Deformable Registration for Longitudinal Breast MRI Screening
MRI screening of high-risk patients for breast cancer provides very high sensitivity, but with a high recall rate and negative biopsies. Comparing the current exam to prior exams reduces the number of follow-up procedures requested by radiologists. Such comparison, however, can be challenging due to the highly deformable nature of breast tissues. Automated co-registration of multiple scans has the potential to aid diagnosis by providing 3D images for side-by-side comparison and also for use in CAD systems. Although many deformable registration techniques exist, they generally have a large number of parameters that need to be optimized and validated for each new application. Here, we propose a framework for such optimization and also identify the optimal input parameter set for registration of 3D T1-weighted MRI of breast using Elastix, a widely used and freely available registration tool. A numerical simulation study was first conducted to model the breast tissue and its deformation through finite element (FE) modeling. This model generated the ground truth for evaluating the registration accuracy by providing the deformation of each voxel in the breast volume. An exhaustive search was performed over various values of 7 registration parameters (4050 different combinations of parameters were assessed) and the optimum parameter set was determined. This study showed that there was a large variation in the registration accuracy of different parameter sets ranging from 0.29 mm to 2.50 mm in median registration error and 3.71 mm to 8.90 mm in 95 percentile of the registration error. Mean registration errors of 0.32 mm, 0.29 mm, and 0.30 mm and 95 percentile errors of 3.71 mm, 5.02 mm, and 4.70 mm were obtained by the three best parameter sets. The optimal parameter set was applied to consecutive breast MRI scans of 13 patients. A radiologist identified 113 landmark pairs (~ 11 per patient) which were used to assess registration accuracy. The results demonstrated that using the optimal registration parameter set, a registration accuracy (in mm) of 3.4 [1.8 6.8] was achieved.
KeywordsBreast MRI Non-rigid registration Finite element analysis Elastix
The authors would like to thank the Canadian Institute of Health Research (CIHR) for funding this work through CIHR grant number 115161.
- 12.Boehler T, Schilling K, Bick U, Hahn HK: Deformable image registration of follow-up breast magnetic resonance images BT—Biomedical image registration: 4th International Workshop, WBIR 2010, Lübeck, Germany, July 11–13, 2010. Proceedings. In: Fischer B, Dawant BM, Lorenz C Eds. Springer Berlin Heidelberg, Berlin, Heidelberg, 2010, pp 13–24Google Scholar
- 13.Oliveira FPM, Tavares JMRS: Medical image registration: A review. In: Computer Methods in Biomechanics and Biomedical Engineering, vol. 17, no. 2. Taylor & Francis, 2014, pp 73–93Google Scholar
- 15.Froh MS, Barber DC, Brock KK, Plewes DB, Martel AL: Piecewise-quadrilateral registration by optical flow—Applications in contrast-enhanced MR imaging of the breast BT—Medical image computing and computer-assisted intervention—MICCAI 2006: 9th International Conference, Copenhagen, Denmark, October 1-. In: Larsen R, Nielsen M, Sporring J Eds. Berlin, Heidelberg: Springer Berlin Heidelberg, 2006, pp 686–693Google Scholar
- 21.Mehrabian H, Samani A: An iterative hyperelastic parameters reconstruction for breast cancer assessment. In: Proceedings of SPIE Medical Imaging: Physiology, Function, and Structure from Medical Images, 2008, vol. 6916, pp 69161C–69161C–9Google Scholar
- 28.Jang JY et al.: Clinical significance of interval changes in breast lesions initially categorized as probably benign on breast ultrasound. Medicine (Baltimore). 96(12):1–7, 2017Google Scholar