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Multicenter reproducibility study of diffusion MRI and fiber tractography of the lumbosacral nerves
Author(s) -
Haakma Wieke,
Hendrikse Jeroen,
Uhrenholt Lars,
Leemans Alexander,
Warner Thorup Boel Lene,
Pedersen Michael,
Froeling Martijn
Publication year - 2018
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.25964
Subject(s) - reproducibility , medicine , intraclass correlation , diffusion mri , lumbosacral joint , nuclear medicine , lumbosacral plexus , fractional anisotropy , radiology , magnetic resonance imaging , anatomy , chemistry , chromatography
Background Diffusion tensor imaging (DTI) has been applied in the lumbar and sacral nerves in vivo, but information about the reproducibility of this method is needed before DTI can be used reliably in clinical practice across centers. Purpose In this multicenter study the reproducibility of DTI of the lumbosacral nerves in healthy volunteers was investigated. Study Type Prospective control series. Subjects Twenty healthy subjects. Field Strength/Sequence 3T MRI. 3D turbo spin echo, and 3.0 mm isotropic DTI scan. Assessment The DTI scan was performed three times (twice in the same session, intrascan reproducibility, and once after an hour, interscan reproducibility). At site 2, 1 week later, the protocol was repeated (interweek reproducibility). Fiber tractography (FT) of the lumbar and sacral nerves (L3–S2) was performed to obtain values for fractional anisotropy, mean, axial, and radial diffusivity. Statistical Tests Reproducibility was determined using the intraclass correlation coefficient (ICC), and power calculations were performed. Results FT was successful and reproducible in all datasets. ICCs for all diffusion parameters were high for intrascan (ranging from 0.70–0.85), intermediate for interscan (ranging from 0.61–0.73), and interweek reliability (ranging from 0.58–0.62). There were small but significant differences between the interweek diffusivity values ( P < 0.0005). Depending on the effect size, nerve location, and parameter of interest, power calculations showed that sample sizes between 10 and 232 subjects are needed for cross‐sectional studies. Data Conclusion We found that DTI and FT of the lumbosacral nerves have intermediate to high reproducibility within and between scans. Based on these results, 10–58 subjects are needed to find a 10% change in parameters in cross‐sectional studies of the lumbar and sacral nerves. The small significant differences of the interweek comparison suggest that results from longitudinal studies need to be interpreted carefully, since small differences may also be caused by factors other than disease progression or therapeutic effects. Level of Evidence: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;48:951–963.