Et. Scholten et al., COMPUTED-TOMOGRAPHY OF THE LARGE-BOWEL WALL - CHOICE OF SLICE THICKNESS AND INTRALUMINAL CONTRAST-MEDIUM, Investigative radiology, 30(5), 1995, pp. 275-284
RATIONALE AND OBJECTIVES. TO determine the relative contribution of sl
ice thickness and intraluminal contrast density to imaging of the larg
e bowel wall. METHODS. The authors used phantom experiments to evaluat
e the partial volume averaging of 2-, 4-, and 8-mm slices on imaging a
single density interface (320/-100 HU) and 5 dual-density interfaces
(320/50/-100 HU, 160/50/-100 HU, 0/50/-100 HU, -100/50/100 HU, and -10
00/50/100 HU). For the experiments with a dual-density interface, whic
h simulated the bowel wall, the phantom was scanned at an angle 45 deg
rees to the scan plane. RESULTS. The most accurate display of interfac
es was obtained with a slice thickness of 2 mm. When using 8-mm slices
, walls can appear to be much thinner or thicker than normal or not ev
en recognizable as a wall depending on the densities in the interface.
Adjusting the density of the intraluminal contrast medium to within t
he range of the mean and window setting will improve the representatio
n of the bowel wall. CONCLUSIONS. Slice thickness has a significant in
fluence on the true representation of the bowel wall using computed to
mography. This effect is greater than the effect of the intraluminal c
ontrast medium density.