RATIONALE AND OBJECTIVES: To determine the relative contribution of slice thickness and intraluminal contrast density to imaging of the large bowel wall. METHODS: The authors used phantom experiments to evaluate 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 -1000/50/100 HU). For the experiments with a dual-density interface, which simulated the bowel wall, the phantom was scanned at an angle 45 degrees to the scan plane. RESULTS: The most accurate display of interfaces 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 even recognizable as a wall depending on the densities in the interface. Adjusting the density of the intraluminal contrast medium to within the range of the mean and window setting will improve the representation of the bowel wall. CONCLUSIONS: Slice thickness has a significant influence on the true representation of the bowel wall using computed tomography. This effect is greater than the effect of the intraluminal contrast medium density.
RATIONALE AND OBJECTIVES: To determine the relative contribution of slice thickness and intraluminal contrast density to imaging of the large bowel wall. METHODS: The authors used phantom experiments to evaluate 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 -1000/50/100 HU). For the experiments with a dual-density interface, which simulated the bowel wall, the phantom was scanned at an angle 45 degrees to the scan plane. RESULTS: The most accurate display of interfaces 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 even recognizable as a wall depending on the densities in the interface. Adjusting the density of the intraluminal contrast medium to within the range of the mean and window setting will improve the representation of the bowel wall. CONCLUSIONS: Slice thickness has a significant influence on the true representation of the bowel wall using computed tomography. This effect is greater than the effect of the intraluminal contrast medium density.
Authors: J J Kolkman; T H Falke; J C Roos; D H Van Dijk; I M Bannink; W Den Hollander; M A Cuesta; A S Peña; S G Meuwissen Journal: Dig Dis Sci Date: 1996-04 Impact factor: 3.199