Transverse Cerebellar Diameter Measurements Research Articles

Agreement between Fetal Brain Ultrasonography and Magnetic Resonance Imaging in the Measurements of the Corpus Callosum and Transverse Cerebellar Diameter.

As the use of magnetic resonance imaging of the fetal brain has evolved, the need to understand its efficiency in the biometry of the fetal brain has broadened. This study aimed to assess the level of agreement and correlation between the two cardinal imaging methods of fetal neuroimaging, ultrasonography (US) and magnetic resonance imaging (MRI), by measuring the corpus callosum (CC) and transverse cerebellar diameter (TCD) in terms of length and percentile. Measurements of CC and TCD length and percentile were documented over a 7-year span in a tertiary referral medical center. All US and MRI examinations were performed in the customary planes and subcategorized by valid reference charts. Exclusion and inclusion criteria were set before the collection and processing of the data. A total of 156 fetuses out of 483 were included in the study. A positive, strong correlation and agreement were found (r = 0.78; ICC = 0.76) between US and MRI in TCD measurements. For CC length measurement, a moderate correlation and moderate agreement (r = 0.51; ICC = 0.49) between US and MRI was observed. TCD and CC percentiles had lower levels of correlation and agreement compared with the length variables. Our study indicates good agreement between MRI and US in the assessment of TCD measurement as a part of antenatal neuroimaging. Furthermore, while the two techniques are not always compatible, they are complementary methods.

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

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 & 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

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

Role of Transcerebellar Diameter Measurement with Ultrasonography in Evaluation of Gestational age in Normal and Growth Restricted Fetuses

Background: To study the usefulness of transcerebellar diameter measurement ultrasonographically for the detection of gestational age in normal and intra uterine growth restricted fetuses and compare the gestation age determined by transcerebellar diameter with that determined by other parameters i.e. biparietal diameter, head circumference, abdominal circumference and femur length. Subjects and Methods: A prospective study with ultrasonographic evaluation of five hundred antenatal patients in gestational age of 14-39 weeks. The transcerebellar diameter was measured and the corresponding gestational age determined. The gestational age was also determined with other parameters such as biparietal diameter, head circumference, abdominal circumference and femur length. Transcerebellar circumference to abdominal circumference ratio was calculated. Results: There is statistically significant relationship between Transcerebellar diameter and gestational age in normal and intra uterine growth retarded pregnancies. Transcerebellar diameter showed good correlation with gestational age (correlation coefficient=0.979) in case of normal pregnancies and( correlation coefficient=0.942 )in cases of intra uterine growth retarded pregnancies Gestational age estimated by transverse cerebellar diameter measurements correlated well with gestational age estimated by biparietal diameter, head circumference, abdominal circumference and femur length. Transcerebellar circumference to abdominal circumference ratio remained fairly constant. Conclusion: Transcerebellar diameter can be used as a independent growth parameter to predict the gestational age in normal and in intrauterine growth retarded pregnancies cases. Transcerebellar diameter to abdominal circumference ratio is fairly constant throughout gestation and thus it is a useful gestational age independent parameter.

FETAL TRANSVERSE CEREBELLAR DIAMETER MEASUREMENT;

Objective: To determine the accuracy of fetal transverse cerebellar diametermeasurement in the prediction of gestational age in growth restricted fetuses. Material andmethods: This controlled was conducted at Sobhraj Maternity Hospital, Karachi from July 2012to June 2013. A total of 100 pregnant women in the third trimester of pregnancy satisfying theeligibility criteria were included. Among these 50 were fetuses with normal fetal growth and50 growth restricted fetuses. Results: The mean transverse cerebellar diameter in the fetusesshowing normal growth was not statistically different from the mean transverse cerebellardiameter in the growth restricted fetuses (p-value = 0.219). Conclusions: Transverse cerebellardiameter measurement can be used reliably for accurate estimation of gestational age in growthrestricted fetuses.

Accuracy of Transverse Cerebellar Diameter measurement by Ultrasonography in the evaluation of fetal age

Background: Perinatal mortality a concern in the developing countries and intrauterine growth restriction (IUGR) is an important cause. Therefore early diagnosis of IUGR babies is the key to prevent complications as well as mortality. Multiple biometric parameters including trans-cerebellar diameter can be used to predict the gestational age. Thus, the present study was designed to measure and compare the trans-cerebellar diameter and evaluates the usefulness of transverse cerebellar diameter as against the conventional parameters and to find out the usefulness of transverse cerebellar diameter in antenatal diagnosis of intrauterine growth retardation. Methods: A cross-sectional study was conducted on normal antenatal women of 15-40 weeks gestational age referred for antenatal ultrasonography between January to December 2015. Total 250 patients were examined. Data collected was compared with the conventional parameters. Results: Good correlation was found between transverse cerebellar diameter (TCD) and other parameters. Also TCD showed a linear relationship between the cerebellar growth and the gestational age. It was found to be better than BPD in circumstances like excessive molding and dolicocephaly. Also TCD measurement was not fraught with problems as encountered in FL measurement. The mean TCD/AC ratio was 13.866%. So it was found that TCD can be used as a reliable parameter for determination of gestational age in mass studies. Conclusion: There is good correlation between TCD and other parameters in normal pregnancies at 15 to 40 weeks of gestation. This implies that, TCD is a better parameter for gestational age assessment compared to BPD and FL.

Accuracy of transverse cerebellar diameter measurement by ultrasonography in the evaluation of foetal age

Background: Assessment of accurate gestational age of fetus is very imperative for proper obstetric management of normal as well as IUGR pregnancies. The objective of this study was to evaluate the accuracy of transverse cerebellar diameter as against the conventional parameters of Biparietal diameter, head circumference, abdominal circumference and femur length in normal pregnant mothers between 15 to 40 weeks and in antenatal diagnosis of intrauterine growth retardation.Methods: Study done on 100 women attending antenatal department, 80 were normal pregnancy cases and 20 were clinically suspected IUGR cases. In each patient BPD, HC, AC, FL and TCD was measured. Correlation of TCD was done with other measured parameters as well as with estimated gestational age of fetus.Results: There was no statistically significant difference between the age and parity distributions of two groups It was seen that 18 cases were below the fifth percentile for AC and HC, 19 cases were below the fifth percentile for BPD and 16 cases were below the fifth percentile for FL. In 16 out of 20 cases the TCD values were within the normal range. Only in 4 cases the TCD values were below the 5th percentile. This difference in number of cases below the 5th percentile for BPD, HC, AC, FL and TCD was statistically significant (p-value=0.001). In 20 IUGR cases the gestational age predicted by transverse cerebellar diameter measurements closely correlated with gestational age predicted by last menstrual period.Conclusions: It was found that there is good correlation between TCD and other parameters. Also, TCD shows good correlation with gestational age. It is better than BPD in circumstances like excessive moulding and dolichocephaly. Also, TCD measurement is not fraught with problems as encountered in FL measurement.

Sonographic Reference Values for Fetal Transverse Cerebellar Diameter in the Second and Third Trimesters in a Nigerian Population

This study aimed to establish reference values of fetal transverse cerebellar diameter (TCD) in a Nigerian population. A cross-sectional convenience study was carried out between June 2013 and May 2014 in Enugu, Nigeria. The sonographic examinations were performed on 697 pregnant women with gestational ages between 14 and 40 weeks. The TCD measurements were obtained from the proximal outer margin to the distal outer margin of cerebellum. The women’s last menstrual period, femur length, biparietal diameter, head circumference, and abdominal circumference were also recorded. The mean (standard deviation) TCD increased from 13.6 (2.2) mm to 27.3 (2.6) mm and 28.9 (2.0) mm to 42.9 (2.0) mm in the second and third trimesters, respectively. The relationship of TCD with gestational age obtained from last menstrual period, femur length, biparietal diameter, head circumference, and abdominal circumference was determined. The TCD had a strong correlation with gestational age ( r = .93; P < .05). Reference values for TCD were established for those patients who attended this clinic. This is a likely data set to use for future research that could focus on similar practices and in other regions of the country for possible generation of a nationwide nomogram.

Ratio of fetal anteroposterior to transverse cerebellar diameter for detection of the cerebellar hypoplasia in the second trimester and comparison with trisomy 18.

Cerebellar hypoplasia, particularly, trisomy 18, represents a chromosomal abnormality. However, morphological assessment of the fetal cerebellum is yet to be established. The purpose of this study was to produce reference values for the fetal transverse cerebellar diameter (TCD), anteroposterior cerebellar diameter (APCD) and the ratio of APCD to TCD (APCD/TCD ratio) in normal fetuses, compared with cases of trisomy 18. This retrospective study included 266 normal singleton pregnancies resulting in term delivery at our institution from 2012-2013. Patients had received ultrasound examinations in the second trimester. TCD and APCD measurements were performed and then APCD/TCD ratio was calculated. Consequently, three cases of trisomy 18 were compared with reference values. Gestational age correlated with TCD (rs = 0.766, P < 0.0001) and APCD (rs = 0.61, P < 0.0001), but not with APCD/TCD ratio (rs = 0.070, P = 0.252). The median APCD/TCD ratio was 0.52 and the standard deviation was 0.05. In cases of trisomy 18, all TCD measurements were located within normal ranges. In contrast, both the APCD and APCD/ TCD ratio displayed lower values than that of normal fetuses. This study showed that not only TCD but also APCD correlated with gestational age, and APCD/TCD ratio indicated a fixed value (almost 0.5) in normal fetuses. Furthermore, APCD and APCD/TCD ratio were deemed useful indicators for cerebellar hypoplasia. In particular, the APCD/TCD ratio proved more convenient, without requiring individual evaluation of TCD and APCD.

3차원초음파에서 임신주수 예측을 위한 선형회귀방정식의 구현

태아의 소뇌는 임신주수에 따라 성장하며 소뇌횡직경 길이의 측정은 임상에서 태아성장 예측의 중요한 지표로 활용하고 있다. 본 연구에서는 임신 20~37주 사이의 산모를 임신 주수별 각 20명씩 총 340명을 대상으로 3차원초음파 탐촉자를 이용하여 태아의 태령 및 태아의 소뇌 양쪽 외단을 측정해 기초자료를 획득하였다. 결과적으로 임신 주수에 따른 태아 소뇌횡직경의 성장을 회귀곡선으로 표시하였고 선형회귀방정식에서 결정계수를 얻었다. 3차원초음파를 이용한 임신주수에 따른 소뇌횡직경 측정방법은 통계적으로 유의(p<0.001)하였으며, 태령을 예측함에 있어 유용하다는 것을 알 수 있었다. 그러므로 임신주수에 따라 증가하는 소뇌횡직경의 측정은 정확한 임신주수의 산정이 가능 할 것이며 임상에서 현재 이용되고 있는 태령측정 방법의 대체 또는 개선방법이라 사료된다. 태아의 성장에 따라 측정하는 소뇌형직경은 임신주수에 따른 태아 성장의 평가가 가능하며, 태아의 머리 모양에 관계없이 성장장애가 있는 경우에도 임신주수의 예측이 가능하다. 따라서 본 연구를 기초자료로 하여 지속적인 연구가 시행된다면 3차원초음파를 이용한 소뇌횡 직경의 측정은 정확한 임신주수 예측에 유용할 것으로 사료된다. Fetal cerebellum is grow depending on the gestational age, measurement of transverse cerebellar diameter(TCD) is being used import indicator of fetal growth prediction in clinical. In this study, the subjects were normal pregnant women 20~37 week of gestation, and the volume scan was conducted on the 340 subjects. The research reports was indicated by regression curve the growth of fetal TCD in accordance with the gestational age. It got to the value of the results from a linear regression equation. Measurement fetal TCD using 3D US was statistically significant(p<0.001) and useful in the prediction of gestational age. TCD increases with gestational age can also distinguish between the normal fetal and prediction of accurate gestational age of fetal growth retardation. If the basic data of the present study, ongoing research is performed, the TCD using by 3D US are expected to be usefully applied in the correct prediction gestational age.

P02.01: Prenatal diagnosis of rhombencephalosynapsis: case series with outcome

Objectives: The cerebellum develops over a long period of time, making it vulnerable to a wide range of disorders such as Dandy-Walker malformation and variant. The advent of three dimensional ultrasonography is an extraordinary advance in fetal medicine diagnosis. The 3DXI is technique of comparing several slices displayed on the same screen, allows a slice-by-slice approach in ascertaining the most accurate measurement to be compared with the 2D. Our objective is to make a comparative evaluation of the transverse cerebellar diameter measurement by 2D ultrasonography (Fig. 1) and 3DXI, multi-slice view in 18–24 weeks fetuses. Methods: This transversal study included 69 healthy fetuses, between 18–24 weeks. The transverse cerebellar diameter was first measured by the conventional bi-dimensional sonography technique, then by 3DXI multi-slice view, using the Medison SonoAce X8 (Medison, Korea). The Wilcoxon signed-ranks test was used to compare the data. Results: The comparison of 69 measures of the cerebellum by 2D ultrasound and 3DXI shows an effective difference between the values obtained by 2D and 3D, indicating that the 3DXI values are larger than 2D (P < 0.01). Conclusions: Our results show that the 3D evaluation of the cerebellum seems to have a statistically significant measurement difference.

Transverse Cerebellar Diameter - A Marker for Estimation of Gestational Age

The cerebellum lies in the posterior cranial fossa. In the embryo, cerebellum appears at the end of fifth week. The cerebellum is easily visualized sonographically. Measurement and demonstration of fetal cerebellum is a new and unique parameter of fetal brain growth and also useful in assessing gestational age. The prospective study was carried out on 50 antenatal patients (20–40 years of age) between 14–40 weeks of pregnancy attending the clinic for routine ultrasound examination. Ultrosonographic measurement of Transverse cerebellar diameter (TCD) was done to assess the Gestational age. Mean TCD was 17.32 mm in 14–20 weeks of gestation, 26.63 mm in 21–30 weeks and 40.73mm in 31–40 weeks. Regression analysis indicates a significant relationship between TCD and gestational age, indicating that TCD is a good marker for estimation of gestional age.

Fetal transcerebellar diameter nomogram in Nepalese population

Introduction: Sonographic determination of gestational age (GA) is becoming increasingly important. Many parameters can be used for establishing GA. The transverse cerebellar diameter (TCD) is a reliable parameter for estimating it. Fetal cerebellum grows progressively along with GA and can predict GA at any trimester. This study was undertaken to construct an institution specific Transcerebellar diameter (TCD) nomogram and to compare its ability to predict gestational age with previously published nomograms. Methods: A cross-sectional nomogram was constructed using TCD measurements of 594 singleton fetuses in Nepalese population by using linear regression model. Measurements were obtained by placing the calipers of the ultrasound machine at the outer &ndash; to- outer margins of the cerebellum. The suitability of previously established TCD nomograms for predicting gestational age was assessed in Nepalese population to determine comparability between nomograms. Results: Gestational age and TCD 50th percentile in mm coincided well till 20th week of gestation. Between 21st to 28th weeks of gestation, there were no clinically important differences between our nomogram and previously published in terms of the predicted gestational age. However, predicted gestational age in third trimester was considerably different by using our nomogram by 1-2 weeks from 29-32 weeks and by 3-6 weeks after 33 weeks. There were differences of 4-6 mm between 29-32 weeks and of 7-11 mm after 33 weeks. Conclusions: TCD measurements had a similar relationship with gestational age across previously published nomograms before 28 weeks. Significant differences occurred in predicting gestational age after 33 weeks. DOI: http://dx.doi.org/10.3126/joim.v32i1.3997Journal of Institute of Medicine, April, 2010; 32:1 pp.19-23

Fetal transcerebellar diameter nomogram in Nepalese population

Introduction: Sonographic determination of gestational age (GA) is becoming increasingly important. Many parameters can be used for establishing GA. The transverse cerebellar diameter (TCD) is a reliable parameter for estimating it. Fetal cerebellum grows progressively along with GA and can predict GA at any trimester. This study was undertaken to construct an institution specific Transcerebellar diameter (TCD) nomogram and to compare its ability to predict gestational age with previously published nomograms. Methods: A cross-sectional nomogram was constructed using TCD measurements of 594 singleton fetuses in Nepalese population by using linear regression model. Measurements were obtained by placing the calipers of the ultrasound machine at the outer – to- outer margins of the cerebellum. The suitability of previously established TCD nomograms for predicting gestational age was assessed in Nepalese population to determine comparability between nomograms. Results: Gestational age and TCD 50th percentile in mm coincided well till 20th week of gestation. Between 21st to 28th weeks of gestation, there were no clinically important differences between our nomogram and previously published in terms of the predicted gestational age. However, predicted gestational age in third trimester was considerably different by using our nomogram by 1-2 weeks from 29-32 weeks and by 3-6 weeks after 33 weeks. There were differences of 4-6 mm between 29-32 weeks and of 7-11 mm after 33 weeks. Conclusions: TCD measurements had a similar relationship with gestational age across previously published nomograms before 28 weeks. Significant differences occurred in predicting gestational age after 33 weeks. DOI: http://dx.doi.org/10.3126/joim.v32i1.3997 Journal of Institute of Medicine , April, 2010; 32:1 pp.19-23

Fetal transverse cerebellar diameter measured by ultrasound does not differ between genders

The aim of this study was to determine the correlation between fetal transverse cerebellar diameter (TCD) and gestational age of male and female fetus in women under low-risk prenatal care between the 13th and 40th week of gestation. A cross-sectional study was carried out with 184 pregnant women, at the age of 18 years or more, gestational age ranging from 13 to 40 weeks, with a single fetus. A single TCD measurement by ultrasound was used for each fetus. Correlations between fetal TCD and gestational age were determined for the whole sample and each gender separately. We identified 102 males and 82 female fetuses. A linear correlation was observed between fetal TCD and gestational age for the whole sample (r = 96.9%; p < 0.001). A significant linear correlation was also observed for both males (r = 97.0%; p < 0.001) and females (r = 96.9%; p < 0.001). Comparing the regression lines between genders, no significant difference was observed. The data of this study suggest TCD fetal ultrasound as a predictive biometric parameter of gestational age independently of fetal gender in the last two trimesters of a pregnancy.

3416: Measurement of transverse cerebellar diameter in assessment of fetal growth restriction by 24 weeks of gestation

3416: Measurement of transverse cerebellar diameter in assessment of fetal growth restriction by 24 weeks of gestation

Diagnóstico da restrição de crescimento fetal pela relação diâmetro transverso do cerebelo e circunferência abdominal

PURPOSE: to evaluate the validity of transverse cerebellar diameter (TCD)/abdominal circumference (AC) ratio in the diagnosis of fetal growth restriction (FGR), determining its best cutoff value and accuracy in symmetric and asymmetric FGR. METHOD: a prospective cross-sectional study, carried out in 250 pregnant women with singleton pregnancies, gestational age between 20 and 42 weeks, with ultrasound confirmation. The TCD measurement was obtained by placing the calipers at the outer margins of the cerebellum, after its localization in the posterior fossa, and slightly rotating the transducer below the plane of the thalami. The abdominal circumference was measured at the on junction of the left portal and umbilical veins. The best TCD/AC cutoff ratio was established by the receiver operator characteristic (ROC) curve. Neonates with TCD/AC ratio greater than the cutoff value were diagnosed as having FGR. We classified as gold standard for FGR the newborn infants who presented birth weight below the 10th percentile. Neonates showing FGR and Rohrer ponderal index between 2.2 and 3 were labeled as symmetric and below 2.2, asymmetric. RESULTS: the cutoff value calculated by the ROC curve for TCD/AC ratio was 16.15. The sensitivity, specificity, accuracy, positive and negative predictive values, and likelihood ratio for positive and negative tests were 77.4, 82.6, 38.7, 96.3, 82, 4.5 and 3.7%, respectively. In the symmetric FGR, sensitivity and specificity were 80.8 and 81.7%, respectively. In the asymmetric FGR, sensitivity and specificity were 60 and 75%, respectively. CONCLUSION: TCD/AC ratio is an effective method in symmetric and asymmetric FGR diagnosis.