STUDY DESIGN

Retrospective review of imaging data from a clinical trial.

OBJECTIVE

To compare the interpretation of lumbar spine magnetic resonance imaging (MRIs) by clinical spine specialists and radiologists in patients with lumbar disc herniation.

SUMMARY OF BACKGROUND DATA

MRI is the imaging modality of choice for evaluation of the lumbar spine in patients with suspected lumbar disc herniation. Guidelines provide standardization of terms to more consistently describe disc herniation. The extent to which these guidelines are being followed in clinical practice is unknown.

METHODS

We abstracted data from radiology reports from patients with lumbar intervertebral disc herniation enrolled in the Spine Patient Outcomes Research Trial. We evaluated the frequency with which morphology (e.g., protrusions, extrusions, or sequestrations) was reported as per guidelines and when present we compared the morphology ratings to those of clinicians who completed a structured data form as part of the trial. We assessed agreement using percent agreement and the kappa statistic.

RESULTS

There were 396 patients with sufficient data to analyze. Excellent agreement was observed between clinician and radiologist on the presence and level of herniation (93.4%), with 3.3% showing disagreement regarding level, of which a third could be explained by the presence of a transitional vertebra. In 3.3% of the cases in which the clinician reported a herniation (protrusion, extrusion, or sequestration), the radiologist reported no herniation on the MRI.The radiology reports did not clearly describe morphology in 42.2% of cases. In the 214 cases with clear morphologic descriptions, agreement was fair (kappa = 0.24) and the disagreement was asymmetric (Bowker's test of symmetry P < 0.0001) with clinicians more often rating more abnormal morphologic categories. Agreement on axial location of the herniation was excellent (kappa = 0.81). There was disagreement between left or right side in only 3.3% of cases (kappa = 0.93).

CONCLUSION

Radiology reports frequently fail to provide sufficient detail to describe disc herniation morphology. Agreement between MRI readings by clinical spine specialists and radiologists was excellent when comparing herniation vertebral level and location within level, but only fair comparing herniation morphology.