[Is facial nerve visible on magnetic resonance imaging?].

The internal architecture of the parotid gland was studied by nuclear magnetic resonance (NMR) imaging, particular attention being paid to the intra-parotid portion of the facial nerve. Currently available apparatuses provide high resolution images of previously poorly elucidated anatomic details. Certain authors consider that images in the axial plane in T1 allow direct visualization of the facial nerve and its branches in the form of low frequency linear signals within the gland. The present study, based on radio-anatomic correlations and date determined in a healthy volunteer, demonstrated that these structures correspond in fact to segments of the excretory canal tree, the facial nerve and its branches being invisible on NMR imaging. It is not possible, therefore, to determine the location of a parotid tumor in relation to these nerve elements using this imaging technique.