Fetal Mri Of The Brain And Spine: Why, When And How?

Abstract

Fetal magnetic resonance imaging (MRI) is nowadays an established second-line imaging modality next to prenatal ultrasound (US). Ultrafast fetal MR sequences allow to “picture freeze" the fetus in utero without the need for sedation. The goal of fetal MRI is to offer an enhanced visualization and characterization of the pathologies detected by routine prenatal sonography, and it is therefore used as a problem-solving technique in a selected patient population. Prenatal sonography remains the imaging modality of choice for evaluating disorders related to the fetus and pregnancy; however, occasionally fetal MRI can identify subtle lesions that remained uncovered by US but may be essential for accurate diagnosis. Furthermore, fetal MRI contributes to selection of intrauterine treatment options and obstetric management, determines immediate postnatal care, and enhances parental counseling. MRI of the fetal brain and spine provides a higher sensitivity and specificity compared to prenatal US, because of several inherent US limitations. Depending on the maternal habitus, maternal bowel gasses, amount of amniotic fluid, and positioning of the child in utero, visualization of the fetal central nervous system (CNS) may be limited by US. Furthermore, the progressing development of the fetal cartilaginous/osseous calvarium and spinal canal during pregnancy may obscure lesions close to the skull or vertebral bodies on US examination. The goal of the workshop is to become familiar with the imaging protocol and indications for fetal MRI of the CNS, enhance your expertise about interpreting fetal MRI of the brain and spine, and become familiar with developmental variants of the fetal brain and spine.