Brain development of the human fetus in magnetic resonance imaging

Ultrasonography is the first step in the in vivo evaluation of fetal central nervous system. However, it is not always easy--or even possible--to carry out this examination because of maternal obesity, oligo- or ahydramnios or fetal position. Magnetic resonance imaging becomes then the only method of assessment. Recognition of cerebral and cerebellar abnormalities requires detailed knowledge of normal development and morphology of the fetal brain.

To show the sequence of fetal brain maturation on MR images on the basis of own material and equipment.

Seventy five fetuses without cerebral abnormalities were selected for the analysis of T2-weighted images of the brain obtained with use of GE Signa 1.5T scanners. No maternal sedation was used. Single-Shot Fast Spin Echo sequence (SSFSE) was applied in T2-weighted images in axial, sagittal and coronal planes in all fetuses. Fast Spoiled Gradient Echo (FSPGR) T1-weighted images were also obtained.

The sequence of fetal brain maturation during the second half of pregnancy was elaborated and discussed.

Magnetic resonance imaging is the most useful method of the evaluation of normal fetal brain development. It should be used as an additional tool in every case of diagnostic difficulties or uncertainty.