Multi-Spectral Optoacoustic Tomography

At the core of EUPHORIA is the MSOT (Multi-Spectral Optoacoustic Tomography) technology. MSOT, like X-Ray or MRI, allows the operator to ‘see inside’ a human body, or a lab animal, or indeed other things. Rather than using X-Ray radiation, or magnetic resonance, MSOT takes advantage of an entirely different phenomenon – the photoacoustic effect. This effect occurs when a tissue of interest, such as the bowel wall, is illuminated by laser pulses, which has a wavelength that allows it to penetrate the skin. Blood molecules within in the tissue absorb light energy; this causes a small (too small for the patient to feel) expansion of the tissue, which in turn causes tiny pressure waves, i.e. this generates ultrasound waves. These are detected using a sensitive ultrasound detector.

Different molecules in the tissue respond in different ways to different light wavelengths. When recording the ultrasound signals generated after illumination with different wavelength (i.e. multi-spectral illumination),  intelligent software can distinguish the molecular composition of the tissue. A particular advantage of MSOT is that it detects blood, blood oxygenation, fat, collagen and other substances that other technologies cannot ‘see’, and so offers new perspectives, and new ways to see inside the body.

Illustration of the MSOT in action. Inflamed regions are highlighted when using the MSOT.

Principle of MSOT measurements in IBD patients.
MSOT enables
trans-abdominal, real-time imaging of disease activity in the colon
wall in IBD patients. Inflamed regions show increased perfusion that
gives rise to MSOT signals without the need of exogenous contrast agents.

MSOT is based on research carried out at the Helmholtz Centre Munich for Environmental Health (HMGU) by the research team of Vasilis Ntziachristos; iThera Medical is a ‘spin out’ company from HMGU.

Color-coded figure showing IBD in remission, moderate IBD, and severe IBD.

Color-coded optoacoustic contrast of haemoglobin concentration overlaid on an
ultrasound image of the colon wall.

The first MSOT systems were mainly used in the research field, to study the health of mice, and how they responded to different drugs. When the power of the technology became clear, iThera and UHE agreed to carry out a feasibility study, to investigate whether MSOT could offer a viable alternative to endoscopy in IBD patients. The results were really positive. However, it was clear that more work was needed on the technology and the imaging software, if MSOT was to have a chance of becoming a routine clinical tool. This led to the EUPHORIA project.

Sensitivity / specificity of MSOT in comparison to established  non-invasive procedures
(adapted from N Engl J Med. 2017 Mar 30;376(13):1294-6)

MSOT is already the subject of a substantial scientific literature; you can read in much more detail about the technology and about the feasibility study in UHE, at the links below: