Figure 1a. Acute appendicitis
in a 23-year-old woman, 31 weeks pregnant, who presented with acute RLQ
pain. The appendix could not be identified at US performed earlier in the
day. Axial single-shot fast SE images show a dilated appendix containing
intraluminal fluid and gas (arrows). The intraluminal ovoid
low-signal-intensity filling defect (arrowhead in b) is consistent
with an appendicolith. Acute appendicitis was confirmed at surgery.
C = cecum, F = fetus. (See also Figs E1 and E2 at
http://radiographics.rsnajnls.org/cgi/content/full/27/3/743/DC1.)