title: Correlation of pain with objective quantification of magnetic resonance images in older adults with chronic low back pain.
abstract: METHODS
  Cross sectional study.
  
  
  OBJECTIVE
  The goal of this study is to identify relationships between objectively measured and subjectively scored parameters and reported pain.
  
  
  BACKGROUND
  Studies have demonstrated the unreliability of magnetic resonance imaging (MRI)-based parameters to identify pathological pain generators of chronic low back pain, but they were based on visual inspection and subjective assessment of lumbar disc features. Advancements in computer image analysis provide objective measurements of lumbar disc features.
  
  
  METHODS
  Two radiologists evaluated 39 axial and sagittal T1- and T2-weighted MR images of patients with chronic axial low back pain (age, >65 yr) and graded 4 subjective lumbar disc parameters (T2 signal intensity, nucleus shape, Modic changes, and osteophyte formation) whose sum is the cumulative MRI score. Objective parameter, MRI index, was calculated as the product of the measured lumbar disc area and total disc MRI signal intensity. Discs were sorted from least to the most degenerated relative to each parameter. Pearson correlation coefficient and multiple linear regression analysis were performed between the reported pain score and each parameter.
  
  
  RESULTS
  The most and least degenerated discs in each patient, as assessed by MRI index, had the highest negative and positive correlation coefficient and regression weight contribution, respectively. All subjective parameters had low correlation coefficients and regression goodness of fit.
  
  
  CONCLUSIONS
  Although limited by small sample size, the objective parameter, MRI index, can be a potential imaging biomarker used to identify possible pain generators. This study presents a potential new application of MR imaging in identifying pain generators of patients with chronic low back pain.
authors.affiliation: Departments of *Orthopaedic Surgery †Radiology ‡Medicine §Psychiatry, and ¶Anesthesiology, University of Pittsburgh, Pittsburgh, PA ‖Geriatric Research Education and Clinical Center, Veterans Administration Pittsburgh Healthcare System, Pittsburgh, PA; and **Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA.
authors.forename: Bernard P
authors.initials: BP
authors.lastname: Bechara
authors.forename: Vikas
authors.initials: V
authors.lastname: Agarwal
authors.forename: John
authors.initials: J
authors.lastname: Boardman
authors.forename: Subashan
authors.initials: S
authors.lastname: Perera
authors.forename: Debra K
authors.initials: DK
authors.lastname: Weiner
authors.forename: Nam
authors.initials: N
authors.lastname: Vo
authors.forename: James
authors.initials: J
authors.lastname: Kang
authors.forename: Gwendolyn A
authors.initials: GA
authors.lastname: Sowa
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D059350:Chronic Pain / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology / Q000523:psychology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000473:pathology*; D055959:Intervertebral Disc Degeneration / Q000150:complications / Q000175:diagnosis* / Q000473:pathology / Q000523:psychology; D016014:Linear Models; D017116:Low Back Pain / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology / Q000523:psychology; D008159:Lumbar Vertebrae / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D010147:Pain Measurement; D058748:Pain Perception; D011237:Predictive Value of Tests; D012720:Severity of Illness Index