Influence of the Size of Regions of Interest on CT Value and Material Decomposition Measurement in Water Phantom by Single-source Dual Energy CT
LIU Ze-qun
SUN Mei-yu
LIU Ai-lian
HAN Zheng
Abstract：Objective: To investigate the effect of different size of Region of interest (ROI) on CT value and material decomposition measurement in the standard water phantom using single-source dual-energy CT. Methods: The standard water phantom provided by GE company was scanned by single-source dual-energy CT machine (Discovery CT 750HD, America GE Company). The image processing was performed on GSI Viewer browser to acquire and record CT value (HU), the concentration value of water-iodine (mg/cm3). The scanning parameters were as follows: scanning visual field: medium, rotating speed of 0.8 seconds/rotation, pitch 0.984, detector width 40 mm, current: 550mA. The two drawn ROIs were round, located in the central part of the water phantom. Their areas were (600±30) mm2 and (3000±30) mm2, and then recorded as ROI1 and ROI2 respectively. Paired samplet test was used for statistical analysis. Results: ROI1 CT value was (2.45±1.83) HU, ROI2 CT value was(2.55±1.68) HU, there was no statistical significance between CT value of ROI1 and ROI2 (P=0.06); The water-iodine value was (1001.22±0.86) mg/cm3 in ROI1, and that of ROI2 was (1001.31±0.84) mg/cm3, there was no statistical significance between water iodine value of ROI1 and ROI2 (P=0.135). Conclusions: Different ROI size will have no effect on the measurement of CT value and the concentration of water-iodine from single-source dual energy CT.
Keywords：gemstone spectral imagingCT valuewater-iodine concentrationthe size of regions of interest
Publication Date：2016-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 129-134 )