Should you believe your eyes when a gadolinium enhanced MRI shows disc inflammation? Maybe not, says new work from the Netherlands.
The study, “Gadolinium Enhancement Is Not Associated With Disc Inflammation in Patients With Sciatica,” was published in the June 15, 2019 edition of Spine.
Niek Djuric, M.D., with the Department of Neurosurgery at the Leiden University Medical Center in The Netherlands and study co-author explained his thinking behind the study to OTW, “Gadolinium enhancement is a commonly used tool to assess the degree of inflammation, especially in pathologies of the brain. This has led to the assumption that gadolinium can also be used to illustrate inflammation of the herniated disc.”
“However, since the inflammation response of the disc is usually rather limited, it can often be hard to interpret the enhancement of the images. Hence we started to question the reliability of this imaging technique.”
To test their hypothesis, the study investigators retrieved disc tissue from 119 patients in their sciatica trial. The investigators were from several centers and they organized the study to be a randomized controlled trial. After harvesting disc tissue, the researchers embedded the tissue in paraffin and stained it with hematoxylin and CD68. They then categorized their tissue samples as having either mild, moderate, or considerable inflammation. Finally, in order to test the efficacy of gadolinium, the research team employed gadolinium contrast media to 96 of the 119 MRIs.
The team found that 74 of the patients showed gadolinium enhancement of the disc herniation and 26 of the nerve root.
Dr. Djuric dissected the study results for OTW, “Gadolinium enhancement of disc was not associated with the degree of inflammation by macrophages. Macrophages play an important role in the resorption of the herniated disc. So, patients with a higher degree of macrophage infiltration may be more likely to benefit from prolonged conservative treatment since their herniated discs will be resorbed faster, leading to a spontaneous relief of their symptoms. A noninvasive tool to assess macrophage infiltration can thus be valuable for deciding to go for surgery or for prolonged conservative treatment. Our results question whether gadolinium is the right tool for this important decision and indicate that we may want to look for a different tool.”
“For those who use gadolinium for clinical decisions, we suggest that they reevaluate its effectiveness in predicting disc inflammation.”
