The relationship between quantitative measures of disc height and disc signal intensity with Pfirrmann score of disc degeneration

Sara Salamat, John Hutchings, Clemens Kwong, John Magnussen, Mark J. Hancock*

*Corresponding author for this work

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5 Citations (Scopus)
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Purpose: To assess the relationship between quantitative measures of disc height and signal intensity with the Pfirrmann disc degeneration scoring system and to test the inter-rater reliability of the quantitative measures. Methods: Participants were 76 people who had recently recovered from their last episode of acute low back pain and underwent MRI scan on a single 3T machine. At all 380 lumbar discs, quantitative measures of disc height and signal intensity were made by 2 independent raters and compared to Pfirrmann scores from a single radiologist. For quantitative measures of disc height and signal intensity a “raw” score and 2 adjusted ratios were calculated and the relationship with Pfirrmann scores was assessed. The inter-tester reliability of quantitative measures was also investigated. Results: There was a strong linear relationship between quantitative disc signal intensity and Pfirrmann scores for grades 1–4, but not for grades 4 and 5. For disc height only, Pfirrmann grade 5 had significantly reduced disc height compared to all other grades. Results were similar regardless of whether raw or adjusted scores were used. Inter-rater reliability for the quantitative measures was excellent (ICC > 0.97). Conclusions: Quantitative measures of disc signal intensity were strongly related to Pfirrmann scores from grade 1 to 4; however disc height only differentiated between grade 4 and 5 Pfirrmann scores. Using adjusted ratios for quantitative measures of disc height or signal intensity did not significantly alter the relationship with Pfirrmann scores.

Original languageEnglish
Article number829
Pages (from-to)1-7
Number of pages7
Publication statusPublished - 1 Dec 2016


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