Comparison of fetal magnetic resonance imaging and ultrasonography for the diagnosis of fetal anomalies

Kim, Min Jae; Kim, Ha Jung; Ji, Hyun Young; Seo, Eun Sung; Choi, Suk Joo; Roh, Cheong Rae; Oh, Soo Young; Kim, Jong Hwa

Abstract

PURPOSE: To compare the accuracy of fetal magnetic resonance imaging (MRI) and prenatal ultrasonography (USG) with postnatal diagnosis for the diagnosis of fetal anomalies.
METHODS
Retrospective analysis of 41 fetuses who underwent fetal MRI with prenatal USG from 2005 to 2008 was performed. In 28 cases of the total population, the final neonatal diagnosis was also analyzed for the consistency of pre- and postnatal diagnoses for each diagnostic tool. Postnatal diagnosis was confirmed by physical examination, radiographic studies (USG, MRI and/or computed tomography), surgery, and/or autopsy.
RESULTS
Mean gestational age at the fetal MRI performed was 26.1+/-4.7 weeks. The most common indication of the fetal MRI was central nervous system (CNS) anomalies (n=12), followed by thoracic anomalies (n=5), abdominal anomalies (n=2), genitourinary anomalies (n=3), head and neck anomalies (n=4), and others (n=2). When compared with postnatal diagnosis, the accuracy of prental MRI was superior to prenatal USG (89% vs. 71%). The cases with additional accurate diagnosis with using fetal MRI were 4 CNS, 1 genitourinary, and 1 craniofacial anomaly. Of notes, there was a case of enlarged cisterna magna in which prenatal MRI missed the diagnosis. In 2 cases (7.1%), both imaging studies made an incorrect prenatal diagnoses.
CONCLUSION
Fetal MRI could confirm the USG diagnosis in most cases and provided more accurate diagnosis in some cases of CNS and thoracic, genitourinary system abnormalities. MRI is expected to be a good adjunctive for USG to improve prenatal diagnosis of fetal anomalies.