Imaging of endolymphatic hydrops in Meniere's disease at 1.5 T using phase-sensitive inversion recovery: (1) demonstration of feasibility and (2) overcoming the limitations of variable gadolinium absorption.

ABSTRACT

Endolymphatic hydrops is the primary histopathological finding in Meniere's disease. We demonstrate the feasibility of imaging endolymphatic hydrops at 1.5 T using phase-sensitive inversion recovery (PS-IR) MRI following intratympanic injection of gadolinium (Gd). PS-IR data were imaged using real reconstruction to enable visualization of the phase of the signal permitting clear definition between bone, unopacified endolymph and perilymph. Data were obtained 24h following injection in 2 control subjects and in 13 successive patients with Meniere's disease. In 11 out of 13 patients, dilated endolymphatic structures were clearly identified as filling defects within the opacified perilymph allowing identification of endolymphatic hydrops. There was a large range in the degree of perilymphatic signal enhancement due to variability in absorption of Gd from the middle ear into the perilymph. The use of multiple TI values allowed confident identification of endolymphatic hydrops in Meniere's patients even when perilymph opacification was suboptimal at one TI value. This is the first time endolymphatic hydrops has been demonstrated at 1.5 T in humans. The methods presented are of significant practical importance and will permit broader application of endolymphatic imaging and may also act to reduce the frequency of failed exams due to inadequate Gd uptake.