Objective: This study aimed to compare the performance of metal artifacts reduction on lumbar spine computed tomography (CT) Images between the commercial tool Gemstone Spectral Imaging (GSI) versus the NUMAR Program.

Material and Method: The efficiency of metal artifacts reduction on lumbar spine CT images using the GSI of GE LightSpeed VCT and the NUMAR Program was compared. The lumbar spine CT images with rod, partial pedicle screw, and full pedicle screw were examined. We have evaluated the outcome of noise level obtained from original images compared with the GSI and NUMAR processing. The percentage reduction of noise was measured, and the mean difference of noise using the GSI and the NUMAR program was also determined.

Results: Noise was reduced in the images using NUMAR Program greater than the use of GSI. The mean of noise of NUMAR were 54.17±17.26 and 64.12±30.69 HU, while the percentage noise reduction were 40.28±20.89 and 61.38±12.29 % for rod and partial pedicle screw images respectively. The mean and percentage reduction of noise of full pedicle images were slightly different. The percentage noise reduction of NUMAR was significantly different in the partial pedicle screw images obtained from GSI (p=0.007), but there was no significant difference in rod and full pedicle screw images (p=0.176 and p=0.884, respectively).

Conclusion: Metal artifacts reduced effectively in rod, partial pedicle screw, and full pedicle screw images using the NUMAR Program. The efficiency of NUMAR Program is similar to commercial GSI tool.