Fetal MR Imaging
Fetal Brain and Spinal Cord MR Imaging
Brain and spine abnormalities detected on the screening ultrasound usually performed at 20 weeks of gestational age can be further clarified by Magnetic Resonance (MR) imaging of the fetal central nervous system (CNS). MR provides a more detailed and accurate image than can be obtained with ultrasound. With a confirmed diagnosis, early identification of candidates for fetal or post-delivery neurosurgery can occur.
The above images show a suprasellar arachnoid cyst. This cyst was successfully treated by neuorsurgery at 32 weeks when the child was delivered.
MR Imaging is performed on a 1.5T strength magnet and images are obtained using radiofrequency pulses (much like ultrasound) produced in a strong electromagnetic field. No known deleterious effects have been documented in the fetus. The study can take from 30 minutes to 60 minutes depending on how much the baby is moving. Very fast pulse sequences are used so that the motion of the baby is less of a problem. Often we must "chase" the fetus a bit. Sequences are repeated if there is too much motion, which could lengthen the study. The MR machine is a closed space so claustrophobic mothers must prepare themselves, but it is not a problem to be brought out of the magnet for a break. The study is noisy so earplugs or earphones are provided.