The Value Of Gemstone Spectral Imaging For Reducing Spinal Metal Artifacts

Objective:To evaluate the practical value of gemstone spectral imaging(GSI)in reducing the metal artifacts of spine,and to find the best monochromatic imaging of image quality.Methods:GSI examination were performed to twenty patients with metal implants of spine,70Kev set of monochromatic images and blend energy images were acquired at the same time. Gemstone spectral imaging (GSI) viewer was used to obtain11sets of monochromatic imagings(40—140keV with interval of10keV) and110keV+MARs images.Three radiologists reviewed all images respectively and assessed the image quality visually using4-point scale.The lengths of the artifacts emanating from the anterior tips of the screw were used to evaluate the degree of artifact.Images with heaviest artifacts level (A) and less or no artifacts level (B) were selected SD value of ROI were measured and the artifact index (AI) was calculated. Statistical analysis was accomplished with SPSS17.0soft package.Results:In Of the11sets of monochromatic images,110keV set had the highest score of image quality,the lengths of artifacts were lowest.There were significant statistical differences between energy spectral images and blend energy images(P<0.05), that is to say, the image quality of energy spectral were significantly better than those of blend energy images.Conclusion:Patients with metal implants of spine,110keV was the best point for quality of monochromatic imaging.Gemstone spectral CT can effectively reduce artifacts of spine metal implants and will provide high image quality in the area with metal implants.