Comparision of US and MR imaging for diagnosis of fetal anomalies

OBJECTIVE: To compare the effectivenesses of magnetic resonance imaging (MRI) and ultrasound (US) in prenatal diagnosis.METHODS: Between May 2008 and May 2010, 154 pregnant women with suspected fetal anomalies were evaluated with MRI and US at the Radiology department of University hospital. 121 cases having final diagnosis were enrolled in to study. Prenatal diagnosis of MRI and US were compared with final diagnosis. Statistical analysis of the difference between the diagnostic accuracies of two methods was performed with the use of Sign test.RESULTS: There were 54 cases with central nervous system (CNS), 20 with genitourinary system (GUS), seven with gastrointestinal system (GIS), three with thoracic, six with extremity and two with facial anomalies. 15 cases had multiple system anomalies. 14 cases could not be inserted to a specific anomaly group and classified as ?others?. Fetal MRI and US gave the same diagnosis in 70 cases (%58). In a case sonographically suspected anomaly was confirmed by MRI. MRI provided additional findings or diagnosis in 21 (%18) cases and changed the diagnosis in 25 (%21) cases. In dört (%3) cases, sonographic findings could not be demonstrated by MRI.Both imaging methods provided correct diagnosis in 62 (%51) cases and wrongly or not diagnosed the anomaly in eight (%7) cases. In 47 (%39) cases MRI was superior to US and in four (%3) cases US was superior to MRI. MRI provided additional diagnostic information to US in 50 % of the cases with CNS anomalies (P<0.001), in %35 of the cases with GÜS (p=0.070) and in %43 of the cases with GİS (p=0.250) anomalies. There was no difference between the diagnostic abilities of two methods in case of extremity-bone, thoracic and facial anomalies.CONCLUSIONS: MRI might be used as an adjunct to US in the prenatal diagnosis especially in case of CNS anomalies.KEY WORDS: prenatal diagnosis; magnetic resonance imaging; MRI; ultrasound; fetal anomaly