title: Prediction of Neurological Impairment in Cervical Spondylotic Myelopathy using a Combination of Diffusion MRI and Proton MR Spectroscopy.
abstract: OBJECTIVE
  In the present study we investigated a combination of diffusion tensor imaging (DTI) and magnetic resonance spectroscopic (MRS) biomarkers in order to predict neurological impairment in patients with cervical spondylosis.
  
  
  METHODS
  Twenty-seven patients with cervical spondylosis were evaluated. DTI and single voxel MRS were performed in the cervical cord. N-acetylaspartate (NAA) and choline (Cho) metabolite concentration ratios with respect to creatine were quantified, as well as the ratio of choline to NAA. The modified mJOA scale was used as a measure of neurologic deficit. Linear regression was performed between DTI and MRS parameters and mJOA scores. Significant predictors from linear regression were used in a multiple linear regression model in order to improve prediction of mJOA. Parameters that did not add value to model performance were removed, then an optimized multiparametric model was established to predict mJOA.
  
  
  RESULTS
  Significant correlations were observed between the Torg-Pavlov ratio and FA (R2 = 0.2021, P = 0.019); DTI fiber tract density and FA, MD, Cho/NAA (R2 = 0.3412, P = 0.0014; R2 = 0.2112, P = 0.016; and R2 = 0.2352, P = 0.010 respectively); along with FA and Cho/NAA (R2 = 0.1695, P = 0.033). DTI fiber tract density, MD and FA at the site of compression, along with Cho/NAA at C2, were significantly correlated with mJOA score (R2 = 0.05939, P < 0.0001; R2 = 0.4739, P < 0.0001; R2 = 0.7034, P < 0.0001; R2 = 0.4649, P < 0.0001). A combination biomarker consisting of DTI fiber tract density, MD, and Cho/NAA showed the best prediction of mJOA (R2 = 0.8274, P<0.0001), with post-hoc tests suggesting fiber tract density, MD, and Cho/NAA were all significant contributors to predicting mJOA (P = 0.00053, P = 0.00085, and P = 0.0019, respectively).
  
  
  CONCLUSIONS
  A linear combination of DTI and MRS measurements within the cervical spinal cord may be useful for accurately predicting neurological deficits in patients with cervical spondylosis. Additional studies may be necessary to validate these observations.
authors.affiliation: Department of Radiological Sciences, David Geffen School of Medicine, University of California-Los Angeles, United States of America; Department of Biomedical Physics, David Geffen School of Medicine, University of California-Los Angeles, United States of America; Department of Bioengineering, Henri Samueli School of Engineering and Applied Sciences, University of California-Los Angeles, United States of America; Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California-Los Angeles, United States of America.
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Ellingson
authors.affiliation: Department of Radiological Sciences, David Geffen School of Medicine, University of California-Los Angeles, United States of America.
authors.forename: Noriko
authors.initials: N
authors.lastname: Salamon
authors.affiliation: Department of Radiological Sciences, David Geffen School of Medicine, University of California-Los Angeles, United States of America; Department of Biomedical Physics, David Geffen School of Medicine, University of California-Los Angeles, United States of America.
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Hardy
authors.affiliation: Department of Neurosurgery and Orthopaedics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States of America.
authors.forename: Langston T
authors.initials: LT
authors.lastname: Holly
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000473:pathology; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000032:analysis; D002794:Choline / Q000032:analysis*; D003404:Creatinine / Q000032:analysis; D056324:Diffusion Tensor Imaging; D005260:Female; D020233:Gait Disorders, Neurologic / Q000209:etiology* / Q000473:pathology; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D019547:Neck Pain / Q000209:etiology / Q000473:pathology; D009412:Nerve Fibers / Q000473:pathology; D010292:Paresthesia / Q000209:etiology* / Q000473:pathology; D011446:Prospective Studies; D066244:Proton Magnetic Resonance Spectroscopy; D013116:Spinal Cord / Q000473:pathology*; D013117:Spinal Cord Compression / Q000209:etiology* / Q000473:pathology; D013130:Spinal Stenosis / Q000150:complications / Q000473:pathology; D055009:Spondylosis / Q000150:complications* / Q000473:pathology; D055815:Young Adult
chemical_list: D001224:Aspartic Acid; C000179:N-acetylaspartate; D003404:Creatinine; D002794:Choline