最新乳腺弥散加权成像的原理和临床应用ppt课件.ppt

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1、乳腺弥散加权成像的原理和临床应用Diffusion-weightedimagingisamodalitythatmakesuseofmagneticresonance(MR)imagingtodepictthediffusivityofwatermoleculesinadefinedvoxelbymeansoftheapplicationofmotion-probinggradients.Thisimagingpropertyisuniqueandprovidesadifferentcontra

2、stmechanismthanthatobservedonconventionalT1-andT2-weightedMRimages.Evaluationofbreastimagesacquiredwithsensitizationtothediffusionofwatermoleculeshasthepotentialtoplayanadjunctroleintheassessmentofbreasttissue.DWI是一种通过运动-探测梯度磁场的应用的方式，在一个有限的像素内，利用磁共振来

3、检测水分子弥散的方法。这种成像方式是唯一，并且与常规的T1和T2加权MR图像相比，提供一个不同的对比机制。乳腺图像的获取来源于对水分子的扩散敏感，其拥有在乳腺组织的评估中发挥辅助作用的潜力。。IntroductionDiffusion-weightedimagingwasinitiallyappliedintheclinicalsettinginthemid-1990sforthediagnosisofacutestroke.Atthattime,diffusion-weightedimagin

4、gdemonstratedahighdiagnosticutility,notonlyintheinvestigationofacutestroke,butalsoindevelopingthedifferentialdiagnosisforotherbrainabnormalities,includingtumorsandabscesses.弥散加权成像在临床上最初的应用是90年代中期对急性脑卒中的诊断，不仅用于检测急性脑卒中，而且发展到别的脑部异常病变的鉴别诊断，包括肿瘤和脓肿。Introd

5、uctionAsaresultofthesefindings,diffusion-weightedbreastimaginghasattractedgreaterinterestamongbreastimagers,withmanycliniciansadvocatingapplicationsbeyondjustclinicalresearch.However,theincorporationintoclinicaldecisionmakingofinformationgleanedfromd

6、iffusion-weightedbreastimaginghasbeenslowcomparedtotheuseofinformationobtainedfromdiffusion-weightedimagingofotherorgans.由于这些发现，乳腺弥散加权成像吸引了乳腺影像学家越来越多的注意，许多医生主张应用不仅仅是临床研究。然而，与其他器官的弥散加权图像的使用相比，应用在乳腺上比较缓慢。IntroductionOnereasonisthatthediagnosticroleofdi

7、ffusion-weightedimaginginbreastimaginghasnotbeenincorporatedintothealreadyestablishedBreastImagingandReportingDataSystemlexicon(11).Contrastmaterial–enhancedbreastMRimagingiscurrentlyacceptedasthemostsensitiveimagingtechniqueforthediagnosisandstaging

8、ofbreastcancer.However,severalstudieshavenotedthatconventionalbreastMRimaging,includingT2-weightedimagingandcontrast-enhancedT1-weightedimaging,islimitedintermsofspecificityintheassessmentofbreasttumors原因之一是弥散加权成像在乳腺成像上的诊断作用还没有纳入到已经确定的BI-RADS系统中。对比增强