Along with our central aim within PREMSOT we developed a handheld label-free video-rate multi-spectral optoacoustic system delivering unprecedented imaging features, with emphasis on imaging hemoglobin saturation / tissue oxygenation and vasculature. We designed an improved detector with enhanced imaging capabilities deep in tissue based on a detailed analysis of the system. The new detector was operated with an MSOT prototype and a flexible software solution in clinical studies on human breast cancer. We introduced a deep-learning-based method for electrical noise removal where we made subtle optoacoustic contrast within a breast tumor visible behind the system noise and visualizing for the first time specific features of different breast tumors. This ability improves the diagnostic value of clinical MSOT.
In parallel we developed theory and algorithms that improve the sensitivity and the quantification accuracy of imaging tissue oxygenation, hypoxia, blood (haemoglobin) volume, vessel and micro-vessel morphology and flow, leading to label-free tissue readings appropriate for precision medicine. We improved the quantification of tissue properties from optoacoustic data by implementing advanced regularization schemes, engineering novel biomarkers, and designing novel data acquisition schemes. We exploited the advantages of the perfectly coregistered optoacoustic and ultrasound images of our system, achieving an improved molecular contrast in depth, thereby increasing the accessibility of medical information.
We have demonstrated in various case studies a broad applicability of MSOT and that it can be used as a novel modality for the assessment of vascular, muscular and metabolic disorders characterized by disturbed blood flow, such as peripheral arterial disease (PAD), deep vein thrombosis (DVT), heart failure and diabetes mellitus. We were able to image muscle hemodynamics and oxygenation changes under conditions of disturbed blood flow. Our results open up new possibilities to investigate muscle oxygenation and metabolism in health and disease using MSOT and attempt to shift the paradigm from only imaging the cause of the disease, towards imaging the target organ (muscle) non-invasively, label-free and in real-time.
Results of PREMSOT were published in more than 60 scientific outputs and were presented at more than 70 national and international conferences addressing the scientific community, industry, medical end-users, and healthcare stakeholders. The results fed directly into successful applications for additional funding to develop new optoacoustic devices or to advance commercialized technologies.
