Ontario Fetal Centre, Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynaecology, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada.
Department of Obstetrics and Gynecology, University Hospitals Leuven, Department of Development and Regeneration, KU Leuven, Leuven, Belgium.
Ultrasound Obstet Gynecol. 2022 Apr;59(4):497-505. doi: 10.1002/uog.24844.
Monochorionic twin pregnancies are at increased risk of single intrauterine death (sIUD) and subsequent brain injury in the surviving twin owing to shared placentation. We assessed the association between middle cerebral artery peak systolic velocity (MCA-PSV) and cerebral injury on magnetic resonance imaging (MRI) and examined the association between cerebral findings on diffusion-weighted imaging (DWI) and those on T2-weighted imaging following spontaneous sIUD.
This was a retrospective cohort study of monochorionic pregnancies complicated by spontaneous sIUD followed at a tertiary center between January 2008 and January 2020. Pregnancies with sIUD following laser treatment, those with selective feticide, double IUD occurring on the same day or sIUD before 14 weeks' gestation were excluded, as were cases in which MCA-PSV was not measured or DWI-MRI was not performed. The ability of MCA-PSV Doppler to predict subsequent cerebral injury on MRI was assessed, and DWI findings were analyzed and compared with those on susceptibility-weighted imaging (SWI) and T2-weighted MRI to determine its diagnostic accuracy.
We assessed 64 monochorionic pregnancies complicated by spontaneous sIUD. Of these, 47 (73.4%) pregnancies underwent fetal brain MRI and met the inclusion criteria. Sixteen (34.0%) of these fetuses demonstrated cerebral injury on MRI. The median interval between the diagnosis of sIUD and MRI examination was 5 days. Fetuses with increased MCA-PSV > 1.5 multiples of the median (MoM) following sIUD were significantly more likely to demonstrate cerebral injury on MRI than were those with normal MCA-PSV (68.8% vs 38.7%; P = 0.05). The sensitivity and specificity of MCA-PSV > 1.5 MoM for predicting cerebral injury on MRI were 68.8% (95% CI, 41.3-88.9%) and 61.3% (95% CI, 42.2-78.2%), respectively. Patterns of early cerebral injury on T2-weighted and SWI-MRI included acute or subacute tissue swelling (n = 6), parenchymal atrophy (n = 7), loss of cortical ribbon (n = 1) and hemorrhage (n = 8). Early MRI within approximately 2 weeks after the diagnosis of sIUD demonstrated abnormal DWI along with coexisting SWI and T2-weighted sequelae in 56.3% (9/16) of cases. When DWI was normal and a second MRI examination was performed later (n = 7), there were no ischemic changes evident on T2-weighted imaging.
Increased MCA-PSV is associated with, but predicts poorly, cerebral injury after sIUD. Early MRI with DWI within approximately 2 weeks after the diagnosis of sIUD is valuable in identifying any cerebral injury. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.
由于胎盘共享，单绒毛膜双胞胎妊娠宫内死亡（sIUD）和随后存活胎儿脑损伤的风险增加。我们评估了大脑中动脉收缩期峰值速度（MCA-PSV）与磁共振成像（MRI）上脑损伤之间的相关性，并检查了 sIUD 后弥散加权成像（DWI）上的脑发现与 T2 加权成像上的脑发现之间的相关性。
这是一项对 2008 年 1 月至 2020 年 1 月在三级中心接受治疗的单绒毛膜妊娠并发自发性 sIUD 的回顾性队列研究。排除了 sIUD 后接受激光治疗、选择性胎儿死亡、同一天发生的双 IUD 或 14 周前发生的 sIUD、MCA-PSV 未测量或未进行 DWI-MRI 的妊娠。评估 MCA-PSV 多普勒预测随后 MRI 上脑损伤的能力，并分析 DWI 发现并与磁敏感加权成像（SWI）和 T2 加权 MRI 进行比较，以确定其诊断准确性。
我们评估了 64 例并发自发性 sIUD 的单绒毛膜妊娠。其中，47 例（73.4%）妊娠接受了胎儿脑部 MRI 检查并符合纳入标准。这些胎儿中有 16 例（34.0%）MRI 上有脑损伤。sIUD 诊断与 MRI 检查之间的中位间隔为 5 天。sIUD 后 MCA-PSV 升高> 1.5 个中位数倍数（MoM）的胎儿在 MRI 上显示脑损伤的可能性明显高于 MCA-PSV 正常的胎儿（68.8%比 38.7%；P=0.05）。MCA-PSV > 1.5 MoM 预测 MRI 上脑损伤的敏感性和特异性分别为 68.8%（95%CI，41.3-88.9%）和 61.3%（95%CI，42.2-78.2%）。T2 加权和 SWI-MRI 上早期脑损伤的模式包括急性或亚急性组织肿胀（n=6）、实质萎缩（n=7）、皮质带丢失（n=1）和出血（n=8）。sIUD 诊断后约 2 周内进行早期 MRI 显示，56.3%（9/16）的病例存在 DWI 异常，同时存在 SWI 和 T2 加权的后遗症。当 DWI 正常且随后进行第二次 MRI 检查时（n=7），T2 加权成像上未见缺血性改变。
MCA-PSV 升高与 sIUD 后脑损伤有关，但预测效果不佳。sIUD 诊断后约 2 周内进行 DWI 的早期 MRI 对于识别任何脑损伤很有价值。©2021 年国际妇产科超声学会。
