When ultrasound cannot sufficiently provide all needed information during the third trimester of pregnancy, many radiologists are adopting 3D magnetic resonance imaging (MRI) for further anatomical exploration, reports RSNA.Org.

While not routinely used during prenatal care, 3-D MRI does offer excellent tissue contrast as a second evaluation in difficult cases or to reinforce an US diagnosis, according to Heron Werner, MD, PhD, at Clínica de Diagnóstico por Imagem in Rio de Janeiro.

US scanning over the past several decades has opened a new window into the study of the fetus, because it is patient-friendly, cost-effective and safe. MRI for fetal imaging has been in use since the 1980s and offers high-resolution images with excellent tissue contrast. It provides additional information about fetal abnormalities and conditions in situations where US cannot provide high-quality images, such as advanced gestational age, reduction of the amniotic fluid and maternal obesity.