A Fast and Scalable Method for Quality Assurance of Deformable Image Registration on Lung CT Scans using Convolutional Neural Networks


Purpose: To develop and evaluate a method to automatically identify and quantify deformable image registration (DIR) errors between lung computed tomography (CT) scans for quality assurance (QA) purposes.

Methods: We propose a deep learning method to flag registration errors. The method involves preparation of a dataset for machine learning model training and testing, design of a three-dimensional (3D) convolutional neural network architecture that classifies registrations into good or poor classes, and evaluation of a metric called registration error index (REI) which provides a quantitative measure of registration error.

Results: Our study shows that, despite having limited number of training images available (10 CT scan pairs for training and 17 CT scan pairs for testing), the method achieves 0.882 AUC-ROC on the test dataset. Furthermore, the combined standard uncertainty of the estimated REI by our model lies within ± 0.11 (± 11% of true REI value), with a confidence level of approximately 68%.

Conclusions: We have developed and evaluated our method using original clinical registrations without generating any synthetic/simulated data. Moreover, test data were acquired from a different environment than that of training data, so that the method was validated robustly. The results of this study showed that our algorithm performs reasonably well in challenging scenarios.


Nuclear Engineering and Radiation Science

Research Center/Lab(s)

Center for Research in Energy and Environment (CREE)

Keywords and Phrases

Deep Learning; Image Registration; Neural Network; Quality Assurance

International Standard Serial Number (ISSN)

0094-2405; 2473-4209

Document Type

Article - Journal

Document Version


File Type





© 2019 American Association of Physicists in Medicine, All rights reserved.

Publication Date

01 Jan 2020

PubMed ID