Standard Plane Identification in Fetal Brain Ultrasound Scans Using a Differential Convolutional Neural Network

Ultrasound scanning has become a highly recommended examination in prenatal diagnosis in many countries. The accurate identification of fetal brain ultrasound scans is crucial to accurate head measurement and brain lesion detection, such as the measurement of the biparietal diameter and the detection of hydrocephalus. In recent years, deep learning has made great progress in the field of image processing. However, there are two difficulties in the identification of fetal brain ultrasound standard planes (FBSPs). First, since the fetal brain tissue is not mature, the fetal brain tissue features are not easy to be detected. Second, because of the expensive collection costs, the amount of labeled image data is limited, which can cause over-fitting and decrease the identification precision. In this study, we proposed a differential convolutional neural network (differential-CNN) to automatically identify six fetal brain standard planes (FBSPs) from the non-standard planes. In this differential-CNN framework, the additional differential feature maps were derived from the feature maps in the original CNN using differential operators. The derivation process did not increase the number of convolution layers and parameters. Moreover, the differential convolution maps have the large advantage of analyzing the directional pattern of pixels and their neighborhoods using additional variation calculations. Therefore, the differential convolution maps would result in good identification performance and cost no extra computational burden. To test the performance of these algorithms, we constructed a dataset consisting of 30,000 2D ultrasound images from 155 fetal subjects ranging from 16 to 34 weeks. The experimental results showed that this method achieved an accuracy of 92.93%. Our work shows that the differential-CNN can be used to facilitate the implementation of the automated identification of FBSPs.