Figure 1b. Transverse multi–detector row CT scans (4 x 2.5-mm collimation, 120 kVp) obtained at the level of the sigmoid colon in a 41-year-old man (body mass index, 26.7 kg/m2) with acute colon diverticulitis. All readers interpreted low- and standard-dose scans as low-grade acute diverticulitis of sigmoid colon. (a) Unenhanced low-dose scan acquired at 30 mAs preset and (b) contrast-enhanced standard-dose scan acquired at 120 mAs preset show fat stranding (arrow) around the colon.