Simulation and assessment of realistic breast lesions

A new method of generating realistic three dimensional simulated breast 12 lesions known as diffusion limited aggregation (DLA) is presented, and compared 13 with the random walk (RW) method. Both methods of lesion simulation utilize a 14 physics-based method for inserting these simulated lesions into 2D clinical mammogram 15 images that takes into account the polychromatic X-ray spectrum, local glandularity 16 and scatter. DLA and RW masses were assessed for realism via a receiver operating 17 characteristic (ROC) study with 9 observers. The study comprised 150 images of which 18 50 were real pathology proven mammograms, 50 were normal mammograms with RW 19 inserted masses and 50 were normal mammograms with DLA inserted masses. The 20 average area under the ROC curve for the DLA method was 0.55 (95% confidence 21 interval 0.51-0.59) compared to 0.60 (95% confidence interval 0.56-0.63) for the RW 22 method. The observer study results suggest that the DLA method produced more 23 realistic masses with more variability in shape compared to the RW method. DLA 24 generated lesions can overcome the lack of complexity in structure and shape in many 25 current methods of mass simulation. 26 Accepted at: Physics in Medicine and Biology 27 A Rashidnasab et al., Phys. Med. Biol. 58 (2013) 5613-5627 28 doi:10.1088/0031-9155/58/16/5613 29 Online at stacks.iop.org/PMB/58/5613 30 Simulation and assessment of realistic breast lesions using fractal growth models 2