prediction of fibrosis and inflammation. RESULTS: Patients with liver fibrosis and inflammation had significantly lower liver ADC than subjects without fibrosis or inflammation with CDI and DTI. For prediction of fibrosis stage > or = 1 and stage > or = 2, area under the ROC curve (AUC) of 0.848 and 0.783, sensitivity of 88.5% to 73.7%, and specificity of 73.3% to 72.7% were obtained, for ADC < or =1.40 x 10(-3) mm(2)/second and < or =1.30 x 10(-3) mm(2)/second (using CDI), respectively. For prediction of inflammation grade > or = 1, AUC of 0.825, sensitivity of 75.0%, and specificity of 78.6% were obtained using ADC < or = 1.30 x 10(-3) mm(2)/second (using CDI). CDI performed better than DTI for diagnosis of fibrosis and inflammation. CONCLUSION: Liver ADC can be used to predict liver fibrosis and inflammation with acceptable sensitivity and specificity.     

DWI及声辐射力脉冲成像在肝纤维化诊断中的价值

目的对比DWI和声辐射力脉冲成像(acoustic radiation force impulse imaging,ARFI)对肝纤维化的诊断价值。方法对50例肝纤维化患者(观察组)及16例健康志愿者(正常对照组)行DWI(b=0、600s/mm 2)扫描,并测量ADC值;2组同时行ARFI检查,检测指标为低频剪切波传播速度(shear wave velocity,SWV)。分析并对比不同组间ADC值和SWV的变化规律。结果SWV波速随肝脏纤维化分期(从S0~S4期)升高而递增,而ADC值则呈降低趋势(P<0.05)。肝纤维化各组与正常对照组间比较差异均有统计学意义,肝纤维化各组组间比较差异均有统计学意义。结论在肝纤维化定量中,ARFI和DWI均具备一定的检测能力。在诊断肝纤维化敏感度方面,ARFI高于DWI;而在特异度方面,DWI优于ARFI,两者皆可检测重度肝纤维化及肝硬化。     

Compartmentation of intracellular water in multicellular tumor spheroids: diffusion and relaxation NMR.

Diffusion and relaxation of water in C6 glioma and MLS human ovarian carcinoma spheroids were measured from 1D projections acquired using a 2D diffusion-relaxation correlation pulse sequence and processed by non-negative least-square (NNLS) analysis. Systematic underestimation of I(s) and ADC(s) were observed for I(s)/(I(s) + I(f)) < 0.001. In the presence of spheroids, two apparent diffusion coefficient (ADC) compartments were observed, where ADC(f), ADC(s), and I(f), I(s) are the respective ADCs and signal intensities of the fast and slow compartments. These compartments differed also in their T(2) relaxation (ADC(s) = 0.5-0.74 x 10(-5) cm(2)/s, T(2) = 36-45 ms; and ADC(f) = 2.2-2.8 x 10(-5) cm(2)/s, T(2) = 280-316 ms). The two ADC compartments and the slow T(2) compartment were consistent with slow exchange. The fast T(2) compartment showed a drift with diffusion weighting, suggesting that it represents water exchanging between compartments that differ in their ADC and T(2). Both ADC(s) and I(s) were markedly attenuated with increasing diffusion time (Delta) for Delta < 100 ms, and increased at longer Delta. These results are consistent with restricted diffusion and fast relaxation of intracellular water for short diffusion time (T(1)' = 46.6 ms), and with predominant extracellular contribution to ADC(s) at longer diffusion times. Magn Reson Med 46:68-77, 2001.