Creation of Computational Breast Phantoms with Extracted Abnormalities from Real Patient Images Nikolay Dukov, Zhivko Bliznakov, Ivan Buliev, and Kristina Bliznakova Abstract The current contribution presents an approach for creation of complex computational breast phantoms, with included breast abnormalities. In-house developed and validated software tool, called BreastSimulator, is used to create different models of healthy breasts, by varying parameters like shape, size, duct tree features, Cooper ligaments, skin, etc. Separately, different 3D tumour models are constructed from segmented tumour regions on sets of real tomosyn- thesis images from real patients. A semi-automatic algo- rithm was developed to segment the abnormalities in the images. The algorithm applies a series of image processing operations and region-growing techniques with minimal interaction from the user to find the areas of the lesions. The flat tumour images are then correctly stacked and stored in a 3D voxel matrix, matching the desired resolution. Relevant information about the lesion (voxel size, matrix size, geometrical centre, etc.) is also saved. Selected tumour models are then inserted at various locations into the computational models of the healthy breasts. Examples of simulated mammographic and tomosynthesis images from such breast phantoms are presented to illustrate the potential of the proposed approach. Combining mathematical breast modelling with segmented real 3D tumour shapes results in the creation of realistic breast phantoms. The approach allows implementation of multiple scenarios and unlimited number of cases, which can be used for further software modelling and investigation of breast imaging techniques. Keywords Breast phantom Á Breast simulator Á Tumour segmentation 1 Introduction Early diagnosis of breast cancer can significantly increase the probability for successful treatment of the disease. Therefore, many efforts are focused on improvement of the existing imaging techniques or investigations of new ones. Along that, anthropomorphic phantoms, either physical or computational, are widely used in the relevant research studies. This work presents an approach for creation of complex computational breast phantoms, with included breast abnormalities. 2 Materials and Methods 2.1 Clinical Data For the current study we have used sets of tomographic images from real patients with lesions. Twenty image sets are acquired from the University Hospital of Leuven, Leu- ven, Belgium, using Siemens Mammomat Inspiration, while 15 image sets are acquired from Alexandrovska University Hospital, Sofia, Bulgaria, where a Giotto Tomo IMS is in service. The pixel size of the tomosynthesis images provided by the Siemens machine from the University Hospital of Leuven is 85 Â 85 lm. The tomosynthesis images are obtained from 26 projection images acquired from a com- pressed breast. The pixel size of the tomosynthesis images provided by the Giotto machine from the Alexandrovska University Hospital is 90 Â 90 lm. The tomograms are reconstructed iteratively from 13 low-dose planar transmis- sion images. The clinical data is priori anonymized and only technical data such as pixel values, voxel size, image dimensions, etc., are kept for the purposes of further pro- cessing and for the creation of the computational breast models and subsequent simulations. N. Dukov (&) Á Z. Bliznakov Á I. Buliev Á K. Bliznakova Technical University of Varna, Varna, Bulgaria e-mail: nikolay.dukov@tu-varna.bg K. Bliznakova e-mail: kristina.bliznakova@gmail.com © Springer Nature Singapore Pte Ltd. 2019 L. Lhotska et al. (eds.), World Congress on Medical Physics and Biomedical Engineering 2018, IFMBE Proceedings 68/1, https://doi.org/10.1007/978-981-10-9035-6_38 213