胎儿磁共振成像-胎儿头颅MRI检查.ppt

《胎儿磁共振成像-胎儿头颅MRI检查.ppt》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、胎儿磁共振成像MRImagingoftheFetus超声－Ultrasound--母体肥胖--羊水过少--妊娠中晚期胎头增大--胎儿颅骨骨化MRI－UltrafastMRI--单次激发快速序列--大FOV--安全性？MRI仅适用于当产前超声不足以解决临床问题时MRI检查技术1.5T及以下MR机体部相共振线圈序列：单次激发FSE(0.5NEX）FIASTA序列常规轴、冠、矢扫描胎儿头颅MRI检查胎儿头颅MR检查主要观察--脑室扩大--可疑后颅窝异常--胼胝体发育不良LimperopoulosC,etal.AJRAmJRoentgenol2008;190:1

2、637–1643.TotalfetusesMRIabnormal9060(67%)ComparisonofantenatalandpostnatalMRfindingsin39of42liveborninfantsCompleteagreement23(59%)Disagreement16(41%)ExcludedfetalMRI6(15%)Revealedadditionalabnormalities10(26%)枕大池(cisternamagna)正常值2－11mm侧脑室体部<10mm异常表现：Dandy-Walker畸形，小脑蚓部发育不良，大枕大池

3、，蛛网膜囊肿小脑蚓部的发育11－12W，小脑及原始蚓部从第四脑室嘴侧发生13－14W，原始顶点可见（第四脑室顶部裂缝）14－16W，小脑蚓部原裂出现16W，小脑蚓部向尾侧发育，于顶点处“折叠”覆盖四脑室顶，第四脑室“闭合”16－17W，锥前裂、顶前裂等可见18－19W，蚓部颅尾方向长度与小脑半球相等11－12W13－14W16W18W17.5w21w22w24w27wAssessmentofVermianMaturity小脑原裂primaryfissure顶点fastigialpoint顶－蚓角tengmento-vermianangle，TVA颅尾径c

4、raniocaudaldiameter，CCDNormalAbnormalTengmento-vermianangle22－weekfetusA.axialsonographyshowedalargecysticposteriorfossawithsmallcerebellarhemispheres.B.thetegmento-vermianangleisincreasedwiththefourthventricleuncovered.Thevermisisverysmall;thereisnoprimaryfissureorfastigialpoint

5、.C.DiagrammaticrepresentationofDWC.D.thecerebellarhemispheresaresmall.Theventricularsystemisdilated,resultinginlargetemporalhorns22－weekfetusSonographyandMRIfindingsaresimilartothepreviouscaseexceptthatthecerebellarhemispheresseemslargerandvermiantissecanbeseeninthemidline.Cranio

6、caudaldiameterCraniocaudaldiameter(perpendiculartofastigialpoint-decliveline)28-weekfetusThecraniocaudaldiameterofvermismeasures10.9mm(equivalentof22weeks).Theexpectedmeasurementis14.8mm.Thetranscerebellardiameterisalsosmall.孕28＋3周，B超提示胎儿脑室扩张14.9mm12.3mm9.8mm上下蚓比小脑蚓部胚胎期呈线性协调发育以顶点

7、为分界上下蚓比例为47％和53％，不随生长发育变化23-weekfetus36-weekfetus大枕大池枕大池蛛网膜囊肿29-weekfetus5-month孕32周，外院超声提示左脑室扩张、枕大池积水孕31周，超声提示：可疑侧脑室增宽知识回顾KnowledgeReview