The Volume of the Cerebellum in the Second Semester of Gestation

Abstract

Background and aimsThe cerebellum (“little brain”), the largest part of hind brain, lies in the posterior cranial fossa, beneath the occipital lobe and dorsal to the brainstem. It develops over a long period: it is one of the first structures in the brain to begin to differentiate, but one of the last to mature. The use of ultrasonography has significantly improved the evaluation of fetal growth and development and has permitted prenatal diagnosis of a variety of congenital malformations.The aim of our study was to evaluate the cerebellar growth and development using 2 different measuring techniques: microMRI and ultrasound technique. The cerebellum measurements were related to gestational age.MethodsWe used 14 human fetuses corresponding to 15–28 gestational weeks, immersed in a 9% formalin solution. Magnetic Resonance Imaging (MRI) was performed by employing a Bruker BioSpec 70/16USR scanner (Bruker BioSpin MRI GmbH, Ettlingen, Germany), operated at 7.04 Tesla for cerebellar volume measurement. Ultrasonographic measurements of the cerebellum diameter were performed on 14 pregnant women, 15 – 28 gestational weeks. Ultrasound scan used 5–10 MHZ for transvaginal approach. Taking into consideration the values of the cerebellum dimensions and considering the general shape of the cerebellum as a transverse ellipsoid, the volume of the cerebellum was calculated by a mathematical formula for ellipsoid volume.ResultsThe study correlates the measurements from the microMRI study with the ultrasounds data and the results are superposable. Both established the exponential volume growth after the 22–23 GW. We used the ellipsoid volume formula for the cerebellar volume using the half of the three diameters of the cerebellum determined by ultrasound measurements:Cerebellar Volume = Ellipsoid volume = 3/4 π r1 r2 r3ConclusionThere is a linear correlation between the microMRI measurements and ultrasound determinations. Based on all collected data we could apply an easy formula to calculate the volume of cerebellum, a useful criterion in the evaluation of the cerebellar development and the appreciation of the gestational age.

Fetal cerebellar development: 3D morphometric analysis of fetal postmortem MRI among Chinese fetuses

“…The study to evaluate the normative fetal brain growth using MRI found the rate of cerebellum maturation rate was high with 4 fold increase in volume from 25-36 weeks of gestation(Clouchoux et al 2012),this is more or less similar to our study which shows 3 fold increase in volume. In another study the cerebellar volume increased seven fold from 20 to 31 weeks of gestation with the exponential curve(R 2 =0.96) being the best fit regression equation (Scott et al 2012), in our study, however, the increase of the cerebellar volume was the best fit by the quadratic equation or the second order polynomial (R 2 =0.994).One study used MRI to study the cerebellar volume, there was a direct correlation between the fetal cerebellar growth and the gestation age, with the second-order polynomial equation as the best fit model(Hatab, Kamourieh, and Twickler 2008),this trend is similar to our study, However dissimilar to a study among fourteen(14) human fetuses using both ultrasound and MRI, found the exponential increase in cerebellar(ellipsoid volume) during the second trimester of pregnancy(Vulturar et al 2018). The non-linear growth curve was observed for the growing cerebellum for the fetuses aged 20-40 weeks of gestation with the differential growth between the two cerebellar hemispheres(Rutten et al 2009).…”

“…The distinction between the normal and abnormal parameters of the growing cerebellum is important for establishment correct diagnosis of posterior fossa malformations (Bertucci et al 2011).The creation of MRI template of normal cerebellar growth is very important in order to differentiate between the normal and the abnormal growth (Chong et al 1997).The study to evaluate the normative fetal brain growth using MRI found the rate of cerebellum maturation rate was high with 4 fold increase in volume from 25-36 weeks of gestation (Clouchoux et al 2012),this is more or less similar to our study which shows 3 fold increase in volume. In another study the cerebellar volume increased seven fold from 20 to 31 weeks of gestation with the exponential curve(R 2 =0.96) being the best fit regression equation (Scott et al 2012), in our study, however, the increase of the cerebellar volume was the best fit by the quadratic equation or the second order polynomial (R 2 =0.994).One study used MRI to study the cerebellar volume, there was a direct correlation between the fetal cerebellar growth and the gestation age, with the second-order polynomial equation as the best fit model (Hatab, Kamourieh, and Twickler 2008),this trend is similar to our study, However dissimilar to a study among fourteen(14) human fetuses using both ultrasound and MRI, found the exponential increase in cerebellar(ellipsoid volume) during the second trimester of pregnancy (Vulturar et al 2018). The non-linear growth curve was observed for the growing cerebellum for the fetuses aged 20-40 weeks of gestation with the differential growth between the two cerebellar hemispheres (Rutten et al 2009).In another study using the fetal ultrasound among two hundred and thirty one(231) healthy fetuses, there was high correlation between the cerebellar volume and the gestational age, with the second degree polynomial being the best fit model(r=0.91, p<0.0001) (Chang et al 2000a),similar to another study using 3D ultrasound which involves fifty two (52) pregnant women at gestational age of 20-32 weeks of gestation which the cerebellar volume correlated highly with the gestational age (r=0.94, p<0.001) (Araujo et al 2007).…”

Update Reference Charts: Fetal Biometry between the 15th and 42nd Week of Gestation

“…A study showed that a difference up to five days can occur between LMP and crown-rump length (CRL) measured by ultrasound, with CRL being the more accurate method for estimating the date of delivery [15]. TCD and gestational age also show a good correlation until the 30 th week of gestation [16,17]. A TCD/AC ratio also showed to be safer in detecting IUGR than the HC/AC ratio [18], which corroborates the importance of sonography of neurological parameters.…”

Comparison of postmortem whole‐body contrast‐enhanced microfocus computed tomography and high‐field magnetic resonance imaging of human fetuses

“…Imaging modalities such as high-field MRI (HF-MRI, ≥ 3 Tesla (T)) and microfocus CT (micro-CT) are potential options for the latter group 15 . Due to increased magnetic field strength, HF-MRI allows submillimeter spatial resolutions, enabling detailed examination of fetal anatomy, including the brain [16][17][18] , inner ear 19 and extremities 20 . Micro-CT, combined with a contrast agent (contrast-enhanced micro-CT), has also been shown to have a high concordance rate with fetal autopsy 13,21 .…”