title: Type II Modic Changes May not Always Represent Fat Degeneration: A Study Using MR Fat Suppression Sequence.
abstract: METHODS
  A radiological study of type II Modic changes (MCs).
  
  
  OBJECTIVE
  The aim of this study was to determine the characteristics of type II MCs on fat suppression (FS) magnetic resonance (MR) images and its association with radiological disc degeneration.
  
  
  BACKGROUND
  Type II MCs are common endplate signal changes on MR images. On the basis of limited histological samples, type II MCs are thought to be stable fat degeneration. FS technique on MR, which can quantify fat content, may be an alternative to explore the pathology of MCs. To date, however, the characteristics of type II MCs on FS sequence have not been studied.
  
  
  METHODS
  Lumbar MR images conducted in a single hospital during a defined period were reviewed to include those with type II MCs and FS images. On FS images, signal status of type II MCs was visually classified as suppressed or not-suppressed. Signal intensity of vertebral regions with and without MCs was measured quantitatively on T2-weighted (T2W) and FS images to calculate fat content index and validate the visual classification. Using image analysis program Osirix, MCs size and adjacent disc degeneration were measured quantitatively. Paired t-tests and logistic regressions were used to determine the associations studied.
  
  
  RESULTS
  Sixty-four lumbar MRIs were included and 150 endplates with type II MCs were studied. Although signal of 37 (24.7%) type II MCs was suppressed on FS images, that of 113 (75.3%) was not suppressed. The discs adjacent to type II MCs had lower signal intensity (0.13 ± 0.003 vs. 0.14 ± 0.004, P < 0.001), lesser disc height (9.73 ± 1.97 vs. 11.07 ± 1.99, P < 0.001) and greater bulging area (80.0 ± 31.4 vs. 61.3 ± 27.5 for anterior bulging, 33.72 ± 21.24 vs. 27.93 ± 12.79 for posterior bulging, and 113.7 ± 39.9 vs. 89.2 ± 35.2 for total bulging, P < 0.05) than normal controls. Type II MCs that were not suppressed on FS image were associated with greater age [odds ratio (OR) = 1.11, P < 0.001], lower height (OR = 0.94, P < 0.05), and greater posterior bulging (OR = 1.05, P < 0.001) at the adjacent disc.
  
  
  CONCLUSIONS
  Signal of most type II MCs was not suppressed on FS MR images, suggesting that there are ongoing complicated pathologies. Type II MCs may not merely represent fat replacement.
  
  
  METHODS
  3.
authors.affiliation: Spine Lab, Department of Orthopedic Surgery, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China.
authors.forename: Zhiyun
authors.initials: Z
authors.lastname: Feng
authors.affiliation: Spine Lab, Department of Orthopedic Surgery, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China.
authors.forename: Yuanhao
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Orthopedic Surgery, Integrated Chinese and Western Medicine Hospital of Zhejiang Province, Hangzhou, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.affiliation: Department of Orthopedic Surgery, Integrated Chinese and Western Medicine Hospital of Zhejiang Province, Hangzhou, China.
authors.forename: Shengping
authors.initials: S
authors.lastname: Hu
authors.affiliation: Spine Lab, Department of Orthopedic Surgery, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005223:Fats / Q000032:analysis*; D005260:Female; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000000981:diagnostic imaging*; D017116:Low Back Pain / Q000175:diagnosis / Q000473:pathology; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D011859:Radiography / Q000379:methods
chemical_list: D005223:Fats