1、Diffusion-weighted MR imaging of Diffusion-weighted MR imaging of the breast:Comparison of the breast:Comparison of apparent diffusion coefficient apparent diffusion coefficient values of normal breast tissue values of normal breast tissue with benign and malignant breast with benign and malignant b
2、reast lesionslesions乳房乳房MRMR扩散加权成像：比较正常扩散加权成像：比较正常乳腺组织与良性和恶性乳腺病变表乳腺组织与良性和恶性乳腺病变表观扩散系数值观扩散系数值 XIA WANJUN XIA WANJUN乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia1 The specificity of conventional magnetic resonance(MR)imaging is lower than its high sensitivity.传统的磁共振（传统的磁共振（MR）成像灵敏度低。）成像灵敏度低。Diffusion-weight
3、ed imaging(DWI),based on alterations in the microscopic motion of water molecules,promises improved specificity for breast MR imaging.In this study,we aimed to determine the diagnostic potential of DWI to differentiate between benign and malignant breast lesions and normal breast tissue.弥散加权成像（弥散加权成
4、像（DWI）的）的基础是水分子的微观运动，是特殊的乳腺磁共振基础是水分子的微观运动，是特殊的乳腺磁共振成像技术。本项研究的目的是探讨成像技术。本项研究的目的是探讨DWI对区分良对区分良性和恶性乳腺病变及正常乳腺组织的潜在诊断性。性和恶性乳腺病变及正常乳腺组织的潜在诊断性。乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia2 Dynamic contrast-enhanced breast MR imaging and DWI were applied to 108 women.Apparent diffusion coefficient(ADC)values wer
5、e obtained for normal breast tissue(n=183),benign lesions(n=66)and malignant lesions(n=58).The results were compared with the patients final diagnoses.对对108名妇女进行动态对比增强乳腺磁共振成名妇女进行动态对比增强乳腺磁共振成像和弥散加权成像。对正常乳腺组织（像和弥散加权成像。对正常乳腺组织（N=183例），良性病变组（例），良性病变组（n=66例），恶性病变例），恶性病变（N=58例）分别进行表观扩散系数（例）分别进行表观扩散系数（ADC）
6、值测）值测定。然后与患者的最终诊断结果进行比较。定。然后与患者的最终诊断结果进行比较。乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia3 The mean age of the patients was 44.9(range 1977)years.There was no difference between the mean age of patients with malignant and benign lesions(45.0 years vs.44.8 years,p=0.9;Students t-test).The ADC measurements o
7、f normal breast tissue were obtained from 183 breasts.患者的平均年龄为患者的平均年龄为44.9岁（范围岁（范围19-77）。恶）。恶性和良性患者的平均年龄之间无显着差异性和良性患者的平均年龄之间无显着差异（45.0岁岁vs44.8年，年，P=0.9;t分布检验分布检验）。正）。正常乳腺组织的常乳腺组织的ADC测量有测量有183例。例。乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia4 On histopathological examination,58 lesions proved to be maligna
8、nt in 42 patients:invasive ductal carcinoma(IDC)n=31;invasive lobular carcinoma(ILC)n=1;mixed invasive lobular and ductal carcinoma(IDC+ILC)n=3;ductal carcinoma in situ n=2;mix IDC+mucinous carcinoma n=1;IDC and pleomorphic carcinoman=1;medullary carcinoma n=1;对对42位患者位患者58例病变进行病理组织学检查，发例病变进行病理组织学检查，
9、发现恶性乳腺浸润性导管癌（现恶性乳腺浸润性导管癌（IDC）31位患者，浸润位患者，浸润性小叶癌（性小叶癌（ILC）1位患者，浸润性导管癌和浸润位患者，浸润性导管癌和浸润性小叶癌（性小叶癌（IDC+ILC）3位患者位患者;导管原位癌导管原位癌2位患位患者者;浸润性导管癌浸润性导管癌+黏液腺癌黏液腺癌 1位患者位患者;浸润性导管浸润性导管癌和多形性癌癌和多形性癌1例，髓样癌例，髓样癌1位患者，位患者，乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia5 malignant phyllodes tumour n=1;diffuse leukaemic infiltrati
10、on of the breast n=1.恶性叶状肿瘤恶性叶状肿瘤1位患者，弥漫性白血病浸润乳腺位患者，弥漫性白血病浸润乳腺1位患者。位患者。The mean size of the malignant lesions was 41.3 34.3 mm.恶性病变的平均大小为恶性病变的平均大小为41.334.3毫米。毫米。A total of 66 benign lesions in 44 patients were included in the study.44位患者位患者66例良性病变的研究。例良性病变的研究。乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia6
11、 35 lesions were histopathologically diagnosed as benign fibroadenoma(n=18),cystosarcoma phyllodes tumour(n=2),fibrocystic changes(n=4),seroma(n=6),fat necrosis(n=2),ductal hyperplasia(n=1),papilloma(n=1)and haematoma(n=1).35例病变组织病理学诊断为良性纤维腺瘤例病变组织病理学诊断为良性纤维腺瘤18例，分叶状囊肉瘤例，分叶状囊肉瘤2例，纤维囊性变例，纤维囊性变4例，血清例，血
12、清肿组肿组6例，脂肪坏死例，脂肪坏死2例，导管上皮增生例，导管上皮增生1例，乳例，乳头状瘤头状瘤1例和血肿例和血肿1例。例。乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia7 31 benign lesions had typical BI-RADS(Breast Imaging Reporting and Data System)2 findings on DCE-MRI and were diagnosed as cyst(n=7),fibroadenoma(n=20)and intramammarian lymph node(n=4).DCE-MRI检查对检
13、查对31例典型的良性病变定例典型的良性病变定BI-RADS分级（乳腺影像报告和数据系统）分级（乳腺影像报告和数据系统）2，并诊断为囊肿并诊断为囊肿7例，纤维腺瘤例，纤维腺瘤20例和乳房淋巴例和乳房淋巴结结4例。例。乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia8 Resu lts：Mean ADC values for benign and malignant breast lesions were 1.04 103 0.29 103 mm2/s and 2.00 103 0.55 103 mm2/s,respectively(p=0.001,Students
14、t-test),while that for normal breast tissue was 1.78 103 0.33 103 mm2/s.With a cut-off value of 1.46 103 mm2/s for ADC in receiver operating characteristic analysis,95%sensitivity and 85%specificity were achieved for differentiating between benign and malignant lesions.结果结果 乳腺良、恶性病变的乳腺良、恶性病变的ADC值平均值
15、分别为值平均值分别为1.0410-30.29103mm2/s和和2.001030.5510-3 mm2/s，（P=0.001，t分布检验），而正常乳腺组织分布检验），而正常乳腺组织1.781030.33103 mm2/s。根据受试者特征取。根据受试者特征取1.46103 mm2/s的的ADC为区分良性和恶性病变的临界值，为区分良性和恶性病变的临界值，得到敏感性为得到敏感性为95和特异性和特异性85。乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia9 Conclusion DWI of the breast can help differentiate benign
16、 and malignant breast lesions from normal breast tissue.结论结论 乳房乳房DWI检查可以帮助区分良性、恶性检查可以帮助区分良性、恶性乳腺病变与正常乳腺组织。乳腺病变与正常乳腺组织。DWI,which can be easily introduced into standard breast MR imaging protocols without increasing imaging times,promises to increase the accuracy of breast MR imaging without contrast
17、media.。DWI在不增加成像时间，通常作为常规的乳在不增加成像时间，通常作为常规的乳房房MR成像检查方法之一，增加乳腺磁共振成像成像检查方法之一，增加乳腺磁共振成像的准确性而无需造影剂。的准确性而无需造影剂。乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia10 Since the specificity of conventional MR imaging,which uses morphological and kinetic criteria,is relatively lower than its high sensitivity,advanced MR
18、 imaging application has a potential role to play in the diagnosis of breast lesions.常规磁共振成像，它采用形态学和动力学的标常规磁共振成像，它采用形态学和动力学的标准，其灵敏度低于相对先进的磁共振成像，先准，其灵敏度低于相对先进的磁共振成像，先进的磁共振成像技术在乳腺病变的诊断中具有进的磁共振成像技术在乳腺病变的诊断中具有潜在的作用。潜在的作用。Diffusion-weighted imaging(DWI)promises improved specificity of breast MR imaging.弥
19、散加权成像（弥散加权成像（DWI）能够提高乳腺）能够提高乳腺磁共振成像的特异性。磁共振成像的特异性。乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia11 DWI is an advanced MR imaging technique based on the diffusion signal of tissues,which reflects the amount of random motion of water molecules into tissues due to thermal agitation(Brownian motion).DWI是一种先进的磁
20、共振成像技术，基于组是一种先进的磁共振成像技术，基于组织的扩散信号，反映了组织中水分子的随机热织的扩散信号，反映了组织中水分子的随机热运动（布朗运动）。运动（布朗运动）。DWI was first introduced for acute cerebral infarction,for which it has become one of the primary imaging modalities.DWI最初引入急性脑梗塞，并已成为主要成最初引入急性脑梗塞，并已成为主要成像方式之一。像方式之一。乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia12 However
21、,it is now being used for other clinical applications over the entire body,and holds great promise for the detection and characterisation of tumours of other organs such as the ovaries,pancreas,prostate and breast.然而，现在被用于整个身体部位的临床检查，然而，现在被用于整个身体部位的临床检查，它在检测卵巢，胰腺，前列腺癌和乳腺肿瘤及描它在检测卵巢，胰腺，前列腺癌和乳腺肿瘤及描述肿瘤征
22、象方面拥有巨大潜力。述肿瘤征象方面拥有巨大潜力。DWI helps in the investigation of breast masses by providing information about the biological behaviour of the tumour.Several studies have evaluated breast lesions using DWI.DWI有助于提供乳腺肿块的生物学行为。一有助于提供乳腺肿块的生物学行为。一些学者采用些学者采用DWI评估乳腺病变。评估乳腺病变。乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwi
23、a13 DWI has been reported to be a useful technique for the discrimination of benign and malignant lesions.已报道已报道DWI是一种区别是一种区别良性和恶性病变有用的技术。良性和恶性病变有用的技术。Malignant lesions with tightly packed cells have a reduced extracellular space,resulting in decreased diffusion of water.The result is a high DWI sig
24、nal intensity and a lower ADC value,indicating restricted diffusion on an ADC map(Figs.13).恶性病变的细胞排列紧密，减少外的空间，从恶性病变的细胞排列紧密，减少外的空间，从而降低水的扩散。其结果是高而降低水的扩散。其结果是高DWI信号强度和低信号强度和低ADC值，值，ADC图（图图（图1-3）上显示扩散受限制。）上显示扩散受限制。乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia14 （图（图1-3）1aFig.1 Histopathological f indings in
25、a 43-year-old woman with invasive ductal carcinoma浸润性导管癌浸润性导管癌.(a)Postcontrast T1-W fat-saturated sagittal image and(b)MIP image of the breast in the axial plane show an enhancing BI-RADS 5 lesion with irregular margins(arrows).(c)DWI with b=600 and(d)ADC map show a mass with restricted diffusion th
26、at was hyperintense on DWI and hypointense on ADC map(arrows).Mean ADC value=0.95 103 mm2/s.ADC:apparent diffusion coefficient;BI-RADS:B reast Imaging Repor t ing and Data System;DWI:diffusion-weighted imaging;MIP:maximum intensity projection1b1c1d乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia15 Fig.2 Hist
27、opathological f indings in a 43-year-old woman with locally advanced invasive ductal carcinoma浸润性导管癌浸润性导管癌.Sagittal MIP reconstructions obtained from the f irst series of post-contrast dynamic images(a)before and(b)after neoadjuvant chemotherapy show minimal decrease in the size of tumour,axillary l
28、ymph nodes and vascularity.ADC maps of DWI(c)before(b=0)and(d)af ter(b=600)neoadjuvant chemotherapy are also seen(black and white arrows show the margin of the lesion).Mean ADC value:before,0.93 103 mm2/s;after,1.08 1033 mm2/s.Post-therapy measurements were not included in the study.ADC:apparent dif
29、 fusion coef ficient;DWI:dif fusion-weighted imaging;MIP:maximum intensity projection2a2b2c2d乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia16 （图（图4和图和图5）。）。3a3b3c3d Fig.3 Histopathologicalf indings in a 32-year-old woman showing leukemic infiltration 白血病浸润白血病浸润of the breast.(a)T2-W sagittal and(b)post-cont
30、rast T1-W fat-saturated subtracted sagit tal images show a huge lesion with central areas of necrosis坏死坏死.(c)DWI with b=600 and(d)ADC map show solid portions of the mass with restricted dif fusion that were hyperintense on DWI and hypointense on ADC map.Mean ADC value=0.31 103 mm2/s.The necrotic cen
31、tral part of the tumour,with relatively higher diffusion,was not included in the ROI during measurements.ADC:apparent diffusion coefficient;DWI:dif fusion-weighted imaging;ROI:region of interest乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia17 On the contrary,benign lesions with a larger extracellular space
32、 have water molecules that are more mobile,and thus higher ADC values(Figs.4&5).相反，良性病变有更大范围内的细胞外的空相反，良性病变有更大范围内的细胞外的空间有更多的水分子移动，因此间有更多的水分子移动，因此ADC值增高（图值增高（图4和图和图5）。）。乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia18 Fig.4 His topathologic al f indings in a 39-year-old woman with fibroadenoma纤维腺瘤纤维腺瘤.(a)Pos
33、t-contrast T1-W fat-saturated subtracted sagittal image shows a BI-RADS 2 solid mass typical of a fibroadenoma with macrolobulated contour,smooth margins,darkinternal septa and typeI enhancement characteristics(arrow).(b)DWI with b=600 and(c)ADC map show a fibroadenoma(arrows)that exhibited no restr
34、iction of dif fusion.Mean ADC value of 2.17 103 mm2/s was higher than that of neighbouring glandular tissue(1.97 103 mm2/s).ADC:apparent diffusion coef ficient;BI-RADS:B reast Imaging Reporting and Data System;DWI:diffusion-weighted imaging4a4b4c乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia19 Fig.5 Histop
35、athological f indings in a 61-year-old woman with intramammarian lymph node乳房淋巴结乳房淋巴结.(a)A xial STIR image shows an intramammarian lymph node(arrow),with a typical hilar notch,that was stable on screening mammograms.(b)ADC map shows a mean ADC value=2.14 103 mm2/s of the lymph node(arrow).ADC:appare
36、nt diffusion coefficient;STIR:shor t tau inversion recovery5a5b乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia20 Similar to the findings of other reports in the literature,our finding,which was based on the ADC values of 58 malignant lesions,66 benign lesions and 183 normal breast tissues,supports the conse
37、nsus that DWI can successfully differentiate between benign and malignant lesions 与其他文献报告相似，我们对与其他文献报告相似，我们对58个恶性病变，个恶性病变，66个良性病变和个良性病变和183例正常乳腺组织的例正常乳腺组织的ADC值的研值的研究，也发现，究，也发现，DWI可以很好的区分良性和恶性病可以很好的区分良性和恶性病变。变。乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia21 In a meta-analysis of 12 studies,Tsushima et al r
38、eported that the ADC values of benign breast tumours were between 1.41 103mm2/s and 2.01 103mm2/s,and those of malignant lesions were in the range of 0.90 103mm2/s to 1.61 103mm2/s.12项研究的综合分析，对马等报道，良性乳腺项研究的综合分析，对马等报道，良性乳腺肿瘤的肿瘤的ADC值介于值介于1.41103mm2/s和和2.01103 mm2/s，和那些恶性病变范围在，和那些恶性病变范围在0.90103mm2/s到到1
39、.61103mm2/s乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia22 The mean ADC values of normal breast tissue in our study were in the range of 1.51 103 mm2/s to 2.37 103mm2/s.The mean ADC value for malignant lesions was found to be 1.04 103 0.29 103mm2/s,which was compatible with that reported in the literature
40、.我们的研究正常乳腺组织的我们的研究正常乳腺组织的ADC值的范围为值的范围为1.51103mm2/s到到2.37103mm2/s。恶性病。恶性病变平均变平均ADC值被认为值被认为1.041030.29103mm2/s，这是与在文献，这是与在文献中报告相相似。中报告相相似。乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia23 The findings of statistical analysis in our series were similar to those in the literature.The mean ADC of benign lesions
41、in our study also showed a value within the reported range,although it was at the higher end.统计分析的结果，与该系列其它文献相似。统计分析的结果，与该系列其它文献相似。虽然良性病变平均虽然良性病变平均ADC高，但也是在我们的研究高，但也是在我们的研究结果的范围内。结果的范围内。It is possible that the inclusion of patients with fibrocystic changes and seromas in the study population may hav
42、e increased the mean ADC value slightly.纤维囊性变和血清肿纤维囊性变和血清肿可能稍增加病灶的平均可能稍增加病灶的平均ADC值。值。乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia24 Due to the wide range of ADC values reported in patients with inflammatory diseases and the false positive results known in this group of patients,these patients were not in
43、cluded in the benign group for statistical analysis in our study.因为炎性疾病因为炎性疾病ADC值范围广，且会造成诊断的值范围广，且会造成诊断的假阳性，所以它不被列入良性研究对象。假阳性，所以它不被列入良性研究对象。Mucinous carcinomas with high mucine content have also been reported to contribute to high ADC values.黏液腺癌粘蛋白含量高，导致黏液腺癌粘蛋白含量高，导致ADC值高。值高。乳房mr扩散加权成像比较正常乳腺组织与良性和恶
44、性乳腺病变表观扩散系数值dwia25 On the contrary,the mucinous and medullary carcinomas in our series exhibited low ADC values.但是相反，我们的研究，粘液性和髓样癌但是相反，我们的研究，粘液性和髓样癌ADC值低。值低。As ADC values have been reported to be higher in the central necrotic areas of malignant tumours,they were measured from the periphery of necro
45、tic tumours in our series.由于已报道中恶性肿瘤中央坏死由于已报道中恶性肿瘤中央坏死ADC值是较高的，值是较高的，而我们的研究中坏死区在肿瘤周边。而我们的研究中坏死区在肿瘤周边。乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia26 The microscopic movement of biological tissues consist of molecular diffusion in the extracellular compartment and microcirculation of blood in the capillary
46、 network(flow).Therefore,perfusion is another factor that affects ADC values.生物组织的微观运动包括在细胞外和微循环的血液生物组织的微观运动包括在细胞外和微循环的血液中的毛细管网络的水分子扩散（流量）。因此，灌注中的毛细管网络的水分子扩散（流量）。因此，灌注是另一个影响是另一个影响ADC值的因素。值的因素。ADC values also differ with various b-values,as seen in the literature.Images with low b-values result in le
47、ss diffusion-weighted images,as a lower gradient is applied.文献报道文献报道ADC值因值因b值的不同而不同。图像的低值的不同而不同。图像的低b值，导致扩散加权图值，导致扩散加权图像较低的梯度。像较低的梯度。乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia27 Also,the extension of microvascular structures in malignant lesions may increase the perfusion effect on ADC values in images
48、 with low b-values.此外，在恶性病变微血管结构灌注增加可能会此外，在恶性病变微血管结构灌注增加可能会影响低影响低b值的值的ADC值。值。However,the signal-to-noise ratio in these images is higher than that in diffusion images with high b-values.低低b值的信号噪声比高于高值的信号噪声比高于高b值所在扩散图像。值所在扩散图像。乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia28 Typically,at least two b-values
49、should be used during DWI in order to enable meaningful ADC interpretation,although accuracy increases when more b-values are used.虽然使用更多的虽然使用更多的b值提高精确度，通常情况下值提高精确度，通常情况下至少两个至少两个b值。值。In our study,we had used b-values of 0 s/mm2 and 600 s/mm2 in order to limit the examination time.我们的研究使用我们的研究使用0 s/m
50、m2和和600 s/mm2 b值，值，以限制测试时间。以限制测试时间。乳房mr扩散加权成像比较正常乳腺组织与良性和恶性乳腺病变表观扩散系数值dwia29 Pereira et al,however,reported no significant difference between the ADC values of benign and malignant lesions when different combinations of b-values were used,and thus concluded that using multiple b-values in a DWI sequ
