Peripheral nerve diffusion tensor imaging (DTI): normal values and demographic determinants in a cohort of 60 healthy individuals

• Published in: European radiology Vol. 28; no. 5; pp. 1801 - 1808
• Main Authors: Kronlage, Moritz, Schwehr, Véronique, Schwarz, Daniel, Godel, Tim, Uhlmann, Lorenz, Heiland, Sabine, Bendszus, Martin, Bäumer, Philipp
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.05.2018; Springer Nature B.V
• Subjects: Adult; Age; Aged; Aged, 80 and over; Aging; Anisotropy; Body mass; Body weight; Demographic variables; Demographics; Diagnostic Radiology; Diffusion; Diffusion Tensor Imaging - methods; Diffusivity; Female; Healthy Volunteers; Humans; Imaging; Internal Medicine; Interventional Radiology; Magnetic resonance imaging; Male; Medicine; Medicine & Public Health; Middle Aged; Nerves; Neuro; Neuroradiology; Peripheral nerves; Peripheral Nerves - diagnostic imaging; Radiology; Regression analysis; Regression models; Reproducibility of Results; Ultrasound; Variables; Young Adult; Peripheral nervous system; Aging; Magnetic resonance imaging; Reference values; Diffusion tensor imaging
• ISSN: 0938-7994; 1432-1084; 1432-1084
• DOI: 10.1007/s00330-017-5134-z

Objective To identify demographic determinants of peripheral nerve diffusion tensor imaging (DTI) and to establish normal values for fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD). Methods Sixty subjects were examined at 3 Tesla by single-shot DTI. FA, AD, RD, and MD were collected for the sciatic, tibial, median, ulnar, and radial nerve and were correlated with demographic variables. Results Mean FA of all nerves declined with increasing age ( r = −0.77), which could be explained by RD increasing ( r = 0.56) and AD declining ( r = −0.40) with age. Moreover, FA was inversely associated with height ( r = −0.28), weight ( r = −0.38) and BMI ( r = −0.35). Although FA tended to be lower in men than women ( p = 0.052), this difference became completely negligible after adjustment to body weight. A multiple linear regression model for FA was calculated with age and weight as predictors (defined by backward variable selection), yielding an R 2 = 0.71 and providing a correction formula to adjust FA for age and weight. Conclusion Peripheral nerve DTI parameters depend on demographic variables. The most important determinants age and weight should be considered in all studies employing peripheral nerve DTI. Key points • Peripheral nerve diffusion tensor imaging (DTI) parameters depend on demographic variables. • Fractional anisotropy (FA) declines with increasing age and weight. • Gender does not systematically affect peripheral nerve DTI. • The formula presented here allows adjustment of FA for demographic variables.