Early detection of ischemic brain injuries by diffusion‐weighted imaging after radiofrequency ablation for fetal reduction in monochorionic pregnancies

Abstract

Background This study aimed to investigate the additional advantages of magnetic resonance imaging (MRI), particularly diffusion‐weighted imaging (DWI) over fetal ultrasound in the detection of acute ischemic cerebral injuries in complicated monochorionic (MC) pregnancies that underwent selective reduction by radiofrequency ablation (RFA). Methods This prospective cohort study was conducted on 40 women with complicated MC pregnancies who were treated by RFA. Fetal brain imaging by DWI and conventional MRI was performed either in the early (within 10 days after RFA) or late phase (after 3–6 weeks) in the surviving fetuses to detect both acute and chronic ischemic injuries. The presence of anemia after RFA was also evaluated by Doppler ultrasound. Results Overall, 13 of the total 43 fetuses (30.23%) demonstrated MRI abnormalities with normal brain ultrasound results including germinal matrix hemorrhage (GMH), extensive cerebral ischemia, and mild ventriculomegaly. Although seven fetuses with GMH eventually survived, fetuses that demonstrated ischemic lesions and ventriculomegaly on MRI died in the uterus. Conclusion The absence of abnormal cerebral lesions or anemia on ultrasound and Doppler exams does not necessarily rule out fetal brain ischemia. Performing early MRI, particularly DWI seems to be a reasonable option for detection of early intracranial ischemic changes and better management of complicated multiple pregnancies which were treated by RFA.

The Current Knowledge of Cerebral Magnetic Resonance Imaging in Monochorionic Twins: A Systematic Review of the Last 20 Years

“…None of the studies included in this review focused solely on the incidence of cerebral injury on fetal MRI in sFGR twins unless the pregnancy was complicated by sIUFD (see Section 3.2.5). Moradi et al investigated the role of MRI, including DWI, in the detection of acute ischemic cerebral injury in MC pregnancies complicated by TTTS and treated with fetoscopic laser surgery [17]. This study also included 11 fetuses (25.6%) with isolated sFGR without TTTS.…”

“…Of note, in 111 cases, sIUFD was caused by selective fetal reduction. The studies reported a median overall incidence of cerebral injury in single survivors of 28.3% (range 0-55%) after sIUFD [8,13,14,16,17,23,25,26,[28][29][30]. We made a distinction between studies with single survivors after selective fetal reduction and other causes of sIUFD because of the different mechanisms of cerebral injury.…”

“…The following four studies also included single survivors after selective fetal reduction [8,13,17,28]. These studies reported a median incidence of cerebral injury in single survivors, including survivors after selective fetal reduction, of 16.5% (3.4-30.2%) after sIUFD.…”

“…Cerebral injury in the survivors consisted of focal cerebral hemorrhage (n = 1), mild ventriculomegaly (n = 2), cerebral artery infarction (n = 1), and germinal matrix hemorrhage (n = 1). Moradi et al reported that 30.2% (13/43) of single survivors, after selective reduction by umbilical cord coagulation, had cerebral injury [17]. These twins were diagnosed with TTTS (n = 19), sFGR (n = 11), fetal reduction (n = 2), TRAP (n = 1), or major structural anomalies (n = 10).…”