3D Medical Ultrasound Technology and Development

3DMedicalUltrasoundTechnologyandDevelopment生医04班宫本洁20043256OverviewThree-dimensionalultrasoundimagingultrasoundstudyiscurrentlyahot,itwilldefinitelyMedicalImaging,andsurgeryandobstetrics,andotherrelateddisciplineshaveapositiveimpactonanimportantclinicalvalueandprospects三维医学超声成像是当前超声研究的一个热点，势必会对影像医学，内外科学和产科学等相关学科产生积极影响，有重要的临床应用价值及前景Overview3-Dultrasoundtechnologyistheintroductionofdigitalbeamformingtechnology,withhigh-resolution,high-qualityimagesandmeasurementsofvariousfunctions,canbevisual,three-dimensionalhumanorgansshowedthatthethree-dimensionalspatialstructures.三维超声技术是采用数字化波束形成技术，具有高分辨率、高质量图像及各种测量功能，能直观、立体显示人体器官的三维空间结构。OverviewInparticularformduringfetaldevelopmentchecks,theuseofthree-dimensionalultrasoundimagingvolumethantwoultrasoundimagingmoreefficient特别是在进行胎儿形态发育检查方面，采用三维超声容积成像比二位超声成像更快捷3-DUltrasoundTechnologyThree-dimensionalultrasoundisbasedontwo-dimensionalultrasoundtechnology,high-quality3Dimagesrequirehigh-qualityimagesbasedon2D三维超声是基于二维超声技术，高质量的三维图像需要高质量的二维图像为基础3-DUltrasoundTechnologyAthree-dimensionalultrasoundprocessconsistsofthefollowingsteps:Datacollection数据采集3Dreconstruction三维重建3DRendering三维渲染3Dimagingoperation三维影像操作DatacollectionInordertoaccessdata,ultrasoundbeammustbecomeathingofthewholeregionchecks.First2Dimaging,andthenthechoiceoftwo-dimensionalimagesofthetargetregionofinterest(sizeandangle)3Dreconstruction.Thiswillenabletheoperatorneednotprobetoomuchemphasisontheaccuracyoflocation(locationinterestedinwhethertheimagecenter),totheacquisitionprocessmoresimpleandconvenient.为了获取数据，超声束必须扫过整个检查区域。首先进行二维成像，然后在二维图像上选择感兴趣的目标区域（尺寸和角度）进行三维重建。这样可以使操作者不必过于强调探头位置的准确性（感兴趣部位是否在图像中心），使采集过程更简单方便。DatacollectionAcquisitionofdataneedcompressionalgorithms,suchdatacanbelessandclearandconvenientstorageandbroadcast.Dataacquisitionincludesnotonlythecontentsofthegray-scaleimageinformation,insomecases,mustalsobebasedonlyDopplervelocityandpowerofinformationtomeetthethree-dimensionalultrasoundimagingmodalitiesdifferentneeds.采集数据需要采用压缩算法，这样可以使数据量少而清晰，方便存储及播放。数据采集不仅包含图像的灰阶信息,在某些情况下,还必须采集多普勒速度和功率信息,以满足三维超声不同成像模式的需要.3DreconstructionAtpresent,theuseofbodymodellawtoachieve3-Dimaging.Invivomodel,thethree-dimensionalobjectsaredividedintoanumberofsequentialsmallcubes,eachcubeisasmallelement,certainnumberofbodyyuanaccordingtothecorrespondingpositionwiththespacecouldconstitutethree-dimensionalimages.目前主要使用体元模型法来实现三维成像。在体元模型中，三维物体被划分成多个依次排列的小立方体，每个小立方体就是一个体元，一定数目的体元按相应的空间位置排列即可构成三维立体图像。3Dreconstruction3DreconstructionElementmodelrequireshighaccuracyandspeedofthecomputersystem.Somethree-dimensionalreconstructionsoftwareinordertoacceleratecomputationalspeedoftheoriginaldata-interlacedorinterlaced-samplingoperation,FuzzyImageinterpolationalgorithmmoresmooth.Buttheactualdiagnosisrequiringthegenerationofthree-dimensionalimagingrespectfortherawdatafordoctorstoprovidethemostrealisticimages.体元模型法需要相当高精度和速度的计算机系统。有些三维重建软件为了加快运算速度对原始数据进行隔行或个双隔行抽样运算，采用模糊插值算法使图像更加平滑。但实际诊断要求生成三维影像尊重原始数据，为医生提供最真实的图像。3Dreconstruction3DRendering3Dstructureoftheobjectivesmappedtothetwo-dimensionalplaneofreality.将三维的目标结构映射到二维平面显示的过程。Grayrender灰度渲染Colorrender彩色渲染GrayrenderSurfacemode:Imageshowsthesurfacecontours(Applicabletothebladder,gallbladderandothercavitycontainingliquidandtheliquidaroundthestructure)表面模式：显示表面轮廓图像(适用于膀胱、胆囊、子宫、胎儿等含液体空腔和被液体环绕的结构)GrayrenderTransparentmode:Underlinesinterestedintheinternalstructureoftheorganshowedsubstantialspatialrelations透明模式：着重显示感兴趣的内部结构，显示实质性脏器的空间位置关系（如血管及包囊等结构）GrayrenderMultiplanarmode:Coronalaccesstostructuredinformation多平面模式：用来获得冠状面的结构信息，克服2维B超仅能对超声束平行的平面成像的限制Inversionmode：Echoshowednostructure,suchasbloodorcavity倒置模式：显示无回声结构，如血液或空腔Colorrender3Dstructureofcolorexaggerated,assistedvascularphysicianobservation,judgmentvasculartrend,relationswiththesurroundingtissueandthelocationofinteresttoevaluatetheperfusion对三维结构进行彩色渲染，辅助医师观察血管，判断血管的走向、与周围组织关系及对感兴趣部位的血流灌注进行评价3DimagingoperationMutiplannerreformatting多平面重建Ultrasonictomographyimages超声断层图像Electronicscalpel电子刀3Dcinemode三维动态Measurement测量AggregateAdvantages:datacollection,reduceinspectiontime,visualimagethatcanshowdynamicprocess,candetectfetalmalformation优势：采集数据量大，检查时间减少，图像直观，能显示动态过程，能检查出胎儿畸形AggregateDisadvantages:3Dreconstructionprocessmustinevitablylostsomeoftheinformation;Imagingspeedneedstoberaised.Isnotcompletelyharmless.缺点：在三维重建过程中不可避免要丢失部分信息；成像速度有待提高；并不是彻底无害的。Forecast未来三维超声技术的发展将得益于计算机和相关领域技术的快速发展。新的算法研究，进一步提高重建速度和图像质量，对检查和诊断提供更准确的依据。高速计算和大容量的存储能力，在三维超声技术的基础上增加时间维度，实现四维实时动态超声已不是难事。