THE VEINS OF THE MEDULLA-OBLONGATA - MRI CROSS-SECTIONAL ANATOMY

Magnetic resonance imaging (MRI) has progressively become the major or even the only imaging procedure for displaying the vascular relations hips of the brainstem in the context of infra-tentorial lesions. In or der to assess the MR sectional anatomy of the bulbar vv. 40 normal pat ients were examined in the MR axial, frontal and sagittal planes after gadolinium IV injection. The bulbar venous networks were inconstantly visualised: anterior vv. (16%). posterior (3%), lateral (8%). The vei n of the lateral recess of the fourth ventricle was constant in the th ree planes; the inferior petrosal sinus could be seen in 82% of cases. Their relation with the posterior fossa structures are emphasised and discussed.