磁共振检查在确定胎儿脑室扩张疾病诊断中的临床适应证探讨

目的 通过对产前超声筛查出的脑室扩张胎儿行磁共振检查,探讨其确定诊断的适应证和应用价值.方法 2006年3月至2007年10月在中国医科大学附属盛京医院行产前超声检查的胎儿26 072例,其中产前超声筛查出胎儿脑室扩张104例,超声筛查孕龄为22周+2～39周+5,平均32周+1.按Gaglioti标准对104例脑室扩张胎儿进行分组:脑室扩张10～12 mm组66例,13～15 mm组22例,16～20 mm组14例,21～25 mm组2例;按脑室扩张部位不同分为单侧脑室扩张组75例,双侧脑室扩张组29例.在超声筛查48 h内对各组胎儿行磁共振检查以确定中枢神经系统疾病诊断,并随访妊娠结局.结果 (1)胎儿脑室扩张的发生率为0.39%(104/26 072).(2)脑室扩张10～12 mm组确定诊断3例(5%,3/66),分别为小脑发育不良、脑血管畸形及胸腹联合畸形各1例,单纯脑室扩张63例;13～15 mm组确定诊断5例(23%,5/22),分别为胼胝体缺如、脑出血、脑出血合并脑脊膜膨出、脑脊膜膨出及颅内占位各1例,单纯脑室扩张17例;16-20 mm组确定诊断6例(43%,6/14),分别为胼胝体缺如4例、脑出血1例、胼胝体缺如合并脑室出血1例,单纯脑室扩张8例;21～25 mm组确定诊断2例(2/2),分别为胼胝体缺如1例、脑出血1例,无单纯脑室扩张.10～12 mm组确定诊断率与其他3组比较,差异有统计学意义(P＜0.01).(3)单侧脑室扩张组中确定诊断4例(5%,4/75),双侧脑室扩张组中确定诊断12例(41%,12/29),两组比较,差异有统计学意义(P＜0.01).(4)104例脑室扩张胎儿中磁共振确定中枢神经系统疾病诊断16例,诊断率为15%.16例疾病胎儿中引产15例,尸体检查结果与磁共振确定疾病诊断完全相同;1例为胼胝体缺如,脑室扩张15 mm,在观察下妊娠至足月分娩,为正常新生儿;其余88例均妊娠至足月分娩,为健康新生儿.结论 超声筛查胎儿侧脑室扩张≥16 mm或双侧脑室扩张时,建议行磁共振检查以确定胎儿中枢神经系统的疾病诊断;脑室扩张≤12 mm的单纯侧脑室扩张不必行磁共振检查,可行超声动态观察,当发现胎儿脑室扩张程度有增加趋势时再行磁共振检查以明确诊断.

MRI diagnosis and analysis of 104 cases of fetal ventriculomegaly by ultrasonography

Objective To evaluate the diagnostic value of MRI in the cases suspected of ventriculomegaly by prenatal uhrasonography.Methods 104 patients of suspected fetal ventriculomegaly (VM) diagnosed by uhrasonography were included from the Shengjing Hospital,China Medical University from March 2006 to October 2007.All cases were divided into 4 groups based on the standard of Gaglioti:10-12 mm(66 cases),13-15 mm(22 cases),16-20 mm(14 cases),and 21-25 mm(2 cases);they included 75 eases of single intracerebroventricular expansion and 29 eases of double intracerebroventricular expansion.All of them were subjected to MRI scan within 48 h of uhrasonographic examination to determine the prenatal diagnosis by MRI pregnancy outcomes.Results Among the 26 072 cases who received prenatal uhrasonography,104 cases (0.39%) were VM. (1) MRI detected 3 cases (5%) in 10-12 mm group:one ease of cerebellar hypoplasia,vascular malformation,chest and abdominal anomalies each; 5 cases(23%)in 13 -15 mm group:one case of agenesis of corpus callosum (ACC),cerebral hemorrhage,cerebral hemorrhage with cerebral meningocele,cerebral meningocele,intracranial mass meningocele each; 6 cases(43% )in 16 -20 mm group:4 cases of ACC,one case of intraventricular hemorrhage and ACC combined with ventricular hemorrhage each; 2 cases in 21-25 mm group:one case of ACC and intraventricular hemorrhage each.(2) MRI detected 4 eases(5%) among 75 unilateral VM cases and 12 eases (41%) among 29 bilateral VM eases.The differences were significant (P＜0.01).MRI diagnosis rate was 15.38% (16 cases).Follow-up of the outcomes of the pregnancy showed induction of 0labor in 15 cases (14%) all of which were the same as MRI results on autopsy,full-term delivery of 88 cases,of which all the neonates were healthy.Conclusions When the expansion width is above 16 mm or bilateral VM is suspected by ultrasonography,we suggest MRI examination to determine fetal central nervous system disease.