目的:在侧脑室扩大和正常后颅窝脑脊液间隙的胎儿中,第三室扩张是一个令人信服的线索,支持诊断导水管狭窄.然而,这种关联假定心室解剖结构正常.结构限制会损害压力引起的顺应性。我们的目的是确定在先天性导水管狭窄(CAS)的情况下,丘脑中间质量(TMI)大小改变如何影响第三脑室的大小。
方法:这项回顾性研究是在IRB批准后在一家专科医院进行的。我们在脑部MRI报告中搜索了所有描述“导水管狭窄”的检查,并包括所有进行过胎儿和产后检查的患者。与CAS无关的下丘脑间粘连和脑积水患者被排除在本研究之外。我们评估了所有MRI是否存在TMI,并记录了第三脑室直径(视上隐窝,中央,和会阴上隐窝)和TMI周长。Spearman相关性用于确定胎儿和产后MRI中TMI周长与第三脑室大小之间的潜在关系。还根据是否存在TMI将患者分为两组。Mann-WhitneyU检验用于比较这些组之间的第三脑室直径。
结果:该研究包括59例患者的胎儿和产后研究。两组的第三心室直径与TMI的周长成反比(胎儿:p=0.001,rho=-0.422,CI=[-0.628-0.181];出生后:p<0.001,rho=-0.653,CI=[-0.782-0.479])。尽管如此,在TMI增大的患者中,当第三脑室中段未扩张或扩张较不严重时,前后凹陷仍发生扩张。与TMI患者相比,缺乏TMI患者的第三心室扩张最为严重(p<0.001)。
结论:在疑似先天性导水管狭窄的患者中,缺乏传统测量的显著的第三脑室增宽有时可以通过TMI增厚来解释。在这种情况下,对于胎儿MRI扩张的证据,评估第三脑室的极端凹陷是很重要的.缩写:TMI=中中膜丘脑;CAS=先天性导水管狭窄。
OBJECTIVE: In fetuses with lateral ventriculomegaly and normal posterior fossa cerebrospinal spaces, third ventricle distention is a compelling clue that supports a diagnosis of aqueductal stenosis. However, this association assumes normal ventricular anatomy. Structural constraints can impair pressure-induced compliance. We aimed to determine how thalamic massa intermedia size alterations may impact the size of the third ventricle in the setting of congenital aqueductal stenosis.
METHODS: This retrospective study was performed at a single academic pediatric hospital after institutional review board approval. We searched our brain MRI reports for all examinations describing aqueductal stenosis and included all the patients who had both fetal and postnatal examinations. Patients with interhypothalamic adhesions and hydrocephalus unrelated to congenital aqueductal stenosis were excluded from this study. We evaluated all the MRIs for the presence of thalamic massa intermedia and documented third ventricle diameters (supraoptic recess, central and suprapineal recesses) and the thalamic massa intermedia circumference. The Spearman correlation was used to identify the potential relationship between the thalamic massa intermedia circumference and third ventricle size in fetal and postnatal MRIs. Patients were also stratified into 2 groups based on the presence or absence of thalamic massa intermedia. Mann-Whitney U tests were used to compare third ventricle diameters between these groups.
RESULTS: The study included both fetal and postnatal studies from 59 patients. The overall third ventricle diameter was inversely proportional to the circumference of the thalamic massa intermedia in both groups (fetal: P = .001, ρ = -0.422; [95% CI, -0.628 to -0.181]; postnatal: P < .001, ρ = -0.653; [95% CI, -0.782 to -0.479]). Nonetheless, dilation of anterior and posterior recesses still occurred when the mid third ventricle was nondilated or less severely dilated in patients with an enlarged thalamic massa intermedia. Third ventricle dilation was most severe in patients lacking a thalamic massa intermedia compared with patients with a thalamic massa intermedia (P < .001).
CONCLUSIONS: In patients with suspected congenital aqueductal stenosis, lack of marked third ventriculomegaly as conventionally measured can sometimes be explained by thickening of the thalamic massa intermedia. In this circumstance, it is important to evaluate the extreme recesses of the third ventricle for evidence of dilation on fetal MRI.