Advanced X-ray Tomographic Imaging

Medical physics research at the Advanced X-ray Tomographic Imaging (AXTI, homophone of actie, meaning action in Dutch) lab focuses on radiation dosimetry, novel image acquisition and processing techniques, physical and perceptual evaluation of image quality, 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 medical physicists and other scientists from around the world.

Our current projects involve the characterization and optimization of tomographic breast imaging methods, including breast tomosynthesis and dedicated breast CT. In addition, novel radiation dose metrics for personalized dosimetry in breast imaging are being developed. Research is also being performed on optimizing and characterizing the technical and clinical performance of functional chest and head 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 collaboration with industry (Siemens Healthcare and Toshiba Medical Systems) and with the Dutch reference centre for screening (LRCB).



  • September 3, 2018: Valentin Koch joined the AXTI group for his MSc internship. He is involved in the project "Image analysis of high-resolution CT cochlea images" under the supervision of Marco Caballo
  • September 3, 2018: Michelle Foko joined the AXTI group for her BSc internship. She is involved in the optimization of softwares for simulation of breast compression using 3D surface scan camera under the supervision of Christian Fedon.
  • 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 analysis and new applications of 3D surface and dedicated CT images of the breast.
  • 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: 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...
  • July 1, 2016: Gerrita van Spijker and Marjolein Bastiaans have started working in the AXTI group as scientific and administrative staff, respectively.
  • 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...