Design and validation of realistic breast models for use in multiple alternative forced choice virtual clinical trials

Premkumar Elangovan, Alistair Mackenzie, David R Dance, Kenneth C Young, Victoria Cooke, Louise Wilkinson, Rosalind M Given-Wilson, Matthew G Wallis, Kevin Wells
2017 Physics in Medicine and Biology  
A novel method has been developed for generating quasi-realistic voxel phantoms which simulate the compressed breast in mammography and digital breast tomosynthesis (DBT). The models are suitable for use in virtual clinical trials requiring realistic anatomy which use the multiple alternative forced choice (AFC) paradigm and patches from the complete breast image. The breast models are produced by extracting features of breast tissue components from digital breast tomosynthesis (DBT) clinical
more » ... ages including skin, adipose and fibro-glandular tissue, blood vessels and Cooper's ligaments. A range of different breast models can then be generated by combining these components. Visual realism was validated using a receiver operating characteristic (ROC) study of patches from simulated images calculated using the breast models and from real patient images. Quantitative analysis was undertaken using fractal dimension and power spectrum analysis. The average areas under the ROC curves for 2D and DBT images were .51±.06 and .54±.09 demonstrating that simulated and real images were statistically indistinguishable by expert breast readers (7 observers); errors represented as one standard error of the mean. The average fractal dimensions (2D, DBT) for real and simulated images were (2.72±.01, 2.75±.01) and (2.77±.03, 2.82±.04) respectively; errors represented as one standard error of the mean. Excellent agreement was found between power spectrum curves of real and simulated images, with average β values (2D, DBT) of (3.10±.17, 3.21±.11) and (3.01±.32, 3.19±.07) respectively; errors represented as one standard error of the mean. These results demonstrate that radiological images of these breast models realistically represent the complexity of real breast structures and can be used to simulate patches from mammograms and DBT images that are indistinguishable from patches from the corresponding real breast images. The method can generate about 500 radiological patches (~30mm x 30mm) per day for AFC experiments on a single workstation. This is the first study to quantitatively validate the realism of simulated radiological breast images using direct blinded comparison with real data via the ROC paradigm with expert breast readers. Keywords Virtual clinical trials, breast model, breast phantom, synthetic breast, image simulation, 2Dmammography, digital breast tomosynthesis. The OPTIMAM project is a 5 year research programme aimed at defining optimal parameters and methods for mammography to improve cancer detection using the Virtual Clinical Trials approach. Rolland J P and Strickland R N 1997 An approach to the synthesis of biological tissue Opt. Express 1, 414-423. Ullman G, Sandborg U M, Hunt R, Dance D R and Carlsson A G 2003 Implementation of pathologies in the Monte Carlo model in chest and breast imaging. Tech. Rep. Institutionen för radiologi, Universitetet i Linköping 94. Shaheen E, Zanca F, Sisini F, Zhang G, Jacobs J and Bosmans H 2010 Simulation of 3D objects into breast tomosynthesis images Radiat. Prot. Dosim. 139, 108-112. Siddon R L 1985 Fast calculation of the exact radiological path for a three-dimensional CT array Med. Phys. 12, 252-255. Ulger H, Erdogan N, Kumanlioglu S and Unue E 2003 Effect of age, breast size, menopausal and hormonal status on mammographic skin thickness Skin Res. Technol. 9, 284-289. van Deventer P V 2005 The blood supply to the nipple-areola complex of the human mammary gland Aes. Plast. Surg. 28, 393-398. Youn I, Choi S, Kook A H and Choi Y J 2016 Mammographic breast density evaluation in Korean women using fully automated volumetric assessment J. Korean Med Sci. 31, 457-462. Young S, Bakic P R, Myers K J, Jennings R J and Park S 2013 A virtual trial framework for quantifying the detectability of masses in breast tomosynthesis projection data Med. Phys. 40, 051914:1-0519141:15.
doi:10.1088/1361-6560/aa622c pmid:28291738 fatcat:5jxenvcgqjfbvnmj6nrlyurqoe