Measurement of the transverse cerebellar diameter in preterm neonates and its use in assessment of gestational age

Abstract

The transverse cerebellar diameter (TCD) serves as a reliable predictor of gestational age (GA) in the fetus and is a standard against which aberrations in other fetal parameters can be compared, especially when the GA cannot be determined by the date of the last menstrual period or an early pregnancy scan. [1][2][3] There are preliminary data available for preterm neonates from 23 to 32 weeks and 6 days (32 +6 ) GA. 4 These data correlate TCD with GA assessed to completed whole weeks of gestation, and the TCD predicted GA to approximately ± 2.5 weeks. 4 The TCD may therefore be less helpful in determining GA in newborn infants. Refinement of the GA assessment to days of gestation may improve the degree of correlation and decrease the confidence intervals (CI) for the prediction of GA. Standard measurements of TCD can also be used in the diagnosis of cerebellar hypoplasia when the GA is known 1 and TCD percentile charts can be used to assess cerebellar growth in preterm infants.There are no data available on the reproducibility of TCD measurements for single or multiple observers.The aims of the present study are: (i) to confirm the relationship between GA and TCD and determine whether it improves with a larger sample size and the estimation of GA to the nearest day; (ii) to define the linear regression equation for prediction of GA by TCD with 95% CI for predicted values; (iii) to define percentile charts for cerebellar growth from 23 to 32 +6 weeks; and (iv) to assess intra-and interobserver reliability for TCD measurements. SUMMARYThis study aims to confirm the relationship between gestational age (GA) and transverse cerebellar diameter (TCD), to define the prediction of GA by TCD, and assess the reliability of TCD measurements. Infants were included in the study if they had a routine cranial ultrasound scan by day 3, and the TCD was measured. Infants were excluded from the study if the GA was not known, if there was any cranio-spinal malformation or grade 3 or 4 intraventricular haemorrhage (IVH). The GA assessment was an early pregnancy scan or certain dates. Cranial ultrasound scans were done with a LOGIQ 500 scanner (GE Medical Systems, Waukesha, WI, USA) with a 7 MHz curvilinear sector probe (GE LOGIQ-C721; GE Medical Systems). The posterior fossa was scanned using the asterion as the acoustic window with the TCD measured in the coronal plane. Intra-and interobserver reliability were assessed. A total of 221 infants of known GA had their TCD measured. The linear regression for GA versus TCD is: GAweeks = (0.470 × TCDmillimetres) + 13.162 (r = 0.89, r 2 = 0.79, P < 0.001). The 95% confidence interval predicts GA to ± 2.33 weeks for a given TCD. Intra-and interobserver intraclass correlation coefficients are 0.98 and 0.99, respectively. Transverse cerebellar diameter correlates closely with GA and predicts GA to ± 2.33 weeks. Measurements of TCD have excellent reproducibility.

Accuracy of fetal transcerebellar diameter nomogram in the prediction of gestational age in singleton gestation at the second and the third trimesters of singleton pregnancy

“…Similar to our findings, fetal imaging studies have shown that TCD correlates closely with GA and that the increase in TCD is linear during the second [20][21][22] and third trimester [5,14,19]. Also, it has been shown that this correlation is not affected significantly by sex, fetal growth restriction, multiple pregnancy, or fetal macrosomy [9,21,23,24].…”

“…The study by Davies et al [14] aimed to confirm the relationship between GA and TCD to define the prediction of GA by TCD and assess the reliability of TCD measurements. TCD was measured in a total of 221 infants with known GA. TCD correlates closely with GA and predicts GA to ± 2.33 weeks.…”

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

“…6 TCD has emerged as a useful parameter for assessing fetal growth retardation. 7 The purpose of the current study is to evaluate the accuracy of transverse cerebellar diameter as against the conventional parameters in assessing gestational age in normal pregnant mothers between 15 to 40 weeks and its usefulness in antenatal diagnosis of intrauterine growth retardation.…”

Neonatal cranial ultrasound: current perspectives

“…62 Another study confirmed the relationship between gestational age and transverse cerebellar diameter. 63 Doppler ultrasound parameters can serve as a tool for predicting developmental delay. It was found that the leftward hemodynamic status of the middle cerebral arteries, as measured by cranial Doppler ultrasound in the neonatal period, predicts early motor outcome in term infants.…”