Optical tomographic imaging of vascular and metabolic reactivity in rheumatoid joints

Abstract

Our group has recently established that joints affected by Rheumatoid Arthritis (RA) can be distinguished from healthy joints through measurements of the scattering coefficient. We showed that a high scattering coefficient in the center of the joint is indicative of a joint with RA. While these results were encouraging, data to date still suffers from low sensitivity and specificity. Possibly higher specificities and sensitivities can be achieved if dynamic measurements of hemodynamic and metabolic processes in the synovium are considered. Using our dual-wavelength imaging system together with previously implemented model-based iterative image reconstruction schemes, we have performed initial dynamic imaging studies involving healthy human volunteers and patients affected by RA. These case studies seem to confirm our hypothesis that differences in the vascular reactivity exist between affected and unaffected joints.

Tomographic x-ray–guided three-dimensional diffuse optical tomography of osteoarthritis in the finger joints

“…[10][11][12] In particular, DOT offers unparallel opportunity to access the molecular and cellular signatures that are contained in the absorption and scattering spectra of joint tissues. 13 In a recent pilot clinical study, we have shown that the optical contrast between OA and normal joints is high, 14 suggesting that DOT has the potential for detecting early OA joints in the hands. Although DOT appears to be especially suited for imaging of the finger joints because of the high signal-to-noise ratio associated with the small volume, the spatial resolution is relatively low due to the multiscattering events that occur along each photon path.…”

Optical tomography as a PDE-constrained optimization problem

“…In this case, all sources and detectors are located on two circles defined by 1 = {(x, y, z) : x 2 + y 2 = 1.5 2 , z 1 = 2.2} and 2 = {(x, y, z) : x 2 + y 2 = 1.5 2 , z 2 = 3.5}. Similar measurement configurations are commonly used in our and other laboratories [38,44,47,69], for example, for optical measurements in finger joints, or small animal studies. For the discrete ordinate method, we use the level symmetric discrete ordinate arrangement and the corresponding weight set from [46].…”