Contrast-enhanced Multispectral Optoacoustic Tomography for Functional Assessment of the Gastrointestinal Transit

Contrast-enhanced Multispectral Optoacoustic Tomography for Functional Assessment of the Gastrointestinal Transit

This clinical trial aims to characterize a novel method of imaging the gastrointestinal tract in healthy subjects. The method is using laser-light and soundwaves and it is performed in a similar manner as conventional ultrasound. It is radiation-free and non-invasive.

Participants will ingest food mixed with the clinically-registered dye Indocyanine green. Researchers will measure the signal of the dye over different segments of the gastrointestinal tract, visualizing gastrointestinal transit.

This clinical trial aims to assess gastrointestinal transit by using contrast-enhanced multispectral optoacoustic tomography (MSOT). MSOT is able to visualize not only endogenous chromophores like hemoglobin but also exogenous chromophores such as Indocyanine green (ICG). Healthy subjects will ingest three different standardized meals, all of which are mixed with ICG. By measuring the signal intensity of ICG during gastrointestinal transit, gut motility can be assessed non-invasive and radiation free.

The goal is to compare transit times for different standardized meals, which are liquid, mushy, and solid.

Inclusion criteria

• Age over 18 years
• Written informed consent

Exclusion Criteria:

General:

• Pregnancy
• Breastfeeding mothers
• Tattoo in the area of the examination
• Subcutaneous fat tissue over 3 cm
• Chronic or acute diseases of the gastrointestinal tract or symptoms suggesting such a disease
• Acute diseases requiring treatment
• Lack of written consent

ICG related:

• Known hypersensitivity to ICG, sodium iodide or iodine.
• Hyperthyroidism, focal or diffuse thyroid autonomy.
• Timely close treatment to check thyroid function with ingestion of radioactive iodine (within two weeks before or after the study)
• Impaired renal function
• Taking the following medications: Beta blockers, anticonvulsants, cyclopropane, bisulfite compounds, haloperidol, heroin, meperidine, metamizole, methadone, morphine, nitrofurantoin, opium alkaloids, phenobarbital, phenylbutazone, probenecid, rifamycin, any injection containing sodium bisulfite