Diffusion and perfusion of the breast

This article is a review of the current published clinical applications of DWI and perfusion of breast MR explaining possibilities and limits of both techniques.DWI in a fast time acquisition and without contrast medium gives information as regards cellularity of breast lesions. The technique can be used for distinguishing between benign and malignant breast lesions and monitoring therapies in locally advanced breast cancer.Perfusion can give additional information as regards vascularization of breast lesions, useful in the characterization of breast lesions doubt at DCE-MRI and also in monitoring chemotherapic effect.     

Diffusion-weighted and diffusion-tensor imaging of normal and diseased uterus

Owing to technical advances and improvement of the software, diffusion weighted imaging and diffusion tensor imaging (DWI and DTI) greatly improved the diagnostic value of magnetic resonance imaging (MRI) of the pelvic region. These imaging sequences can exhibit important tissue contrast on the basis of random diffusion (Brownian motion) of water molecules in tissues. Quantitative measurements can be done with DWI and DTI by apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values respectively. ADC and FA values may be changed by various physiological and pathological conditions providing additional information to conventional MRI. The quantitative DWI assists significantly in the differentiation of benign and malignant lesions. It can demonstrate the microstructural architecture and celluler density of the normal and diseased uterine zones. On the other hand, DWI and DTI are useful for monitoring the treatment outcome of the uterine lesions. In this review, we discussed advantages of DWI and DTI of the normal and diseased uterus.     

扩散加权成像与MRI动态增强检测小乳腺癌的比较研究

目的 比较扩散加权成像(DWI)与动态对比增强MR成像(DCE MRI)对小乳腺癌的检出敏感性,并评价DWI的临床应用价值.方法 经病理证实的48例共70个乳腺小病灶(最大径≤2 cm)被纳入研究对象,其中恶性病灶45个,良性25个.所有患者均行DWI和DCE MRI,DCEMRI采用快速小角度激发(FLASH)序列,绘制病灶的时间.信号强度曲线(TIC),DWI采用回波平面成像(EPI)序列加用全局自动校准部分并行采集(GRAPPA)技术,取2个扩散敏感因子(b)值(800、1000 s/mm2)行横断面扫描,测量病灶的表观扩散系数(ADC)值.对2种检查方法 的诊断结果 进行比较.结果 DCE MRI正确诊断了40个小乳腺癌及19个良性小病灶,TIC显示小乳腺癌的敏感性及阳性预测值分别为88.9%(40/45)及87.0%(40/46).DWI中,在2种b值(800、1000 s/mm2)条件下小乳腺癌平均ADC值分别为(1.153±0.192)×10-3和(1.079±0.186)×10-3 mm2/s,而良性小病灶的平均ADC值为(1.473±0.252)×10-3和(1.419±0.255)×10-3 mm2/s;同组患者在2种b值条件下的ADC值差异无统计学意义(P＞0.05),而良恶性2组小病灶的ADC值差异有统计学意义(P＜0.01);b值取1000 s/mm2 时,根据DWI信号结合ADC值测量结果 可以正确诊断39个小乳腺癌及19个良性小病灶,其对小乳腺癌检出的敏感性及阳性预测值均为86.7%(39/45).DWI与DCEMRI的诊断结果 有很好的一致性,DWI联合DCE MRI可以提高检出的敏感性及阳性预测值,分别达93.3%(42/45))及91.3%(42/46).结论 DWI对小乳腺癌具有较高的检出率,且ADC值的测量可以为良恶性病变的鉴别提供有价值的诊断信息.     

Diffusionsgewichtete Brustbildgebung

Diffusion-weighted imaging (DWI) of the breast provides additional contrast information in breast magnetic resonance imaging (MRI). The DWI procedure can easily be implemented in the routine breast MRI protocol with little time expenditure regarding image acquisition and evaluation. Evaluation of the DW images can be performed with or without the routine breast MRI sequences (T2w and T1w with contrast material) but evaluation in combination with the routine program is highly recommended. Objective analysis of the tissue diffusion can be achieved by calculating the apparent diffusion coefficient (ADC) value with the scanner software. The choice of the DW sequence, evaluation and determination of the ADC threshold to differentiate between benign and malignant lesions should be scanner adapted. The use of DW imaging qualifies for routine use regarding the differentiation between malignant and benign breast lesions. Non-mass-like lesions and monitoring neoadjuvant chemotherapy can also be evaluated with DW sequences. The benefit of the additional information from DW-MR mammography to characterize non-mass-like lesions and in the course of neoadjuvant chemotherapy remains unclear to date.     

DWI联合Fischer评分法对乳腺良恶性肿块的鉴别

目的:探讨DWI联合Fischer评分法对乳腺良恶性肿块的鉴别诊断价值。方法:回顾性分析42例经DWI与Fis-cher评分法诊断的乳腺肿块,计算各方法的诊断敏感性、特异性、准确性。结果:恶性病灶的ADC值较良性病灶降低,但其鉴别良恶性病灶的敏感性较低。时间-信号强度曲线中的Ⅲ型曲线多考虑为恶性,但良恶性病灶均可出现Ⅱ型曲线。结论:研究显示,DWI联合Fischer评分法对乳腺良恶性病灶的鉴别诊断具有较高的敏感性和特异性,能够提高乳腺癌的诊断准确率。     

表观扩散系数在乳腺病变诊断中的应用价值

目的:对比乳腺良、恶性病变的表观扩散系数(apparent diffusion coefficient,ADC),探讨DWI在乳腺病变中的诊断价值.材料和方法:搜集术前行MR检查并经病理证实的236例乳腺病变,采用平面回波-扩散加权成像序列(EPH)WI);测量病变区和对侧正常乳腺腺体的ADC值,应用t检验比较良、恶性病变及正常腺体ADC值的差异,采用接收者工作特征曲线(receiver operating characteristic curve,ROC)确定良、恶性病变的ADC界值;根据BI-RADS MRI将乳腺病变分为肿块性病变和非肿块性病变,比较ADC值在两组病变中定性诊断效能.结果:236例乳腺病变中,恶性病变ADC值[(1.08±0.32)X 10-3mm2/s]显著低于良性病变[(1.48±0.35)×102mm2/s],差异有统计学意义(P=0.01);根据ROC曲线确定ADC界值为1.25×10-2mm2/s,诊断敏感性和特异性分别为78.2%和77.5%.肿块性病变良、恶性ADC界值为1.15×10-3mm2/s(敏感性和特异性分别为79.8%和81.8%),非肿块性病变良、恶性ADC界值为1.35×10-3mm2/s(敏感性和特异性分别为78%和72%).绪论:根据ADC界值可以鉴别乳腺良、恶性病变;对肿块性病变和非肿块性病变应采用不同的ADC界值;DWI对肿块性病变的诊断效能优于非肿块性病变.     

小b值扩散加权成像对乳腺癌的诊断价值

目的:探讨小b值扩散加权成像(DWI)在诊断乳腺癌中的价值.方法:采用Philips 1.5T磁共振扫描仪对48例乳腺疾病患者行常规SE序列扫描、单次激发自旋回波-回波平面成像(SE-EPI)序列DWI及动态增强扫描.48例患者共检出53个病灶,其中良性肿瘤29个,恶性肿瘤24个,均经手术及病理证实;选择健康志愿者20...     

The role of diffusion-weighted imaging and the apparent diffusion coefficient (ADC) values for breast tumors.

OBJECTIVE: We wanted to evaluate the role of diffusion-weighted imaging (DWI) and the apparent diffusion coefficient (ADC) for detecting breast tumors, as compared with the T1- and T2-weighted images. MATERIALS AND METHODS: Forty-one female patients underwent breast MRI, and this included the T1-, T2-, DWI and dynamic contrast-enhanced images. Sixty-five enhancing lesions were detected on the dynamic contrast-enhanced images and we used this as a reference image for detecting tumor. Fifty-six breast lesions were detected on DWI and the histological diagnoses were as follows: 43 invasive ductal carcinomas, one mucinous carcinoma, one mixed infiltrative and mucinous carcinoma, seven ductal carcinomas in situ (DCIS), and four benign tumors. First, we compared the detectability of breast lesions on DWI with that of the T1- and T2-weighted images. We then compared the ADCs of the malignant and benign breast lesions to the ADCs of the normal fibroglandular tissue. RESULTS: Fifty-six lesions were detected via DWI (detectability of 86.2%). The detectabilities of breast lesions on the T1- and T2-weighted imaging were 61.5% (40/65) and 75.4% (49/65), respectively. The mean ADCs of the invasive ductal carcinoma (0.89+/-0.18 x 10(-3)mm(2)/second) and DCIS (1.17+/-0.18 x 10(-3)mm(2)/ second) are significantly lower than those of the benign lesions (1.41+/-0.56 x 10(-3)mm(2)/second) and the normal fibroglandular tissue (1.51+/-0.29 x 10(-3)mm(2)/ second). CONCLUSION: DWI has a high sensitivity for detecting breast tumors, and especially for detecting malignant breast tumors. DWI was an effective imaging technique for detecting breast lesions, as compared to using the T1- and T2-weighted images.     

3.0T磁共振在乳腺检查中的初步应用

目的:探讨3.0T磁共振利用体部相控阵线圈进行乳腺检查的临床应用价值.方法:36例乳腺疾病患者中隆乳术后26例,乳腺癌6例,乳腺良性病变4例,均行常规MR T1WI、T2WI和压脂序列T2WI,17例行动态增强扫描,13例行扩散加权成像,并与术后病理结果进行对照分析.结果:36例乳腺疾病患者均能显示显示乳腺结构及邻近组织情况,图像清晰无变形.22例聚丙烯酰胺水凝胶注射隆乳术后患者,注入物于T1WI呈稍低信号、T2WI呈高信号,在脂肪抑制T2WI上显示最清晰,呈均匀高信号;4例角鲨烯注射液隆胸术后,注入物在T1WI和T2WI上呈小颗粒状脂肪信号影.6例乳腺癌于DWI上呈明显高信号,动态增强曲线呈早期信号快速上升,中晚期信号强度逐渐降低表现;4例发现腋窝淋巴结转移.4例乳腺良性病变,动态增强曲线呈逐渐上升改变.结论:3.0T磁共振结合体部相控阵线圈可显示隆胸材料的性质和分布,常规MRI扫描结合DWI和动态增强扫描对乳腺良恶性病变的鉴别诊断有重要临床价值.     

扩散敏感因子800时乳腺良恶性病变ADC界值的确定

目的：确定扩散敏感因子为800s/mm^2时乳腺良恶性病变的ADC界值,评价MR扩散加权成像（DWI）对乳腺良恶性病变鉴别诊断的价值。方法：回顾性分析经手术病理证实的70例（78个病灶）乳腺病变的DWI图像,其中良性病变26例（31个病灶）,恶性病变44例（47个病灶）。测量DWI图像上显示的病变表观扩散系数（ADC）值。通过ROC曲线确定ADC值的诊断阈值,并以此值进行鉴别诊断,同时计算ROC曲线下面积。结果：良恶性病变的ADC值均符合正态性分布,良恶性病变的ADC平均值分别为（1.46±0.26）×10^-3mm^2/s和（1.02±0.19）×10^-3mm^2/s,恶性病变的ADC值明显低于良性病变（P〈0.05）。约登指数最大法确定的ADC诊断阈值为1.28×10^-3mm^2/s,以此值进行鉴别诊断时的敏感度、特异度和诊断符合率分别为93.6%,75.9%,86.8%;阳性似然比最大法确定的ADC诊断阈值为1.035×103mm^2/s,以此值进行鉴别诊断时的敏感度、特异度和诊断符合率分别为46.8%,96.6%,65.8%;ROC曲线下面积为0.905（95%可信区间为0.836-0.975）。结论：扩散敏感因子为800s/mm^2时乳腺良恶性病变的ADC界值确定为1.28×10^-3mm^2/s,DWI的ADC值测定有助于乳腺良恶性病变的鉴别诊断。     

乳腺良恶性病变的磁共振弥散加权成像鉴别诊断

目的:探讨3.0T磁共振扩散加权成像在乳腺良恶性病变鉴别诊断中的价值,并研究乳腺癌患者病变ADC值与雌激素受体(ER)表达间的相关性.方法:经病理证实的32例女性患者(年龄29～61岁,平均45岁)纳入研究,其中恶性组17例,全部为乳腺癌.所有病例均使用Siemens Verio 3.0T超导磁共振成像仪,行常规MRI...     

高b值MR扩散加权成像在乳腺良恶性病变诊断中的应用价值

目的 评价高b值MR DWI及ADC值在乳腺良恶性病变诊断中的应用价值.方法 165例患者在行乳腺MR动态增强扫描前行不同b值(分别为500、1500 s/mm2)的DWI扫描,对171个怀疑或高度怀疑恶性病变者行回顾性分析.以正常乳腺组织为参考基准,选择增强图像中异常强化的高信号病变,同时在高b值(b= 1500 s/mm2)DWI中视觉判定是高信号的病变定义为恶性病变阳性结果,否则为良性病变阴性结果.对其中111个DWI视觉判定阳性结果的病变计算ADC值.依据全部病变穿刺活检病理诊断结果,应用Fisher精确检验和Wilcoxon秩和检验对比分析高b值DWI视觉评估中恶性和良性病变的阳性和阴性病灶数,以ADC值=1.13×10-3 mm2/s作为临界值,计算诊断的特异度和敏感度.结果 乳腺病变穿刺活检病理证实的171个乳腺病变中,91个恶性病变,80个良性病变.高b值DWI视觉评估,139个阳性结果中,恶性病变83个,良性病变56个;32个阴性结果中,良性病变24个,恶性病变8个(非肿块性导管原位癌),差异有统计学意义(P＜0.01).所有浸润性癌和肿块样导管原位癌(DCIS)在DWI视觉判定中为阳性,8例非肿块性DCIS判定为假阴性,总体的敏感度为91.2％ (83/91),特异性为30.0％ (24/80).110个肿块样病变和1个局灶性病变DWI视觉评估阳性结果的病变中,63个恶性病变平均ADC值为(0.73±0.24)×10-3 mm2/s,48个良性病变平均ADC值为(1.19±0.42)×10-3mm2/s,差异有统计学意义(Z=5.818,P＜0.01).以ADC值=1.13×10-3mm2/s作为临界值时,61个恶性病变为阳性结果,2个黏液癌为假阴性结果;27个良性病变为阴性结果,21个良性病变为假阳性,诊断敏感度是96.8％(61/63),特异度为56.2％ (27/48).结论 高b值DWI及ADC值对乳腺良恶性病变的鉴别诊断有一定的作用,但在诊断非肿块性乳腺病变时仍需慎重.     

弥散加权成像鉴别乳腺良恶性病变的价值初探

目的　探讨弥散加权成像（diffusionweightedimaging,DWI）的表面弥散系数（apparentdiffusioncoefficients,ADC）鉴别乳腺良恶性病变的价值。方法　健康志愿者10人,经手术病理证实的乳腺病变49例,其中恶性肿瘤26例,良性病变23例。DWI采用单次激发回波平面成像（echo-planarimaging,EPI）技术,14例取5个b值（b为扩散敏感度）,余者取2个b值,计算ADC值。以恶性肿瘤ADC值单侧上界95%容许区间为界限判断病灶的良恶性,诊断结果与动态增强比较。结果　除1例原位癌和1例小腺瘤外,DWI显示所有良恶性病变。恶性肿瘤组ADC值为(0.9608±0.2043)×10     

Role of diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) in differentiating between benign and malignant breast lesions

Objective

To assess the role of DWI and ADC in differentiating between benign and malignant breast lesions.

Materials and methods

51 patients (age range 24–66 years; mean age 48 years) were included in our study. MRI was done using bilateral fat-suppressed T2- weighted fast spin-echo, STIR, axial T1-weighted fast spin-echo. DWI series were acquired using echo planar imaging pulse sequences incorporated with diffusion gradients and finally dynamic contrast enhancement study was done.

Results

Sixty three lesions were detected in 51 patients included in our study. Twenty one lesions were malignant, three lesions were intermediate and twenty two lesions were fibroadenoma according to the final histopathological study and seventeen lesions were breast cysts. A total of 21 lesions showed lower ADC values than benign lesions and were in the range of 0.76–1.29 × 10⁻³ mm²/s and were diagnosed as malignant breast lesions. The sensitivity and specificity for DWI in the differentiating malignant from benign breast lesions were calculated and showed 95.4% and 97.5%, respectively.

Conclusion

DWI is easy to obtain in short scan time and easy to evaluate, and ADC values can differentiate between benign and malignant breast lesions with high sensitivity and specificity.     

磁共振扩散加权成像在乳腺病变诊断中的应用

目的：探讨单纯磁共振扩散加权成像对诊断乳腺病变的临床应用价值。方法：对临床拟诊为乳腺肿块的37例患者行磁共振扩散加权成像检查,并获得病理证实,其中良性病灶18个,恶性病灶19个。描记扩散图像上病变的兴趣区,由软件计算获得表观扩散系数（ADC）值。对获取数据进行统计分析,采用t检验对良性和恶性病变的ADC值进行比较。结果：12例良性病变在DWI上呈等信号或高信号,但ADC值升高或下降不明显,6例良性病变DWI上呈高信号,ADC值明显下降;19例恶性肿瘤DWI上呈高信号,ADC值明显下降。良性病变组ADC值为（1.474±0.441）×10^-3mm^2/s,恶性病变组ADC值为（1.082±0.160）×10^-3mm^2/s,两者间差异有显著性意义（P=0.002）。结论：MR扩散加权成像ADC值测量在乳腺病变定性诊断中有一定的辅助诊断价值。     

乳腺癌MR弥散加权成像研究进展

MR在乳腺癌诊断方面的应用价值已经得到广泛认同,为增加检出乳腺癌的敏感性,需应用多种MR扫描技术。然而,常规MR在检测及描述乳腺病变特征时具有一定的局限性,弥散加权成像作为一种重要的功能成像技术,能够反映组织的生物物理学特征,有较大的发展前景。弥散加权成像是唯一能够检测活体组织内水分子弥散运动的非侵入性方法,可以检测出组织结构在分子水平上的改变。其成像时间短,敏感性高,无需使用对比剂,并且能比常规MR检查更早的发现病变,因此,它已经广泛应用于脑部疾病中,也越来越多地应用于乳腺疾病方面。本文就弥散加权成像在乳腺癌的应用方面予以综述。     

磁共振扩散加权成像及动态增强MRI在乳腺病变中的应用价值

目的 探讨月经周期对正常乳腺实质磁共振扩散加权成像(DWI)表观扩散系数(ADC)值的影响,并评价动态增强MRI(DCE-MRI)及DWI在乳腺病变鉴别诊断中的价值。方法 选取健康女性志愿者34例、乳腺病变患者96例,所有病例均经外科手术或针吸病理证实,其中良性病变者36例,共44个病灶;恶性病变者60例,共70个病灶...     

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.     

Benign neck masses showing restricted diffusion: Is there a histological basis for discordant behavior?

Diffusion weighted imaging (DWI) evolved as a complementary tool to morphologic imaging by offering additional functional information about lesions. Although the technique utilizes movement of water molecules to characterize biological tissues in terms of their cellularity, there are other factors related to the histological constitution of lesions which can have a significant bearing on DWI. Benign lesions with atypical histology including presence of lymphoid stroma, inherently increased cellularity or abundant extracellular collagen can impede movement of water molecules similar to malignant tissues and thereby, show restricted diffusion. Knowledge of these atypical entities while interpreting DWI in clinical practice can avoid potential misdiagnosis. This review aims to present an imaging spectrum of such benign neck masses which, owing to their distinct histology, can show discordant behavior on DWI.     

MR背景抑制扩散加权成像在乳腺癌的应用

目的 探讨MR扩散加权成像(DWI)结合短时间反转恢复回波成像(STIR-EPI)背景抑制(BS)技术在乳腺癌成像的技术参数及其可行性.方法 回顾性分析26例乳腺癌的MR DWIBS测得各组织的表观扩散系数(ADC),利用三维最大强度投影(3D-MIP)重组及黑白反转技术,观察病变显示效果.观察乳腺痛DWI及DWIBS两种方法的显示率.对乳腺各组织的ADC值进行随机区组设计的方差分析,在乳腺癌与良性病变ADC值的比较中,采用t检验.对两种成像方法乳腺癌的显示率进行配对资料X2检验.结果 在扩散敏感因子(b)=800 mm2/s的图像中,乳腺癌多表现为高信号,其ADC值分别为:肿瘤实质(0.93±0.25)×10-3 mm2/s、瘤内坏死灶(2.06±0.17)×10-3 mm2/s、正常腺体(1.92±0.23)×10-3 mm2/s、转移性淋巴结(1.10 ± 0.14)×10-3mm2/s,各种组织间两两比较,差异具有统计学意义(P值均＜0.01).DWIBS经MIP重组及黑白反转技术,病变周围组织信号被抑制,得到类正电子发射体层成像(PET)图像.在乳腺癌中,DWIBS对肿瘤实质(92.3/)及转移性淋巴结(88.4/)的显示率要高于DWI序列(分别为57.6/和42.3/),差异有统计学意义(x2值分别为8.307、12.235,P均＜0.05).乳腺癌与良性病变ADC值分别为(1.092±0·17)×10-3和(2.154±0.53)×10-3mm2/s,差异有统计学意义(t=8.626,P＜0.05).结论 MRDWIBS在显示病灶方面有一定优势,应用DWI结合ADC值对乳腺癌的诊断具有临床应用前景.