Validation of a software platform for 2D and 3D phase contrast imaging: Preliminary subjective evaluation

A complete software platform based on anthropomorphic breast models used with both planar and three-dimensional phase contrast breast imaging is presented and subjectively validated. For the development of the platform, tests with three anthropomorphic breast phantoms, available both in computational and physical form, were designed and implemented. The models are characterized with different complexity: two phantoms are with spheres and one anthropomorphic. Further on, two of the physical breast models were created with the use of 3D printing techniques. These phantoms with thickness of 40 mm and 31 mm, respectively, were based on digital phantoms created with in-house developed software tools. The third physical breast phantom is the L1 phantom developed at Katholieke Universiteit Leuven with 58 mm thickness. Based on this physical phantom, a computational one was created. The three physical breast phantoms were imaged at ID17 biomedical imaging line at ESRF. Two acquisition setups were used: planar and limited angle tomography modes. Simulated and experimental planar and three-dimensional images were compared in terms of visual reproducibility. Results showed that phantoms characterized with more simple structure produce subjectively similar experimental and simulation appearance in terms of object reproduction and similar edge effects. The thicker phantom demonstrated lower visual coincidence between the two types of planar images, due to higher thickness and higher energy incident beam. The results of this study will be used in the design of new experimental study, to be conducted at lower incident beam energy as well as improving the modelling of phase contrast imaging by using Monte Carlo techniques

Quality Assurance and Accreditation of BME programs in Europe

Quality assurance and accreditation is an essential aspect for the harmonization of BME curricula in Europe. The definition of common criteria per curricula definition and credit transfer might not be effective is the actual implementation and outcome by means of an effective Quality Assessment system. The purpose of the present contribution is to present a review of existing Quality Assessment systems existing in European and partner countries for BME programs, aiming to identify a possible common basis for the definition of a template guidance document and eventual constraints resulting from local legislation that might prevent harmonization

Physical anthropomorphic breast phantoms for X-ray imaging techniques: Manufacturing approach

Anthropomorphic physical phantoms in radiology permit unlimited exposure. In breast imaging, they are used to validate, evaluate and optimise novel imaging techniques for screening and diagnosis, as well as for systems’ quality control. The purpose of this study is to exploit three technologies for manufacturing of 3D breast phantoms and assessed their anatomical and radiological realism through specific x-ray imaging examinations

Radiomics software for breast imaging optimization and simulation studies

Background and Objective: The development, control and optimisation of new x-ray breast imaging modalities could benefit from a quantitative assessment of the resulting image textures. The aim of this work was to develop a software tool for routine radiomics applications in breast imaging, which will also be available upon request. Methods: The tool (developed in MATLAB) allows image reading, selection of Regions of Interest (ROI), analysis and comparison. Requirements towards the tool also included convenient handling of common medical and simulated images, building and providing a library of commonly applied algorithms and a friendly graphical user interface. Initial set of features and analyses have been selected after a literature search. Being open, the tool can be extended, if necessary. Results: The tool allows semi-automatic extracting of ROIs, calculating and processing a total of 23 different metrics or features in 2D images and/or in 3D image volumes. Computations of the features were verified against computations with other software packages performed with test images. Two case studies illustrate the applicability of the tool – (i) features on a series of 2D ‘left’ and ‘right’ CC mammograms acquired on a Siemens Inspiration system were computed and compared, and (ii) evaluation of the suitability of newly proposed and developed breast phantoms for x-ray-based imaging based on reference values from clinical mammography images. Obtained results could steer the further development of the physical breast phantoms. Conclusions: A new image analysis toolbox was realized and can now be used in a multitude of radiomics applications, on both clinical and test images

The Napoli-Varna-Davis project for virtual clinical trials in X-ray breast imaging

Virtual clinical trials (VCTs) have been proposed to overcome the limitations of clinical trials using a patient population. VCTs are in-silico reproductions of medical examinations using digital models of the patients and simulated imaging devices. In this work, we present a VCT framework for imaging and dosimetry in breast computed tomography (BCT), digital breast tomosynthesis (DBT) and 2D digital mammography (DM), realized by Univ. Napoli Federico II in collaboration with the medical physics teams at Univ. California Davis and the Medical University of Varna, Bulgaria. Computational phantoms of the uncompressed (pendant) breast were generated by clinical BCT scans acquired at UC Davis. A dataset of digital breast phantoms was produced by means of voxel classification of the uncompressed breast CT images. The voxels were classified as air, skin, adipose and glandular tissue using a semi-automatic algorithm. A software compression algorithm (developed at U. Varna) applied to the 3D phantoms produces compressed breast digital phantoms for virtual DM and DBT investigations using a clinical scanners' technical specifications and geometry as inputs. Monte Carlo simulations, based on Geant4, were used to provide in-silico reproductions of real scans of a given patient breast model. The software permits the estimation of mean glandular dose (MGD) in 2D and 3D imaging as well as the 3D dose distribution. The platform produces breast projection images which are then reconstructed using analytical or iterative algorithms. Patient-specific MGD estimations, as well as simulated BCT volume data sets were compared with the clinical BCT scans. The VCT platform reported herein will be used for scanner optimization and for virtual trials comparing BCT against mammography and DBT, in terms of image quality and glandular dose distributions. In addition to in-silico evaluation, 3D printing methods were used to produce compressed and uncompressed anthropomorphic breast phantoms from the patient image-derived digital breast phantoms for the purpose of experimental validation