As with any imaging modality, there are limits to sensitivity and individual variation. To be effective, it is often necessary to image a very limited area of the body. If the imaging test is to be effective, the ordering physician must have a very strong suspicion of the particular area of the body most worth imaging. In many cases, the MRN technique does not adequately suppress images from small blood vessels and this can lead to lack of certainty in nerve identification. This problem is an area of very active research and a number of good solutions will be available soon.
False positives can occur.
It is essential for any abnormality observed on an MRN imaging study to be carefully correlated with the patient's symptoms, exam and possibly also electrophysiologic findings. In many cases, image directed injections are required to confirm the relevance of a pathology suspected from an image finding. Finally, it is most important for physician and patient to understand the MR Neurography is optimized for the imaging of nerves as a single tissue. Although nerve tumors are well seen, other types of tumors, bone degenerative disease, and other conditions are best evaluated by existing traditional methods optimized for those tissue. MR Neurography is the best way to obtain images of nerves but is not the best way to observe other tissues.