Complementary Roles of Sonography and Magnetic Resonance Imaging in the Assessment of Fetal Urinary Tract Anomalies

Objective. The purpose of our study was to determine whether fetal magnetic resonance imaging (MRI) provides additional information that might affect the obstetric management of pregnancies complicated by sonographically diagnosed fetal urinary tract anomalies. Methods. Fetal MRI and sonography were used to study 39 women with suspected fetal urinary tract anomalies in the second and third trimesters of pregnancy. Results. In 24 of 39 cases (61%), fetal MRI confirmed the sonographic diagnosis. In 14 cases (36%), fetal MRI modified the initial sonographic diagnosis and counseling but did not change obstetric management. In 1 case (3%), the addition of fetal MRI resulted in a substantial change in the management of the pregnancy. Conclusions. During the second and third trimesters of pregnancy, fetal MRI showed fetal urinary tract anomalies in excellent anatomic detail. Fetal MRI is a useful complementary tool in the assessment of sonographically diagnosed fetal urinary tract anomalies. In a small percentage of cases, it can have a substantial impact on obstetric management.