Phase-contrast & dark-field imaging
Exploiting the refractive index and small-angle scattering of X-rays for contrast channels beyond conventional attenuation, both at grating-based lab setups and at synchrotrons.
Fig. from IEEE TIP 2026 · CC-BY
About
I’m a physicist and researcher at the Technical University of Munich. My research focuses on improving X-ray imaging through two additional contrast channels, phase and dark-field, which let us spot details that conventional scanners miss. For example, they can distinguish frozen from unfrozen tissue during cryoablation, a tumor treatment, or reveal minuscule changes in tissue composition caused by disease.
I am particularly excited about virtual histology, a novel technique for visualizing tissue samples in 3D at micrometer resolution. It has great potential to improve diagnoses and disease research, because it shows tissue in its original 3D context without cutting it into thin slices, as is still standard practice in pathology.
Apart from my research, I love to communicate how science and technology can be used for good, such as improving healthcare and making our society healthier. I do this through YouTube videos, podcasts, blog articles and the occasional science slam.
If you would like to collaborate, or get in touch about software, website or video projects, feel free to reach out!
Research
Cover article
Quantitative Stain Mapping in X‑Ray Virtual Histology
Advanced Science 13, 21 (2026) · Article e74957
A method that generates microscopy-style histological images directly from 3D X-ray scans of excised tissue. This lets researchers navigate a specimen’s full 3D volume in a familiar histological format, without destroying it in the process.
X-ray virtual histology
Getting anatomical and tissue-level information out of 3D X-ray scans to aid biomedical research and diagnosis, without physically cutting the sample the way conventional histology requires.
Dynamic & functional tomography
Multimodal monitoring of dynamic processes, by adding phase-contrast and dark-field channels to conventional CT for enhanced contrast and quantitative information. One example: tracking tissue cryoablation as it happens.
Media & Press
P.M. magazine · Jul 2026
Cancer diagnostics in 3D(German)
Interview about my virtual histology research in Germany’s second-largest popular-science magazine. We discuss how 3D X-ray imaging of excised tissue could improve cancer diagnostics, letting doctors examine tumors without slicing them into thin sections.
TUM press release · Mar 2026
Seeing more with less
TUM feature on an advanced X-ray imaging technique that extracts more information from biological specimens while lowering radiation dose.
Hereon press release · Jan 2026
From Tissue Section to 3D Image
Press release on a 3D X-ray method that brings standard histology staining together with whole-specimen imaging, so researchers can see tissue structure in 3D rather than only in thin 2D sections.
FastForwardScience · 2025
Why are X-ray images still black and white?(German)
Award-winning short explainer video on why medical X-rays have been monochrome for over a century and how spectral X-ray imaging is finally adding color. The technique distinguishes materials by their energy-dependent attenuation, with the goal of catching disease earlier and more reliably.
Young Scientist Award (Long)Best Debut Video · FastForwardScience 2025
Photo: Simon Esser / Wissenschaft im Dialog
Publications
Peer-reviewed. Full, up-to-date list on ORCID and Google Scholar.
First Author
Advanced Science · 2026 · Cover article
Quantitative Stain Mapping in X‑Ray Virtual Histology
First method to generate stain-specific 3D maps directly from X-ray scans of excised tissue, letting researchers explore a full specimen in the familiar language of histology, without physically sectioning it.
Optica · 2026
Near-perfect efficiency in X-ray phase microtomography
Extracts three simultaneous contrast channels (attenuation, phase, and dark-field) while keeping radiation dose as low as physically possible, maximizing information per absorbed dose. Particularly relevant for imaging sensitive biological tissue at synchrotron sources.
IEEE Transactions on Image Processing · 2026
Extending the Field of View in Modulation-Based X‑Ray Phase Microtomography
Stitches overlapping modulator scans to image specimens significantly larger than the detector field of view, making phase and dark-field tomography practical for samples that would otherwise not fit.
Scientific Reports · 2024
X-ray dark-field computed tomography for monitoring of tissue freezing
Demonstrates real-time dark-field CT tracking of the ice front during tissue cryoablation, a minimally invasive cancer treatment, providing multimodal feedback that enables better control of the treatment procedure.
Co-Author3 papers · show ↓
Light: Science & Applications · 2026
Directional Dark Field for Nanoscale Full-Field Transmission X-Ray Microscopy
Directional dark-field signal measured for the first time in a nanoscale full-field X-ray microscope, revealing oriented nanostructures within specimens at sub-micron resolution.
Scientific Reports · 2024
Self-supervised denoising of grating-based phase-contrast computed tomography
Removes noise artifacts from grating-based CT without needing paired clean/noisy training data. This is useful when ground-truth clean images are impossible to obtain experimentally.
Medical Physics · 2025
Grating-based x-ray dark-field mammography: Assessing complementary imaging information in simple cystic lesions and typical fibroadenoma
Dark-field mammography differentiates simple cysts from fibroadenomas, which conventional attenuation-based mammography cannot reliably do. Assessed in a clinical lesion study.
Education
- 2023-2026Dr. rer. nat., Technical University of MunichAwarded: summa cum laude (with highest honours).
Thesis: Quantitative Modulation-based X-ray Microtomography.
Developed methods using 2D modulator grids to imprint a known
pattern on the X-ray beam and track its distortions, recovering
phase, attenuation, and dark-field channels quantitatively.
The resulting pipelines are now in routine use for user experiments
at beamlines P05 and P07 at DESY (Helmholtz-Zentrum Hereon).
Supervisor: Prof. Dr. Julia Herzen.
↓ Download Thesis - 2025Visiting Researcher, Monash University, Australia6-month research stay with the X-ray Imaging Group of Prof. Dr. Kaye Morgan and Prof. Dr. David Paganin. Ran experiments at the MCT (Micro Computed Tomography) beamline of the Australian Synchrotron, collecting the main dataset for the Advanced Science paper on X-ray virtual histology.
- 2020-2022M.Sc. Biomedical Engineering & Medical Physics, Technical University of MunichBest of cohort. Thesis: Dynamic X-ray dark-field tomography for monitoring of cryoablation
- 2017-2020B.Sc. Physics, Technical University of MunichGraduated in top 10% of cohort
Awards
- 2025FastForwardScience: Young Scientist Award (Long) & Best Debut VideoFirst prize in two categories for the video
“Why are X-ray images still black and white?”
- 2020-2022Bayerische EliteAkademie: selective two-year programmeInterdisciplinary training in responsible leadership, entrepreneurship,
and ethics across residential modules
Services
I work with researchers and institutions on scientific software, science communication websites, and explainer video production.
Scientific software
Custom image processing software for large datasets, from synchrotron beamlines to lab setups.
Learn moreWebsites
Websites for researchers, labs and science communication projects that are easy to understand.
Learn moreVideo production
Explainer videos and lab shoots, from script and filming to editing and motion graphics.
Learn moreWriting
Essays on Medium about the surprising physics of everyday things, and the stories behind why we believe what we believe.
Contact
Have a question, a project or an idea for a collaboration? Send me a message.
Or by email: mail [at] dominikjohn.com
Technical University of Munich · Munich, Germany