Related papers: Collaborative Quantization Embeddings for Intra-Subject Prostate MR Image Registration

Collaborative Quantization Embeddings for Intra-Subject Prostate MR Image Registration

URL: http://arxiv.org/abs/2207.06189v2
Date: Thu, 14 Jul 2022 07:41:55 GMT
Title: Collaborative Quantization Embeddings for Intra-Subject Prostate MR Image Registration
Authors: Ziyi Shen, Qianye Yang, Yuming Shen, Francesco Giganti, Vasilis Stavrinides, Richard Fan, Caroline Moore, Mirabela Rusu, Geoffrey Sonn, Philip Torr, Dean Barratt, Yipeng Hu
Abstract summary: This paper describes a development in improving the learning-based registration algorithms. We propose a hierarchical quantization method, discretizing the learned feature vectors using a jointly-trained dictionary. Based on 216 real clinical images from 86 prostate cancer patients, we show the efficacy of both the designed components.
Score: 13.1575656942321
License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Abstract: Image registration is useful for quantifying morphological changes in longitudinal MR images from prostate cancer patients. This paper describes a development in improving the learning-based registration algorithms, for this challenging clinical application often with highly variable yet limited training data. First, we report that the latent space can be clustered into a much lower dimensional space than that commonly found as bottleneck features at the deep layer of a trained registration network. Based on this observation, we propose a hierarchical quantization method, discretizing the learned feature vectors using a jointly-trained dictionary with a constrained size, in order to improve the generalisation of the registration networks. Furthermore, a novel collaborative dictionary is independently optimised to incorporate additional prior information, such as the segmentation of the gland or other regions of interest, in the latent quantized space. Based on 216 real clinical images from 86 prostate cancer patients, we show the efficacy of both the designed components. Improved registration accuracy was obtained with statistical significance, in terms of both Dice on gland and target registration error on corresponding landmarks, the latter of which achieved 5.46 mm, an improvement of 28.7\% from the baseline without quantization. Experimental results also show that the difference in performance was indeed minimised between training and testing data.