Fetal Congenital Abnormalities: Clinical Utility of 3T MRI in Late 2nd & 3rd Trimesters

PURPOSE: To assess and compare utility of fetal MRI over prenatal ultrasound in management of fetal congenital abnormalities detected in late 2nd and 3rd trimesters (after legal limit of termination). METHODS: 3T MRI was performed in 43 pregnant women with period of gestation ≥20 weeks with suspected congenital abnormalities on ultrasound (USG). Half-Fourier acquisition single shot turbo spin echo sequence was used with T1 sequence wherever required. Ultrasonographic and MRI findings were compared and grouped as: findings concordant on both (Category I), MRI added information with no significant change in diagnosis (Category II), MRI added information with significant change in diagnosis (Category III) or USG superior to MRI (Category IV). Clinical utility of the fetal MRI was assessed in changing fetal prognostication and delivering peri/postnatal management with respect to USG in each of these categories. RESULTS: 18/43(41.8%) showed concordant USG and MRI findings without change in management. In 9/43(20.9%), MRI added information with no significant change in diagnosis causing change in prognosis and management in 4/9(44.4%) and 2/9(22.2%) respectively. In 15/43(34.9%), MRI added information with significant change in diagnosis that worsened prognosis in 13/15(86.7%) and aided in management in 6/15(40%). In 1/43(2.4%), USG was superior than MRI with no influence on management. CONCLUSIONS: Fetal MRI improves ultrasonographic diagnosis leading to change in fetal prognostication in a significant proportion of pregnancies. MRI can help in deciding mode of deliveries. It can act as a preliminary imaging which aids in post-natal management in an unstable baby where cross-sectional imaging is difficult. Funding Information: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Declaration of Interests: None. Ethics Approval Statement: Ethical clearance was obtained from the institutional ethics committee.