Aim: To determine any difference which may exist between the interpretation of nerve root compression demonstrated by an MRI scan as assessed by a radiologist compared to a spinal surgeon.

Introduction: There are a few standardized criteria for attempting to quantify the degree of lumbosacral nerve root compression demonstrated by radiological investigations. However, these are not validated and are not commonly employed. It is possible that the interpretation of films by surgeons is different to that by radiologists. If this is the case it could have important consequences, particularly if potential surgical targets are not recognised. We sought to investigate this potential discrepancy.

Method: Data from consecutive patients undergoing lumbosacral nerve root decompression, by a single surgeon, between 2002 and 2005 was prospectively analysed. Inclusion criteria were:

uni- or bilateral single level nerve root decompression

The MRI report of these patients was then scrutinised to see if the decompressed nerve root had been reported as significantly compressed on the pre-operative scan.

Results: Only 75 % of films had a formal radiological report. Of reported films 22% had not reported the surgical target which rose to 33% for L5 nerve root compression.

Conclusion: Consideration needs to be given to the potential placebo effect of surgery, the nature of the compressive pathology, the clinical details supplied to the radiologist and how the surgical decision making was made.

However, in this sample a large minority of MRIs had no formal report. Of those that were reported, there was underreporting of potential surgical targets by radiologists. This implies that there could be a high incidence of false negative MRI reporting with potentially treatable conditions being unrecognised.