甲状腺恶性结节CT纹理分析参数与结节内癌基因表达的相关性研究

目的检测甲状腺恶性结节CT纹理分析参数,探讨其与结节内癌基因表达的相关关系。方法选择2014年12月～2018年2月间在本院进行甲状腺结节切除术治疗的甲状腺结节患者311例(409个病灶),收集其切除的结节病灶标本,并根据病理检查结果分为恶性组287个,良性组122个。检测甲状腺结节CT纹理,分析参数水平及结节内原癌基因、抑癌基因表达量。结果恶性组CT纹理分析参数中熵值(6.94±0.78),高于良性组(5.88±0.65)(t=13.187,P=0.000)。两组偏度、峰态水平差异无统计学意义(t=-1.113、-1.062,P=0.133、0.144)。恶性组甲状腺结节中原癌基因RET、RAS、TRK、PAX8-PPARγ1 mRNA的表达量均高于良性组甲状腺结节;抑癌基因DMBT1、DPC4、PTEN、TIP30 mRNA的表达量均低于良性组甲状腺结节(t=15.563、19.834、12.422、23.745、-13.367、-6.386、-9.674、-20.182,P均0.05)。甲状腺恶性结节的CT熵值与其中原癌基因表达量呈正相关,与抑癌基因表达量呈负相关(γ=0.310、0.298、0.463、0.571、-0.287、-0.354、-0.274、-0.417,P均0.05)。结论 CT纹理分析参数中的熵值可用于甲状腺良恶性结节鉴别,且其具体水平与恶性结节中癌基因表达量直接相关,在判断结节恶性程度方面具有一定意义。     

CT图像纹理分析在鉴别良恶性肺结节中的价值

目的 评价CT纹理分析在鉴别肺良恶性结节中的价值.方法 回顾性分析110例孤立性肺结节(SPNs)(恶性55例,良性55例)的CT平扫图像,所有结节均经组织病理学或临床随访证实.提取肺结节CT平扫图像的对比度、能量、熵、相关以及一致性等5个灰度共生矩阵纹理参数进行分析.使用t检验比较良恶性结节纹理特征的差异.使用受试者工作特征曲线(ROC)分析确定各参数的最佳临界值,并评价各参数诊断肺良恶性结节的敏感性、特异性、准确性、阳性及阴性预测值.结果 5个纹理特征中,能量、一致性和熵的ROC曲线下面积(AUC)分别为0.997、0.918、0.976.恶性结节的能量、一致性小于良性结节,熵大于良性结节(P＜0.001).使用最佳临界值标准,能量、一致性和熵的敏感性分别为0.982,0.818,1.000,特异性分别为0.964,0.909,0.910,准确性为0.973,0.864,0.945,阳性预测值为0.964,0.9,0.915,阴性预测值为0.981,0.833,0.980.结论 CT纹理特征定量分析是一种有前景的能够准确鉴别良恶性肺结节的手段.     

ＣＴ灰度直方图对实性肺结节的鉴别诊断价值

目的:探讨CT灰度直方图对实性肺结节良恶性的鉴别诊断价值.方法:回顾性分析经组织病理学或临床随访证实的110例实性肺结节患者的CT图像,其中恶性55例,良性55例.选取肺结节最大CT平扫轴面图像勾画感兴趣区并采用Matlab软件生成灰度直方图.采用Mann-Whitney U检验比较良恶性结节灰度直方图参数的差异.建立ROC曲线并以组织病理学或临床随访结果为依据计算曲线下面积(AUC).使用最佳临界值评价灰度直方图诊断良恶性肺结节的敏感度、特异度、准确度、阳性预测值及阴性预测值.结果:恶性结节的偏度(0.281±0.181)大于良性结节(-0.592±0.194),差异有统计学意义(P＜0.001);恶性结节的峰度(2.786±0.252)小于良性结节(3.553±0.331),差异有统计学意义(P＜0.05),两者的ROC曲线下最大面积分别为0.894和0.996.使用最佳临界值标准,峰度和偏度鉴别诊断肺结节良恶性的敏感度分别为0.982、0.946,特异度分别为1.000、0.764,准确度分别为0.990、0.845,阳性预测值分别为1.000、0.797,阴性预测值分别为0.982、0.913.结论:CT灰度直方图可作为肺结节良恶性鉴别诊断的重要辅助手段.     

双源CT双能量技术鉴别甲状腺良恶性结节的临床应用研究

目的 探讨双源CT能量成像在鉴别甲状腺良恶性结节中的临床应用价值.方法 收集91例经双源CT双能量扫描的甲状腺结节患者,获得单能量40~190 keV图像及碘图,计算线性融合图像与各单能量图像对比噪声比(CNR),测量动静脉期良恶性结节各单能量图像CT值、碘图正常甲状腺、结节、同层面颈动脉碘浓度值,绘制良恶性结节CT值衰减趋势图,计算曲线斜率、正常甲状腺与甲状腺结节内碘浓度差异(ICD)、碘浓度差异比(ICDNR)、标准化碘浓度比(NIC),采用配对样本t检验并绘制受试者工作特征(ROC)曲线比较上述定量参数值诊断恶性结节效能.结果 动、静脉期甲状腺结节在不同能量水平下CNR均有统计学差异(P<0.0001),动脉期最佳CNR在70 keV为11.61±1.71,静脉期最佳CNR在60 keV为10.55±1.09;良恶性结节动脉期单能谱曲线斜率(λ)分别为1.66±0.48,3.31±1.33,ICD分别为(2.83±1.23)mg/mL,(2.10±0.98)mg/mL,ICDNR分别为0.50±0.23,0.38±0.27,差异均有统计学意义(F=-89.43,4.036,2.791,P均<0.05),λ恶性结节大于良性,ICD及ICDNR良性结节大于恶性;静脉期曲线斜率分别为3.85±2.47,1.24±1.26,NIC分别为0.57±0.32,0.39±0.13,差异有统计学意义(F=8.651,4.893,P均<0.05),均良性结节大于恶性;动脉期ICDNR曲线下面积(AUC)最大为0.913,诊断敏感度为100%,特异度为87.5%.结论 动、静脉期分别采用70 keV及60 keV单能量图像可提高甲状腺结节检出率,能量相关定量参数值对良恶性结节鉴别诊断有较大临床应用价值.     

能谱CT钙基图像对甲状腺良恶性结节的鉴别诊断价值

目的 探讨能谱CT钙基图像定量分析对甲状腺良恶性结节的鉴别诊断价值.方法 收集经手术病理证实的82例甲状腺结节患者(共98个结节),所有患者术前均行甲状腺能谱CT平扫及双期增强扫描.根据病理结果,将甲状腺结节分为恶性组(61个)和良性组(37个),另选50例患者的对侧正常甲状腺组织作为正常组,比较3组平扫期钙浓度的差异.绘制受试者工作特征(ROC)曲线,得出最佳诊断阈值及诊断的敏感度和特异度.结果 恶性组、良性组和正常组的平扫期钙浓度(mg/cm3)分别为5.52±2.72、10.72±4.68和24.66±7.58,两两比较差异均有统计学意义(P值均<0.001).平扫期诊断甲状腺恶性结节的最佳钙浓度值为6.065 mg/cm3,敏感度为65.6%,特异度为91.9%.结论 能谱CT能够定量评估甲状腺结节的钙浓度,对鉴别甲状腺良恶性结节有一定价值.     

基于增强CT的胃肠道间质瘤纹理分析对术前危险度分级的预测价值

目的探讨增强CT纹理分析预测胃肠道间质瘤(GISTs)危险度分级的可行性。方法选取本院55例经手术病理证实的胃肠道间质瘤的影像学资料。基于增强CT扫描成像的直方图纹理分析及灰度共生矩阵纹理分析提取与肿瘤异质性的相关的纹理参数,包括平均值(mean)、方差(Variance)、偏度(skewness)、峰度(kurtosis)、10%分位像素值、50%分位像素值、90%分位像素值、能量(energy)、自相关(correlation)、对比度(Contrast)及熵值(entropy)纹理参数。根据术后病理结果分成极低/低危组、中危组、高危组。分析不同组纹理参数差异及纹理参数与肿瘤危险度分级、直径、Ki-67的相关性。采用ROC曲线分析纹理参数鉴别极低/低危组与中-高危组间质瘤的价值。结果均值、偏度、方差、10%分位像素值、50%分位像素值、90%分位像素值、对比度及自相关在不同危险度GISTs间差异均无统计学意义(均P0.05);峰度、能量及熵在三组间存在差异,差异均有统计学意义(均P0.05)。峰度及熵与肿瘤长径、Ki-67指数及肿瘤危险度分级呈正相关,能量与三者呈负相关关系,相关性具有统计学意义(P0.05)。ROC曲线分析显示,峰度0.63为阈值时,诊断的敏感度为71.8%,特异度为63.7%;能量0.20为阈值时,敏感度为79.4%,特异度为70.1%;熵界1.10为阈值时,敏感度为85.3%,特异度为76.8%。结论基于增强CT的纹理分析可在胃肠道胶质瘤术前危险度分级中发挥重要作用,其中以能量和熵值参数价值最高。     

Logistic回归模型评价常规超声及实时剪切波弹性成像技术对甲状腺结节良恶性鉴别诊断的价值

目的应用Logistic回归模型评价常规超声特征及实时剪切波弹性成像技术对甲状腺良恶性结节鉴别诊断的价值。方法对80例甲状腺结节患者(108个结节)行常规超声及实时剪切波弹性成像检查,测得结节的杨氏模量值,以病理结果为金标准,应用ROC曲线得出良恶性结节的诊断临界值。总结结节术前二维灰阶、彩色多普勒及剪切波弹性成像的声像图特征,筛选出对甲状腺结节良恶性鉴别诊断最有价值的指标,并建立二分类Logistic回归模型。结果病理诊断108个甲状腺结节,良性组36个,恶性组72个。甲状腺良、恶性结节的最大杨氏模量值分别为(46.43±20.84)k Pa和(81.79±32.06)k Pa;平均杨氏模量值分别为(36.59±19.29)k Pa和(62.96±29.13)k Pa。良、恶性结节杨氏模量最大值和平均值差异均有统计学意义(P<0.05)。最大值与平均值ROC曲线下面积分别为0.828和0.783,分别以最大值52.00 k Pa和平均值37.35 k Pa作为诊断截点值,其诊断敏感度、特异度为91.7%、61.1%和86.1%、55.6%。Logistic回归分析显示进入回归方程的3个特征变量为纵横比、钙化及杨氏模量值,该Logistic回归模型对甲状腺结节良恶性预报的正确率为89.7%(35/39),ROC曲线下面积为0.949。结论实时剪切波弹性成像技术有助于鉴别甲状腺结节的良恶性,二分类Logistic回归模型筛选出对甲状腺结节良恶性鉴别诊断有意义的诊断指标,具有较高的临床应用价值。     

实时剪切波弹性成像鉴别甲状腺结节良恶性的定量分析

目的应用剪切波弹性成像测定甲状腺结节的杨氏模量值,探讨其在结节良恶性鉴别诊断中的价值.资料与方法对79例甲状腺结节患者进行实时剪切波弹性成像,测得结节的杨氏模量值,以病理结果为“金标准”,绘制 ROC 曲线,分析鉴别良恶性病灶的参考界值.结果79例共分析甲状腺结节88个,良性63个,恶性25个,良性结节的平均、最大杨氏模量值分别为(27.56±25.22)kPa 和(41.79±30.66)kPa,恶性结节的平均、最大杨氏模量值分别为(88.38±35.27)kPa 和(137.36±56.81)kPa ;良恶性结节杨氏模量最大值和平均值差异有统计学意义(P <0.05);甲状腺结节杨氏模量最大值与平均值诊断恶性病变的 ROC 曲线下面积为0.971和0.802(P <0.05),分别以结节杨氏模量最大值90.34kPa 和平均值60.25kPa 作为诊断界值,其诊断敏感度、特异度为90.34%、86.89%和63.67%、91.66%;2名观察者间符合率为93.2%(Kappa =0.83).结论剪切波弹性成像测得的甲状腺结节杨氏模量最大值与平均值可以定量评价病灶硬度,有助于甲状腺结节良恶性的鉴别诊断.     

64层螺旋CT灌注成像对甲状腺病变的应用价值

目的 通过分析甲状腺良恶性结节CT灌注成像各个参数的差异,探讨64层螺旋CT灌注成像在甲状腺病变诊断及鉴别诊断中的临床应用价值.方法 对51例因甲状腺疾病拟手术治疗的患者行术前甲状腺CT平扫定位+灌注成像检查.良性结节40例,其中甲状腺肿20例,甲状腺腺瘤20例;恶性结节11例,全部是甲状腺癌.计算各灌注参数的平均值,包括血容量(BV)、血流量(BF)、灌注达峰时间(TTP)和毛细血管表面通透性(PS)的平均值,并进行统计学分析.结果 多层螺旋CT甲状腺灌注图像可以清晰显示甲状腺病变的大小和轮廓,并计算病变内部的组织灌注参数.良性结节组BF(249.89±43.95) ml·min-1.100g-1、BV值(28.69±6.17)ml·100g-1、TTP值(15.21±2.60)s、PS值(39.30±7.21)ml·min-1.100g-1.恶性结节组BF值(258.80±44.47) ml·min-1·100g-1、BV值(28.15-±3.02) ml·100g-1、TTP值(13.56±1.25)s、PS值(66.63±12.07)ml.min-1·100g-1.甲状腺良恶性结节的BV值及BF值差异无统计学意义(P =0.779;P =0.555),PS值及TTP值的差异具有统计学意义(P =0.000;P =0.048).甲状腺良恶性结节时间-密度曲线(TDC)的波形不同,良性结节多表现为缓升缓降(Ⅲ)型,而恶性结节多表现为缓升平台(Ⅱ)型.结论 MSCT灌注成像在甲状腺良恶性结节鉴别诊断方面可提供一定的补充信息,PS在鉴别诊断中价值较大,TDC有一定参考价值.     

甲状腺结节MSCT灌注成像与微血管密度相关性

目的 研究不同性质甲状腺结节CT灌注成像与微血管密度(MVD)的相关性.方法 随机选取52例甲状腺病变患者,良性组40例,恶性组12例,均采用常规CT平扫和同层动态灌注扫描,计算出血流量(BF)、血容量(BV)、表面通透性(PS)、平均通过时间(MTT)及达峰时间(TTP),良恶性甲状腺结节CT灌注参数各值分别与各组病例术后病理免疫组织化学染色的MVD高倍镜下(×400)计数值进行Pearson相关分析,良性组及恶性组甲状腺结节CT灌注参数及MVD采用t检验.结果 良、恶性甲状腺结节CT灌注参数BV值分别为(13.97 ±11.34)ml/100 g、(22.89±11.56)ml/100 g,良、恶性甲状腺结节BV差异有统计学意义(t=2.211,P=0.034 ＜0.05),BF、TTP、PS、MTr差异均无统计学意义(P =0.234、0.112、0.614、0.709);良、恶性甲状腺结节的MVD间存在显著差异(t=7.621,P=0.000 ＜0.001);良性组PS值与MVD间呈正相关(r=0.404,P=0.05),恶性组PS值与MVD间呈负相关(r=-0.601,P=0.039 ＜0.05),其余各指标BF、BV、TIP、MTT与MVD间均无相关性.结论 CT灌注成像可对甲状腺结节微血管血流动力学状况进行量化评估,其各种灌注参数中以BV值对甲状腺良恶性病变的鉴别诊断价值最大,良、恶性甲状腺结节CT灌注参数PS与MVD具有良好的相关性,对术前间接评价肿瘤的血管生成及良恶性有重要价值.     

Kurtosis and skewness assessments of solid lung nodule density histograms: differentiating malignant from benign nodules on CT

Purpose

The purpose of our study was to assess pulmonary nodule characteristics using density histogram kurtosis and skewness and to distinguish malignant from benign nodules.

Materials and methods

Ninety-three lung nodules on CT were analyzed, including 72 malignant and 21 benign nodules. They were completely solid or solid with limited ground-glass opacity. Based on their CT characteristics, nodules were categorized into type A, homogeneous nodules with uniform internal structures and clear margins, and type B, inhomogeneous nodules with heterogeneous structures or uneven margins. Kurtosis and skewness were calculated from density histograms to compare type A and B nodules and malignant and benign nodules. Receiver-operating characteristic (ROC) curves were generated to assess kurtosis and skewness for discriminating between different nodule types.

Results

Type A nodules (n = 35) had greater kurtosis and reduced skewness (p < 0.001) compared to type B nodules (n = 58). Malignant tumor kurtosis was greater than that of benign nodules (type A, p < 0.05; type B, p = 0.001). Type B malignant tumors had reduced skewness compared to benign nodules (p < 0.05). ROC curves provided relatively high values for the area under the curve (0.71–0.83).

Conclusion

Kurtosis and skewness assessments of density histograms may be useful for differentiating malignant from benign nodules.     

Role of diffusion weighted magnetic resonance imaging in differentiation of benign and malignant thyroid nodules

Objective

Is to evaluate the potential application of diffusion-weighted echo planar imaging in the differentiation of benign and malignant thyroid nodules in patients referred for FNAC and to correlate the imaging patterns & values of these lesions with their pathological nature.

CT纹理分析对鉴别直肠癌患者K-ras基因突变的可行性研究

目的:探讨CT纹理分析(CTTA)技术对鉴别直肠癌患者K-ras基因突变的可行性研究.方法:回顾性分析33例经病理证实的直肠癌患者的CT图像,其中K-ras突变型18例、野生型15例.使用TexRad软件对病灶最大层面的平扫及门静脉期图像进行分析,获得基于不同空间缩放因子(SSF=0和2～6)的6个特征性纹理参数值,包括均值(mean)、标准差(standard deviation,SD)、熵值(entropy)、偏度值(skewness)、峰值(kurtosis)及正像素均值(mean of positive pixels,MPP).比较两组间各参数值的差异.结果:平扫CT图像:当SSF取2～4时,野生型组中病灶的熵值(分别为4.3、4.2、4.3)高于突变型(分别为4.1、4.0和4.0),差异均有统计学意义(P＜0.05);当SSF=2、熵取界值4.245时,诊断敏感度及特异度均为73.3％;当SSF=3、熵取界值4.095时,诊断敏感度及特异度分别为80.0％、61.1％;当SSF=4、熵取界值4.205时,诊断敏感度为73.3％、特异度为72.2％.增强CT图像上各纹理参数值在两组间的差异均无统计学意义(P＞0.05).结论:CT纹理分析能够对预测直肠癌患者有无K-ras基因突变提供一定的诊断信息.     

Whole-lesion histogram analysis metrics of the apparent diffusion coefficient as a marker of breast lesions characterization at 1.5 T

IntroductionTo retrospectively assess the role of whole-lesion apparent diffusion coefficient (ADC) in the characterization of breast tumors by comparing different histogram metrics.Methods49 patients with 53 breast lesions underwent magnetic resonance imaging (MRI). ADC histogram parameters, including the mean, mode, 10th/50th/90th percentile, skewness, kurtosis, and entropy ADCs, were derived for the whole-lesion volume in each patient. Mann–Whitney U-test, area under the receiver-operating characteristic curve (AUC) were used for statistical analysis.ResultsThe mean, mode and 10th/50th/90th percentile ADC values were significantly lower in malignant lesions compared with benign ones (all P < 0.0001), while skewness was significantly higher in malignant lesions P = 0.02. However, no significant difference was found between entropy and kurtosis values in malignant lesions compared with benign ones (P = 0.06 and P = 1.00, respectively). Univariate logistic regression showed that 10th and 50th percentile ADC yielded the highest AUC (0.985; 95% confidence interval [CI]: 0.902, 1.000 and 0.982; 95% confidence interval [CI]: 0.896, 1.000 respectively), whereas kurtosis value yielded the lowest AUC (0.500; 95% CI: 0.355, 0.645), indicating that 10th and 50th percentile ADC values may be more accurate for lesion discrimination.ConclusionWhole-lesion ADC histogram analysis could be a helpful index in the characterization and differentiation between benign and malignant breast lesions with the 10th and 50th percentile ADC be the most accurate discriminators.     

Initial experience of 3 tesla apparent diffusion coefficient values in differentiating benign and malignant thyroid nodules

Purpose:

To evaluate the role of diffusion‐weighted magnetic resonance imaging (DWMRI) in differentiating benign and malignant thyroid nodules using a 3 Tesla (T) MRI scanner.

Materials and Methods:

Twenty‐eight nodules in 25 patients and 14 healthy control cases were included in the study. DWMRI was acquired with 6 b values with a 3T MRI scanner. The apparent diffusion coefficient (ADC) values of the nodules were calculated from reconstructed ADC map images and were compared with the final histopathological diagnoses.

Results:

The mean ADC value of the benign nodules was 1548 ± 353.4 (×10^?6 mm²/s), and the mean ADC of the malignant nodules was 814 ± 177.12 (×10^?6 mm²/s). The normal thyroid tissue had a mean ADC value of 1323.43 ± 210.35 × 10^?6 mm²/s (958–1689 × 10^?6 mm²/s) in the healthy control group. The ADC values were significantly different among the three groups (P = 0.001). An ADC value of 905 × 10^?6 mm²/s was determined to be the cutoff value for differentiating benign and malignant nodules, with 90% (55.5–98.3) sensitivity and 100% (81.3–100.0) specificity.

Conclusion:

This study suggests that the ADC values of nodules measured with a 3T MRI scanner could help in differentiating benign thyroid nodules from malignant nodules. J. Magn. Reson. Imaging 2013;37:1077–1082. © 2012 Wiley Periodicals, Inc.

     

Prospective evaluation of solitary thyroid nodule on 18F-FDG PET/CT and high-resolution ultrasonography

Purpose

The utility of 18F-FDG PET/CT in the assessment of thyroid nodules is unclear as there are several conflicting reports on the usefulness of SUV as an indicator to distinguish benign from malignant thyroid lesions. This study incorporated an additional parameter, namely dual time point imaging, to determine the diagnostic accuracy of PET/CT imaging. The performance of 18F-FDG PET/CT was compared to that of high-resolution ultrasound which is routinely used for the evaluation of thyroid nodules.

Methods

Two hundred patients with incidentally detected solitary thyroid nodules were included in the study. Each patient underwent ultrasound and PET/CT evaluation within 7 days of each other, reported by an experienced radiologist and nuclear medicine specialist, respectively, in a blinded manner. The PET/CT criteria employed were maximum SUV (SUV_max) at 60 min and change in SUV_max at delayed (120 min) imaging. Final diagnosis was based on pathological evaluation and follow-up.

Results

Of the 200 patients, 26 had malignant and 174 had benign nodules. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of ultrasound were 80.8, 81.6, 39.6, 96.6 and 81.5%, respectively. Using SUV_max at 60 min as the diagnostic criterion, the above indices were 80.8, 84.5, 43.8, 96.7 and 84%, respectively, for PET/CT. The SUV_max of malignant thyroid lesions was significantly higher than benign lesions (16.2 ± 10.6 vs. 4.5 ± 3.1, respectively; p = 0.0001). Incorporation of percentage change in SUV_max at delayed imaging as the diagnostic criterion yielded a slightly improved sensitivity, specificity, PPV, NPV and accuracy of 84.6, 85.6, 46.8, 97.4 and 85.5%, respectively. There was a significant difference in percentage change in SUV_max between malignant and benign thyroid lesions (14.9 ± 11.4 vs. ?1.6 ± 13.7, respectively; p = 0.0001). However, there was no statistically significant difference (95% confidence interval) between the diagnostic performance of PET/CT and ultrasound.

Conclusions

Routine use of 18F-FDG PET/CT with SUV_max at 60 min as the sole diagnostic criterion does not appear to have a significant advantage over high-resolution ultrasound in the evaluation of thyroid nodules. Incorporation of dual time point imaging enhances image interpretation, and yields a higher diagnostic performance, yet it is not statistically significant. Bearing in mind the cost, limited availability and radiation exposure, routine use of 18F-FDG PET/CT for distinguishing benign from malignant thyroid nodules cannot be recommended.     

探讨超声弹性成像对甲状腺良恶性结节鉴别诊断的应用价值

目的:研究超声弹性成像在鉴别甲状腺良、恶性结节临床诊断中的应用价值。方法:对术前52例(93个)甲状腺结节进行常规二维、彩色多普勒超声及弹性成像检查,对弹性成像进行分析,并与病理结果进行对照。结果:93个甲状腺结节中,良性结节64个,恶性结节29个。其良性结节中,47个结节评为1～2分,恶性结节中,27个结节评为4～5分,两组弹性成像评分比较有统计学差异(P<0.01)。其诊断恶性结节的敏感性87.10%、特异性96.77%、准确性93.55%。结论:超声弹性成像对鉴别甲状腺良恶性病变提供很大的帮助。     

Diagnostic accuracy of MRI textural analysis in the classification of breast tumors

ObjectiveTo investigate whether textural analysis (TA) of MRI heterogeneity may play a role in the clinical assessment and classification of breast tumors.Materials and methodsFor this retrospective study, patients with breast masses ≥1 cm on contrast-enhanced MRI were obtained in 69 women (mean age: 51 years; range 21–78 years) with 77 masses (38 benign, 39 malignant) from 2006 to 2018. The selected single slice sagittal peak post-contrast T1-weighted image was analyzed with commercially available TA software [TexRAD Ltd., UK]. Eight histogram TA parameters were evaluated at various spatial scaling factors (SSF) including mean pixel intensity, standard deviation of the pixel histogram (SD), entropy, mean of the positive pixels (MPP), skewness, kurtosis, sigma, and Tx_sigma. Additional statistical tests were used to determine their predictiveness.ResultsEntropy showed a significant difference between benign and malignant tumors at all textural scales (p < 0.0001) and kurtosis was significant at SSF = 0–5 (p = 0.0026–0.0241). The single best predictor was entropy at SSF = 4 with AUC = 0.80, giving a sensitivity of 95% and specificity of 53%. An AUC of 0.91 was found using a model combining entropy with sigma, which yielded better performance with a sensitivity of 92% and specificity of 79%.ConclusionTA of breast masses has the potential to assist radiologists in categorizing tumors as benign or malignant on MRI. Measurements of entropy, kurtosis, and entropy combined with sigma may provide the best predictability.     

Quantitative diffusion-weighted MR imaging in the differential diagnosis of breast lesion

The role of diffusion-weighted magnetic resonance imaging (DWI) to differentiate breast lesions in vivo was evaluated. Sixty women (mean age, 53 years) with 81 breast lesions were enrolled. A coronal echo planar imaging (EPI) sequence sensitised to diffusion (b value=1,000 s/mm²) was added to standard MR. The mean diffusivity (MD) was calculated. Differences in MD among cysts, benign lesions and malignant lesions were evaluated, and the sensitivity and specificity of DWI to diagnose malignant and benign lesions were calculated. The diagnosis was 18 cysts, 21 benign and 42 malignant nodules. MD values (mean±SD ×10⁻³ mm²/s) were (1.48±0.37) for benign lesions, (0.95±0.18) for malignant lesions and (2.25±0.26) for cysts. Different MD values characterized different malignant breast lesion types. A MD threshold value of 1.1×10⁻³ mm²/s discriminated malignant breast lesions from benign lesions with a specificity of 81% and sensitivity of 80%. Choosing a cut-off of 1.31×10⁻³ mm²/s (MD of malignant lesions -2 SD), the specificity would be 67% with a sensitivity of 100%. Thus, MD values, related to tumor cellularity, provide reliable information to differentiate malignant breast lesions from benign ones. Quantitative DWI is not time-consuming and can be easily inserted into standard clinical breast MR imaging protocols.