动态增强MRI在诊断颈部淋巴结病变中的价值

目的:探讨动态增强MRI(DCE-MRI)在颈部良恶性淋巴结中的诊断价值。方法:采用GE1.5T磁共振扫描仪及颈部相控阵线圈对46例单侧或双侧颈部淋巴结肿大患者行MRI平扫、动态增强MRI检查,其中26例为恶性病变,20例为良性病变,均经手术及病理证实。分析比较良恶性淋巴结病变的MRI征象,计算病灶峰值增强率Emax,峰值时间Tmax,最大强化速率Slopemax,并根据病变最高强化区ROI测量值,绘制病灶的时间-信号强度曲线(SI-Time曲线)。结果:良性淋巴结多为椭圆形,淋巴结周围水肿,脂肪边缘模糊,与周围软组织界限不清,动态强化参数Emax为(168.23±117.89)%,Tmax为(70.17±8.75)s,Slopemax为(2.96±2.03)%/s;而恶性淋巴结则呈类圆形或球形,轮廓较清晰,动态强化参数Emax为(192.74±106.84)%,Tmax为(61.92±21.37)s,Slopemax为(3.37±1.83)%/s。良、恶性淋巴结病变动态增强MRI的峰值增强率Emax、峰值时间Tmax及最大强化速率Slopemax之间的差异无显著性意义(P>0.05)。时间-信号强度曲线类型良性淋巴结病变多表现为Ⅰ型,而恶性淋巴结病变多为Ⅲ型,Ⅱ型曲线均可见于良性和恶性淋巴结病变。结论:淋巴结MRI可提供病灶的形态学及血流动力学特征,有助于良、恶性淋巴结的诊断。     

动态增强MRI鉴别乳腺良恶性病变的价值

目的：探讨动态增强MRI对乳腺良恶性病变的鉴别诊断价值。方法：对147例经手术病理证实的乳腺疾病患者行MRI平扫和动态增强检查。分析比较乳腺良恶性病变的MRI征象。包括形态学、内部信号及其动态增强特征等，计算病灶峰值增强率Emax，峰值时间Tmax，最大强化速率Slope max，并根据病变最高强化区ROI测量值，绘制病灶的时间-信号强度曲线。结果：147例患者共计病灶152个。其中恶性87个，良性65个。分析比较病变的形态学及动态增强表现，发现乳腺良性病变多呈类圆形或分叶状．边缘光整，无毛刺、边界多清晰，强化均匀或伴有内部分隔等，动态强化参数Emax多大于90％，Tmax多大于240s。Slopemax。多大于3％／s；恶性病变则多为不规则形。边缘可伴毛刺，与周围结构分界不清，强化不均匀，病灶常呈环形强化，导管样强化，Emax多大于90％，Tmax多大于240s。而Slopemax多大于3％／s。时间-信号曲线类型恶性病变多表现为Ⅱ或Ⅲ型，良性病变则多为Ⅰ或Ⅳ型。结论：乳腺MRI不仅提供了病灶丰富的形态学信息，而且还通过动态增强进一步揭示病变的血流动力学特征，从而有助于对乳腺病变作出准确的定性诊断，更有效地鉴别诊断乳腺良恶性病变。     

乳腺疾病的动态增强MRI与微血管密度相关性研究

目的　研究乳腺良恶性病变的动态增强MRI特征 ,并探讨动态强化特征与微血管密度 (MVD)的相关性。资料与方法　对 5 7例乳腺疾病患者行动态增强MRI。所有病例均经病理证实并行免疫组织化学染色及微血管计数。比较良恶性病变的最大强化率、信号强度达峰值时间、最大相对强化速率、信号强度 时间曲线 (SI Time曲线 )类型及MVD ,并进一步分析动态强化参数及SI Time曲线类型与MVD的关系。结果　 5 7例共计 6 1个病灶 ,恶性33个 ,良性 2 8个。良恶性病变的动态强化参数、SI Time曲线类型及MVD均有显著差异 (P <0 .0 5 )。恶性病变多呈早期快速显著强化 ,良性病变多呈延迟缓慢强化或不强化。恶性病变微血管丰富 ,良性病变微血管稀少。动态强化参数及SI Time曲线类型与MVD及其分级显著相关 (P <0 .0 5 ) ;“周边强化征”与病灶周边微血管丰富、中央微血管稀少有关。结论　乳腺良恶性病变的动态增强MRI特征与MVD及其分布密切相关 ,可用来估计乳腺肿瘤的血管生成情况     

乳腺良恶性病变动态增强MRI表现特征与血管生成相关性的初步研究

目的探讨乳腺良恶性病变动态增强MRI表现特征与微血管密度(MVD)和血管内皮生长因子(VEGF)表达水平之间的相关性.方法以38例行动态增强MR乳腺检查并经病理及组织切片免疫组织化学(简称免疫组化)染色证实的患者为研究对象.动态增强MRI评价病变指标包括早期增强率、强化峰值和时间-信号强度曲线.病理组织切片经Ⅷ因子相关抗原和VEGF免疫组化染色,测定病变组织MVD和VEGF表达水平,并进一步分析动态增强MRI上述表现特征、MVD和VEGF之间的相互关系.结果 38例中,恶性病变21例,良性病变17例.恶性病变MVD和VEGF表达水平高于良性病变,差异具有非常显著意义(P<0.01),且VEGF表达水平与MVD呈正相关性(P<0.01).在38例乳腺良恶性病变中,早期增强率>60%和曲线类型为Ⅱ、Ⅲ型的乳腺病变的MVD 和VEGF表达水平明显高于早期增强率<60%和曲线类型为Ⅰ型的乳腺病变,除时间-信号强度曲线类型分布与VEGF表达水平之间差异无显著意义外(P>0.05),其余差异均具有非常显著意义(P<0.01).乳腺良恶性病变强化峰值之间差异无显著意义(P>0.05).分析微血管分布显示恶性病变外周与中央区MVD的比值(1.27)高于良性病变外周与中央区MVD的比值(1.12),且恶性病变边缘区MVD高于中心区(P<0.05).结论乳腺良恶性病变动态增强MRI特性及方式与MVD及分布密切相关,且能部分反映乳腺肿瘤血管生成特性.     

3.0T磁共振动态增强扫描显示乳腺肿瘤血管与微血管密度的相关性

目的 探讨乳腺肿瘤MR动态增强扫描显示肿瘤血管分级与微血管密度在鉴别乳腺良、恶性肿瘤方面的应用价值.方法 术前对70例乳腺肿瘤患者进行磁共振动态增强扫描检查,术后应用免疫组化方法检测乳腺肿瘤组织内微血管密度,并分析其与磁共振显示的肿瘤血管之间的相关性.结果 乳腺恶性肿瘤组织的血管分级以Ⅱ～Ⅲ级为主,良性肿瘤以Ⅰ～Ⅱ级为主,把Ⅱ～Ⅲ级与0～Ⅰ级肿瘤的术后病理标本以CD105 和CD34标记的微血管密度进行比较,有显著性差异(P＜0.05).结论 CD105标记的微血管密度和磁共振动态增强扫描显示的血管形态分级可用于判断乳腺肿瘤血管生成的活性,可作为术前鉴别乳腺良、恶性肿瘤的有效方法.     

动态增强MRI对乳腺环形强化病灶的诊断价值

目的 研究乳腺内环形强化病变的MRI表现及病理特征,探讨动态增强MRI对乳腺环形强化病灶的诊断价值.方法 回顾性分析23例乳腺MRI上环形强化病例,所有病例均经手术、病理或临床治疗证实.结果 23例乳腺环形强化病变中,恶性病灶17例,良性病灶6例,病灶增强形态特征、早期增强率等及时间-信号强度时间曲线在良恶性乳腺病变中差异均有显著性意义(P<0.05).结论 乳腺环形强化高度提示恶性肿瘤,动态增强MRI通过分析病灶形态学特征和强化方式,可以有效地鉴别诊断乳腺环形强化病灶的良恶性.     

动态增强磁共振成像与磁共振波谱在鉴别乳腺良恶性肿瘤中的价值比较

目的 比较动态增强磁共振成像与磁共振波谱在诊断乳腺良、恶性肿瘤中的价值.方法 回顾分析经病理证实的65例乳腺肿瘤,其中恶性39例,良性26例,所有病例均行磁共振3D T1WI动态增强扫描及磁共振波谱采集.在GEADW4.2工作站进行后处理及图像分析,分别计算良、恶性肿瘤的早期强化率,判断时间-信号强度曲线(TIC)类型,计算波谱曲线3.23 ppm处胆碱(Cho)峰信噪比.结果 动态增强扫描的早期强化率,时间-信号强度曲线(TIC)及MRS在鉴别良、恶性肿瘤方面均有显著意义(P＜0.01).早期强化率的变异程度较大,良、恶性病变间重叠范围较大,其敏感性为97.4%,特异性30.7%,准确性70.7%,阳性预测值为67.8%,阴性预测值为88.9%.时间-信号强度曲线(TIC)的敏感性为87.2%,特异性为69.2%,准确性为80.0%,阳性预测值为80.9%,阴性预测值为78.3%.MRS的敏感性为61.5%,特异性为92.3%,准确性为73.8%,阳性预测值为92.3%,阴性预测值为61.5%.动态增强扫描的早期强化率及TIC的敏感性(分别为97.4%和87.2%)均高于MRS(61.5%)(P＜0.01),但其特异性均明显较MRS(92.3%)低(P＜0.01),尤其是早期强化率,其特异性只有30.7%;阳性预测值(分别为67.8%和80.9%)亦较MRS(92.3%)低(P＜0.01).结论 动态增强磁共振成像与磁共振波谱结合,可以提高乳腺癌的正确诊断率.     

乳腺肿瘤高频彩超及超声造影与微血管密度的相关性

目的 分析乳腺良恶性肿瘤高频彩超、超声造影(CEUS)与微血管密度(MVD)的相关性,探讨超声造影对乳腺肿瘤的诊断价值.资料与方法 82例原发性乳腺肿瘤患者于术前行常规高频彩超检查,观察病灶灰阶图像特征及血流特征;启动造影模式行实时灰阶谐波超声造影检查,应用时间-信号强度曲线分析软件分析病灶增强达峰时间(TTP)、峰值强度(PI)、曲线下面积(AUC);采用免疫组化测定肿瘤内MVD,分析超声造影定量参数与MVD的相关性.结果 恶性组肿瘤血流Adler分级低于良性组(P＜0.05);超声造影显像特点:恶性组血管数量多且粗细不等,良性组血流束细窄、平直;恶性组TTP低于良性组,PI及AUC高于良性组(P＜0.05),MVD显著高于良性组(P＜0.001);肿瘤MVD计数随血流Adler分级升高而升高,CDF1血流丰富程度与MVD呈正相关(r=0.456,P＜ 0.01); PI与MVD呈显著正相关(r=0.783,P＜0.01).结论 超声造影能客观评价乳腺肿瘤血供,术前应用CDFI结合超声造影在体检查肿瘤血管,可为早期诊断乳腺肿瘤提供信息.     

MRI三维动态增强减影技术鉴别乳腺良恶性病变的研究

目的探讨磁共振三维动态增强减影技术在乳腺癌诊断中的应用价值。方法52例乳腺病变磁共振检查分别进行反转恢复法加权成像、动态增强扫描、减影成像。评价乳腺良恶性病变的MRI征象(包括形态学、内部信号及其动态增强特征等)、早期增强率、峰值增强率、峰值时间、时间-信号强度(T-SI)曲线等指标的诊断价值。结果乳腺癌的形态学特征性表现有形态不规则、环形强化和毛刺征。乳腺良性病变特征性表现有类圆形或分叶状,边缘光整,强化均匀及强化后可见低信号间隔。良恶性病变的早期增强率、达到峰值强化的时间以及曲线类型分布之间的差异有显著性意义(P<0.05),峰值增强率无显著性意义。结论MRI三维动态增强减影技术能满意显示乳腺良恶性病变的形态学特征和增强的血液动力学特点,是诊断乳腺癌十分有用的检查方法。     

MRI脂肪抑制技术在乳腺肿瘤诊断中的应用

目的 评价MRI脂肪抑制技术在乳腺肿瘤诊断中的应用价值.方法 对60例女性乳腺(包括40例恶性和20例良性病变)进行MRI检查,选用频率饱和法压脂或反转恢复成像,30例行压脂三维动态增强扫描,并绘制它们的时间-信号强度动态曲线.结果 MRI脂肪抑制的乳腺图像显示40例46个良性病灶,20例22个恶性病灶.增强扫描MRI 30例显示38个病灶,20个良性,18个恶性.18个恶性病灶对比强化程度较病灶平扫时信号明显增高.乳腺动态增强的时间-信号强度曲线分型流出型14例恶性、2例良性;平台型3例恶性、2例良性;单相型1例恶性、16例良性;两者差异有显著性意义(P《0.01).单相型提示良性,平台型提示可疑恶性,流出型提示恶性.结论 MRI脂肪抑制成像及动态增强扫描是诊断乳腺肿瘤的有效方法.     

动态增强MRI对眼眶病变诊断及鉴别诊断的价值

目的运用动态增强MR技术，分析病变的强化特点，以提高对不同眼眶病变的认识，尤其是不同良性肿瘤及恶性肿瘤的强化特点，进而提高MRI的诊断价值。方法共41例，均为单发病灶，均行MR检查，术后均得到病理证实。其中良性肿瘤和类肿瘤病变3l例，恶性肿瘤病变10例。使用1．5T超导MR机，头颅线圈采集。MR平扫包括：横断面T1WI、T2WI及T1WI矢状和冠状面扫描。层厚4mm。增强检查为使用对比剂后立即连续动态扫描，以观察病变的动态变化状况。对所测得的平扫及动态增强信号强度值（前、后），计算其强化率（E％）并得到时间-密度曲线（TIC），并进行统计学分析。结果（1）良恶性肿瘤第1分钟内平均强化率（E1％）比较：恶性肿瘤的E1％〉60％，而良性肿瘤的E1％〈60％，二者差异有统计学意义（P〈0．05）；（2）27例良性肿瘤除脑膜瘤外，绝大多数（88．9％，24例）强化为线型；（3）10例恶性肿瘤和3例脑膜瘤为平台型强化。（4）3例炎性假瘤和1例肉芽肿病变，表现为流出型。（5）12例海绵状血管瘤有特殊的强化模式，表现为局部点状和小结节状强化，然后逐步向全肿瘤扩展。结论动态增强MR检查，对鉴别良恶性肿瘤有明显意义；对鉴别肿瘤和炎症也可提供重要的诊断依据；少数病种，如海绵状血管瘤有特殊的强化模式。     

Diagnostic value of dynamic contrast-enhanced MRI for submucosal palatal tumors

Objectives

To evaluate the diagnostic value of dynamic contrast-enhanced MRI (DCE-MRI) for differentiating between benign and malignant tumors in the palate.

Materials and methods

26 patients with submucosal palatal tumors were preoperatively examined using DCE-MRI. Their maximum contrast index (CImax), time of CImax (Tmax), and washout ratios (WR300 and WR600) were determined from contrast index curves. The submucosal palatal tumors were divided into two groups according to their Tmax values: the early enhancement group (Tmax < 300 s) consisted of 9 malignant tumors and 6 benign tumors, while the late enhancement group (Tmax ≥ 300 s) included one malignant tumor and 10 benign tumors. We compared the following DCE-MRI parameters between the benign and malignant tumors: CImax and Tmax in all cases and CImax, Tmax, and the washout ratios in the early enhancement group. In addition, we performed a regression analysis of the relationships between tumor size and DCE-MRI parameters; i.e., CImax, Tmax, and washout ratios, among the malignant salivary gland tumors and pleomorphic adenomas.

Results

In all cases and the early enhancement group, significant differences in Tmax were detected between the benign and malignant tumors (P < 0.001 and P < 0.05, respectively), and the optimal Tmax cutoff value for differentiating between them was found to be 165 s. None of the other parameters displayed significant differences between the benign and malignant tumors. Only the WR600 of the pleomorphic adenomas was significantly correlated with tumor size (R² = 0.92, P < 0.001).

Conclusions

Tmax is a useful parameter for distinguishing between benign and malignant submucosal palatal tumors.     

Improved diagnostic accuracy of breast MRI through combined apparent diffusion coefficients and dynamic contrast‐enhanced kinetics

This study investigated the relationship between apparent diffusion coefficient (ADC) measures and dynamic contrast‐enhanced magnetic resonance imaging (MRI) kinetics in breast lesions and evaluated the relative diagnostic value of each quantitative parameter. Seventy‐seven women with 100 breast lesions (27 malignant and 73 benign) underwent both dynamic contrast‐enhanced MRI and diffusion weighted MRI. Dynamic contrast‐enhanced MRI kinetic parameters included peak initial enhancement, predominant delayed kinetic curve type (persistent, plateau, or washout), and worst delayed kinetic curve type (washout > plateau > persistent). Associations between ADC and dynamic contrast‐enhanced MRI kinetic parameters and predictions of malignancy were evaluated. Results showed that ADC was significantly associated with predominant curve type (ADC was higher for lesions exhibiting predominantly persistent enhancement compared with those exhibiting predominantly washout or plateau, P = 0.006), but was not significantly associated with peak initial enhancement or worst curve type (P > 0.05). Univariate analysis showed significant differences between benign and malignant lesions in both ADC (P < 0.001) and worst curve (P = 0.003). In multivariate analysis, worst curve type and ADC were significant independent predictors of benign versus malignant outcome and in combination produced the highest area under the receiver operating characteristic curve (0.85 and 0.78 with 5‐fold cross validation). Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.     

动态增强MRI时间信号强度曲线在卵巢良恶性肿瘤鉴别中的价值

目的探讨动态增强MRI时间信号强度曲线(TIC)鉴别卵巢肿瘤良恶性的价值。方法收集2016年1月—2017年8月间于我院超声检查发现盆腔附件肿块的71例女性病人,年龄14～78岁,中位年龄52岁。所有病人行MRI常规及动态增强检查后经手术获得病理结果。利用工作站在肿块实性区和正常子宫外肌层设置兴趣区获取TIC,以子宫外肌层强化曲线为基准,对卵巢肿块实性区的TIC类型进行校正,分析曲线类型与良恶性卵巢肿瘤的关系。采用χ~2检验比较良恶性肿瘤间3种TIC类型差异。结果 71例病人中包括卵巢恶性肿瘤40例,良性肿瘤26例,交界性肿瘤5例。上述3种肿瘤的TIC类型的差异有统计学意义(P0.05)。良性肿瘤以Ⅰ型TIC为主(73.1%),恶性肿瘤以Ⅲ型TIC为主(77.5%)。MRI+TIC鉴别肿瘤良恶性的敏感度、特异度、阳性预测值和阴性预测值较单独常规MRI检查各指标均有不同程度提高。结论动态增强MRI及其TIC对卵巢良恶性肿瘤具有重要的鉴别诊断价值。     

乳腺磁共振成像:组织学与病灶定性、定量特征的相关性

目的　通过分析定性、定量MR特征鉴别良、恶性乳腺病灶。方法　对 46例患者的病灶定性、定量MR特征及BI -RADS分类积分与组织学的相关性进行比较。结果　定性特征中的形状、边缘类型、T2 WI相对信号强度、早期周边环形强化、晚期不均匀强化、时间 -信号强度曲线类型与恶性具有统计学显著相关性 (Ρ <0 .0 5 ) ;定量特征中的强化峰值时间、增强曲线最大斜率和流出率与恶性具有统计学显著相关性 (Ρ <0 .0 0 1) ;BI -RADS分类积分系统与恶性具有统计学显著相关性 (Ρ <0 .0 0 1)。结论　定性、定量特征相结合能够提高乳腺病灶诊断的准确性。     

Magnetic resonance characterization of tumor microvessels in experimental breast tumors using a slow clearance blood pool contrast agent (carboxymethyldextran-A2-Gd-DOTA) with histopathological correlation

Carboxymethyldextran (CMD)-A2-Gd-DOTA, a slow clearance blood pool contrast agent with a molecular weight of 52.1 kDa, designed to have intravascular residence for more than 1 h, was evaluated for its potential to characterize and differentiate the microvessels of malignant and benign breast tumors. Precontrast single-slice inversion-recovery snapshot FLASH and dynamic contrast-enhanced MRI using an axial T1-weighted three-dimensional spoiled gradient recalled sequence was performed in 30 Sprague-Dawley rats with chemically induced breast tumors. Endothelial transfer coefficient and fractional plasma volume of the breast tumors were estimated from MRI data acquired with CMD-A2-Gd-DOTA enhancement injected at a dose of 0.1 mmol Gd/kg body weight using a two-compartment bidirectional model of the tumor tissue. The correlation between MRI microvessel characteristics and histopathological tumor grade was determined using the Scarff-Bloom-Richardson method. Using CMD-A2-Gd-DOTA, no significant correlations were found between the MR-estimated endothelial transfer coefficient or plasma volumes with histological tumor grade. Analysis of CMD-A2-Gd-DOTA-enhanced MR kinetic data failed to demonstrate feasibility for the differentiation of benign from malignant tumors or for image-based tumor grading.     

MR动态增强鉴别良恶性骨肿瘤及肿瘤样病变的价值

目的探讨磁共振动态增强时间-信号强度曲线(time-signal intensity curve,TIC)和动态强化参数早期动态增强的斜率值(Slope)、边缘-中心向心强化程度比(Rrim-center)在鉴别良、恶性骨肿瘤及肿瘤样病变的价值。资料与方法选择临床资料完整的骨肿瘤及肿瘤样病变患者61例行动态增强扫描,利用工作站配置的MeanCurve分析软件直接得到病变实质、邻近肌肉及相同层面的动脉TIC,测量指标包括TIC类型、Slope、Rrim-center。统计学分析结果以P<0.05为差异有统计学意义。结果 61例良恶性骨肿瘤TIC类型:23例良性骨肿瘤及肿瘤样病变中,I型0例,Ⅱ型7例(30.4%),Ⅲ型13例(56.5%),Ⅳ型3例(13.0%);38例恶性骨肿瘤中,I型11例(28.9%),Ⅱ型17例(44.7%),Ⅲ型10例(26.4%),Ⅳ型0例;良、恶性骨肿瘤TIC类型分布差异有统计学意义;TIC取I、Ⅱ型曲线为恶性诊断标准,诊断恶性肿瘤的敏感性为73.68%,特异性为69.57%,准确性为72.13%,阳性预测值为80%,阴性预测值为61.54%。动态增强参数比较,良性骨肿瘤Slope...     

Dynamic breast MR imaging: are signal intensity time course data useful for differential diagnosis of enhancing lesions?

PURPOSE: To assess the relevance of the signal intensity time course for the differential diagnosis of enhancing lesions in dynamic magnetic resonance (MR) imaging of the breast. MATERIALS AND METHODS: Two hundred sixty-six breast lesions were examined with a two-dimensional dynamic MR imaging series and subtraction postprocessing. Time-signal intensity curves of the lesions were obtained and classified according to their shapes as type I, which was steady enhancement; type II, plateau of signal intensity; or type III, washout of signal intensity. Enhancement rates and curve types of benign and malignant lesions were compared. RESULTS: There were 101 malignant and 165 benign lesions. The distribution of curve types for breast cancers was type I, 8.9%; type II, 33.6%; and type III, 57.4%. The distribution of curve types for benign lesions was type I, 83.0%; type II, 11.5%; and type III, 5.5%. The distributions proved significantly different (chi 2 = 139.6; P < .001). The diagnostic indices for signal intensity time course were sensitivity, 91%; specificity, 83%; and diagnostic accuracy, 86%. The diagnostic indices for the enhancement rate were sensitivity, 91%; specificity, 37%; and diagnostic accuracy, 58%. CONCLUSION: The shape of the time-signal intensity curve is an important criterion in differentiating benign and malignant enhancing lesions in dynamic breast MR imaging. A type III time course is a strong indicator of malignancy and is independent of other criteria.