Fetal Brain Volume Research Articles

Measurement of fetal liver, brain and placental volumes with echo-planar magnetic resonance imaging.

To quantify accurately in utero fetal liver, brain and placental volumes using echo planar imaging, and to assess whether the technique has the potential to enhance intrauterine fetal assessment. Thirty-two singleton, complicated pregnancies were scanned using echo planar imaging, a form of magnetic resonance imaging. Pregnancies were subdivided on the basis of whether the fetus was found subsequently to have an individualised birthweight ratio above (n = 21) or below (n = 11) the 10th centile. Comparisons of the organ volumes of these two groups were made. The first quantitative in utero measurement of fetal liver volume showed a linear relation between liver volume and gestational age in fetuses where the individualised birthweight ratio was above the 10th centile (the normal growth group). Ten of the 11 liver volume measurements of fetuses subsequently found to have an individualised birthweight ratio below the 10th centile fell on or outside the 95% confidence limits established for the normal growth group. In contrast, no such differences were demonstrated when the brain and placental volumes were considered, with 10 of the 11 brain measurements and all of the 11 placental measurements falling within the 95% confidence limits of the normal growth group. A single measurement of fetal liver volume using echo planar imaging enabled accurate identification of fetuses subsequently found to have individualised birthweight ratios below the 10th centile. If these findings are repeated in larger, more representative studies, this suggests that the technique has the potential to contribute to intrauterine fetal assessment.

Prenatal growth of the human cerebral cortex: brainprint analysis.

To construct a series of flat maps (brainprints) that document the prenatal growth of human cerebral cortex and help identify sulcal landmarks for division of cortical regions of interest (ROIs) on mapped surfaces, the authors photographed and traced histologic whole-brain slices of 25 normal human fetal brains aged 18-42 weeks gestation. Brainprints of both cerebral hemispheres from each fetus were constructed with semiautomatic brain-mapping software, and each map was divided into five ROIs based on sulcal landmarks: frontal, parietal, insular, occipital, and temporal cortices. Surface areas of cerebral hemispheres and the five ROIs were estimated. Corrected for histologic shrinkage, brainprint estimates of human fetal cortical surface area were approximately twice those of previous estimates. Cortical lobe proportions at 18 weeks appeared to be unchanged to term. Surface area estimates correlated with fetal age, brain weight, and brain volume. This collection of cortical maps may guide future quantitative analyses of cerebral hemispheric growth in premature and term infants who undergo magnetic resonance imaging, which may, in turn, help predict neurobehavioral outcomes of early cortical damage.

First-trimester diagnosis of exencephaly

First-trimester diagnosis of fetal exencephaly is reported. Vaginal ultrasonography showed a normal volume of fetal brain with abnormal internal anatomy. The diagnosis was confirmed by repeat ultrasonography at 14 weeks and at subsequent termination of pregnancy. This is the earliest reported diagnosis of exencephaly by prenatal ultrasonography.

Revised guidance on acceptable limits of exposure during nuclear magnetic resonance clinical imaging.

Revised guidance on acceptable limits of exposure during nuclear magnetic resonance clinical imaging.