title: Comparison between pain at discography and morphological disc changes at axial loaded MRI in patients with low back pain.
abstract: OBJECTIVE
  Discogenic pain is induced by axial load, but there are no studies evaluating the influence of dynamic MRI in relation to provoked pain at discography. The aim of this study was to investigate the relationship between discography-induced pain and morphological disc changes, occurring during axial loaded MRI (alMRI). A secondary aim was to compare and register the frequency of provoked concordant pain at alMRI and discography.
  
  
  METHODS
  41 patients with assumed discogenic pain were investigated with MRI, alMRI and pressure-controlled discography (PCD) (119 discs). Provoked pain at both discography and alMRI was classified as concordant or discordant with daily pain as reference. A concordant discogram required pain intensity ≥5/10 (numerical rating scale) at ≤50 psi and one negative control disc. A concordant provocation at alMRI required pain intensity ≥5/10. The relationship between concordant pain at discography and morphological disc measures (degeneration, height, bulge, angle, area, and circumference) at MRI/alMRI was investigated.
  
  
  RESULTS
  Changes in the morphological appearance occurred in at least one disc level in all patients when loaded and unloaded MRI were compared. However, no significant differences between concordant and discordant discograms in terms of morphological disc features at conventional MRI or alMRI were found. 78 % of the patients reported concordant provoked pain during the alMRI.
  
  
  CONCLUSIONS
  In the majority of patients with low back pain, discography as well as alMRI provoked concordant pain. Loading of the spine, alMRI, revealed however no clinically useful morphological characteristics in the discs with concordant discograms. Alternative or more sensitive diagnostic methods are needed to understand load-induced discogenic pain.
authors: Department of Radiology, Sahlgrenska University Hospital, Smörslottsgatan 1, 416 85, Gothenburg, Sweden, hanna.hebelka@vgregion.se.
authors: Hanna
authors: H
authors: Hebelka
authors: Helena
authors: H
authors: Brisby
authors: Tommy
authors: T
authors: Hansson
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000473:pathology* / Q000502:physiology; D055959:Intervertebral Disc Degeneration / Q000473:pathology* / Q000503:physiopathology; D017116:Low Back Pain / Q000473:pathology* / Q000503:physiopathology; D008159:Lumbar Vertebrae / Q000473:pathology* / Q000502:physiology; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods; D011300:Preoperative Care; D011446:Prospective Studies; D016474:Weight-Bearing / Q000502:physiology*