Researchers at Helmholtz Munich and the Technical University of Munich (TUM) have created a new medical imaging tool called “fast-RSOM” that can capture highly detailed images of the body’s smallest blood vessels directly through the skin, without invasive procedures. By making it possible to detect early signs of cardiovascular risk, the technology could allow doctors to act sooner, tailor treatments more precisely, and support better long-term heart health.
Some of the earliest warning signs of cardiovascular disease begin in the body’s tiniest blood vessels. These early changes involve subtle problems in how blood vessels widen and narrow, a condition known as microvascular endothelial dysfunction (MiVED). Until now, there has been no precise, non-invasive way to directly observe or measure these changes in people.
“With fast-RSOM, we can, for the first time, non-invasively assess endothelial dysfunction at single-capillary and skin-layer resolution in humans,” says Dr. Hailong He, first author of the study and researcher at the Institute of Biological and Medical Imaging at Helmholtz Munich and TUM. Dr. Angelos Karlas, co-first author, Vascular Surgeon and Senior Research Scientist at TUM University Hospital, adds: “Our novel approach offers an unprecedented view of how cardiovascular disease manifests at the microvascular level.”
Detecting Risk Before Symptoms Develop
Fast-RSOM captures high-resolution, dynamic biomarkers linked to MiVED, revealing small but meaningful impairments in blood vessel function. These changes often appear well before noticeable symptoms or larger-scale signs of cardiovascular disease. They are commonly associated with known risk factors such as smoking, high blood pressure, or obesity.
Rather than estimating risk based only on these conditions, fast-RSOM directly measures the physical effects they have already caused in the microvascular system. This allows clinicians to see how the smallest blood vessels are functioning long before serious complications emerge.
By identifying these early signals, fast-RSOM creates new opportunities for earlier diagnosis, prevention, and more accurate monitoring of cardiovascular health. The technology could help pinpoint individuals at higher risk with greater precision and track how lifestyle changes or medical treatments affect blood vessel function over time.
Moving Toward Clinical Use
The research team plans to test fast-RSOM in larger and more diverse patient populations and work toward integrating its biomarkers into everyday clinical practice. Because the device is portable, fast, and non-invasive, it could eventually be used in outpatient settings as part of routine cardiovascular risk assessments.
“By enabling earlier interventions and more precise monitoring, fast-RSOM could transform how cardiovascular diseases are prevented and managed — improving outcomes for patients and reducing healthcare costs in the long term,” says Prof. Vasilis Ntziachristos, Director of the Bioengineering Center at Helmholtz Munich and Professor for Biological Imaging at TUM.
What Is RSOM?
RSOM (Raster Scan Optoacoustic Mesoscopy) is a non-invasive imaging technique that uses brief pulses of light to generate ultrasound signals, producing detailed 3D images of structures beneath the skin. It can detect very small changes in blood vessels, oxygen levels, and tissue composition that traditional imaging methods cannot see. By combining strong contrast with depth, RSOM supports early detection of conditions such as cardiovascular disease and diabetes. Its compact design may also make advanced diagnostic tools more widely available outside specialized research facilities. The technology was developed by the team led by Vasilis Ntziachristos.
About the Researchers
Dr. Hailong He is a researcher at the Institute of Biological and Medical Imaging at Helmholtz Munich and at the Technical University of Munich (TUM).
Dr. Angelos Karlas is a Board-Certified (Germany) Vascular Surgeon and Senior Research Scientist at the Clinic and Polyclinic for Vascular and Endovascular Surgery at the TUM University Hospital, Hospital Rechts der Isar, in Munich, Germany. He also serves as the Clinical Research Lead at the Chair for Computer-Aided Medical Procedures and Augmented Reality at the Technical University of Munich (TUM).
Prof. Vasilis Ntziachristos is the Director of the Bioengineering Center and the Director of Institute of Biological and Medical Imaging at Helmholtz Munich. He also holds the Chair of Biological Imaging at the Technical University of Munich (TUM) and is a founding member and in the Board of Directors of TranslaTUM, TUM’s Central Institute for Translational Cancer Research. He is affiliated with Munich partner site of the German Centre for Cardiovascular Research (DZHK).
