Implicit Neural Representations for Deformable Image Registration

Deformable medical image registration has in past years been revolutionized by the use of convolutional neural networks. These methods surpass conventional image registration techniques in speed but not in accuracy. Here, we present an alternative approach to leveraging neural networks for image registration. Instead of using a convolutional neural network to predict the transformation between images, we optimize a multi-layer perceptron to represent this transformation function. Using recent insights from differentiable rendering, we show how such an implicit deformable image registration (idir) model can be naturally combined with regularization terms based on standard automatic differentiation techniques. We demonstrate the effectiveness of this model on 4D chest CT registration in the DIR-LAB data set and find that a three-layer multi-layer perceptron with periodic activation functions outperforms all published deep learning-based results on this problem, without any folding and without the need for training data. The model is implemented using standard deep learning libraries and flexible enough to be extended to include different losses, regularizers, and optimization schemes.</p

Parental experiences of rapid exome sequencing in cases with major ultrasound anomalies during pregnancy

BACKGROUND: Adding rapid Exome Sequencing (rES) to conventional genetic tests improves the diagnostic yield of pregnancies showing ultrasound abnormalities but also carries a higher chance of unsolicited findings. We evaluated how rES, including pre- and post-test counseling, was experienced by parents investigating its impact on decision-making and experienced levels of anxiety. METHODS: A mixed-methods approach was adopted. Participating couples (n=46) were asked to fill in two surveys (pre-test and post-test counseling) and 11 couples were approached for an additional interview. RESULTS: All couples accepted the rES test-offer with the most important reason for testing emphasizing their hope of finding an underlying diagnosis that would aid decision-making. The actual impact on decision-making was low, however, since most parents decided to terminate the pregnancy based on the major and multiple fetal ultrasound anomalies and did not wait for their rES results. Anxiety was elevated for most participants and decreased over time. CONCLUSION: Major congenital anomalies detected on ultrasound seem to have more impact on prenatal parental decision-making and anxiety then the offer and results of rES. However, the impact of rES on reproductive decision-making and experienced anxiety requires further investigation, especially in pregnancies where less (severe) fetal anomalies are detected on ultrasound. This article is protected by copyright. All rights reserved