177: Use of fetal magnetic resonance imaging (MRI) for the evaluation of fetal anomalies detected by standard obstetrical ultrasound (US)

Abstract

FETAL ANOMALIES DETECTED BY STANDARD OBSTETRICAL ULTRASOUND (US) LESLEY BEVAN, FRANCESCA FACCO, SVENA JULIEN, TALBOT CHRISTOPHER, Northwestern University, Obstetrics and Gynecology, Chicago, Illinois, Children’s Memorial Hospital, Institute for Fetal Health, Chicago, Illinois OBJECTIVE: To evaluate the utility of MRI in the diagnosis of US detected fetal anomalies. STUDY DESIGN: Retrospective chart review of patients who underwent fetal US and subsequent MRI at our institution over a 3 year period. Data collected included US diagnosis and gestational age (GA) at US and MRI. MRI findings were reviewed and compared with initial US findings and diagnosis. RESULTS: 70 cases were identified. Forty-seven (67%) MRI=s were performed for central nervous system (CNS) abnormalities, 10 (14%) for cardiovascular/thoracic anomalies, 6 (9%) for genitourinary or gastrointestinal anomalies, and 7 (10%) for other indications. MRI enhanced or altered the diagnosis in 67% of the cases. There was no difference in GA of cases in which MRI enhanced or altered US diagnosis versus cases in which MRI yielded no additional information (25.0 versus 25.3 weeks, P .67). MRI confirmed the original US diagnosis in 87% of cases, provided additional clinically useful information regarding the initial diagnosis in 36% of cases, diagnosed an additional anomaly in 26% of cases, and refuted the original diagnosis in 13% of cases. The percentage of cases altered in some way by MRI, stratified by US findings, is presented in the table below. MRI=s performed for CNS anomalies were more likely to provide an additional diagnosis not originally seen on US than MRI’s performed for any other indication (17/47 (36%) vs. 1/22 (5%), P .004). CONCLUSION: MRI enhances the evaluation of US detected fetal anomalies. It is particularly useful in the evaluation of the fetus with an US detected CNS anomaly.