Eur Radiol (2012) 22:1797–1802 DOI 10.1007/s00330-012-2410-9 NEURO New diffusion metrics for spondylotic myelopathy at an early clinical stage Masaaki Hori & Issei Fukunaga & Yoshitaka Masutani & Atsushi Nakanishi & Keigo Shimoji & Koji Kamagata & Koichi Asahi & Nozomi Hamasaki & Yuriko Suzuki & Shigeki Aoki Received: 23 October 2011 / Revised: 16 December 2011 / Accepted: 29 December 2011 / Published online: 13 March 2012 # The Author(s) 2012. This article is published with open access at Springerlink.com Abstract Objectives To investigate the use of root mean square dis- placement (RMSD) and mean diffusional kurtosis (DK) metrics of q-space imaging data to estimate spinal cord compression in patients with early cervical spondylosis. Methods We studied 50 consecutive patients at our institu- tion (22 male, 28 female; mean age 58 years; age range 20– 86 years) who had clinical signs and symptoms suggestive of early clinical stage cervical myelopathy. After conven- tional magnetic resonance (MR) imaging, diffusion tensor and q-space image data were acquired using 3-T MR imag- ing. Fractional anisotropy (FA), apparent diffusion coeffi- cient (ADC), RMSD and mean DK values were calculated M. Hori (*) : I. Fukunaga : A. Nakanishi : K. Shimoji : K. Kamagata : K. Asahi : N. Hamasaki : S. Aoki Department of Radiology, School of Medicine, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan e-mail: mahori@juntendo.ac.jp I. Fukunaga Department of Health Science, Graduate School of Human Health Sciences, Tokyo Metropolitan University, 7-2-10, Higashiogu, Arakawa, Tokyo 116-8551, Japan Y. Masutani Division of Radiology and Biomedical Engineering, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan Y. Suzuki Philips Electronics Japan, Ltd, Philips Bldg. 13-37 Kohnan 2-chome, Minato-ku, Tokyo 108-8570, Japan and compared between compressed and uncompressed spi- nal cords. Results FA and mean DK values were significantly lower and RMSD was significantly higher (P0 0.0060, 0.0020 and 0.0062, respectively; Mann–Whitney U test with the Bon- ferroni correction) in compressed spinal cords than in uncompressed cords. ADC was also higher in compressed cords, but this difference was not statistically significant. Conclusions In the evaluation of spinal cord damage in early cervical spondylosis, mean DK and RMSD values in the spinal cord may be highly sensitive indicators of micro- structural change and damage. Key Points Absolute surgical indications for cervical spondylosis with myelopathy remain to be established. Diffusion tensor MRI shows abnormalities in normal- appearing but compressed spinal cord. Non-Gaussian diffusion analysis is highly sensitive in revealing spinal cord damage. Keywords Cervical spondylosis . Spinal cord . Non- Gaussian . Diffusion kurtosis imaging . Diffusion tensor imaging Introduction Cervical spondylosis is a common degenerative disease. In this condition, disk degeneration, bone formation with osteophytic changes, and hypertrophy of the ligamentum flavum can result in spinal canal narrowing and cervical cord myelopathy. Routine clinical magnetic resonance (MR) imaging is widely performed to evaluate morpholog- ical changes in cervical spondylosis, but there is only a weak correlation between MR imaging findings and clinical