Advanced X-ray Tomographic Imaging

Medical physics and biomedical engineering research at the Advanced X-ray Tomographic Imaging (AXTI, homophone of actie, meaning action in Dutch) lab focuses on novel image acquisition, processing and analysis techniques, physical and perceptual evaluation of image quality, radiation dosimetry, tomographic image reconstruction, and advanced computational simulation methods in diagnostic x-ray based imaging, especially for breast and body tomographic imaging.

The aim of the AXTI lab is to perform state-of-the-art, clinically relevant research by working side by side with clinicians from the Department of Radiology and Nuclear Medicine at Radboudumc and collaborating with commercial partners, medical physicists, and scientists from around the world.

Thanks to the group members covering a wide range of skills and expertise, the research performed by AXTI spans all stages of the medical imaging chain, from the physics of image generation to the development of Artificial Intelligence algorithms for image quality improvement and radiomics-based tumor characterization. Some of the projects that AXTI is involved in include characterization and optimization of advanced tomographic breast imaging methods for cancer detection, diagnosis, and therapy response monitoring improvement. In addition, novel radiation dose metrics for personalized dosimetry in breast imaging are being developed, and research is also being performed on optimizing and characterizing the technical and clinical performance of functional lung and cardiac CT.

AXTI is part of the “Women’s Cancers” research theme of the Radboud Institute for Health Sciences (RIHS). Our research is funded primarily by the National Institutes of Health of the USA and the Susan G. Komen Foundation for the Cure. The lab also works in close collaboration with industry (Siemens Healthineers and Canon Medical Systems) and with the Dutch Expert Centre for Screening (LRCB).



  • December 12, 2019: Christiana Balta will defend her PhD thesis with the title 'Objective image quality assessment in X-ray breast imaging' at 12.30 in the Aula of the Radboud University.
  • May 1, 2019: Olga Sliwicka started working as a PhD student at the AXTI group, focusing on cardiac perfusion imaging in acute chest pain.
  • March 26, 2019: Alejandro Rodriguez-Ruiz has succesfully defended his PhD thesis titled "Artificial intelligence & tomosynthesis for breast cancer detection".
  • March 18, 2019: Domenico Pangallo joined the AXTI group for his MSc thesis about quantitative image analysis of breast cancer in dedicated breast CT imaging, under the supervision of Marco Caballo.
  • March 10, 2019: Twan Cuijpers joined the AXTI group for his MSc internship. He will work with Joana Boita in a project from LRCB (Dutch Expert Centre for Screening) that intends to create a visualization tool for teaching in mammography.
  • January 24, 2019: Ioannis Sechopoulos was named Fellow of the American Association of Physicists in Medicine ( AAPM) due to his distinguished contributions to medical physics and the esteem in which he is held by his peers
  • December 5, 2018: The work by Marco Caballo and Ioannis Sechopoulos about using machine learning to generate super-resolution digital breast phantoms for accurate simulations of new imaging systems, published in Physics in Medicine and Biology, was covered in Physics World and in Aunt Minnie
  • November 23, 2018: Dagmar Grob was awarded for the best 4-slide short talk at the PhD retreat of Radboud Institute for Health Sciences (22 - 23 November 2018)
  • November 5, 2018: Marta Pinto started working as a PhD student at the AXTI group, focusing on image processing algorithms for image quality improvement in digital breast tomosynthesis.
  • September 3, 2018: Michelle Foko joined the AXTI group for her BSc internship. She is involved in the work of Christian Fedon in optimization of a software for simulation of breast compression using 3D surface scan camera.
  • September 3, 2018: Valentin Koch joined the AXTI group for his MSc internship. He will work with Marco Caballo in the project "Image analysis of high-resolution CT cochlea images"
  • August 10, 2018: Christian Fedon has been awarded a travel grant to start a research collaboration with The Catholic University of South Korea. The topic is "Characterization of the breast in the Asian population for dosimetric modeling"
  • March 1, 2018: Dagmar Grob was awarded for the Best Paper Presentation in the chest session of the “MyThesis in 3 Minutes” at the ECR 2018. Presentation was about the quantitative comparison of dual-energy CT and subtraction CT in pulmonary embolism-induced perfusion defects on iodine maps.
  • December 12, 2017: The work by Alejandro Rodriguez-Ruiz and Ioannis Sechopoulos on the comparison of radiologists and artificial intelligence for detecting breast cancer in mammography, which was presented at the RSNA 2017, was covered in Aunt Minnie .
  • September 13, 2017: Marco Caballo got the first place in the poster competition organized at the Summer school "Advanced methods in biomedical image analysis" (Brno, Czech Republic) with his work entitled "An automatic segmentation algorithm for tissue classification of dedicated breast CT images".
  • April 4, 2017: At the European Congress of Radiology 2017, Vienna, Alejandro Rodríguez-Ruiz was awarded the Best Scientific Paper Presentation award within the topic Breast for his talk "One-view Digital Breast Tomosynthesis: Do we need more?"
  • March 6, 2017: Marco Caballo started working as a PhD student at the AXTI group, focusing on novel image computing algorithms for breast CT images.
  • December 23, 2016: Koen Michielsen started working as a post-doctoral researcher at the AXTI group, focusing on 3D reconstruction of breast CT and digital breast tomosynthesis.
  • December 9, 2016: Dr. James G. Nagy is visiting the Radboudumc and will give a special lecture in December 9th entitled: 'Object Motion and Image Reconstruction'.
  • November 29, 2016: Christian Fedon started working as a post-doctoral researcher at the AXTI group, with the aim to develop a new personalized and global breast dosimetry model.
  • November 22, 2016: The AXTI group has a new vacancy for a PhD student to expand the impact of tomographic imaging in breast cancer: analysis and new applications of 3D surface and dedicated CT images of the breast. Please apply before December 12th. More information...
  • October 19, 2016: Joana Boita joined the AXTI group as a PhD student to work on developing, optimizing and validating a VGA test of mammographic image quality to predict clinical performance.
  • October 4, 2016: Dr. Michael McNitt-Gray is visiting the Radboudumc and will give a special lecture in October 4th entitled: ‘Quantitative Imaging and Radiomics in CT: The Effects of Acquisition and Reconstruction Parameters’
  • July 1, 2016: Gerrita van Spijker and Marjolein Bastiaans have started working in the AXTI group as scientific and administrative staff, respectively.
  • July 1, 2016: During the first half of 2016, AXTI was present at several international conferences and courses held in Vienna, Leuven, Varna, Malmö and Washington DC. Find out more...
  • May 23, 2016: The AXTI group has a new vacancy for a PhD student to work on the image quality improvement and performance assessment of dedicated breast CT. Please apply before June 3rd. More information...