超声影像病灶提取及分析

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1、上海交通大学硕士学位论文超声影像病灶提取及分析姓名：李亚卿申请学位级别：硕士专业：生物医学工程指导教师：张素20090101上海交通大学工学硕士学位论文摘要称性度量有较大的影响，与人眼对对称性的评价相差较大。提出利用质心的方法对对称性进行了度量，该方法避免了首先要确定对称轴，再计算对称度这一缺点，对该方法与人眼对对称度的评价进行了比较，具有较好的一致性。最后，本文对病灶区域形状越复杂肿瘤越倾向于恶性的医生诊断经验进行验证。对分割后的病灶区域进行复杂性度量。首先采用了单一的度量方法，发现单一的度量方法难以表达形状的复杂程度，然后采用了提升(boosting)方法将几种方法综合

2、起来，形成了对复杂度的综合评价。关键词：交互式分割，椭圆度，对称度，复杂度，提升第II页上海交通大学工学硕士学位论文ABSTRACTABSTRACTUltrasonicdetectionofbreastcancerhasbecomeanimportantmeansofearlydiagnosis.Thecontourofthelesionandtheinfiltrationoftheskincanbedescribedbyextractingfeaturesofthecontour.Andtheechoofthetumorcanbedescribedbygray-scale

3、informationandtextureinformation.Theseinformationreflectthetendencyofbenignandmalignanttumorsfromdifferentdirections.SothedigitizedoftheseinformationcanbeveryhelpfulforbuildingtheCADsystem.ForthereasonthatUltrasoundimagesareofgreatnoise,theinteractivesegmentationischosen.TheLiveWireinterac

4、tivesegmentationhasbeenstudied,themostimportantisconstructionofthecostfunction,afterthatdifferentwaysofconstructionsofthecostfunctionarecompared.Single-scaleandmulti-scaleEdgeFlowvectorfieldarestudied,multi-scaleEdgeFlowvectorisusedascostfunctionofLiveWireinteractivesegmentation.Whilelesio

5、nstendtobeelliptical,thetumorstendtobemorebenign.Thelesionisellipticalfitted,afterthatthesimilaritytotheellipseiscalculated.Theassessmentsoftheregionsimilaritytoellipsearecomparedbetweentheman-eyeandthemethodabove.Symmetryoflesionaftersegmentationoftheimageiscalculated.Thefirstwayistouseth

6、esymmetryofthepolygonmeasurementmethodandfoundthatthedefectsofthemethodarethesamplingmethodsandgroupingmethods,theyhaveagreaterinfluenceonthemeasurement,andit’sverydifferentfromtheassessmentofhumaneye.ThesecondwayistouseCenterofmass,byusingthismethod,itavoidsthenecessitytoidentifythesymmet

7、ryaxis,andit’smoresimilartohumaneyes.Themorecomplextheshapeoflesion,themoreitinclinedtobeamalignanttumor.Toevaluatethecomplexityoflesion,firstsinglefeatureisused,butsinglefeatureisdifficulttodescribethecomplexity,thendifferentfeaturesareintegratedintoonemodelt