About us

ARISTRA is the radiology network for physicians and patients. We bring the knowledge of international radiology specialists to you. Founded by physicians, we connect specialists in different fields, infrastructure providers, international researchers, and patients to achieve optimal MRI imaging for everybody involved.
Currently, we cooperate with 12 partner practices in Germany, the Netherlands, and Switzerland to bring this knowledge close to patients.

The ARISTRA-network

What Moves Us?
In our day-to-day work, we as physicians experience that competition is increasing on all levels. The growth in knowledge of medical specialties has reached a speed that a single person can hardly keep up. At the same time, there are more and more legal requirements to be considered. The challenges regarding practice marketing, digitization, and practice management are increasing.
Our Idea for a Modern Radiology
Our mission is to shape these challenges through cooperation, interdisciplinary knowledge exchange, and networking across specialist boundaries. ARISTRA brings together young radiologists starting their medical practice, established panel doctors, specialists from various disciplines, and international specialists from many different fields.
Together we form an open, interdisciplinary radiology network.
For a chance in the future, high-quality radiology must be open to new concepts. Radiology cannot exist on its own. The field should position itself as a diagnostic interface in clinical treatment paths for colleagues and patients. Radiologists have the opportunity to play a central role in interdisciplinary cooperation in the reorganization of care structures. For this, a professional exchange at eye level with clinical colleagues is essential.
We offer state-of-the-art MRI technology and optimal diagnostic quality. To achieve this, we cooperate with infrastructure providers and the leading vendors for medical imaging devices.
This way, as many patients as possible, can benefit from the capabilities of the ARISTRA network.
In addition, through our teleradiology services, we help practices and hospitals broaden their medical portfolio. They gain specialist expertise and expand their services. Staff shortages due to vacation or illness can also be absorbed on short notice and unbureaucratically.
The Specialist Network
At ARISTRA, we believe in solid general radiology education. Additionally, subspecialization offers vast benefits for patients and clinical colleagues. To achieve that, radiologists require continuous education through more flexibility in their daily work.
During our research at leading universities, we have experienced that many treatment options don't get used on a broad scale. Top international researchers have specialized in various fields of medical imaging. But due to limited capacities, they can't reach all patients who can benefit from their knowledge.

ARISTRA invites international experts to bring their imaging knowledge to patients. Our network integrates medical specialists in neuroradiology, cardiology, musculoskeletal imaging, urology, and more.
Patients can ensure that they receive state-of-the-art MRI imaging and diagnostics at any time and from any location. The experts reach more patients with their skills and can still be sure that their knowledge remains protected.
Together with you, we can further develop the ARISTRA network. Whether you are a radiographer, a radiologist in private practice, a nuclear medicine physician, a specialist in any discipline, a person interested in teleradiology working from home, or an international specialist: We created a network that benefits everyone involved

If you would like to expand the ARISTRA network with us, if medical quality for patients is your priority, and if you are looking for change and self-fulfillment in a dynamic team, please contact us. We are looking forward to meeting you!


ARISTRA is a physician-led company that has brought together a diverse team. The medical quality is always in the foreground.
Dr. med. Michael Ho, CEO of ARISTRA
Michael Ho leads a private radiology practice in Münster. As part of his further training as a radiology specialist, he has worked clinically and scientifically on imaging of the peripheral nerves at Heidelberg University Hospital and most recently at Zurich University Hospital, among other places.
Dr. med. Michael Ho
General Counsel of ARISTRA Dr. iur. Rodrigo Weihermann
As co-founder and Group General Counsel, Rodrigo Weihermann is responsible for the Legal and Compliance division in the ARISTRA Group. He has a broad range of experience in various legal fields, which he acquired through his previous work in major international law firms and in a corporate context.
Dr. iur. Rodrigo Weihermann
Group General Counsel
Markus Konrad is a partner in a business consulting company. He is advising clients in controlling, corporate succession, financial due diligence, and business valuation. He is a publicly appointed and sworn expert for business valuation.
Dr. rer. pol. Markus Konrad
Finance Lead
Graphic designer Sonja Marie Urban
Sonja Marie Urban is responsible for the corporate identity of ARISTRA. Thanks to several years of experience as a graphic designer at an international advertising agency and her subsequent work as a digital designer on the corporate side, she has extensive knowledge in the field of creative corporate and product communication.
Sonja Marie Urban
Design Expert
Radiologist PD Dr. med. Daniel Truhn, Dipl.-Phys., MSc from Cologne, Aachen
Daniel Truhn is an expert on the application of artificial intelligence in magnetic resonance imaging. He studied physics and medicine in Aachen and London. At the University Hospital in Aachen, he is a senior physician and researching how machine learning can make radiologists more efficient in their work.
PD Dr. med. Daniel Truhn, Dipl.-Phys., MSc
Product Development Lead
Application specialist Lukas Sevcik, Imaging Lead of ARISTRA
Lukas Sevcik is an expert for applications in X-ray diagnostics. He has ten years of professional experience as a radiographer in Germany and Switzerland, specializing in MRI. He is responsible for the management of the radiographer team and the operational processes at the ARISTRA sites.
Lukas Sevcik
Lead Staff Leasing
Video Producer Jonas Zadow
Jonas Zadow has been working in media production for more than 20 years. He has realized a variety of projects, from music productions to social media campaigns and concert videos. For ARISTRA, he develops not only our media productions but also our social media channels.
Jonas Zadow
Media Production Lead
Radiologist PD Dr. med. Erika Jung-Ulbrich
Erika Jung-Ulbrich is an expert in musculoskeletal radiology with a focus on MR imaging. She has a postdoctoral degree in musculoskeletal radiology from the University of Zurich and worked for several years as a senior physician at the University Hospital Zurich.
PD Dr. med. Erika Jung-Ulbrich
Show more


Our team of board-certified radiologists offers worldwide second opinions services for all imaging modalities, including MRI, CT, and X-ray.

The international specialist network

Neuroradiologist Dr. med. Kira Lutz from Stuttgart
Dr. Kira Lutz is a radiologist and an expert in neurological-psychiatric and ENT (Ear, Nose & Throat) imaging with many years of expertise.
Dr. med. Kira Lutz
Radiologist PD Dr. med. Markus Zimmermann
Markus Zimmermann is an expert in interventional radiology. There, his focus lies on oncological interventions. He also specialized in abdominal imaging, with a focus on CT and MRI diagnostics of the liver. For several years, he worked as a senior physician at the University Hospital of RWTH Aachen. There he was responsible for angiography.
PD Dr. med. Markus Zimmermann
Matthias Wagner, M.D., expert in pediatric neuroradiology
Matthias Wagner, M.D., is an expert in pediatric neuroradiology. He gained experience in Switzerland, the USA and Canada.
Dr. med. Matthias W. Wagner
Radiologist Prof. Dr. med. Philipp Bäumer, MSc from Heidelberg, Germany
Prof. Bäumer is a specialist in diagnostic radiology with an additional focus on neuroradiology. He habilitated in neuroradiology at the University of Heidelberg. There he acquired vast expertise in peripheral nerve imaging over many years.
Prof. Dr. med. Philipp Bäumer, MSc
Specialist in radiology and neuroradiology
Radiologist Prof. Dr. Shinji Naganawa from Nagoya, Japan
Prof. Naganawa is a professor of radiology at Nagoya University, Japan. His radiological expertise is on inner ear imaging, and his particular focus lies on vertigo, tinnitus, and Morbus menière.
Prof. Dr. Shinji Naganawa
Expert in inner ear imaging
Radiologist Prof. Dr. med. Wibke Müller-Forell
Prof. Müller-Forell is a neuroradiologist with a special focus on eye imaging. She is particularly well-known for her research and experience in orbital imaging and teaching at the medical school of the Universitätsmedizin Mainz.
Prof. Dr. med. Wibke Müller-Forell
Specialist Orbita

The radiologists in our practices

Annika Kowoll is an expert in neuroradiology. She specialized in neuroradiology and neurology. She worked successfully in the clinical field as a senior physician at the University Hospital Knappschaftskrankenhaus Bochum. There she also researched in the fields of neurooncology and stroke research.
Dr. med. Annika Kowoll
Dortmund, Germany
Radiologist Jonas Roesler from Hannover
Jonas Roesler completed his training as a specialist in various large hospitals focusing on internal medicine and surgery. One of his strengths is his versatility in internal medicine issues. He has been running a private radiology practice for over a year.
Jonas Roesler
Hanover, Germany
Dr. med. Michael Ho, CEO of ARISTRA
Michael Ho leads a private radiology practice in Münster. As part of his further training as a radiology specialist, he has worked clinically and scientifically on imaging of the peripheral nerves at Heidelberg University Hospital and most recently at Zurich University Hospital, among other places.
Dr. med. Michael Ho
Münster, Germany
Radiologist Dr. med. Nikolaus Loehr from Zurich
Dr. med. Nikolaus Loehr is a practicing radiologist focusing on MRI of the musculoskeletal system. He studied at the University of Zurich, assisted in orthopedics at the Endoklinik Zurich, and published and received his graduate degree in trauma surgery.
Dr. med. Nikolaus Loehr
Zürich, Switzerland
Our interdisciplinary team of doctors consists of an exclusive selection of international specialists. Educated at the best institutions, all experts have profound experience in both medical research and patient care.
Expertise of the ARISTRA network