超声弹性成像对肝脏良恶性肿瘤鉴别诊断价值的研究

第二军医大学硕士学位论文超声弹性成像对肝脏良恶性肿瘤鉴别诊断价值的研究姓名：龚建峰申请学位级别：硕士专业：影像医学与核医学指导教师：郭佳2011-05超声弹性成像对肝脏良恶性肿瘤鉴别诊断价值的研究-1-摘要研究背景与目的肝细胞癌是世界范围内最常见的恶性肿瘤之一，发病率居世界第五，死亡率高居第三。超声检查是诊断肝脏疾病最常用的手段之一，由于其方便、无创、价廉等特点，被广泛的应用在各种肝脏疾病的诊断和鉴别诊断中。常规超声检查主要通过观察病灶的大小、边缘、形态、内部回声等信息，对肝脏疾病做出良恶性诊断，存在一定的局限性。超声弹性成像技术是近年发展起来的新技术，是1991年由Ophir等首次提出，它通过了解所检测组织的硬度以判别其良恶性，该技术在浅表器官的检查中已有较为成熟的应用，尤其对鉴别诊断乳腺良、恶性病变的价值得到了肯定。有研究报道，超声弹性成像诊断乳腺肿瘤的敏感性、特异性及准确性可达78.0%、98.5%及93.8%。超声弹性成像虽然目前还不能完全代替常规超声，但是它明显提高了超声诊断乳腺肿瘤的准确性。而超声弹性成像在肝脏肿瘤中的研究和应用较少，其不同于浅表器官的弹性成像，具有一定的特殊性。本研究对肝脏占位性病变进行实时超声弹性成像研究，并结合病理进行对照，旨在探讨超声弹性成像在鉴别诊断肝脏良恶性肿瘤中的应用价值。方法1、超声弹性成像鉴别肝脏良恶性肿瘤的价值评估：用常规超声及超声弹性成像技术分别对207例患者的224个肝脏肿瘤进行检查，所有患者均经手术病理证实。常规超声和弹性成像的检查结果与病理结果进行比较。2、超声弹性应变率比值在肝脏肿瘤诊断中的应用价值的研究：对145例患者共157个肝脏肿瘤进行超声弹性成像检查,获得弹性成像图后,测量病灶与周围组织的弹性应变率比值（strainratio,SR）,经病理对照后,采用接收者工作特征(receiveroperatorcharacteristic,ROC)曲线分析SR诊断良恶性肿瘤的准确性,并确定临界点。结果1、超声弹性成像鉴别肝脏良恶性肿瘤的价值评估：病理结果:良性病灶77个，包括肝血管瘤62个，肝局灶性结节增生6个，肝血管内皮细胞瘤3个，肝血管平滑肌脂肪瘤2个，肝脓肿4个；恶性病灶147个，其中肝细胞型肝癌113个，胆管细胞型肝癌11个，混合型肝癌8个，转移性肝癌15个。第二军医大学硕士学位论文-2-常规二维超声诊断肝脏肿瘤的敏感性为74.8%，特异性74.0%，准确性为74.6%。超声弹性成像诊断肝脏肿瘤的敏感性为83.7%，特异性为87.0%，准确性为84.8%，阳性预测值为92.5%，阴性预测值为73.6%。2、超声弹性应变率比值在肝脏肿瘤诊断中的应用价值的研究：良性肿瘤的SR为2.75±1.26，恶性肿瘤的SR为8.33±4.45，两者差异具有显著的统计学意义（P0.01）。其中胆管细胞型肝癌组的SR最高，转移性肝癌组与肝细胞型肝癌组次之，肝血管瘤组最低。通过ROC曲线确定的最佳诊断临界点是4.0，敏感性、特异性、准确性、阳性预测值和阴性预测值分别是89.4%、86.8%、88.5%、93.0%和80.7%。曲线下面积(AUC)=0.941。结论1、超声弹性成像鉴别诊断肝脏肿瘤良恶性的准确性较常规超声高。超声弹性成像技术为诊断肝脏肿瘤提供了一种全新的方法，有助于肝脏肿瘤良恶性的鉴别。2、弹性应变率比值测量可以较为客观的反映病灶的硬度情况,是一种更为准确客观的诊断肝脏良恶性肿瘤的超声弹性成像新方法。关键词弹性成像，超声检查，肝脏肿瘤，弹性应变率比值超声弹性成像对肝脏良恶性肿瘤鉴别诊断价值的研究-3-AbstractBackground&ObjectiveHepatocellularcarcinomaisthefifthmostcommoncancerintheworldandthethirdmostcommoncauseofcancermortality.Ultrasonographyisoneofthemostcommonlyusedmethodindiagnosisanddifferentialdiagnosisofvariousliverdisease,becauseofitsconvenience,noninvasive,inexpensiveandhighrepeatability.Theconventionalultrasonicinspectionmakesthedifferentialdiagnosisofbenignandmalignanttumorsmainlythroughtheobservationofthelesionsize,edge,morphology,echogenicityofliverdisease,whichhassomelimitations.UltrasonicElastography(UE)isanoveltechniqueestablishedbyOphirin1991.UEmakesthediagnosisofbenignandmalignanttumorsthroughthedetectionofthelesionrigidity.UEisappropriateforandmaturelyusedinthesuperficialtumors,especiallyinthedifferentialdiagnosisofbenignfrommalignantbreastlesions.Real-timeultrasonicelastographyisuser-friendlywithahighaccuracyrate,therebyimprovingBmodeultrasoundassessment,andtheelastographysensitivitywas78.0%,specificitywas98.5%andoverallaccuracywas93.8%.But,somestudieswereapprovedtodemonstratethatUEwiththeproposedimagingclassificationhadalmostthesamediagnosticperformanceasconventionalultrasonographyinassessingbreastlesions.UEdoesnothavethepotentialtoreplaceconventionalB-modeultrasonographyforthedetectionofbreastcancer,butmaycomplementconventionalultrasonographytoimprovethediagnosticperformance.However,therewerefewworkstouseUEinlivertumors.Theelastographycharacteristicsoflivertumors,withanobviousparticularity,arenotdifferentwiththatofsuperficialtumors.Inthecurrentstudy,thereal-timeUEwasevaluatedinliverneoplasms,andcomparedwiththeresultsofpostoperativepathologicaldiagnosis.TheobjectiveofthisstudyistoinvestigatetheapplicationvalueofUEindifferentialdiagnosisofliverbenignandmalignanttumors.Methods1.Ultrasonicelastographyindifferentiatingbenignandmalignantlivertumors.Atotalof207patientswith224livertumorswereexaminedbyconventionalultrasonographyandultrasonicelastography.Allthepatientsunderwentsurgeryandthelesionswereconfirmedbypostoperativepathology.Theresultsofconventional第二军医大学硕士学位论文-4-ultrasonographyandultrasonicelastographywerecomparedwiththepathologicalfindings.2.Valueofthestrainratiointhediagnosisoflivertumorsbyultrasonicelastography.Ultrasonicelastographywasperformedin145patientswith157livertumorstoobtainthestrainimages.Thestrainratioofthetumorswasthencalculated.Bycomparingwiththeresultsofpathologicaldiagnosis,thecut-offpointforthestrainratiowasdeterminedusingthereceiveroperatingcharacteristiccurve.Results1.Ultrasonicelastographyindifferentiatingbenignandmalignantlivertumors.Pathologicalexaminationshowedthat77lesionswerebenignand147lesionsweremalignant.Thebenignlesionsincluded62hepatichemangioma,6focalnodularhyperplasia,3hepatichemangioendothelioma,2hepaticangiomyolipomaand4liverabscess.Themalignantlesionsincluded113hepatocellularcarcinoma,11intrahepaticcholangiocarcinoma,8mixedhepaticcarcinomaand15metastaticlivercarcinoma.Thesensitivity,specificity,andaccuracyofconventionalultrasonographyfordiagnosingmalignantlivertumorswere74.8%，74.0%and74.6%.However,thesensitivity,specificity,andaccuracyofultrasonoicelastographyfordiagnosingmalignantlivertumorswere83.7%，87.0%and84.8%.2.Valueofthestrainratiointhediagnosisoflivertumorsbyultrasonicelastography.Thestrainratioofbenigntumorswassignificantlylowerthanthatofmalignantones(2.75±1.26vs8.33±4.45,P0.01).Thestrainratioofintrahepaticcholangiocarcinomawashighest,followedbymetastaticlivercarcinoma，hepatocellularcarcinoma,andhepatichemangioma.Thecut-offpointforstrainratiowassetas4.0.Thes