胎儿磁共振成像-胎儿头颅MRI检查课件

胎儿磁共振成像MRImagingoftheFetus胎儿磁共振成像_胎儿头颅MRI检查超声－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

胎儿磁共振成像_胎儿头颅MRI检查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

胎儿磁共振成像_胎儿头颅MRI检查胎儿头颅MRI检查胎儿磁共振成像_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

--胼胝体发育不良胎儿磁共振成像_胎儿头颅MRI检查LimperopoulosC,etal.AJRAmJRoentgenol2008;190:1637–1643.TotalfetusesMRIabnormal

9060(67%)ComparisonofantenatalandpostnatalMRfindingsin39of42liveborninfantsCompleteagreement23(59%)Disagreement16(41%)ExcludedfetalMRI6(15%)Revealedadditionalabnormalities10(26%)

胎儿磁共振成像_胎儿头颅MRI检查枕大池(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，蛛网膜囊肿胎儿磁共振成像_胎儿头颅MRI检查小脑蚓部的发育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胎儿磁共振成像_胎儿头颅MRI检查

11－12W13－14W16W18W胎儿磁共振成像_胎儿头颅MRI检查17.5w21w22w24w27w胎儿磁共振成像_胎儿头颅MRI检查AssessmentofVermianMaturity小脑原裂primaryfissure顶点fastigialpoint顶－蚓角tengmento-vermianangle，TVA颅尾径craniocaudaldiameter，CCD胎儿磁共振成像_胎儿头颅MRI检查

NormalAbnormalTengmento-vermianangle胎儿磁共振成像_胎儿头颅MRI检查22－weekfetusA.axialsonographyshowedalargecysticposteriorfossawithsmallcerebellarhemispheres.B.thetegmento-vermianangleisincreasedwiththefourthventricleuncovered.Thevermisisverysmall;thereisnoprimaryfissureorfastigialpoint.C.DiagrammaticrepresentationofDWC.D.thecerebellarhemispheresaresmall.Theventricularsystemisdilated,resultinginlargetemporalhorns胎儿磁共振成像_胎儿头颅MRI检查22－weekfetusSonographyandMRIfindingsaresimilartothepreviouscaseexceptthatthecerebellarhemispheresseemslargerandvermiantissecanbeseeninthemidline.胎儿磁共振成像_胎儿头颅MRI检查CraniocaudaldiameterCraniocaudaldiameter(perpendiculartofastigialpoint-decliveline)胎儿磁共振成像_胎儿头颅MRI检查胎儿磁共振成像_胎儿头颅MRI检查28-weekfetusThecraniocaudaldiameterofvermismeasures10.9mm(equivalentof22weeks).Theexpectedmeasurementis14.8mm.Thetranscerebellardiameterisalsosmall.胎儿磁共振成像_胎儿头颅MRI检查孕28＋3周，B超提示胎儿脑室扩张14.9mm12.3mm9.8mm胎儿磁共振成像_胎儿头颅MRI检查上下蚓比小脑蚓部胚胎期呈线性协调发育以顶点为分界上下蚓比例为47％和53％，不随生长发育变化胎儿磁共振成像_胎儿头颅MRI检查23-weekfetus胎儿磁共振成像_胎儿头颅MRI检查36-weekfetus大枕大池胎儿磁共振成像_胎儿头颅MRI检查枕大池