Transverse Cerebellar Diameter Research Articles

Diagnostic Accuracy of Fetal Transverse Cerebellar Diameter (TCD) Measurement as an Individual Parameter for Prediction of Gestational Age in Pregnant Ladies

Objective: To determine a relation between fetal transverse cerebellar diameter (TCD) and gestational age from 14 to 36 weeks in pregnant ladies including local population of Karachi from different areas. Methodology: One hundred and seventeen pregnant women were included. The sample size was determined via Online WHO EPI sample size calculator considering the previous study (21) via correlation (r=0.94) with confidence interval 95% and power of test 90%. Booked cases of pregnant women age ranging between 18-40 years with singleton pregnancies of any parity seeking ultrasound for antenatal care were included. Pregnant women with known case of hypertension, diabetes mellitus or diagnosed case of pregnancy induced hypertension or gestational diabetes &fetal structural anomalies were excluded. Demographics and obstetrical data including name, age, parity and relevant records of gestational age from early dating sonographic scan were recorded. Under supervision of expert radiologist in addition to regular biometry parameters T.C.D was also recorded for determination of gestational age. Recorded data was analyzed electronically via SPSS version 22. Results: A quantitative analysis of 117 patients For determination of a correlation between transverse cerebellar diameter (TCD) and gestational age of fetus revealed that out of total 117 pregnant women 29 were primiparous, six were grand multiparous (>5 parity) and the rest were multiparous. Mean ± SD of maternal age was 26.4±4.7 years with minimum 18 and maximum 40 years. Pearson’s correlation coefficient showed that a strong and linear correlation was found among fetal transverse cerebellar diameter & the gestational age i.e. (r=0.99) P<0.005. Conclusion: Between Transverse cerebellar diameter and the gestational age of the fetus between 15 to 36 weeks, a linear correlation was noted. Hence, it can be utilized as a reliable predictor of gestational age. Keywords: Fetal Transverse Cerebellar Diameter, Ultrasound, Gestational Age.

Evaluation of Intracranial Structures of Fetuses With Congenital Heart Defects.

We classified congenital heart defects (CHDs) according to cerebral blood flow oxygenation and aimed to evaluate the effect on the size of brain structures in these fetuses. The study which was designed retrospectively, included 28 patients with fetal CHDs and 76 patients without fetal anomalies. The width and length of the cavum septum pellucidum significantly increased in the CHD group (P=.002, P=.004). The biparietal diameter and z scores were significantly lower in the single ventricle (SV) (P=.006, P=.019), and the head circumference (HC) and z scores were significantly lower in the transposition of great arteries (TGA) (P=.013, P=.038). The transverse cerebellar diameter, the cerebellar HC and the cerebellar hemisphere area values were lower in the SV (P=.005, P=.017, P=.044). Brain structure changes are more pronounced in groups with low cerebral oxygenation, especially in the SV and the TGA.

Ultrasound correlation of transcerebellar diameter with last menstrual period for gestational age in second and third trimester of pregnancy

Background: Foetal biometry is useful modality in assessment of gestational age (GA) for good obstetric outcome. Objectives: To compare ultrasonographic measurement of transverse cerebellar diameter (TCD) with other previously established foetal ultrasound biometric parameters. Methods: An analytical cross-sectional study was conducted from August 2020 to February 2021 in Department of Radiology at Kathmandu Medical College after ethical clearance. Convenience sampling technique was utilised to include all pregnant women in second and third trimester with known last menstrual period (LMP). Written informed consent was taken from those willing to participate. Congenital malformations, multiple pregnancies, irregular menstrual cycle, and maternal illness were excluded. Data were entered and analysed by using SPSS v.22. Descriptive statistics like mean, standard deviation, and percent were used. Inferential statistics (t- test and Pearson correlation) was also used to see the correlation between different variables. Results: Among 100 participants who participated in the study, 63 (63%) were primigravida with singleton pregnancy without any congenital anomalies. The mean foetal heart rate was 144.9 ± 13.6. The mean GA based on LMP, TCD, and other parameters were 30.86 ± 7.76 weeks, 31.07 ± 8.45 weeks, and 29.75 ± 6.61 weeks respectively. In 15-28 weeks, all parameters had nearly equal r-values. Among all, TCD revealed highest correlation (0.888). In 29-40 weeks, there was considerable difference in r-values. The second most accurate correlation was seen with head circumference (r = 0.874). Conclusion: TCD being stable parameter not affected by foetal growth status maybe preferred over other parameters in estimating foetal gestational age.

Transcerebellar Diameter: an effective tool in estimating gestational age

Background: Estimating correct gestational age is the first and foremost goal of obstetrician and gynaecologist and cannot be underestimated. Commonly the parameters used are BPD, head circumference (HC), Femur length (FL), Abdominal circumference (AC). Recently transverse cerebellar diameter is a new diagnostic tool to measure the gestational age. Aim: To determine the accuracy of transverse cerebellar diameters in estimating gestational age, taking LMP as the gold standard. Study design: Descriptive Cross-Sectional Study. Setting: This study was conducted at Department of Obstetrics & Gynaecology, JPMC, Karachi, Pakistan Duration: Six months after the approval of synopsis from January 29 2021 to 28 July 2021. Methods: Ultrasonographic measurement of Transverse Cerebellar Diameter(TCD) was taken. Routine measurements of crown-rump length or bi-parietal diameter were also done. Accuracy was considered if the difference between TCD and LMP was ≤2 mm. Correlation of age on LMP with TCD was tested using Kendall’s tau-b test and its scatter plot as generated. All the collected data was entered into a proforma attached at the end and used electronically for research purposes. Results: A total of 114 patients were inducted after informed consent. Their mean age was 28.18±27.24 years. Maternal age was 28.18 ±27.24 years, maternal weight was 60.59 ±9.64 kg and BMI was 23.58±3.63 kg/m2.Median (IQR) of gravida was 2.0 (2). Mean of gestational age on LMP was 33.84 ±5.29 and was significantly more as measured by TCD was 31.51±5.05 (p<.001). Age on LPM and TCD showed linear correlation. Accuracy of TCD was documented in 108 (94.7%). Conclusion: It is to be concluded that transverse cerebellar diameter was found to be equally good and relatively comparable with LMP in predicting gestational age. Keywords: Gestational Age; Intrauterine Growth Restriction; Last Menstrual Period; Miscarriage; Stillbirth

Reference chart for transverse cerebellar diameter in developing fetuses according to their gestational age in Indian population

ObjectivesThe objective of the study was to develop reference chart and to evaluate the efficacy of transverse cerebellar diameter (TCD) as one of the fetal biometric parameters used in ultrasonography to determine gestational age in the Indian population. Also, in this study we compared our findings with similar studies done on different ethnic populations to check effect of different ethnicity, environmental and nutritional factors in development of TCD.DesignA retrospective cross‐sectional study.MethodIn this study routine antenatal check‐ups of 300 singleton pregnant women were done after obtaining ethical clearance from Institute Ethical Committee. Ultrasonographic measurements of various fetal biometric parameters were taken which included, biparietal diameter (cm), head circumference (cm), abdominal circumference (cm), femur length (cm) and transverse cerebellar diameter (cm). Reference chart with mean TCD for corresponding gestational age (GA) in weeks was developed and compared with results of similar other studies.ResultsStatistically significant correlation found between TCD and gestational age (R2=0.92, p=0.0006). Gradually increasing linear pattern obtained between the development of TCD and corresponding gestational age of the fetus. Therefore, it is more reliable parameter to be used in regression formulae used in USG machine to predict accurate gestational age of fetus. When reference charts for TCD is compared with findings in other studies in different ethnic population, it is found that there is statistically significant difference exists.ConclusionsIn normally developing fetuses the TCD has linear correlation with advancing gestational age. Therefore, along with other fetal biometric parameters measurement TCD can be used in determination of gestational age for more accuracy. Thus by preventing over or under estimation of gestational age will help in reducing no judicious use of health resources and medical interventions. A separate reference chart is required for every different population because ethnicity, nutrition and environmental factors can have impact on normal TCD values. This will help to avoid misinterpretation of data to determine gestational age in various ethnic populations.

Brainstem and cerebellar volumes at magnetic resonance imaging are smaller in fetuses with congenital heart disease

Congenital heart disease is associated with an increased risk of smaller brain volumes and structural brain damage, and impaired growth of supratentorial brain structures in utero has been linked to poor neurodevelopmental outcomes. However, little is known on brainstem and cerebellar volumes in fetuses with congenital heart disease. Moreover, it is not clear whether impaired infratentorial growth, if present, is associated with only certain types of fetal cardiac defects or with supratentorial brain growth, and whether altered biometry is already present before the third trimester. This study aimed to investigate brainstem and cerebellar volumes in fetuses with congenital heart disease and to compare them to infratentorial brain volumes in fetuses with normal hearts. Secondarily, the study aimed to identify associations between infratentorial brain biometry and the type of cardiac defects, supratentorial brain volumes, and gestational age. In this retrospective case-control study, 141 magnetic resonance imaging studies of 135 fetuses with congenital heart disease and 141 magnetic resonance imaging studies of 125 controls with normal hearts at 20 to 37 gestational weeks (median, 25 weeks) were evaluated. All cases and controls had normal birthweight and no evidence of structural brain disease or genetic syndrome. Six types of congenital heart disease were included: tetralogy of Fallot (n=32); double-outlet right ventricle (n=22); transposition of the great arteries (n=27); aortic obstruction (n=24); hypoplastic left heart syndrome (n=22); and hypoplastic right heart syndrome (n=14). First, brainstem and cerebellar volumes of each fetus were segmented and compared between cases and controls. In addition, transverse cerebellar diameters, vermian areas, and supratentorial brain and cerebrospinal fluid volumes were quantified and differences assessed between cases and controls. Volumetric differences were further analyzed according to types of cardiac defects and supratentorial brain volumes. Finally, volume ratios were created for each brain structure ([volume in fetus with congenital heart disease/respective volume in control fetus]× 100) and correlated to gestational age. Brainstem (cases, 2.1 cm3 vs controls, 2.4 cm3; P<.001) and cerebellar (cases, 3.2 cm3 vs controls, 3.4 cm3; P<.001) volumes were smaller in fetuses with congenital heart disease than in controls, whereas transverse cerebellar diameters (P=.681) and vermian areas (P=.947) did not differ between groups. Brainstem and cerebellar volumes differed between types of cardiac defects. Overall, the volume ratio of cases to controls was 80.8% for the brainstem, 90.5% for the cerebellum, and 90.1% for the supratentorial brain. Fetuses with tetralogy of Fallot and transposition of the great arteries were most severely affected by total brain volume reduction. Gestational age had no effect on volume ratios. The volume of the infratentorial brain, which contains structures considered crucial to brain function, is significantly smaller in fetuses with congenital heart disease than in controls from midgestation onward. These findings suggest that impaired growth of both supra- and infratentorial brain structures in fetuses with congenital heart disease occurs in the second trimester. Further research is needed to elucidate associations between fetal brain volumes and neurodevelopmental outcomes in congenital heart disease.

Early second-trimester three-dimensional transvaginal neurosonography of fetal midbrain and hindbrain: normative data and technical aspects.

To provide a detailed description of the sonographic appearance and development of various fetal structures of the midbrain and hindbrain (MBHB) during the early second trimester, and to evaluate the impact of the frequency of the transvaginal sonography (TVS) transducer on the early recognition of these structures. This was a retrospective analysis of three-dimensional volumetric datasets of the MBHB from apparently normal fetuses at 14-19 gestational weeks, acquired by TVS in the midsagittal view through the posterior fontanelle. Using a multiplanar approach, we measured the tectal thickness and length, aqueductal thickness, tegmental thickness and width and height of the Blake's pouch (BP) neck. In addition, we assessed the existence of early vermian fissures, the linear shape of the brainstem and the components of the fastigium. The correlation between gestational age according to last menstrual period and sonographic measurements of MBHB structures was evaluated using Pearson's correlation (r). A subanalysis was performed to assess the performance of a 5-9-MHz vs a 6-12-MHz TVS transducer in visualizing the MBHB structures in the early second trimester. Sixty brain volumes were included in the study, obtained at a mean gestational age of 16.2 weeks (range, 14.1-19.0 weeks), with a transverse cerebellar diameter range of 13.0-19.8 mm. We found a strong correlation between gestational age and all MBHB measurements, with the exception of the tectal, tegmental and aqueductal thicknesses, for which the correlation was moderate. There was good-to-excellent intraobserver and moderate-to-good interobserver correlation for most MBHB measurements. We observed that the BP neck was patent in all fetuses between 14 and 18 weeks with decreasing diameter, and that the aqueductal thickness was significantly smaller at ≥ 18 weeks compared with at < 16 weeks. The early vermian fissures and the linear shape of the brainstem were present in all fetuses from 14 weeks. We found that, in the early second trimester, the horizontal arm of the presumed 'fastigium' evolves from the fourth ventricular choroid plexus and not the posterior vermis, indicating that this is not the fastigium. Standard- and high-resolution TVS transducers performed similarly in the assessment of MBHB anatomy. Detailed early second-trimester assessment of the MBHB is feasible by transvaginal neurosonography and provides reference data which may help in the early detection of brain pathology involving the MBHB. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Prenatal diagnosis of rhombencephalosynapsis: neuroimaging features and severity of vermian anomaly.

To describe the prenatal neuroimaging spectrum of rhombencephalosynapsis (RES) and criteria for its classification according to the severity of vermian anomaly. In this multicenter retrospective study of fetuses with RES between 2002 and 2020, the medical records and brain ultrasound and magnetic resonance images were evaluated comprehensively to determine the severity of the vermian anomaly and the presence of associated brain findings. RES was classified, according to the pattern of vermian agenesis and the extent of the fusion of the hemispheres, as complete RES (complete absence of the vermis) or partial RES (further classified according to the part of the vermis that was missing and, consequently, the region of hemispheric fusion, as anterior, posterior, severe or mixed RES). Findings were compared between cases with complete and those with partial RES. Included in the study were 62 fetuses with a gestational age ranging between 12 and 37 weeks. Most had complete absence of the vermis (complete RES, 77.4% of cases), a 'round-shaped' cerebellum on axial views (72.6%) and a transverse cerebellar diameter (TCD) < 3rd centile (87.1%). Among the 22.6% of cases with partial RES, 6.5% were classified as severe partial, 6.5% as partial anterior, 8.1% as partial mixed and 1.6% as partial posterior. Half of these cases presented with normal or nearly normal cerebellar morphology and 28.5% had a TCD within the normal limits. Infratentorially, the fourth ventricle was abnormal in 88.7% of cases overall, and anomalies of the midbrain and pons were frequent (93.5% and 77.4%, respectively). Ventriculomegaly was observed in 80.6% of all cases, being more severe in cases with complete RES than in those with partial RES, with high rates of parenchymal and septal disruption. This study provides prenatal neuroimaging criteria for the diagnosis and classification of RES, and identification of related features, using ultrasound and magnetic resonance imaging. According to our findings, a diagnosis of RES should be considered in fetuses with a small TCD (severe cerebellar hypoplasia) and/or a round-shaped cerebellum on axial views, during the second or third trimester, especially when associated with ventriculomegaly. Partial RES is more common than previously thought, but presents an extreme diagnostic challenge, especially in cases with normal or nearly-normal cerebellar morphobiometric features. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Association between Fat-Free Mass and Brain Size in Extremely Preterm Infants.

Postnatal growth restriction and deficits in fat-free mass are associated with impaired neurodevelopment. The optimal body composition to support normal brain growth and development remains unclear. This study investigated the association between body composition and brain size in preterm infants. We included 118 infants born <28 weeks of gestation between 2017–2021, who underwent body composition (fat-free mass (FFM) and fat mass (FM)) and cerebral magnetic resonance imaging to quantify brain size (cerebral biparietal diameter (cBPD), bone biparietal diameter (bBPD), interhemispheric distance (IHD), transverse cerebellar diameter (tCD)) at term-equivalent age. FFM Z-Score significantly correlated with higher cBPD Z-Score (rs = 0.69; p < 0.001), bBPD Z-Score (rs = 0.48; p < 0.001) and tCD Z-Score (rs = 0.30; p = 0.002); FM Z-Score significantly correlated with lower brain size (cBPD Z-Score (rs = −0.32; p < 0.001) and bBPD Z-Score (rs = −0.42; p < 0.001). In contrast weight (rs = 0.08), length (rs = −0.01) and head circumference Z-Score (rs = 0.14) did not. Linear regression model adjusted for important neonatal variables revealed that FFM Z-Score was independently and significantly associated with higher cBPD Z-Score (median 0.50, 95% CI: 0.59, 0.43; p < 0.001) and bBPD Z-Score (median 0.31, 95% CI: 0.42, 0.19; p < 0.001); FM Z-Score was independently and significantly associated with lower cBPD Z-Score (median −0.27, 95% CI: −0.42, −0.11; p < 0.001) and bBPD Z-Score (median −0.32, 95% CI: −0.45, −0.18; p < 0.001). Higher FFM Z-Score and lower FM Z-scores were significantly associated with larger brain size at term-equivalent age. These results indicate that early body composition might be a useful tool to evaluate and eventually optimize brain growth and neurodevelopment.

Estimated Brain Volume at Term Age in Very Preterm Infants with Uncomplicated Grade II And III Intraventricular Haemorrhage

Background and aims: In very pre-term new-borns, cerebral lesions are usually complicated with neuro-developmental issues. But un-complicated intra-ventricular haemorrhage (IVH) has no reliable associations with poor outcomes. Objective: In the current work we aimed to assess the impact of un-complicated brain haemorrhage on assessed brain size at term-equivalent ages (TEA), through standard indices made from cranial ultrasound (cUS). Methods: This study included 87 very pre-term babies [< 32 weeks’ gestational age (GA)] up to and at TEA which were divided into two groups; group one included infants with uncomplicated grades II or III IVH, and group two included infants with normal cUS. A previously described standards based on linear measurements were used to calculate the estimated brain volumes at TEA and to compare between the two groups using independent groups t-test; p-value ≤ 0.05 was considered significant. Results: 19 very pre-term babies with un-complicated IVH and 68 with normal images have been studied. Bi-parietal diameter at TEA was shorter in the IVH new-borns (72 vs 87 mm, p-value < 0.05) while thalamo-occipital distance was longer in IVH infants (23.7/21.4 mm, p-value < 0.05)). But, there were non-significant changes at TEA for bi-frontal diameter (69.3 vs 70.1 mm), transverse cerebellar diameter (51.1 vs 49.9 mm), valued cranial size (384/414cc3), valued cerebral size (338/341cc3) and Levene’s ventricular index (1.38/1.23 cm). Conclusions: There is no difference in assessed cerebral size at TEA, built on measures performed at the bedside via cranial US among very pre-term new-borns with dependably ordinary images and those with un-complicated grade II and grade III IVH.

VP35.05: Comparison of estimation of gestational age by transverse cerebellar diameter with biparietal diameter in third trimester of pregnancy

VP35.05: Comparison of estimation of gestational age by transverse cerebellar diameter with biparietal diameter in third trimester of pregnancy

Fetal Transverse Cerebellar Diameter (TCD) Measurement for Gestational Age Prediction in the Second and Third Trimesters of Pregnancy

Background: The purpose of this study was to see how accurate transverse cerebellar diameter (TCD) measurement is at predicting gestational age in normal fetuses. In the 2 nd &amp; 3 rd trimesters of pregnancy a range of sonographics fetal biometric characteristics can be utilized to determine gestational age. Other parameters, such as bi-parietal diameter and fetal length, are used to determine transcerebellar diameter. Objective(s): To determine the predictability of GA estimated from fetal TCD assessed on ultrasonography in the 2 nd and 3 rd trimesters of pregnancy. Methodology: This was a cross-sectional study conducted at the Ch. Mohammad Akram teaching and research hospital on 84 pregnant healthy ladies with fetuses ranging in age from 18 to 45 years old. During the 2 nd and 3 rd trimesters of pregnancy a routine ultrasound scan was done. In additions to the standard biometric parameter the transcerebellar diameter was estimated. Results: The TCD of 84 patients as a measure of gestational age in weeks. These were generated from data collected during the study and include mean and standard deviation TCD measurements of 84 participants ranging in gestational age from 14 to 40 weeks. The current research found a significant link between the GA of TCD and the GA of BPD and fetal length. The TCD(mm) mean and standard deviations were 33.74 ± 11.762 respectively. The TCD gestational age mean and standard deviations were 28.160 ± 6.7942 respectively. Bi-parietal diameter (mm) has a mean and standard deviation of 68.24 ± 18.503. Bi-parietal diameter had a mean and standard deviation of 27.996 ± 6.9099 gestational age. The standard deviation and mean 50.32 ± 16.265 mm Fetal length The mean and standard deviation of fetal length gestational age are 27.423 ± 6.7625. Different criteria such as transcerebellar diameter, biparietal diameter, and femur length, are used to establish the gestational age of the fetus in this cross-sectional analysis. Conclusion(s): The TCD is a set of accurate variables for assessing GA in pregnant women in the 2 nd and 3 rd trimesters. Key words: Transcerebellar diameter; Gestational age; Fetal length ; Bi-parietal diameter. DOI: 10.7176/JHMN/93-08 Publication date: September 30 th 2021

Exposure to ambient air pollution and fetal cerebellar transverse diameter: a longitudinal study

BACKGROUND AND AIM: Vulnerability to adverse health effects of air pollution begins during the fetal period, as emerging evidence suggests that exposures to fine particulate matter (PM2.5) and nitrogen dioxide (NO2) are associated with low birth weight and prematurity. We aimed to determine the extent to which PM2.5 and NO2 exposures during the preconception period and early pregnancy are associated with cerebellar development as measured by fetal ultrasound. METHODS: Participants were 854 mother-fetal pairs enrolled in the NYU Children’s Health and Environmental Study (CHES) (New York City, 2016-2019). Clinical data on transverse cerebellar diameter (TCD, mm) from ultrasound examinations of pregnant women were extracted from electronic health records. We used a tree-based machine learning method of random forests and gradient boosting machines to predict daily PM2.5 and NO2 at residential addresses. Average PM2.5 and NO2 exposure during three months pre-conception, as well as first and second trimesters were calculated using daily exposure. Associations between each air pollutant and repeatedly measured TCD were examined using linear mixed models adjusted for time of cerebellar measurement, maternal age, pre-pregnancy body mass index, race/ethnicity, employment, education, depressive symptoms, and parity. RESULTS:The mean gestational age was 18.31 weeks (SD=1.91) at the time of first TCD measurement and 24.06 weeks (SD=5.45) at second TCD measurement. Exposures to PM2.5 during the pre-conception period and the first trimester were associated with a smaller TCD (β per µg/m³=-0.15, 95% CI: -0.30, 0.01, and β=-0.30, 95% CI: -0.47, -0.13, respectively). Exposures to NO2 during the pre-conception period and the first trimester were associated with a smaller TCD (β per ppb=-0.05, 95% CI: -0.08, -0.01, and β=-0.05, 95% CI: -0.09, -0.01, respectively). There were no associations between second trimester exposures and TCD. CONCLUSIONS:Exposure to PM2.5 and NO2 during the pre-conception period and early pregnancy may influence fetal brain development. KEYWORDS: Particulate matter, nitrogen dioxide, air pollution, pregnancy, fetal growth, cerebellum

Fetal Brain Biometric Measurements on 3D Super-Resolution Reconstructed T2-Weighted MRI: An Intra- and Inter-observer Agreement Study.

We present the comparison of two-dimensional (2D) fetal brain biometry on magnetic resonance (MR) images using orthogonal 2D T2-weighted sequences (T2WSs) vs. one 3D super-resolution (SR) reconstructed volume and evaluation of the level of confidence and concordance between an experienced pediatric radiologist (obs1) and a junior radiologist (obs2). Twenty-five normal fetal brain MRI scans (18–34 weeks of gestation) including orthogonal 3-mm-thick T2WSs were analyzed retrospectively. One 3D SR volume was reconstructed per subject based on multiple series of T2WSs. The two observers performed 11 2D biometric measurements (specifying their level of confidence) on T2WS and SR volumes. Measurements were compared using the paired Wilcoxon rank sum test between observers for each dataset (T2WS and SR) and between T2WS and SR for each observer. Bland–Altman plots were used to assess the agreement between each pair of measurements. Measurements were made with low confidence in three subjects by obs1 and in 11 subjects by obs2 (mostly concerning the length of the corpus callosum on T2WS). Inter-rater intra-dataset comparisons showed no significant difference (p > 0.05), except for brain axial biparietal diameter (BIP) on T2WS and for brain and skull coronal BIP and coronal transverse cerebellar diameter (DTC) on SR. None of them remained significant after correction for multiple comparisons. Inter-dataset intra-rater comparisons showed statistical differences in brain axial and coronal BIP for both observers, skull coronal BIP for obs1, and axial and coronal DTC for obs2. After correction for multiple comparisons, only axial brain BIP remained significantly different, but differences were small (2.95 ± 1.73 mm). SR allows similar fetal brain biometry as compared to using the conventional T2WS while improving the level of confidence in the measurements and using a single reconstructed volume.

Normal human brainstem development in vivo: aquantitative fetal MRI study.

ABSTRACTObjectivesTo characterize spatiotemporal growth differences of prenatal brainstem substructures and cerebellum, using linear biometry and planimetry on fetal magnetic resonance imaging (MRI).MethodsIn this retrospective study, we included fetuses with normal brain and a precise midsagittal T2‐weighted brain MRI sequence obtained between May 2003 and April 2019. The cross‐sectional area, rostrocaudal diameter and anteroposterior diameter of the midbrain, pons (basis pontis and pontine tegmentum), medulla oblongata and cerebellar vermis, as well as the transverse cerebellar diameter, were quantified by a single observer. The diameters were also assessed by a second observer to test inter‐rater variability.ResultsWe included 161 fetuses with normal brain and a precise midsagittal MRI sequence, examined at a mean ± SD gestational age of 25.7 ± 5.4 (range, 14 + 0 to 39 + 2) weeks. All substructures of the fetal brainstem and the cerebellum could be measured consistently (mean ± SD interobserver intraclass correlation coefficient, 0.933 ± 0.065). We provide reference data for diameters and areas of the brainstem and cerebellum in the second and third trimesters. There was a significant quadratic relationship between vermian area and gestational age, and all other measured parameters showed a significant linear growth pattern within the observed period (P < 0.001). A significant change in the relative proportions of the brainstem substructures occurred between the beginning of the second trimester and the end of the third trimester, with an increase in the area of the pons (P < 0.001) and a decrease in that of the midbrain (P < 0.001), relative to the total brainstem area.ConclusionsThe substructures of the fetal brainstem follow a distinct spatiotemporal growth pattern, characterized by a relative increase in the pons and decrease in the midbrain, between 15 and 40 weeks of gestation. Caution is needed when interpreting fetal brainstem appearance during the early second trimester, as the brainstem proportions differ significantly from the adult morphology. The reference data provided herein should help to increase diagnostic accuracy in detecting disorders of defective hindbrain segmentation. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Normal cavum veli interpositi at 14-17 gestational weeks: three-dimensional and Doppler transvaginal neurosonographic study.

To provide evidence to support the hypothesis that the midline cyst-like fluid collection that is frequently observed on fetal brain ultrasound (US) imaging during the early second trimester represents a normal transient cavum veli interpositi (CVI). This was a retrospective analysis of 89 three-dimensional normal fetal brain volumes, acquired by transvaginal US imaging in 87 pregnant women between 14 and 17 gestational weeks. The midsagittal view was studied using multiplanar imaging, and the maximum length of the fluid collection located over (dorsal to) the tela choroidea of the third ventricle was measured. We calculated the correlation of the transverse cerebellar diameter (TCD) and of the maximum length of the fluid collection with gestational age according to last menstrual period. Color Doppler images were analyzed to determine the location of the internal cerebral veins with respect to the location of the fluid collection. Reports of the second-trimester anatomy scan at 22-24 weeks were also reviewed. Interhemispheric fluid collections of various sizes were found in 55% (49/89) of the volumes (mean length, 5 (range, 3.0-7.8) mm). There was a strong correlation between TCD and gestational age (Pearson's correlation, 0.862; P < 0.001). There was no correlation between maximum fluid length and gestational age (Pearson's correlation, -0.442; P = 0.773). Color Doppler images were retrieved in 32 of the 49 fetuses; in 100% of these, the internal cerebral veins coursed within the echogenic roof of the third ventricle. The midline structures were normal at the 22-24-week scan in all cases. In approximately half of normal fetuses, during the evolution of the midline structures of the brain, various degrees of fluid accumulate transiently in the velum interpositum, giving rise to a physiologic CVI. Patients should be reassured that this is a normal phenomenon in the early second trimester that, if an isolated finding, has no influence on fetal brain development. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Prenatal Ultrasound Diagnosis of Biometric changes in the Brain of Growth Restricted Fetuses. A Systematic Review of Literature.

Fetal growth restriction (FGR) occurs when the fetus does not reach its intrauterine potential for growth and development as a result of compromise in placental function. It is a condition that affects 5 to 10% of pregnancies and is the second most common cause of perinatal morbidity and mortality. Children born with FGR are at risk of impaired neurological and cognitive development and cardiovascular or endocrine diseases in adulthood. The purpose of the present revision is to perform a literature search for evidence on the detection and assessment by ultrasound of brain injury linked to FGR during fetal life. Using a systematic approach and quantitative evaluation as study methodology, we reviewed ultrasound studies of the fetal brain structure of growth-restricted fetuses with objective quality measures. A total of eight studies were identified. High quality studies were identified for measurement of brain volumes; corpus callosum; brain fissure depth measurements, and cavum septi pellucidi width measurement. A low-quality study was available for transverse cerebellar diameter measurement in FGR. Further prospective randomized studies are needed to understand the changes that occur in the brain of fetuses with restricted growth, as well as their correlation with the changes in cognitive development observed.

Evaluation of the Fetal Transverse Cerebellar Diameter (TCD) Measurement for Prediction of Gestational Age in 2nd and 3rd Trimesters of Pregnancy

Background: To study the usefulness of transcerebellar diameter measurements ultrasonographically for detection gestational age as early period. transcerebellar diameter with that determined by other parameter i.e. bi-parietal diameter, fetal length , abdominal circumference and the head circumference. Objective(s): Study aim is to see how accurate fetal transverse cerebellar diameter measured at predicting GA in the pregnancy patients second and third trimesters. Methodology: This was a cross-sectional analysis performed in Ch. Mohammad Akram teaching and research hospital with sample size of 116 pregnant healthy females with fetus normal aged 18 to 40 year. A regular ultrasound scan was performed in the pregnancy second and third trimesters. The transcerebellar diameter was calculated in additions to normal biometric parameter. Results: A observe TCD measured in mm of 116 patients was seen in a nomogram based on gestational age in weeks. This was based on the information gathered during the study. mean TCD measurements in 28 patients between the ages 14 and 20 week was 13.0 mm to 20.3mm, 41 patient between the ages 21 and 30 weeks has a mean TCD measurement of 22.2mm to 33.9mm, and 47 patients between the ages of 31 and 42 weeks has a mean TCD measurement of 37.5 weeks to 58.0. Conclusion(s): The TCD is accurate parameters for the assessment of GA in the 2 nd & 3 rd trimester of pregnant women. Keywords: Gestational age; Transcerebellar diameter; Head Circumference; Fetal length; Abdominal Circumference; Bi-parietal diameter. DOI: 10.7176/JHMN/90-11 Publication date: June 30 th 2021

Cortical spectral matching and shape and volume analysis of the fetal brain pre- and post-fetal surgery for spina bifida: a retrospective study

PurposeA retrospective study was performed to study the effect of fetal surgery on brain development measured by MRI in fetuses with myelomeningocele (MMC).MethodsMRI scans of 12 MMC fetuses before and after surgery were compared to 24 age-matched controls without central nervous system abnormalities. An automated super-resolution reconstruction technique generated isotropic brain volumes to mitigate 2D MRI fetal motion artefact. Unmyelinated white matter, cerebellum and ventricles were automatically segmented, and cerebral volume, shape and cortical folding were thereafter quantified. Biometric measures were calculated for cerebellar herniation level (CHL), clivus-supraocciput angle (CSO), transverse cerebellar diameter (TCD) and ventricular width (VW). Shape index (SI), a mathematical marker of gyrification, was derived. We compared cerebral volume, surface area and SI before and after MMC fetal surgery versus controls. We additionally identified any relationship between these outcomes and biometric measurements.ResultsMMC ventricular volume/week (mm3/week) increased after fetal surgery (median: 3699, interquartile range (IQR): 1651–5395) compared to controls (median: 648, IQR: 371–896); P = 0.015. The MMC SI is higher pre-operatively in all cerebral lobes in comparison to that in controls. Change in SI/week in MMC fetuses was higher in the left temporal lobe (median: 0.039, IQR: 0.021–0.054), left parietal lobe (median: 0.032, IQR: 0.023–0.039) and right occipital lobe (median: 0.027, IQR: 0.019–0.040) versus controls (P = 0.002 to 0.005). Ventricular volume (mm3) and VW (mm) (r = 0.64), cerebellar volume and TCD (r = 0.56) were moderately correlated.ConclusionsFollowing fetal myelomeningocele repair, brain volume, shape and SI were significantly different from normal in most cerebral layers. Morphological brain changes after fetal surgery are not limited to hindbrain herniation reversal. These findings may have neurocognitive outcome implications and require further evaluation.

ISUOG Practice Guidelines (updated): sonographic examination of the fetal central nervous system. Part 2: performance of targeted neurosonography.

ISUOG Practice Guidelines (updated): sonographic examination of the fetal central nervous system. Part 2: performance of targeted neurosonography.