Xingsheng Zhao, Presenter: Nothing to Disclose

Maoyi Zhou MD, PhD, Abstract Co-Author: Nothing to Disclose

Weiguang Shao, Abstract Co-Author: Nothing to Disclose

Xin Li Li MD, Abstract Co-Author: Nothing to Disclose

Jingang Liu, Abstract Co-Author: Nothing to Disclose

Shuai Zhang, Abstract Co-Author: Nothing to Disclose

Xu Yan, Abstract Co-Author: Nothing to Disclose

Huizhi Cao, Abstract Co-Author: Nothing to Disclose

Guangzhi Wang MBBS, Abstract Co-Author: Nothing to Disclose

Dongwen Zhang, Abstract Co-Author: Nothing to Disclose

Yuanning Ying MD, Abstract Co-Author: Nothing to Disclose

To assess the the clinical value of Gemstone Spectral Imaging ( GSI) in the elimination of the beam-hardening artifact (BHAs) from iodine contrast agent and bone.

Nine tubes filled with degrees diluted solutions (0-100mg/100ml) of iodine contrast media in a phantom took GSI scan and routine polychromatic energy of 120 kilovolt peak (kVp) scan on Discovery CT750HD. The scan included stationary and movement state，which were in different amplitude (2.5, 5, 10mm) and frequency (5, 10, 15, 20 BMP). A series of CT images were obtained from a single GSI acquisition: monochromatic images at 40-140 kiloelectron volts (keV) with interval of 1 keV. Regions of interest (ROI) were selected the area of artifacts most seriously, and the background noise was expressed by the SD value. Image noise index (NI) of images were calculated and compared between the polychromatic and monochromatic images. Statistical analysis were using t test. The optimal monochromatic level which provided best BHA reduction was determined by NI. and compared to the conventional polychromatic images. The impact of degrees keV, frequency and amplitude to beam-hardening artifact elevation was investigated by multivariate regression analysis.

Image quality of GSI group was significantly higher than 140kVp group. Degrees of keV had a negative correlation (r =- 0.61) with noise index, while the amplitude and frequency of movement were positively correlated with noise index, r=0.40, 0.26, respectively. Beam-hardening artifact can be effectively eliminated at 91-94 keV.

GSI can reduce hardening artifacts of high density agent and improve image quality significantly. Degrees of keV have the greatest impact to hardening artifacts, followed by amplitude, frequency.

GSI can reduce hardening artifacts of high density agent and improve image quality significantly to make precise diagnosis of some diseases in body.  

Zhao, X, Zhou, M, Shao, W, Li, X, Liu, J, Zhang, S, Yan, X, Cao, H, Wang, G, Zhang, D, Ying, Y, Initial Results of Reduction the Beam-hardening Artifact from Iodine Contrast Agent in High-Definition CT Gemstone Spectral Imaging: Experimental Study.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11009046.html