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,adc课件

Diffusion-weightedMRimagingofthebreast:Comparisonofapparentdiffusioncoefficientvaluesofnormalbreasttissuewithbenignandmalignantbreastlesions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XIAWANJUNThespecificityofconventionalmagneticresonance(MR)imagingislowerthanitshighsensitivity.传统的磁共振（MR）成像灵敏度低。Diffusion-weightedimaging(DWI),basedonalterationsinthemicroscopicmotionofwatermolecules,promisesimprovedspecificityforbreastMRimaging.Inthisstudy,weaimedtodeterminethediagnosticpotentialofDWItodifferentiatebetweenbenignandmalignantbreastlesionsandnormalbreasttissue.弥散加权成像（DWI）的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DWI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。Dynamiccontrast-enhancedbreastMRimagingandDWIwereappliedto108women.Apparentdiffusioncoefficient(ADC)valueswereobtainedfornormalbreasttissue(n=183),benignlesions(n=66)andmalignantlesions(n=58).Theresultswerecomparedwiththepatients’finaldiagnoses.对108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（N=183例），良性病变组（n=66例），恶性病变（N=58例）分别进行表观扩散系数（ADC）值测定。然后与患者的最终诊断结果进行比较。Onhistopathologicalexamination,58lesionsprovedtobemalignantin42patients:invasiveductalcarcinoma(IDC)n=31;invasivelobularcarcinoma(ILC)n=1;mixedinvasivelobularandductalcarcinoma(IDC+ILC)n=3;ductalcarcinomainsitun=2;mixIDC+mucinouscarcinoman=1;IDCandpleomorphiccarcinoman=1;medullarycarcinoman=1;对42位患者58例病变进行病理组织学检查，发现恶性乳腺浸润性导管癌（IDC）31位患者，浸润性小叶癌（ILC）1位患者，浸润性导管癌和浸润性小叶癌（IDC+ILC）3位患者;导管原位癌2位患者;浸润性导管癌+黏液腺癌1位患者;浸润性导管癌和多形性癌1例，髓样癌1位患者，malignantphyllodestumourn=1;diffuseleukaemicinfiltrationofthebreastn=1.恶性叶状肿瘤1位患者，弥漫性白血病浸润乳腺1位患者。Themeansizeofthemalignantlesionswas41.3±34.3mm.恶性病变的平均大小为41.3±34.3毫米。Atotalof66benignlesionsin44patientswereincludedinthestudy.44位患者66例良性病变的研究。35lesionswerehistopathologicallydiagnosedasbenignfibroadenoma(n=18),cystosarcomaphyllodestumour(n=2),fibrocysticchanges(n=4),seroma(n=6),fatnecrosis(n=2),ductalhyperplasia(n=1),papilloma(n=1)andhaematoma(n=1).35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2例，纤维囊性变4例，血清肿组6例，脂肪坏死2例，导管上皮增生1例，乳头状瘤1例和血肿1例。

Results：MeanADCvaluesforbenignandmalignantbreastlesionswere1.04×10−3±0.29×10−3mm2/sand2.00×10−3±0.55×10−3mm2/s,respectively(p=0.001,Student’st-test),whilethatfornormalbreasttissuewas1.78×10−3±0.33×10−3mm2/s.Withacut-offvalueof1.46×10−3mm2/sforADCinreceiveroperatingcharacteristicanalysis,95%sensitivityand85%specificitywereachievedfordifferentiatingbetweenbenignandmalignantlesions.结果乳腺良、恶性病变的ADC值平均值分别为1.04×10-3±0.29×10−3mm2/s和2.00×10−3±0.55×10-3mm2/s，（P=0.001，t分布检验），而正常乳腺组织1.78×10−3±0.33×10−3mm2/s。根据受试者特征取1.46×10−3mm2/s的ADC为区分良性和恶性病变的临界值，得到敏感性为95％和特异性85％。ConclusionDWIofthebreastcanhelpdifferentiatebenignandmalignantbreastlesionsfromnormalbreasttissue.结论乳房DWI检查可以帮助区分良性、恶性乳腺病变与正常乳腺组织。DWI,whichcanbeeasilyintroducedintostandardbreastMRimagingprotocolswithoutincreasingimagingtimes,promisestoincreasetheaccuracyofbreastMRimagingwithoutcontrastmedia.。DWI在不增加成像时间，通常作为常规的乳房MR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。SincethespecificityofconventionalMRimaging,whichusesmorphologicalandkineticcriteria,isrelativelylowerthanitshighsensitivity,advancedMRimagingapplicationhasapotentialroletoplayinthediagnosisofbreastlesions.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。Diffusion-weightedimaging(DWI)promisesimprovedspecificityofbreastMRimaging.弥散加权成像（DWI）能够提高乳腺磁共振成像的特异性。However,itisnowbeingusedforotherclinicalapplicationsovertheentirebody,andholdsgreatpromiseforthedetectionandcharacterisationoftumoursofotherorganssuchastheovaries,pancreas,prostateandbreast.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述肿瘤征象方面拥有巨大潜力。DWIhelpsintheinvestigationofbreastmassesbyprovidinginformationaboutthebiologicalbehaviourofthetumour.SeveralstudieshaveevaluatedbreastlesionsusingDWI.DWI有助于提供乳腺肿块的生物学行为。一些学者采用DWI评估乳腺病变。DWIhasbeenreportedtobeausefultechniqueforthediscriminationofbenignandmalignantlesions.已报道DWI是一种区别良性和恶性病变有用的技术。Malignantlesionswithtightlypackedcellshaveareducedextracellularspace,resultingindecreaseddiffusionofwater.TheresultisahighDWIsignalintensityandalowerADCvalue,indicatingrestricteddiffusiononanADCmap(Figs.1–3).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DWI信号强度和低ADC值，ADC图（图1-3）上显示扩散受限制。（图1-3）1aFig.1Histopathologicalfindingsina43-year-oldwomanwithinvasiveductalcarcinoma浸润性导管癌.(a)PostcontrastT1-Wfat-saturatedsagittalimageand(b)MIPimageofthebreastintheaxialplaneshowanenhancingBI-RADS5lesionwithirregularmargins(arrows).(c)DWIwithb=600and(d)ADCmapshowamasswithrestricteddiffusionthatwashyperintenseonDWIandhypointenseonADCmap(arrows).MeanADCvalue=0.95×10−3mm2/s.ADC:apparentdiffusioncoefficient;BI-RADS:BreastImagingReportingandDataSystem;DWI:diffusion-weightedimaging;MIP:maximumintensityprojection1b1c1d（图4和图5）。3a3b3c3d

Fig.3Histopathologicalfindingsina32-year-oldwomanshowingleukemicinfiltration白血病浸润ofthebreast.(a)T2-Wsagittaland(b)post-contrastT1-Wfat-saturatedsubtractedsagittalimagesshowahugelesionwithcentralareasofnecrosis坏死.(c)DWIwithb=600and(d)ADCmapshowsolidportionsofthemasswithrestricteddiffusionthatwerehyperintenseonDWIandhypointenseonADCmap.MeanADCvalue=0.31×10−3mm2/s.Thenecroticcentralpartofthetumour,withrelativelyhigherdiffusion,wasnotincludedintheROIduringmeasurements.ADC:apparentdiffusioncoefficient;DWI:diffusion-weightedimaging;ROI:regionofinterestOnthecontrary,benignlesionswithalargerextracellularspacehavewatermoleculesthataremoremobile,andthushigherADCvalues(Figs.4&5).

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ADC值增高（图4和图5）。

Fig.4Histopathologicalfindingsina39-year-oldwomanwithfibroadenoma纤维腺瘤.(a)Post-contrastT1-Wfat-saturatedsubtractedsagittalimageshowsaBI-RADS2solidmasstypicalofafibroadenomawithmacrolobulatedcontour,smoothmargins,darkinternalseptaandtypeIenhancementcharacteristics(arrow).(b)DWIwithb=600and(c)ADCmapshowafibroadenoma(arrows)thatexhibitednorestrictionofdiffusion.MeanADCvalueof2.17×10−3mm2/swashigherthanthatofneighbouringglandulartissue(1.97×10−3mm2/s).ADC:apparentdiffusioncoefficient;BI-RADS:BreastImagingReportingandDataSystem;DWI:diffusion-weightedimaging4a4b4cSimilartothefindingsofotherreportsintheliterature,ourfinding,whichwasbasedontheADCvaluesof58malignantlesions,66benignlesionsand183normalbreasttissues,supportstheconsensusthatDWIcansuccessfullydifferentiatebetweenbenignandmalignantlesions与其他文献报告相似，我们对58个恶性病变，66个良性病变和183例正常乳腺组织的ADC值的研究，也发现，DWI可以很好的区分良性和恶性病变。Inameta-analysisof12studies,TsushimaetalreportedthattheADCvaluesofbenignbreasttumourswerebetween1.41×10−3mm2/sand2.01×10−3mm2/s,andthoseofmalignantlesionswereintherangeof0.90×10−3mm2/sto1.61×10−3mm2/s.12项研究的综合分析，对马等报道，良性乳腺肿瘤的ADC值介于1.41×10−3mm2/s和2.01×10−3mm2/s，和那些恶性病变范围在0.90×10−3mm2/s到1.61×10−3mm2/sThemeanADCvaluesofnormalbreasttissueinourstudywereintherangeof1.51×10−3mm2/sto2.37×10−3mm2/s.ThemeanADCvalueformalignantlesionswasfoundtobe1.04×10−3±0.29×10−3mm2/s,whichwascompatiblewiththatreportedintheliterature.我们的研究正常乳腺组织的ADC值的范围为1.51×10−3mm2/s到2.37×10−3mm2/s。恶性病变平均ADC值被认为1.04×10−3±0.29×10−3mm2/s，这是与在文献中报告相相似。DuetothewiderangeofADCvaluesreportedinpatientswithinflammatorydiseasesandthefalsepositiveresultsknowninthisgroupofpatients,thesepatientswerenotincludedinthebenigngroupforstatisticalanalysisinourstudy.因为炎性疾病ADC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。MucinouscarcinomaswithhighmucinecontenthavealsobeenreportedtocontributetohighADCvalues.黏液腺癌粘蛋白含量高，导致ADC值高。Onthecontrary,themucinousandmedullarycarcinomasinourseriesexhibitedlowADCvalues.但是相反，我们的研究，粘液性和髓样癌ADC值低。AsADCvalueshavebeenreportedtobehigherinthecentralnecroticareasofmalignanttumours,theyweremeasuredfromtheperipheryofnecrotictumoursinourseries.由于已报道中恶性肿瘤中央坏死ADC值是较高的，而我们的研究中坏死区在肿瘤周边。Typically,atleasttwob-valuesshouldbeusedduringDWIinordertoenablemeaningfulADCinterpretation,althoughaccuracyincreaseswhenmoreb-valuesareused.虽然使用更多的b值提高精确度，通常情况下至少两个b值。Inourstudy,wehadusedb-valuesof0s/mm2and600s/mm2inordertolimittheexaminationtime.我们的研究使用0s/mm2和600s/mm2b值，以限制测试时间。Pereiraetal,however,reportednosignificantdifferencebetweentheADCvaluesofbenignandmalignantlesionswhendifferentcombinationsofb-valueswereused,andthusconcludedthatusingmultipleb-valuesinaDWIsequencewasunnecessary.但是Pereira等人报告，不同的b值测量D的不同ADC值,对区别良性和恶性病变没有明显差异。因而认为，使用多个b值在DWI序列是不必要的。Woodhamsetalreportedthatb<750mm2/swashighlyefficientdetectingbreastmasses.Woodhams等报道，B<750mm2/s可以高效检测乳腺肿块。ThediagnosticaccuracyofDWIforbreastcanonlybeascertainedoncetechnicalparametersandpost-processingproceduresarestandardisedforthemodality.DWI对乳腺的诊断准确率在于技术参数和后处理程序方法的标准化。Majortechnicallimitationsassociatedwithitaredistortionoftheimagessecondarytosusceptibility,chemicalshift,motionartefactsandlowspatialresolution.与它相关的主要技术限制是敏感性低的失真的图像，化学位移，运动伪影和低空间分辨率。Evenunderoptimalcircumstances,smalllesionsmaynotbevisualisedonADCmaps,asKinoshitaetalhavereportedthatlesions<10mmindiametercannotbedemonstratedbyDWI.即使在最理想的情况下，小的病灶可能不会ADC图上可见，木下等人报道，病灶直径<10毫米的病灶DWI显示欠佳。Anotherlimitationisthatofnonmass-likeenhancinglesionsthatformlargeandnon-compactlesionswithnormalparenchymainterveningwithinthetumour.另一个限制是非肿块型增强的病变，该病变肿瘤细胞排列不紧密，病灶范围广中间夹杂正常组织成分。Non-IDCs,lobularcarcinomainsitu,atypicalductalhyperplasia,papillomas,hormonalchangesandfibrocysticdiseasemayshowthistypeofenhancement.非乳腺浸润性导管癌，小叶原位癌，导管上皮不典型增生，乳头状瘤，荷尔蒙的变化和纤维囊性疾病，可能会出现该类型的强化。AccordingtoGuoetalandSinhaetal,themeanADCvalueisinverselyproportionaltocellulardensity,andtherefore,theselesionsmayexhibitlessrestrictionofdiffusion.根据Guo和Sinha等的研究，平均ADC值是与细胞密度成反比，因此，这些病变较少表现出限制扩散。WhentherangeofADCvalueswasconsidered,aslightoverlapwasobservedintheADCvaluesofbenignandmalignantlesions,bothintheliteratureandinourseries.无论文献还是我们的研究发现，良性和恶性病变的ADC值的范围有一个轻微的重叠。Somebenignconditions,suchashaematomas,abscesses,fibrosisandinflammatorylesions,areknowntoexhibitlowADCvalues.一些良性病灶，如血肿，脓肿，纤维化和炎症改变具有低ADC值。TheFinally,itshouldbenotedthatDWIcannotreplacedynamicbreastMRimagingwithcontrast,butcanbeusedasacomplementarytechniquetoevaluatebreastmasses.最后，应注意的是，DWI不能取代动态乳腺MR成像当做增强对比，但可以用作一个互补的技术来评估乳腺肿块。DWImayals