Department of Radiology, Pediatric Radiology Section, Aurora, Colorado, USA.
Children's Hospital Colorado, Aurora, Colorado, USA.
Fetal Diagn Ther. 2022;49(7-8):293-300. doi: 10.1159/000526231. Epub 2022 Aug 2.
The aim of this study was to determine the feasibility of fetal MRI in identifying the normal anal dimple (AD) and compare it with prenatal ultrasound (US).
Retrospective review of 130 patients with both fetal MRI and US. The gestational age (GA) was stratified into four groups: (1) 16 to 21 weeks-6 days; (2) 22 to 27 weeks-6 days; (3) 28 to 33 weeks-6 days; and (4) 34 weeks and beyond. Steady-state free precession (SSFP) and single shot fast spin echo (SSFSE) axial T2 MRI and transverse US images of the fetal perineum were analyzed, and visualization of the AD was determined. Clinical indication, gender, single versus multiple gestation, best MRI sequence where it was seen, and postnatal AD information were recorded.
The AD was visualized in 125/130 fetal MRIs, and visualization was independent of GA (p 0.230). US visualized the AD in 67/130 cases, and the best GA for visualization was in group 3 (p < 0.001). There was no difference in AD visualization between SSFSE and SSFP sequences (p 0.167).
Prenatal visualization of the AD by MRI is feasible and superior to US, independent of GA. Adding AD visualization to routine screening prenatal US and MRI may increase recognition of anorectal malformation.
本研究旨在确定胎儿 MRI 识别正常肛门凹痕（AD）的可行性，并将其与产前超声（US）进行比较。
回顾性分析 130 例同时接受胎儿 MRI 和 US 检查的患者。将孕龄（GA）分为四组：（1）16 至 21 周-6 天；（2）22 至 27 周-6 天；（3）28 至 33 周-6 天；（4）34 周及以上。分析胎儿会阴部的稳态自由进动（SSFP）和单次快速自旋回波（SSFSE）轴 T2 MRI 和横断 US 图像，并确定 AD 的可视化情况。记录临床指征、性别、单胎或多胎妊娠、最佳可见 MRI 序列以及产后 AD 信息。
130 例胎儿 MRI 中有 125 例显示 AD，且 GA 与 AD 可视化无关（p 0.230）。US 显示 AD 的有 67/130 例，最佳 GA 为第 3 组（p < 0.001）。SSFSE 和 SSFP 序列对 AD 的可视化无差异（p 0.167）。
MRI 产前显示 AD 是可行的，且优于 US，与 GA 无关。在常规产前 US 和 MRI 筛查中增加 AD 可视化可能会提高对肛门直肠畸形的识别。
