Changes in three-dimensional and thermal measures during rheumatoid arthritis flare. A 45-year-old Caucasian female with well-controlled rheumatoid arthritis was imaged. Nine days later, she developed an acute flare of her symptoms and was re-imaged on day 10. (a) Pre- and post-flare wrist region of interest and volume. (b) Pre- and post-flare surface distance color map demonstrating post-flare swelling (dashed arrow), not present in pre-flare image (solid arrow). (c) Pre- and post-flare thermograms and heat distribution index (HDI). (d) Pre- and post-flare relative frequency distributions of temperatures. SDI, surface distribution index.