Purpose: To evaluate the contribution of MRI to ultrasound (US) in the diagnosis of fetal anomalies.
Materials and Methods:After informed consent and institutional review board approval, concomitant US and MR imaging were performed for 184 fetuses with suspected anomalies in university hospital. Postnatal final diagnoses were obtained for 183 anomalies in 151 fetuses either by radiological examination, surgery, autopsy, or inspection. The prenatal US and MR diagnoses were compared with respect to postnatal diagnoses. Sign test was used to determine the statistical significance.Results: Both ultrasound and MR imaging correctly diagnosed 93 (50%) cases and failed in 12 (7%) cases. Ultrasound was superior in 7 (4%) cases. MR imaging was superior in 71 (39%) cases (P < 0.001). MR contributed to the prenatal diagnosis by the confirmation of the suspected US diagnosis in 13%, by demonstration of additional findings in 31% and by changing the diagnosis in 56% of the cases. The contribution rates were 55% for the central nervous system (CNS) (P < 0.001), 44% for thorax (P ¼ 0.016), 38% for gastrointestinal system (GIS) (P ¼ 0.031) and 29% for genitourinary system (GUS) (P ¼ 0.003) anomalies. In facial, cardiac and extremity-skeletal system anomalies, there was not a significant contribution of MR imaging over US.Conclusion: MR imaging can be used as an adjunct to US in the prenatal diagnosis of fetal anomalies of not only the CNS but also the non-CNS origin especially those involving the GIS, GUS and thorax. ULTRASOUND (US) IS the standard and primary modality used for the imaging of the fetus. It is widely available, easy to apply, cost-effective, safe for the fetus and allows real-time imaging. However, it has some limitations. Especially in case of oligohydramnios, large maternal body habitus and inappropriate fetal position, its effectiveness reduces. Also in the evaluation of some body parts and complex pathologies, the results of US might be unclear (1,2). In such cases, MR imaging is being increasingly used as a complementary imaging modality.Magnetic resonance imaging has the potential to improve diagnostic accuracy of the prenatal imaging and facilitate the pregnancy management (3-5). It offers a high spatial, temporal, and contrast resolution, which makes the detailed study of fetal pathologies possible. To date, it has not been shown that MR imaging has any adverse effects on the fetal growth or development (2,6).Multiple studies have up to now been published to compare the effectiveness of the prenatal US and MR imaging. These studies showed that MR imaging provides additional information to US in 36% to 57% of the cases (3,4,7,8). Although this effect has been well-established for CNS anomalies, it has not been well-documented for non-CNS anomalies. Additionally, there were some important limitations of these previous studies. In most of these studies, the comparison of the imaging methods had been made without postnatal correlation and MR results had been accepted as the gold-standard. Secondarily, in most...