Tianjin Medical Journal ›› 2023, Vol. 51 ›› Issue (6): 642-647.doi: 10.11958/20221330

• Clinical Research • Previous Articles     Next Articles

Clinical value of energy spectrum CT combined with MARs technique for artifact removal of dentures of different materials

GAN Lu1,2(), LIU Ji2, YUAN Chen2, WANG Yuen2, LI Xueming2, YANG Shiming2, LIU Bin1,   

  1. 1 Department of Radiology, the First Affiliated Hospital of Anhui Medical University, Hefei 230022, China
    2 Department of Radiology, Huainan Oriental Guangji Hospital
  • Received:2022-09-08 Revised:2023-03-03 Published:2023-06-15 Online:2023-06-20
  • Contact: E-mail:lbhyz321@126.com

Abstract:

Objective To investigate the clinical value of energy spectrum CT single energy imaging and single energy + multi artifact reduction system (MARs) in removing artifacts around denture, and compare effects of different denture materials on image quality. Methods One hundred patients with denture implantation were scanned, including 30 cases of nichcr alloy, 30 cases of porcelain and 40 cases of glue bracket + stainless steel bracket. Under the same CT scanning parameters, energy spectrum imaging (GSI) was used to obtain mixed energy images (QC), single energy images of 70-140 keV and single energy+MARs images. At the level of the most serious denture artifact in each patient, two areas of interest (ROI) were defined: ROI1 selected at the head muscle without artifact in the same level and ROI2 selected the light-dark artifact area of soft tissue of tongue in the middle of the mouth with ROI of about 150-200 mm2. The average noise (SD) and CT were measured respectively, and the artifact index (AI) was calculated. SD and AI were used as objective evaluation parameters. The image quality of mixed energy image, single energy image and single energy+MARs image were subjectively scored by two senior attending radiologists. Results The noise and artifact index of adjacent tissues of three materials, namely, nickel-chromium alloy, porcelain, glue holder + stainless steel holder, decreased with the increase of tube voltage, and it was significantly lower than QC above 90 keV, which was significantly lower than that of QC mixed energy image. The SD and AI of single energy+MARs images were significantly lower than those of single energy images with same parameters. The contrast of oral soft tissue decreased significantly with the increase of tube voltage. The contrast of oral soft tissue was the best at 110 keV+MARs, and the subjective score was the highest. Comparing the best imaging parameters of three kinds of dentures, namely, nichcr alloy, porcelain plate, glue plate+stainless steel plate, SD and AI of porcelain base were the smallest. Conclusion Energy spectrum scanning combined with MARs technology can effectively reduce metal artifacts of nichcr alloy, adhesive bracket + stainless steel bracket and porcelain, and can be used as an effective method to remove artifacts of dental prosthesis.

Key words: dentures, artifacts, MARs technology, single energy technology, energy spectrum imaging

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