Feasibility of reducing artifacts of spine metal implants at 3.0 T MRI

Objective To investigate the feasibility of reducing spine metal artifacts with metal artifacts reduction technique (WARP) at 3.0 T MRI. Methods This study included 15 cervical and 14 lumbar spine cases. The image quality of WARP sequences and conventional sequences were compared (5 score evaluation scale) as well as the signal to noise ratio (SNR) and contrast noise ratio (CNR) of the image artifacts. The scanning time was recorded. Paired-t test and Mann-Whitney test were used respectively to compare the SNR and CNR, and qualitative scoring between the two sequences. P<0.05 was considered to indicate a significant difference. Results The image distortion and blur of the WARP sequences were obviously reduced as compared to the conventional sequences. The SNR and CNR of artifacts of the WARP sequences were lower than that of the conventional sequences (All P<0.05). The image quality scores of WARP sequences in cervical and lumbar spines[4(3 to 5) and 4(3 to 5)] were higher than that of conventional sequences[3(2 to 4),3(2 to 4)](P<0.05). The scanning time of cervical spines in WARP sequence (14 min 9 s) was increased by 64 s (8.2%) ,and the time of lumbar spines (13 min 41 s) decreased by 9 s (1.1%) . Conclusion The WARP sequences at 3.0 T could effectively reduce the artifacts of metallic prosthesis in cervical and lumbar spine without prolonging the scanning time at 3.0 T MRI. Key words: Magnetic resonance imaging; Spine; Metal artifacts; Image quality