The method is tailored to the contrast agent ICG (indocyanine green; e.g. ICG-Pulsion®), which is approved in Europe as an agent for imaging diagnostics of microcirculation. The altered microcirculation as an early and characteristic feature of inflammation is clinically and experimentally well understood.
In vivo fluorescence imaging has several important advantages over other imaging techniques: there is no exposure to harmful radiation, it is relatively inexpensive, images can be acquired rapidly, and evaluations can be done at different sites after electronic transfer. The Xiralite® X4 device is an on-site method at the point of care with real time results, which can be performed by a trained technician. The data acquired give an instantaneous overview of all joints in both hands.
The Rheumascan procedure can be performed without notable preparations of the patient. The examination takes only 6 minutes. Already about 60 seconds after intravenous contrast administration, altered microcirculation of joints, tendons, bones and ligaments will be displayed due to an increased signal of the contrast agent. With Rheumascan, the physician simultaneously receives information of the activity of the disease in more than 30 joints of both hands.
The fluorescence camera system Xiralite® X4 is the first device that can perform a Rheumascan on a routine basis. Xiralite® X4 excites the fluorescence of ICG by illuminating the hands with light emitting diodes (LEDs) of the dark red spectral range. The software XiraView® operates the examination and assists in data acquisition and analysis. Immediately after completion of the image acquisition, assessment of the exam starts. Physicians may judge the sequence of single pictures or composite images covering varying time periods.