Quantifying metal-induced susceptibility artifacts of the instrumented spine at 1.5T using fast-spin echo and 3D-multispectral MRI. J Magn Reson Imaging 2017 Jan;45(1):51-58
Date
05/27/2016Pubmed ID
27227824DOI
10.1002/jmri.25321Scopus ID
2-s2.0-84971324230 (requires institutional sign-in at Scopus site) 10 CitationsAbstract
PURPOSE: To evaluate magnetic resonance imaging (MRI) artifacts near metallic spinal instrumentation using both conventional metal artifact reduction sequences (MARS) and 3D multispectral imaging sequences (3D-MSI).
MATERIALS AND METHODS: Both MARS and 3D-MSI images were acquired in 10 subjects with titanium spinal hardware on a 1.5T GE 450W scanner. Clinical computed tomography (CT) images were used to measure the volume of the implant using seed-based region growing. Using 30-40 landmarks, the MARS and 3D-MSI images were coregistered to the CT images. Three independent users manually segmented the artifact volume from both MR sequences. For five L-spine subjects, one user independently segmented the nerve root in both MARS and 3D-MSI images.
RESULTS: For all 10 subjects, the measured artifact volume for the 3D-MSI images closely matched that of the CT implant volume (absolute error: 4.3 ± 2.0 cm3 ). The MARS artifact volume was ∼8-fold higher than that of the 3D-MSI images (30.7 ± 20.2, P = 0.002). The average nerve root volume for the MARS images was 24 ± 7.3% lower than the 3D-MSI images (P = 0.06).
CONCLUSION: Compared to 3D-MSI images, the higher-resolution MARS images may help study features farther away from the implant surface. However, the MARS images retained substantial artifacts in the slice-dimension that result in a larger artifact volume. These artifacts have the potential to obscure physiologically relevant features, and can be mitigated with 3D-MSI sequences. Hence, MR study protocols may benefit with the inclusion both MARS and 3D-MSI sequences to accurately study pathology near the spine.
LEVEL OF EVIDENCE: 2 J. Magn. Reson. Imaging 2017;45:51-58.
Author List
Kaushik SS, Karr R, Runquist M, Marszalkowski C, Sharma A, Rand SD, Maiman D, Koch KMAuthor
Kevin M. Koch PhD Center Director, Professor in the Radiology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AgedCervical Vertebrae
Female
Humans
Image Enhancement
Image Interpretation, Computer-Assisted
Imaging, Three-Dimensional
Internal Fixators
Lumbar Vertebrae
Magnetic Resonance Imaging
Male
Metals
Middle Aged
Reproducibility of Results
Sensitivity and Specificity
Spinal Fusion