Jihoon Cha MD, Presenter: Nothing to Disclose

Hyung-Jin Kim MD, Abstract Co-Author: Nothing to Disclose

Sung Tae Kim MD, Abstract Co-Author: Nothing to Disclose

Yi Kyung Kim MD, Abstract Co-Author: Nothing to Disclose

Mina Song PhD, Abstract Co-Author: Nothing to Disclose

Pyoung Jeon, Abstract Co-Author: Nothing to Disclose

Keon Ha Kim, Abstract Co-Author: Nothing to Disclose

Hong Sik Byun MD, Abstract Co-Author: Nothing to Disclose

To assess the usefulness of gemstone spectral imaging (GSI) dual-energy CT (DECT) utilizing metal artifact reduction software (MARs) to reduce dental reconstruction artifact

The DECTs were performed by using fast kV-switching GSI between 80 and 140 kV in 20 patients with metallic dental prosthesis. The CT data were retro-reconstructed with/without MARs, and with synthesised monochromatic energy in the range of 40 – 140 keV. For the qualitative analysis, two radiologists evaluated 70 keV and 100 keV images with and without MARs for tongue and bilateral buccal and parotid areas by using a 4-point scale with the larger point being considered to have the better image quality. The margin and internal architecture of metallic denture were also assessed with a 3-point scale. The locations and characteristics of MARs-related artifact if any were also recorded. For the quantitative analysis, manually-drawn region of interests (ROIs) were placed in the tongue and bilateral buccal and parotid areas and the ratios of standard deviation (SD) of Hounsfield unit (HU) measured at each area were compared between with and without MARs in the range of 40 – 140 keV.

The GSI-MARs reconstruction markedly reduced the dental reconstruction artifacts in the buccal area (score of 1.55 without MARs vs. 3.10 with MARs for 70 keV, P<0.001, ratio of SD=56%), and the tongue (score of 1.30 without MARs vs. 2.25 with MARs for 70 keV, P<0.001, ratio of SD=38%). Parotid area did not show significant artifact reduction (score of 3.35 without MARs vs. 3.50 with MARs for 70 keV, ratio of SD=101%). The margin and internal architecture of the metal were more clearly delinated with MARs (score of 1.00 without MARs vs. 2.75 with MARs for 70 keV, P<0.001). MARs-related artifacts were most commonly occurred in the deep center of the neck, including retropharynx, pre- and paravertebral space and spinal cord. Metal artifacts were reduced slightly more in the high keV images than in the low keV images (score of 2.25 with 70 keV+MARs vs. 2.45 with 100 keV+MARs for tongue, P=0.042).

Dual-energy CT with GSI-MARs can reduce dental metal-related artifacts and improve delineation of the prosthesis and periprosthetic region.

Dual-energy CT with GSI-MARs can reduce dental reconstruction artifacts and may improve the image quality by better delineation of the anatomic structure.

Cha, J, Kim, H, Kim, S, Kim, Y, Song, M, Jeon, P, Kim, K, Byun, H, Gemstone Spectral Imaging Dual-energy CT with and without Metal Artifact Reduction Software for Dental Reconstruction Artifact.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14013338.html