扩散峰度成像对上皮性卵巢癌分型的鉴别诊断

目的 探讨扩散峰度成像（DKI）对Ⅰ型与Ⅱ型上皮性卵巢癌（EOC）的鉴别诊断价值。 方法 回顾性收集经手术病理证实的45例EOC病人的临床、病理及影像资料,平均年龄（50±13）岁。根据术后病理结果对EOC病人进行分组,分为Ⅰ型组（24例）和Ⅱ型组（21例）。所有病人均于术前行盆腔DKI检查,由2名放射科医师在DKI各参数伪彩图上分别测量平均扩散峰度（MK）、平行扩散峰度（Ka）、垂直扩散峰度（Kr）、平均扩散系数（MD）、平行扩散系数（Da）、垂直扩散系数（Dr）、各向异性分数（FA）、峰度各向异性分数（FAk）。采用Fisher确切概率检验、独立样本t检验或Mann-Whitney U检验比较2组间临床、病理及影像资料的差异,对差异有统计学意义的参数绘制受试者操作特征（ROC）曲线,分析其鉴别诊断效能。 结果 病理表现上,Ⅰ型中交界性肿瘤占比最高（50.0%）,Ⅱ型中浆液性癌占比最高（61.9%）;Ⅰ型中高分化癌占50%,Ⅱ型多表现为中低分化癌 （76.2%）,Ⅰ型EOC的分化程度高于Ⅱ型;Ⅰ型多数处于Ⅰ期（79.2%）,Ⅱ型多处于Ⅲ期(57.1%)（均P<0.05）。MRI影像上, Ⅰ型病灶多表现为囊性(41.7%)或囊实性（33.3%）,Ⅱ型多表现为实性（52.3%）;Ⅱ型（66.7%）腹水发生率高于Ⅰ型（29.2%）（均P<0.05）。Ⅰ型的MK、Ka和Kr值低于Ⅱ型,MD、Da和Dr值高于Ⅱ型（均P<0.05）。ROC曲线分析显示,MK阈值为0.504时,鉴别2组诊断的曲线下面积（AUC,0.817）最大,诊断敏感度（95.2%）、阴性预测值（92.9%）、准确度（78.9%）也最高,Da阈值为2.190时鉴别诊断的AUC（0.770）最小,而特异度（76.2%）、阳性预测值（75.9%）最高。 结论 DKI序列的定量参数MK、Ka、Kr、MD、Da及Dr均有助于鉴别Ⅰ型与Ⅱ型EOC,其中MK值鉴别诊断效能更大。     

多模型体素不相干运动成像对直肠癌的诊断价值

目的：探讨体素不相干运动（IVIM）不同模型参数诊断直肠癌的可行性。方法：回顾性分析直肠癌组（32例）和直肠正常组（35例）的MRI-IVIM序列资料,测算并比较正常直肠组织和癌组织的单指数、双指数、拉伸指数模型参数值,利用ROC曲线评估不同参数诊断直肠癌的阈值和效能;评价同组间同类型参数彼此间的相关性,并分析原因。结果：直肠癌组的标准扩散系数（ADC-stand）、慢速扩散系数（ADC-slow）、拉伸因子（α）、分布扩散系数（DDC）值均低于直肠正常组（均P<0.05）,ROC曲线下面积依次为0.929、0.911、0.849、0.718,相关阈值分别是1.275×10^-3 mm²/s、0.838×10^-3 mm²/s、0.737和1.045×10^-3 mm²/s;在直肠正常组与直肠癌组中,ADC-stand、ADC-slow、DDC三者之间均呈一定程度的正相关（均P<0.05）。结论：IVIM不同模型参数具备区分正常直肠组织与直肠癌组织的潜力,且不同参数之间存在一定的相关性,其可作为一种新的直肠癌影像评估手段应用于临床。     

双指数和拉伸指数模型IVIM-MRI对上皮性卵巢癌分型的诊断价值

目的:探讨体素内不相干运动(IVIM)双指数和拉伸指数模型对Ⅰ型和Ⅱ型上皮性卵巢癌(EOC)的鉴别诊断价值。方法:回顾性将术前在本院行常规及IVIM序列MRI扫描且经病理证实的40例EOC患者纳入本研究。其中,组织病理学分型为Ⅰ型者22例,Ⅱ型者18例。测量肿瘤实质区的真扩散系数(D)、伪扩散系数(D^*)、灌注分数(f)、分布扩散系数(DDC)和拉伸指数(α)值,比较两组间上述各参数值的差异,对组间差异具有统计学意义的参数采用ROC曲线分析其诊断效能。结果:Ⅰ型EOC的D、D^*、DDC及α值均高于Ⅱ型EOC[(1.159±0.678)×10^-3 vs.(0.568±0.282)×10^-3mm²/s,P<0.001;12.350(5.752,21.925)×10^-3 vs. 5.01(3.23,14.58)×10^-3mm²/s,P=0.033;(2.195±0.744)×10^-3 vs....     

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。     

MRI对上皮性卵巢癌组织学分型的诊断应用

常规MRI可从形态学角度评估上皮性卵巢癌（EOC）组织学分型,扩散加权成像（DWI）、体素内不相干运动成像（IVIM）及动态增强MRI（DCE-MRI）等功能成像技术可进行定量后处理分析。基于MRI的影像组学通过全面分析Ⅰ型和Ⅱ型EOC的影像特征,在术前可以预测EOC分型,有助于制定个体化治疗方案及评估预后。就DWI、IVIM、DCE-MRI及影像组学在鉴别EOC分型中的应用进行综述。     

IVIM双指数及拉伸指数模型评估宫颈癌放化疗疗效的价值

【摘要】目的：探讨体素内不相干加权运动磁共振成像双指数、拉伸指数模型评估宫颈癌放化疗疗效的价值。方法：30例经活检证实为宫颈癌的患者放化疗前、放化疗1个月后行MRI扫描，扫描序列包括矢状面T2WI，横轴面T2WI、T1WI、DWI、IVIM（12个b值，范围0～2000s/mm2）。双指数模型测得病变区纯水分子扩散系数（D)、伪扩散系数（D*）、灌注分数（f），拉伸指数模型测得水分子扩散异质性指数（α），扩散分布系数（DDC）。测量各扫描时间点肿瘤最大面积及相关参数，并分析其动态变化及相关性。结果:宫颈癌病灶的D值、f值、DDC值在放化疗后升高，分别由0.642×10-3mm2/s，18.8%，0.84×10-3mm2/s升高至0.777×10-3mm2/s，36.3%，2.2×10-3mm2/s差异有统计学意义（P<0.05）；α、D*值在放化疗前后分别为0.775，9.59×10-3mm2/s至0.486，39.8×10-3mm2/s差异无统计学意义（P>0.05）。结论：IVIM双指数、拉伸指数相关参数可动态监测宫颈癌放化疗过程中的细微变化，D值、DDC值能有效监测放化疗疗效，f值可作为放化疗疗效的潜在观察指标。     

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.     

定量IVIM参数对肾脏乏脂性错构瘤与乳头状细胞癌的鉴别诊断价值

【摘要】目的：评价定量IVIM参数对肾乏脂性错构瘤与乳头状肾细胞癌的鉴别诊断价值。方法：47例经手术病理证实的肾脏乏脂性错构瘤（n=21）与肾乳头状细胞癌（n=26）患者术前采用3.0T MR进行多b值DWI（b值为0~1700s/mm2）扫描。基于双指数模型计算相应的IVIM参数：纯扩散系数（D）,假扩散系数（D*）,灌注分数（f）。采用独立样本t检验或Mann-Whitney U检验进行分析两组肿瘤的IVIM参数,采用受试者工作特征曲线分析IVIM参数对两组肿瘤的鉴别价值。结果：乳头状肾细胞癌f值明显低于肾乏脂性错构瘤（0.227±0.077 vs 0.417±0.117,P＜0.001）;D值明显高于肾乏脂性错构瘤［（0.745±0.197）×10-3mm2/s vs （0.610±0.117）×10-3mm2/s,P＜0.05］,D*在两种肿瘤间差异无统计学意义（P=0.085）。IVIM参数值鉴别两者的AUC、敏感度、特异度和诊断阈值分别为f：0.918、91.3%、85.2%和0.312,D：0.684、51.9%、95.7%和0.789×10-3mm2/s。结论：肾乏脂性错构瘤与乳头状肾细胞癌的定量IVIM扩散与灌注参数值具有一定差异。灌注分数 f可用于术前两者的鉴别诊断。     

3.0T MRI水通道蛋白分子成像在胰腺癌的应用价值

目的:探讨3.0T MRI水通道蛋白分子成像定量参数(ADCAQPs)在胰腺癌的应用价值.方法:采用GE Discovery MR750 3.0T磁共振扫描仪对临床或手术病理证实的37例胰腺癌患者行胰腺多b值DWI.应用水通道蛋白AQPs模型、非高斯IVIM双指数模型和拉伸指数模型分析多b值DWI,测量胰腺癌和非癌胰腺组织的水通道蛋白扩散系数(ADCAQPs)、纯扩散系数(ADCslow)和分布扩散系数(DDC),采用独立样本t检验进行统计学分析.结果:胰腺癌的ADCAQPs值和ADCslow值明显高于非癌胰腺组织(0.346 vs.0.202μm2/ms,P＜0.001;0.611 vs 0.521×10-3 mm2/s,P=0.037),胰腺癌的DDC值明显低于非癌胰腺组织(1.244 vs 1.679×10-3mm2/s,P=0.013),差异均有统计学意义.与ADCslow和DDC相比,ADCAQPs鉴别胰腺癌和非癌胰腺组织时的诊断效能更高(0.890＞0.699＞0.640).胰腺癌的ADCAQPs值和ADCslow值呈正相关(r=0.414,P=0.015).结论:水通道蛋白扩散系数ADCAQPs和非高斯模型DWI扩散系数(ADCsl、DDC)可以有效鉴别胰腺癌和非癌胰腺组织,ADCAQPs是鉴别胰腺癌和非癌胰腺组织的最佳参数,3.0T MRI水通道蛋白分子成像是无创性早期诊断和鉴别胰腺癌与非癌胰腺组织的理想方法之一.     

IVIM磁共振成像对乳腺非肿块强化病变的诊断价值

【摘要】目的：探讨多b值双指数模型体素内不相干运动（IVIM）扩散加权磁共振成像对于乳腺非肿块强化病灶的鉴别诊断价值。方法：前瞻性研究2015年12月-2016年6月本院乳腺MRI检查拟诊为非肿块强化（NME）的患者,术前均行MRI常规序列成像及IVIM序列扫描,追踪所有手术患者的病理结果,最终入组经病理确诊的乳腺良性NME病变 20例（20个病灶）和恶性NME病变27例（30个病灶）。分别测量良恶性病灶组单指数模型DWI的表观扩散系数（ADC）和IVIM相关参数（灌注分数f、假性扩散系数D*和纯扩散系数D）,并进行比较;绘制两组ADC 值及IVIM相关参数值的受试者操作特征曲线（ROC）,分析两种不同指数模型诊断乳腺非肿块强化的最佳参数、诊断阈值和诊断价值。结果：恶性病灶的ADC值和D值［（1.06±0.27）×10-3mm2/s、（0.85±0.24）10-3mm2/s］均小于良性病灶［（1.32±0.23）×10-3mm2/s、（1.31±0.32）×10-3mm2/s］,f值［20.10%（13.38%,40.88%）］大于良性病灶［10.45%（6.28%,22.55%）］,差异均有统计学意义（P=0.001,P＜0.001,P=0.010）,两组间D*值差异无统计学意义（P=0.578）。ROC曲线分析得到D值的曲线下面积（AUC）最大,为0.908,而ADC和f值的AUC分别为0.794和0.717。当ADC取最佳诊断阈值1.15×10-3mm2/s时,诊断敏感度和特异度分别为76.9%和76.5%。当D取最佳诊断阈值1.03×10-3mm2/s时,诊断敏感度和特异度分别为85.0%和73.3%。当f取最佳诊断阈值13.60%时,诊断敏感度和特异度分别为76.7%和70.0%。结论：多b值双指数模型IVIM DWI参数中D、f值有助于乳腺非肿块强化良恶性病变的鉴别,其中D值诊断价值最大。     

体素内不相干运动成像对胰腺癌的诊断价值

目的:探究DWI单指数模型、体素内不相干运动成像双指数模型及拉伸指数模型对胰腺癌诊断的临床应用价值。方法:回顾性收集分析经证实胰腺癌30例;同期检查胰腺正常者25例,行3.0T MRI-DWIeDWI,HR DWI扫描。测量记录两组单指数模型、双指数模型、拉伸指数模型各参数值。结果:ADC.Standard ADC,D-mono,D*-mono,D*-Bi,DDC、α值差异均有统计学差异(P<0.05)。α值ROC曲线下面积>0.9,AUC为0.905,ADC,D-moono,D*-mono,D*-Bi,DDC值ROC曲线下面积在0.75~0.9之间,AUC分别为0.725,0.873,0.899,0.773,0.767,standard ADC曲线下面积>0.5,AUC值0.538结论:IVIM多个参数对PC的诊断效能较常规DWI序列ADC值更高;其中IVIM序列拉伸指数模型的α值是鉴别胰腺癌与正常组织的最佳参数.     

Characterization of continuously distributed cortical water diffusion rates with a stretched-exponential model.

Experience with diffusion-weighted imaging (DWI) shows that signal attenuation is consistent with a multicompartmental theory of water diffusion in the brain. The source of this so-called nonexponential behavior is a topic of debate, because the cerebral cortex contains considerable microscopic heterogeneity and is therefore difficult to model. To account for this heterogeneity and understand its implications for current models of diffusion, a stretched-exponential function was developed to describe diffusion-related signal decay as a continuous distribution of sources decaying at different rates, with no assumptions made about the number of participating sources. DWI experiments were performed using a spin-echo diffusion-weighted pulse sequence with b-values of 500-6500 s/mm(2) in six rats. Signal attenuation curves were fit to a stretched-exponential function, and 20% of the voxels were better fit to the stretched-exponential model than to a biexponential model, even though the latter model had one more adjustable parameter. Based on the calculated intravoxel heterogeneity measure, the cerebral cortex contains considerable heterogeneity in diffusion. The use of a distributed diffusion coefficient (DDC) is suggested to measure mean intravoxel diffusion rates in the presence of such heterogeneity.     

IVIM参数在脊柱转移瘤与脊柱结核鉴别诊断中的价值

目的 探讨3.0 T MR体素内不相干运动(IVIM)对于脊柱转移瘤与脊柱结核、脊柱转移瘤原发灶鉴别诊断的应用价值.方法 搜集经穿刺或手术病理证实为脊柱转移瘤(71例,其中肺癌43例,乳腺癌14例,肾癌14例)和脊柱结核(25例)患者的影像资料,用后处理软件测量感兴趣区(ROI)的标准表观扩散系数(ADCstand)、...     

单指数、双指数模型多b值DWI在胰腺癌的应用价值

目的 探讨单指数、体素内不相干运动成像(IVIM)双指数模型多b值扩散加权成像(DWI)定量参数在胰腺癌的应用价值.方法 应用3.0T磁共振扫描仪对临床或手术证实的37例胰腺癌患者行胰腺多b值DWI.应用单指数、IVIM双指数模型分析多b值DWI,测量胰腺癌和癌周胰腺组织的标准化表观扩散系数(ADCstandard)、纯扩散系数 (ADCslow)、假扩散系数(ADCfast) 和灌注分数(f),并应用独立样本t检验进行统计学分析.结果 胰腺癌的ADCslow值高于癌周胰腺组织的ADCslow值(0.611×10-3 mm2/s vs 0.521×10-3 mm2/s,P=0.037),而胰腺癌的ADCfast和f值低于癌周胰腺组织的ADCfast和f值(5.066×10-3 mm2/s vs 7.188×10-3 mm2/s,P=0.035;55.8% vs 64.0%,P=0.016),差异均有统计学意义.胰腺癌的ADCstandard值和ADCslow值显著正相关(r =0.824,P=0.000);ADCfast值和f值显著负相关(r=-0.558,P=0.000).结论 IVIM-DWI的灌注相关参数(ADCfast、f)和扩散相关参数(ADCslow)可以有效鉴别胰腺癌和癌周胰腺组织,IVIM-DWI是无创性早期诊断和鉴别胰腺癌与癌周胰腺组织的理想方法之一.     

腹部IVIM-DWI应用研究及进展

体素内不均一运动(IVIM)是指MR扩散加权成像(DWI)上体素内信号衰减同时包括真性水分子扩散和毛细血管网中随机血流微循环灌注,导致表观扩散系数(ADC)值反映的信息有限。采用多b值可获取系列DWI影像,根据双指数模型拟合,可同时获得组织的扩散和灌注信息,更全面地分析组织扩散成像数据。IVIM-DWI目前已广泛应用于肝脏、胰腺、肾脏、前列腺等脏器,就该技术在腹部MR成像中的应用研究现状及进展予以综述。     

Utility of Intravoxel Incoherent Motion MR Imaging for Distinguishing Recurrent Metastatic Tumor from Treatment Effect following Gamma Knife Radiosurgery: Initial Experience

BACKGROUND AND PURPOSE:Intravoxel incoherent motion MR imaging can simultaneously measure the diffusion and perfusion characteristics of brain tumors. Our aim was to determine the utility of intravoxel incoherent motion–derived perfusion and diffusion parameters for assessing the treatment response of metastatic brain tumor following gamma knife radiosurgery.MATERIALS AND METHODS:Ninety-one consecutive patients with metastatic brain tumor treated with gamma knife radiosurgery were assessed by using intravoxel incoherent motion imaging. Two readers independently calculated the 90th percentile and the 10th percentile histogram cutoffs for perfusion, normalized CBV, diffusion, and ADC. Areas under the receiver operating characteristic curve and interreader agreement were assessed.RESULTS:With the combination of the 90th percentile histogram cutoff for perfusion and the 10th percentile histogram cutoff for diffusion, the sensitivity and specificity for differentiating recurrent tumor and treatment were 79.5% and 92.3% for reader 1 and 84.6% and 94.2% for reader 2, respectively. With the combination of the 90th percentile histogram cutoff for normalized CBV and the 10th percentile histogram cutoff for ADC, the sensitivity and specificity for differentiating recurrent tumor and treatment were 69.2% and 100.0% for reader 1 and 74.3% and 100.0% for reader 2, respectively. Compared with the combination of 90th percentile histogram cutoff for normalized CBV and the 10th percentile histogram cutoff for ADC, adding intravoxel incoherent motion to 90th percentile histogram cutoff for normalized CBV substantially improved the diagnostic accuracy for differentiating recurrent tumor and treatment from 86.8% to 92.3% for reader 1 and from 89.0% to 93.4% for reader 2, respectively. The intraclass correlation coefficients between readers were higher for perfusion parameters (intraclass correlation coefficient range, 0.84–0.89) than for diffusion parameters (intraclass correlation coefficient range, 0.68–0.79).CONCLUSIONS:Following gamma knife radiosurgery, intravoxel incoherent motion MR imaging can be used as a noninvasive imaging biomarker for differentiating recurrent tumor from treatment effect in patients with metastatic brain tumor.

Perfusion MR imaging techniques have significantly advanced and can now provide information regarding tumor physiology. There are several reports suggesting the usefulness of dynamic susceptibility contrast-enhanced perfusion MR imaging for differentiating recurrent metastatic brain tumor from stereotactic radiosurgery–induced radiation necrosis.^1–3 However, quantitative brain perfusion measurement remains a challenge for currently available MR perfusion methods. DSC and dynamic contrast-enhanced MR imaging are inhibited by their signal nonlinearity, and arterial spin-labeling exhibits, in addition to a low signal-to-noise ratio, a strong dependence on the transit time.Le Bihan et al⁴ defined intravoxel incoherent motion (IVIM) as the microscopic translational motion occurring in each image voxel in MR imaging. In biologic tissue, this incoherent motion includes molecular diffusion of water and microcirculation of blood in the capillary network, referred to as “perfusion.” These 2 phenomena account for the biexponential decay of the signal intensity on DWI when different diffusion b-values are applied. With the IVIM theory, both true molecular diffusion and water molecule motion in the capillary network can be estimated by using a single diffusion imaging-acquisition technique. As opposed to DSC, dynamic contrast-enhanced imaging, and arterial spin-labeling, IVIM has a unique capillary dependence that is not sensitive to the coherent laminar flow of arteries and veins. The measurement of IVIM is intrinsically local (ie, the encoding and readout are performed at the same location).⁵In our clinical experience, the major advantage of IVIM MR imaging is that because it allows the simultaneous acquisition of diffusion and perfusion parameters, it can provide both measures within corresponding solid lesions without the requirement for a further coregistration processing step. In the current study, we attempted to validate the IVIM-derived perfusion and diffusion parameters by using the clinicoradiologic correlation in patients with post-gamma knife radiosurgery (GKRS) metastatic brain tumor. We also assessed the diagnostic accuracy and added value of the IVIM method for differentiating recurrent tumor from treatment effect, compared with the combination of DSC perfusion MR imaging and DWI, which has commonly been used as a parameter for brain tumor imaging.Our hypothesis was that the difference in vascularity between recurrent tumor and the treatment effect can be assessed by using an IVIM-derived perfusion fraction (f); and the combination of f and the true diffusion parameter (D) would show diagnostic performance comparable with the combination of normalized CBV (nCBV) and the ADC. The purpose of this study was to determine the utility of IVIM-derived perfusion and diffusion parameters for assessing the treatment response of metastatic brain tumor following GKRS.     

不同定量测量参数对子宫肌瘤IVIM扩散和灌注特点显示的差异

目的 研究用直方图计算的不同定量测量参数对子宫肌瘤体素内不相干运动(IVIM)扩散和灌注特点显示的差异.方法 63例患者80个子宫肌瘤,进行了MR 3D T2WI和IVIM成像,根据肌瘤T2WI信号将肌瘤分为Funaki 1型、2型、3型.分别用直方图计算3种类型肌瘤的IVIM扩散系数(D)、灌注系数(D*)和灌注分数(f)的平均值、位于直方图左侧第25%(D25、D*25、f25)、50%(D50、D*50、f50)、75%(D75、D*75、f75)位置的数值.使用方差分析对3种肌瘤的IVIM定量测量参数进行比较.结果 80个肌瘤中Funaki分型1型肌瘤44个,2型肌瘤24个,3型肌瘤12个,3种肌瘤间D的直方图计算值和均值都有显著性差异(P<0.05),但灌注参数只有D*75有显著性差异(P<0.05).3种肌瘤的f不论是直方图计算值还是均值都无显著性差异.结论 用直方图计算子宫肌瘤IVIM的扩散参数没有比均值提供更多的信息,但直方图计算灌注参数D*75较均值更能反映不同类型肌瘤的灌注特点.