Conjoined lumbosacral nerve roots: direct demonstration on MR neurography.

Indirect signs of conjoined nerve roots have been well described on conventional lumbar spine magnetic resonance imaging. Direct demonstration of developmentally united nerve roots makes it quite easily appreciable on MR neurography imaging and has not been described before. We report two cases of conjoined nerve roots and their imaging appearances on three-dimensional magnetic resonance neurography. A brief description of the imaging technique and relevance of these anatomic variants is discussed.