胎儿磁共振成像-胎儿头颅MRI检查

1、胎儿磁共振成像MR Imaging of the Fetus超声 一 Ultrasound-母体肥胖一羊水过少-妊娠中晚期胎头增大 一胎儿颅骨骨化 MRI - Ultrafast MRI一单次激发快速序列 -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 序歹 U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-駢月氐体发育不良Total fetusesMRI abnormal9060 (67%)Comparison of antenat

2、al and postnatal MR findings in 39 of42 live born infantsComplete agreement23 (59%)Disagreement16 (41%)Excluded fetal MRI6 (15%)Revealed additionalabnormalities10 (26%)Limperopoulos C & aL A JR A 加 J Roentgenol 2008; 190:16371643.枕大池(cisterna magna)正常值2 - 11mm侧脑室体部vlOmm异常表现：Dandy-Walker畸形小脑蚓部发 育

3、不良，大枕大池，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 一 12W13 一 14W17.5w21w22w24w27wpreulmifiate fissureprimary fBsurep<«olminate fissureptimaz/fis-sufecentral lobuleCMwai lobule

4、OeCliveFASTI® 4LPOIVTfoliumfoliumtegmenJumlubprmoduleteamen! umprepyra midal fissurepramfcnucleus, qradlkseconckry (poitpyramldal) fiMurscandal y ip(M t p vra middl)i fk uj c eu*uuhprep)*ramidal fesureAssessment of Vermian Maturity小脑原裂 primary fissure顶点、fastigial point顶一蚓角 tengmento-vermian ang

5、le 5 TV A 颅尾径 craniocaudal diameter CCDTengmento-vermian angleNormalAbnormal22 - week fetusA. axial sonography showed a large cystic posterior fossa with small cerebellar hemispheres.B the tegmentermian angle is increased with the fourth ventricle uncovered The vermis is very small; there is no prim

6、ary fissure or fastigial point.C. Diagrammatic representation of DWCD. the cerebellar hemispheres are small.The ventricular system is dilated, resulting in large temporal horns22 - week fetusSonography and MRI findings are similar to the previous case except that the cerebellar hemispheres seems lar

7、ger and vermian tisse can be seen in the midline.Craniocaudal diameterCraniocaudal diameter (perpendicular to fastigial point-declive line)TABLE 1. Predicted Cerebellar Vermian CraniocaudaliDiameter229Menstrual Age, wkMean Diameter mm144.6155.3166 1176.8187.519g.32090219.72210.42311.22431.92512.6261

8、3.42714 128J4.82915.63016.1311703217.7331S.534】9.23519.93620.73723.43822.13922 94023.628-week fetusThe craniocaudal diameter of vermis measures 10.9mm (equivalent of22 weeks). The expected measurement is 14.8mmThe transcerebellar diameter is also small.孕28+ 3周，B超提示胎儿脑室扩张12.3mm14.9mm上下蚓比小脑蚓部胚胎期呈线性协调发育以