Foetal Brain Biometry using Magnetic Resonance Imaging in an Indian Population- A Retrospective Cohort Study

Abstract

Introduction: The utility of Magnetic Resonance Imaging (MRI) has increased significantly in the assessment of foetal brain development. Foetal biometry is a part of every imaging examination and is needed to confirm that the growth is proceeding normally. Aim: To provide normal MRI reference biometric data of the foetal brain in Indian population. Materials and Methods: This was a retrospective cohort study conducted in the Department of Radiodiagnosis at Sri Ramachandra Hospital, Chennai, Tamil Nadu, India. The data was collected from the MR imaging studies done between January 2013 to December 2020. The present study was carried out on 101 foetuses with gestational age ranging from 20 to 38 gestational weeks with normal brain appearance. Following biometric parameters had been obtained: skull occipitofrontal diameter and Biparietal Diameter (BPD), Brain-Biparietal Diameter (BPD) and fronto-occipital length, Head Circumference (HC), atrial diameter, vermian height, width and area. Descriptive statistics was used to calculate the median value with Interquartile Range (IQR). A p-value of less than 0.05 was considered as significant using Spearman’s rank correlation. Results: The skull occipitofrontal diameter (r-value=0.88, p-value <0.001), skull biparietal diameter (r-value=0.92, p-value <0.001), brain biparietal diameter (r-value=0.95, p-value <0.001), brain fronto-occipital length (r=0.94, p-value <0.001), head circumference (r-value=0.92, p-value <0.001), atrial diameter (r-value=0.86, p-value <0.001), Vermian height (r-value=0.86, p-value <0.001), Vermian width (r-value=0.84, p-value <0.001) and Vermian area (r-value=0.88, p-value <0.001) showed positive correlation with gestational age. Mean Head Circumference (HC) and BPD values were almost similar to the standard Indian reference mean values of ultrasound. All biometric parameters were compared with the European references. The values from present study were found to be in the lower range of the European biometric values. Conclusion: Normal biometric MRI data of the foetal brain in an Indian population from 20 to 38 weeks gestational age was presented. A significant correlation was found between gestational age and parameters. MRI BPD and HC values showed a positive correlation with ultrasound BPD and HC values.

Keywords

• biparietal diameter
• gestational age
• head circumference
• occipital length