Florian Müller © Copyright: Private


Florian Müller

Group leader


+49 241 80 36681



Rare cancer types pose a significant challenge for patients and physicians. Experts classify cancers as rare when fewer than 6 out of 100,000 people are diagnosed with them each year. Unfortunately, it is often very difficult to diagnose and treat these diseases. Both Osteomyelofibrosis (OMF) and Ependymoma are rare conditions that are difficult to diagnose and treat. Osteomyelofibrosis (OMF) is a progressive malignant disease of the bone marrow responsible for blood cell production. Ependymoma is a tumor that originates from the ependymal tissue of the central nervous system, typically intracranial in children and within the spinal cord in adults. In both cases, early diagnosis plays a crucial role. Modern imaging methods such as Positron Emission Tomography (PET) and Magnetic Resonance Imaging (MRI) using radiomic biomarkers can provide a deeper analysis of the pathophysiological processes, thereby enabling improved diagnosis, classification, stratification, prognosis, and assessment of treatment success.

To enhance diagnosis, PET and MRI have been used in combination as MR/PET for approximately 10 years. In PET, a weakly radioactive contrast agent (18F-FDG) is injected, which accumulates mainly in tumor cells over time. The PET image reflects the degree of contrast agent accumulation, allowing for the localization of tumors, including OMF and Ependymoma. Although MR/PET is considered one of the most sensitive imaging techniques, the spatial resolution of PET remains limited compared to MRI or conventional X-rays, with approximately 4 mm.

The goal of the project is to improve the spatial resolution of PET for MR/PET to nearly 1 mm, enabling the visualization of even the smallest tumors or minute changes within tumors. To achieve this, a whole-body MR/PET tomograph is being developed, equipped with high-resolution local PET detectors. Similar to local receiving coils in MRI, these local PET detectors will lead to high-resolution local PET images as part of the overall imaging process through innovative image reconstruction techniques.

Such a highly precise tomograph could also be used in many other metabolic diseases, such as Alzheimer's disease, and, due to the low radiation exposure, enable early diagnosis as well as monitoring of therapy success and progression.

The project is conducted as a collaborative project in partnership with Hyperion Hybrid Imaging Systems (Aachen), under the leadership of the University Hospital Aachen.


Press Release and Public Relations (German only):

Blog AC forscht


Scientific Publications:

Naunheim, S., Kuhl, Y., Solf, T., Schug, D., Schulz, V., & Mueller, F. (2023). Analysis of a convex time skew calibration for light sharing-based PET detectors. Physics in Medicine & Biology, 68(2), 025013.

Kuhl, Y., Naunheim, S., Schug, D., Schulz, V., & Mueller, F. (2023). Angular Irradiation Methods for DOI Calibration of Light-Sharing Detectors-A perspective for PET In-System Calibration. IEEE Transactions on Radiation and Plasma Medical Sciences.

Mueller, F., Naunheim, S., Kuhl, Y., Radermacher, H., Gegenmantel, E., Schug, D., ... & Schulz, V. (2023). HD-MetaPET: Development of a long axial field-of-view (LAFOV) PET/MRI system with dedicated local PET detectors for spatial resolution enhancement. Nuklearmedizin-NuclearMedicine, 62(02), 164-164.

Naunheim, S., Kuhl, Y., Schug, D., Schulz, V., & Mueller, F. (2023). Improving the Timing Resolution of Positron Emission Tomography Detectors using Boosted Learning--A Residual Physics Approach. IEEE Transactions on Neural Networks and Learning Systems.

  BMBF Logo

This work is funded by the German Federal Ministry of Education and Research under contract number 13GW0621B within the funding program ‘Recognizing and Treating Psychological and Neurological Illnesses - Potentials of Medical Technology for a Higher Quality of Life’(‘Psychische und neurologische Erkrankungen erkennen und behandeln - Potenziale der Medizintechnik für eine höhere Lebensqualität nutzen’).