title: A New MRI Grading System for Cervical Foraminal Stenosis Based on Axial T2-Weighted Images.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the reliability of a new magnetic resonance imaging (MRI) grading system for cervical neural foraminal stenosis (NFS).
  
  
  METHODS
  Cervical NFS at bilateral C4/5, C5/6, and C6/7 was classified into the following three grades based on the T2-weighted axial images: Grade 0 = absence of NFS, with the narrowest width of the neural foramen greater than the width of the extraforaminal nerve root (EFNR); Grade 1 = the narrowest width of the neural foramen the same or less than (but more than 50% of) the width of the EFNR; Grade 2 = the width of the neural foramen the same or less than 50% of the width of the EFNR. The MRIs of 96 patients who were over 60 years old (M:F = 50:46; mean age 68.4 years; range 61-86 years) were independently analyzed by seven radiologists. Interobserver and intraobserver agreements were analyzed using the percentage agreement, kappa statistics, and intraclass correlation coefficient (ICC).
  
  
  RESULTS
  For the distinction among the three individual grades at all six neural foramina, the ICC ranged from 0.68 to 0.73, indicating fair to good reproducibility. The percentage agreement ranged from 60.2% to 70.6%, and the kappa values (κ = 0.50-0.58) indicated fair to moderate agreement. The percentages of intraobserver agreement ranged from 85.4% to 93.8% (κ = 0.80-0.92), indicating near perfect agreement.
  
  
  CONCLUSIONS
  The new MRI grading system shows sufficient interobserver and intraobserver agreement to reliably assess cervical NFS.
authors.affiliation: Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Institute of Radiation Medicine, Seoul National University Medical Research Center, Seongnam 13620, Korea.
authors.forename: Sujin
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Institute of Radiation Medicine, Seoul National University Medical Research Center, Seongnam 13620, Korea.
authors.forename: Joon Woo
authors.initials: JW
authors.lastname: Lee
authors.affiliation: Department of Radiology, SMG-SNU Boramae Medical Center, Seoul 07061, Korea.
authors.forename: Jee Won
authors.initials: JW
authors.lastname: Chai
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul 03080, Korea.
authors.forename: Hye Jin
authors.initials: HJ
authors.lastname: Yoo
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul 03080, Korea.
authors.forename: Yusuhn
authors.initials: Y
authors.lastname: Kang
authors.affiliation: Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Institute of Radiation Medicine, Seoul National University Medical Research Center, Seongnam 13620, Korea.
authors.forename: Jiwoon
authors.initials: J
authors.lastname: Seo
authors.affiliation: Department of Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA.
authors.forename: Joong Mo
authors.initials: JM
authors.lastname: Ahn
authors.affiliation: Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Institute of Radiation Medicine, Seoul National University Medical Research Center, Seongnam 13620, Korea.
authors.forename: Heung Sik
authors.initials: HS
authors.lastname: Kang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011859:Radiography; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D013130:Spinal Stenosis / Q000000981:diagnostic imaging* / Q000473:pathology
keywords: Cervical spine; Classification; Neural foraminal stenosis; Severity grading system