单、双指数扩散加权成像联合动态增强磁共振成像对乳腺TIC Ⅱ型良恶性病变的鉴别诊断价值

目的 探讨单、双指数扩散加权成像联合动态增强磁共振成像(DWI+IVIM+DCE-MRI模型)对TICⅡ型乳腺良恶性病变的诊断价值方法 回顾性分析经病理证实的乳腺肿块患者115例,TICⅡ型良性组30例,恶性组85例,所有病例均行DWI、IVIM及DCE-MRI检查。分析两组间的表观扩散系数(ADC)、纯扩散系数(D)、灌注相关扩散系数(D^*)、灌注分数(f)及容量转移常数(K^trans)、血管外细胞外间隙容积比(V_e)、速率常数(K_ep)值;绘制ROC曲线比较其诊断效能。结果 TICⅡ型良性组ADC、D值高于恶性组,而K^trans、K_ep、V_e值低于恶性组,差异有统计学意义(P<0.05)。ADC、D、K^trans、K_ep、V_e的AUC差异不具有统计学意义(Z=0.01～1.64,P>0.05),但D值的特异度及准确度最高。DWI模型的AUC为0.725,...     

体素不相干运动与三维动脉自旋标记在胶质瘤中的对照研究

目的 与三维动脉自旋标记(3D ASL)对照,探讨体素不相干运动(IVIM)在胶质瘤分级中的应用价值.方法 搜集胶质瘤患者24例,其中高、低级别胶质瘤患者分别为13例和11例.受试者术前行多b值DWI(MBDWI)和三维伪连续动脉自旋标记(3D PCASL)序列扫描,MB-DWI采用0～3500 s/mm2间共20个b值,采用双指数模型软件处理获得快扩散系数D*(fast ADC),慢扩散系数D(slow ADC)以及快速扩散所占的容积分数f(fraction of fast ADC)三种参数化图像;ASL数据经工作站处理产生的脑血流量(CBF)图.分别测量肿瘤实质区最大CBF值及其相应区域的D*、D、f值,以对侧正常半卵圆中心白质做对照,计算其比值rTBF,rD*,rD,rf.所得数据经统计软件进行组间比较并对CBF值与D *、f值进行相关性分析,P＜0.05具有统计学意义.结果 高级别胶质瘤组的TBF值、rTBF和D*值显著高于低级别胶质瘤组,f值、rf值和D值、rD值正好相反,rD *值无统计学差异;相关分析结果显示肿瘤TBF值与D*值呈正相关性,而与f值呈负相关(P＜0.05);对侧正常半卵圆中心CBF值和D*值呈正相关性(P＜0.01),而与f值无相关性(P＞0.05).结论 IVIM双指数模型所得D*值、D值及f值在高、低级别胶质瘤中存在统计学差异,在评估脑胶质瘤血流灌注方面D*值与ASL结果之间有较好的相关性.     

体素内不相干运动DWI对子宫内膜癌术前肿瘤分级评估

【摘要】目的:探讨体素内不相干运动扩散加权成像在子宫内膜癌术前肿瘤分级中应用价值。方法:搜集49例子宫内膜癌患者行单指数模型及双指数模型DWI检查,其中G1组15例,G2组20例,G3组14例。利用Matlab软件测量所有病例的纯扩散系数(D)值、灌注相关扩散系数(D*)值、灌注分数(f)值及表观扩散系数（ADC）值。分析评估各参数值与子宫内膜癌肿瘤分级之间相关性。比较不同病理级别各参数值差异,采用ROC曲线分析ADC值及D值鉴别G3级子宫内膜癌诊断效能。结果:ADC值及D值与子宫内膜癌病理分级之间均呈负相关(r=-0.362及-0.373,P=0.011及0.021)。G1、G2及G3组间D值(F=8.887,P=0.001)及ADC值（F=6.205,P=0.004）差异有统计学意义。ADC值及D值在G1与G3、G2与G3之间有显著差异,而在G1与G2之间无显著差异。ADC值及D值鉴别G3级和G1～2级子宫内膜癌曲线下面积分别为0.773及0.806。据最佳诊断切点值,ADC值及D值鉴别诊断G3级子宫内膜癌的敏感度分别为64.29%及92.86%,特异度80.00％及65.71%,阳性预测值分别为56.25%及52.00%,阴性预测值分别为84.85%及95.80%,诊断准确度分别为75.51%及73.47%。结论：ADC值和D值均有助于术前评估子宫内膜癌病理分级,且在鉴别G3级子宫内膜癌中具有相似诊断效能。     

IVIM成像与DWI在乳腺良恶性病变鉴别诊断中的比较

目的 比较体素内不相干运动(IVIM)成像双指数模型、拉伸指数模型与扩散加权成像(DWI)单指数模型各参数在乳腺良恶性病变鉴别诊断中的价值.方法 回顾性分析257例经病理证实的乳腺病变患者(共276个病灶,包括197个恶性病变,79个良性病变).所有患者均行MRI常规检查及多b值DWI检查,获得传统DWI及IVIM各参数.比较各参数在正常乳腺组织、乳腺良性病变及恶性病变中的统计学差异,采用受试者工作特征(ROC)曲线确定各参数诊断乳腺恶性病变的阈值以及曲线下面积(AUC)、诊断敏感性和特异性.结果 正常乳腺组织、乳腺良性病变及恶性病变的表观扩散系数(ADC)、慢速表观扩散系数(slow ADC)、快速表观扩散系数(fast ADC)、灌注分数(f)、扩散分布指数(DDC)及扩散异质性指数(α)值均有统计学差异(P<0.001).ADC、slow ADC、f、DDC和α的AUC分别为0.865、0.861、0.742、0.85和0.735;ADC、slow ADC、DDC和α的最佳诊断阈值分别为1.105×10-3 mm2/s,0.883×10-3 mm2/s,1.025×10-3 mm2/s和0.842,slow ADC敏感性最高(90.3%),DDC特异性最高(79.5%).双指数模型中slow ADC与fast ADC联合诊断的AUC为0.882;拉伸指数模型DDC与α联合诊断的AUC为0.853.结论 3种模型对于乳腺病变良恶性的鉴别都具有较高的价值,传统ADC的诊断准确性较高,slow ADC敏感性较高,DDC特异性较高.双指数模型中slow ADC与fast ADC联合诊断具有较高的价值.     

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.     

MR体素内不相干运动成像评价宫颈癌组织学特征的初步研究

目的 探讨MR体素内不相干运动(IVIM)成像评价宫颈癌组织学特征的可行性.方法 搜集24例宫颈癌患者(宫颈癌组)和24例因盆腔其他病变检查而宫颈正常者(宫颈正常组)的MRI资料.所有患者均行MR常规序列及IVIM序列扫描,测量宫颈癌组和宫颈正常组的标准表观扩散系数(ADC)、慢表观扩散系数(D)、快表观扩散系数(D*)和f值.比较宫颈癌与正常宫颈、宫颈癌不同病理类型以及不同病理分级上述各参数值的差异,采用受试者工作特征(ROC)曲线下面积评价各参数值的诊断效能.结果 宫颈癌组的标准ADC值、D值、f值均低于宫颈正常组,差异有统计学意义(P=0.000、0.000、0.001),ROC曲线下面积分别为0.872、0.848和0.762.宫颈鳞癌组的标准ADC值、D值、f值均低于官颈腺癌组,D*值高于宫颈腺癌组,差异有统计学意义(P=0.000、0.037、0.004、0.000),ROC曲线下面积分别为0.938、0.975、0.900和0.938.宫颈鳞癌高分化、中分化和低分化三组间标准ADC值、D值、D*值及f值差异无统计学意义(P=0.500、0.753、0.341、0.266).结论 IVIM成像能定量反映宫颈癌的组织学特征,具有临床应用价值.     

校正灌注因素后实际扩散系数评价肌炎不同病理阶段的扩散特征

目的 通过计算校正灌注因素后的实际扩散系数(D)和表观扩散系数(ADC)定量分析肌炎不同病理阶段的组织特征.资料与方法 对8名健康志愿者和10例肌炎患者行扩散加权成像(DWI),采用22个扩散敏感梯度进行扫描.用双指数函数拟合方法计算D、灌注体积分数(f)及灌注系数(D*).同时用单指数甬数方法计算ADC值.对正常肌肉、肌肉炎性病变、肌肉脂肪浸润和正常皮下脂肪等组织的扩散特点和微循环灌注特点进行分析.结果 正常肌肉、皮下脂肪、肌肉炎性改变及脂肪浸润等各组织的ADC值均高于D值.正常肌肉的ADC、D、f和D*值分别为(1.62±0.14)×10-3mm2/s、(1.44±0.10)×10-3mm2/s、0.11±0.07和(19.4±12.12)×10-3 mm2/s.肌肉炎性病变的D和ADC值均高于正常肌肉;肌肉脂肪浸润的D低于正常肌肉,明显高于皮下脂肪,肌肉脂肪浸润的ADC值虽低于正常肌肉,但与皮下脂肪差异无统计学意义.肌肉炎性病变的f值较小,与病理所示血管床密度减低一致;肌肉脂肪浸润的f值低于皮下脂肪,同时其D*低于正常肌肉和皮下脂肪.结论 DWI可定量评价肌炎不同病理阶段的组织特征,使得MRI对疾病的研究从形态学上升到病理生理学水平.校正灌注因素后的D值能够更准确地反映组织的扩散特征.     

磁共振扩散加权成像ADC值和eADC值与肝细胞癌血管生成的关系

目的 分析不同b值时肝细胞癌(hepatocellular carcinoma, HCC)的表观扩散系数(apparent diffusion coefficient, ADC)值和指数化表观扩散系数(exponential apparent diffusion coefficient, eADC)值、灌注ADC值和eADC值 (ADCperf值和eADCperf值)在评价肿瘤血管生成的价值.方法 选取行手术切除并经病理证实的肝细胞癌病例31例,手术前行DWI扫描并计算低、中、高b值时的ADC值、eADC值、ADCperf值和eADCperf值.利用免疫组化技术检测HCC边缘和中心VEGF、Flk-1的表达情况、PCNA指数及微血管和成熟血管的数目、平均面积、总面积、周长、直径、异型指数以及动脉数、静脉数、血管成熟指数和平均灌注分数等.将DWI各测量指标与以上血管参数进行对照分析.结果 在肝脏与HCC之间,中、高b值组ADC值和eADC值,及ADCperf值和eADCperf值存在统计学差异(P＜0.05).在病灶边缘与中心之间ADCperf值及eADCperf值均存在统计学差异(P＜0.05).在病灶边缘,低、中b值组内的ADC值与微血管平均面积均为正相关(P＜0.05),eADC值则与成熟血管平均面积负相关(P＜0.05).另外,病灶边缘的eADCperf值与动脉数呈正相关(P=0.048, r=0.558),在病灶中心,ADCperf值与微血管平均面积正相关(P=0.038, r=0.628).结论 低、中b值时ADC值和eADC值易受血管因素的影响,eADCperf值可作为评价HCC的动脉情况的简便的指标.     

单/双指数模型DWI评估裸鼠肺腺癌移植瘤早期化疗疗效的对比研究

目的:探讨单、双指数模型DWI评估裸鼠肺腺癌移植瘤早期化疗疗效的可行性和准确性,并筛选最佳参数.方法:在48只雌性裸鼠中建立肺腺癌移植瘤模型,并将其随机分为治疗组A及对照组B,A组和B组分别采用腹腔内注射顺铂和生理盐水.每组各随机抽取4只裸鼠(AM组、BM组)于4个时间点(第0、3、7和10天)行体素内不相干运动成像(IVIM-DWI),测量病灶的体积及表观扩散系数(ADC)、真实扩散系数(D)、灌注分数(f)和灌注相关扩散系数(D*).两组各16只裸鼠(AP、BP组)分别在对应的4个时间点每次随机抽取4只进行病理学检查.比较各组不同时间点肿瘤体积和DWI参数值,并采用受试者工作特征曲线(ROC)分析各参数值的诊断效能.结果:化疗第3、7、10天AM组肿瘤的ADC和D值较BM组明显升高,f值明显降低(P＜0.05).化疗第10天AM组肿瘤体积较BM组明显缩小(P＜0.05),而第3、7天肿瘤体积的差异无统计学意义(P＞0.05).治疗第3天各参数的ROC下面积依次是0.917(D)、0.833(ADC)和0.667(f);以D值＞1.02×10-3mm2/s作为阈值,敏感度和特异度分别为83.3％和100％;以ADC值＞1.08×10-3mm2/s作为阈值,敏感度和特异度分别为66.7％和100％.病理检查显示,在化疗第3、7和10天时AP组肿瘤细胞坏死和出血较BP组明显增多,AP组微血管密度(MVD)及细胞增殖抗原67(Ki67)的表达水平随时间延长而下降,AP组与BP组间MVD及Ki67表达水平分别在第7、10天及第3、7、10天时差异有统计学意义(P＜0.05).结论:肺腺癌移植瘤化疗后D、ADC和f值的改变早于肿瘤体积的变化;D值对肺腺癌早期化疗疗效的评价可能优于ADC值.     

脾脏体素不相干运动扩散加权成像在肝硬化Child-Pugh分级中的价值

目的初步探讨脾脏体素不相干运动扩散加权成像(IVIM-DWI)在肝硬化Child-Pugh分级中的应用价值。方法纳入观察60例肝硬化患者(Child-Pugh分级:A级20例,B级20例,C级20例),所有受试者均行脾脏多b值DWI检查。分别测量脾脏单指数[标准扩散系数(ADC-stand)]、双指数[慢速扩散系数(ADC-slow)、快速扩散系数(ADC-fast)和扩散分数(f)]及拉伸指数模型参数[分布扩散系数(DDC)和拉伸因子(α)],比较脾脏在肝硬化不同Child-Pugh分级间各参数值的差异;采用ROC曲线评价各参数值诊断阈值及效能。结果脾脏ADC-fast值在A、B、C级分别为9.021±0.171、7.781±0.131、6.665±0.152,组内两两比较差异有统计学意义(P0.05),分别选择合适的诊断阈值,可使上述敏感度及特异度均达到65.0%及以上。脾脏ADC-stand值、ADC-slow值、f值、DDC值、α值三组之间均无统计学意义。结论脾脏IVIM-DWI中的ADC-fast值有助于临床进行肝硬化程度分级。     

DWI对胰腺癌的诊断价值

目的：探讨磁共振扩散加权成像（DWI）及表观扩散系数（ADC）对胰腺癌诊断价值。方法：搜集胰腺癌患者35例,正常对照组共32例。DWI选用b值分别为50、400、700s／mm^2,分别测量胰腺癌组织、癌周胰腺组织及正常对照组的ADC值,并进行对比分析;分别测量胰腺癌组织在T2WI,DWI（b=400s／mm^2）及磁共振增强扫描图像中病灶最大直径,并进行分析。结果：3组b值所测得ADC值统计结果示胰腺癌组织与正常对照组、癌周胰腺组织之间均有统计学意义;正常对照组与癌周胰腺组织之间均无统计学意义。胰腺癌组织在T2WI,DWI（b=400s／mm^2）及动态增强图像中最大直径测量无统计学差异。结论：DWI可以较清楚地显示胰腺癌病灶,b值为400s／mm^2时图像效果最佳,与ADC值测定共同分析对胰腺癌病灶的检出有价值。     

Comparison of the Diagnostic Value of Mono-exponential,Bi-exponential,and Stretched Exponential Signal Models in Diffusion-weighted MR Imaging for Differentiating Benign and Malignant Hepatic Lesions

Purpose:To compare the diagnostic value of mono-exponential, bi-exponential, and stretched exponential diffusion-weighted imaging (DWI) for differentiating benign and malignant hepatic lesions.Methods:This prospective study was approved by our Institutional Review Board and the patients provided written informed consent. Magnetic resonance imaging was acquired for 56 patients with suspected liver disease. This identified 90 focal liver lesions with a maximum diameter >10 mm, of which 47 were benign and 43 were malignant. Using home-built software, two radiologists measured the DWI parameters of hepatic lesions for three models: the apparent diffusion coefficient (ADC) from a mono-exponential model; the true diffusion coefficient (D), pseudo-diffusion coefficient (D^*), and perfusion fraction (f) from a bi-exponential model; and the distributed diffusion coefficient (DDC) and water molecular diffusion heterogeneity index (α) from a stretched exponential model. The parameters were compared between benign and malignant hepatic lesions.Results:ADC, D, D^*, f, and DDC values were significantly lower for malignant hepatic lesions than for benign lesions (P < 0.0001–0.03). Although logistic regression analysis demonstrated that DDC was the only statistically significant parameter for differentiating benign and malignant lesions (P = 0.039), however, the areas under the receiver operating characteristic curve for differentiating benign and malignant lesions were comparable between ADC (0.98) and DDC (0.98) values.Conclusion:DDC values obtained from the stretched exponential model could be also used as a quantitative imaging biomarker for differentiating benign and malignant hepatic lesions, however, the diagnostic performance was comparable with ADC values.     

Residual tumour detection in post-treatment granulation tissue by using advanced diffusion models in head and neck squamous cell carcinoma patients

PurposeTo evaluate the detectability of the residual tumour in post-treatment granulation tissue using parameters obtained with an advanced diffusion model in patients with head and neck squamous cell carcinoma (HNSCC) treated by chemoradiation therapy.Materials and methodsWe retrospectively evaluated 23 patients with HNSCC after the full course of chemoradiation therapy. The diffusion-weighted image (DWI) acquisition used single-shot spin-echo echo-planar imaging with 11 b-values (0–1000). We calculated 10 DWI parameters using a mono-exponential model, a bi-exponential model, a stretched exponential model (SEM), a diffusion kurtosis imaging (DKI) model and a statistical diffusion model (SDM) in the region of interest (ROI) placed on the post-treatment granulation tissue. The presence of residual tumour was determined by histological findings or clinical follow-up.ResultsAmong the 23 patients, seven patients were revealed to have residual tumour. The univariate analysis revealed significant differences in six parameters between the patients with and without residual tumour. From the receiver operating characteristic curve analysis, the highest area under curve was detected in the center of the Gaussian distribution of diffusion coefficient (D_s) obtained by the SDM. The multivariate analysis revealed that the D_s and diffusion heterogeneity (α) obtained by the SEM were predictors for the presence of residual tumour.ConclusionDWI parameters obtained by advanced fitting models will be one of the diagnostic tools for the detection of residual tumour.     

经量化的扩散加权成像对肝脏占位性病变的鉴别诊断价值

目的：探讨经量化的扩散加权成像(DWI)在肝脏占位性疾病影像诊断中的价值。方法本组回顾性分析120例肝脏占位性病变患者及对照组12例正常肝脏的影像资料,应用3.0T MR 行常规 MR 及 DWI,120例患者共检出179个病灶(其中53个肝癌、61个转移瘤、32个肝血管瘤及33个肝囊肿),分析其与对照组的 DWI 图及表观扩散系数(ADC)图,并测量 ADC 值,比较其间是否存在统计学差异。结果本组研究 b 值选择800 s/mm2,(1)其中33个肝囊肿呈低信号,51个肝癌、61个肝转移瘤及32个肝血管瘤呈高信号,肝囊肿的 DWI 图像信号与肝癌、肝转移瘤及肝血管瘤有显著性差异(P <0.05);(2)肝癌、肝转移瘤 ADC 伪彩图大体呈冷色系表现,肝囊肿、肝血管瘤 ADC 伪彩图大体呈暖色系表现;(3)肝癌、肝转移瘤、肝血管瘤、肝囊肿平均 ADC 值相互间行两两比较,总体上存在统计学差异(P <0.05),但肝癌与肝转移瘤之间两两比较,无统计学差异(P >0.05),通过结合背景肝,比较肝癌的病灶/背景肝 ADC 值与肝转移瘤的病灶/背景肝 ADC 值,二者差异有显著性(P <0.05)。结论DWI 和 ADC 图分析及ADC 值测量可为肝脏占位性病的诊断及鉴别诊断提供重要的补充信息。     

Liver diffusion-weighted MR imaging: the tower of Babel?

There is a growing amount of literature regarding diffusion-weighted imaging (DWI) of the liver. The apparent diffusion coefficient (ADC) was introduced in 1986 and is used extensively in studies. However, methods for calculating ADC vary considerably and the value of the ADC strongly depends on the b values chosen for its calculation. Indeed, the ADC incorporates the effects of both diffusion and perfusion, which can vary independently. Since signal attenuation as a function of b follows a bi-exponential pattern, other diffusion/perfusion coefficients can be calculated using DWI, and these may provide more meaningful measurements than the ADC. The absence of standardization for both the terminology and the methodology in DWI of the liver makes it difficult for readers to understand the technique used and strongly limits comparisons between studies. Here, we review the main principles of DWI of the liver, the limits of the ADC, and the exciting capabilities of multi-parametric DWI. We also insisted on the need for a common language for DWI of the liver.     

Effects of microperfusion in hepatic diffusion weighted imaging

Objective  

Clinical hepatic diffusion weighted imaging (DWI) generally relies on mono-exponential diffusion. The aim was to demonstrate that mono-exponential diffusion in the liver is contaminated by microperfusion and that the bi-exponential model is required.     

Correlation between 3 T apparent diffusion coefficient values and grading of invasive breast carcinoma

PurposeThe aim of this study was to evaluate whether the apparent diffusion coefficient (ADC) provided by 3.0 T (3 T) magnetic resonance diffusion-weighted imaging (DWI) varied according to the grading of invasive breast carcinoma.Materials and methodsA total of 92 patients with 96 invasive breast cancer lesions were enrolled; all had undergone 3 T magnetic resonance imaging (MRI) for local staging. All lesions were confirmed by histological analysis, and tumor grade was established according to the Nottingham Grading System (NGS). MRI included both dynamic contrast-enhanced and DWI sequences, and ADC value was calculated for each lesion. ADC values were compared with NGS classification using the Mann–Whitney U and the Kruskal–Wallis H tests. Grading was considered as a comprehensive prognostic factor, and Rho Spearman test was performed to determine correlation between grading and tumor size, hormonal receptor status, HER2 expression and Ki67 index. Pearson's Chi square test was carried out to compare grading with the other prognostic factors.ResultsADC values were significantly higher in G1 than in G3 tumors. No significant difference was observed when G1 and G3 were compared with G2. Tumor size, hormonal receptor status, HER2 expression and Ki67 index correlated significantly with grading but there was a significant difference only between G1 and G3 related to the ER and PR status, HER2 expression and Ki67 index. There was no statistically significant difference in lesion size between the two groups.ConclusionADC values obtained on 3 T DWI correlated with low-grade (G1) and high-grade (G3) invasive breast carcinoma. 3 T ADC may be a helpful tool for identifying high-grade invasive breast carcinoma.     

食管癌MR扩散加权成像研究进展

MR扩散加权成像是活体状态下评价组织水分子与微循环的扩散运动的一种无创性手段,为肿瘤诊断、分期及治疗效果评估提供重要信息。扩散加权成像的表观扩散系数(ADC)可作为一种有价值的放射学定量指标,应用于食管癌的早期诊断,评价肿瘤血管生成及分期、分级,预测放化疗疗效及评估治疗效果。就扩散加权成像在食管癌中的应用予以综述。     

MR扩散加权成像在氟尿嘧啶治疗小鼠皮下移植肝癌疗效评价中的价值

目的:探讨磁共振DWI成像技术在氟尿嘧啶治疗小鼠皮下移植肝癌疗效评价中的作用.方法:将小鼠随机分为两组,制备小鼠H22皮下种植肝癌模型.种植成功第5天后,A组隔天给予氟尿嘧啶腹腔注射,B组给予蒸馏水灌胃.第15天进行MR检查,测量肿瘤组织的表观扩散系数(ADC).检查完毕后处死小鼠,测量血清中血管生成因子(VEGF)水平;取瘤体及脾脏分别称重,计算肿瘤指数及脾脏指数;检测新鲜肿瘤组织肝癌细胞凋亡的DNA百分比.将两组小鼠的ADC值及实验室数据行t检验,分析两组小鼠ADC值与各实验室结果的相关性.结果:在扩散敏感因子(b)=600s/mm~2及1200s/mm~2的DWI图像中,肝癌多表现为高信号,其内的坏死部分为低信号.A组、B组肿瘤实质部分的ADC值分别为:780±122mm~2/s、596.50±80.17mm~2/s;1421 ±160mm~2/s、1232.804-85.02mm~2/s,两者具有统计学差异(P<0.05).肿瘤实质成分的ADC值与血清中VEGF水平、肝癌细胞凋亡的DNA百分比、处死后称得的瘤体及脾脏重量存在相关性.结论:ADC值可以反映氟尿嘧啶对肿瘤生长抑制的情况,MR DWI技术及ADC值在氟尿嘧啶治疗小鼠皮下移植肝癌疗效评价方面具有可行性.