Dual energy CT (DECT) for measurement of tophus volume. Upper panel views represent two-dimensional DECT images of uric acid deposits in (A) foot and ankle and (B) metatarsophalangeal joints. With the application of the three-material decomposition algorithm (18), uric acid deposits are depicted in red, whereas calcium in bone is depicted in blue. Lower panel views represent volume-rendered three-dimensional DECT images. See p 603.