Magnetic resonance neurography

The protons and the water molecules of which they are part have subtly different movement characteristics that relate to their biophysical surroundings.

From the time of the first clinical use of MRI in the mid-1970s until 1992, however, despite the active work of many thousands of researchers, there was no reliable method for visualizing nerve.

Filler and Howe discovered that the problem was that most of the image signal in nerves came from protons that were not involved in anisotropic diffusion.

Subsequent research has further demonstrated the biophysical basis for the ability of MR Neurography to show nerve injury and irritation.

The need for long echo times also characterizes the type of inversion recovery fat suppression sequences used for neurography nerve imaging.

Standard spinal MRI only demonstrates the anatomy and numerous disk bulges, bone spurs or stenoses that may or may not actually cause nerve impingement symptoms.

[21] In addition several formal large scale outcome trials carried out with high quality "Class A" methodology[22][23][24] have been published that have verified the clinical efficacy and validity of MR Neurography.

Recent patent litigation concerning MR Neurography has led some unlicensed centers to discontinue offering the technique.

[28] In 2010, RadioGraphics - a publication of the Radiological Society of North America that serves to provide continuing medical education to radiologists - published an article series taking the position that Neurography has an important role in the evaluation of entrapment neuropathies.

[29] Magnetic resonance neurography does not pose any diagnostic disadvantage relative to standard magnetic resonance imaging because neurography studies typically include high resolution standard MRI image series for anatomical reference along with the neurographic sequences.

Although it has been in use for fifteen years and is the subject of more than 150 research publications, most insurance companies still classify this test as experimental and may decline reimbursement, resulting in the need to file appeals.