Background:
Magnetic resonance Imaging (MRI) is increasingly used for detailed visualization of the fetus as well as pregnancy structures although ultrasound(US) remains the predominant modality for evaluating disorders related to pregnancy overall. MRI does not have the limitations of US thanks to its multiplanar capability, lack of ionizing radiation, and excellent soft-tissue contrast. The most common indications for fetal MRI are neurological. MRI is commonly used to investigate underlying etiologies of brain abnormalities that are not detected by US. Cortical malformations, heterotopias and anomalies of the corpus callosum are well depicted by MRI. It can confirm the diagnosis of ventriculomegaly or other associated abnormalities not detected by sonography. Posterior fossa abnormalities that can be evaluated by prenatal MRI include Dandy-Walker syndrome, Dandy-Walker variant, mega cisterna magna (> 10 mm), arachnoid cyst and Chiaris malformation type II. Evaluation of the spinal column is important to detect abnormalities such as neural tube defects.