Background: It is still challenging to detect endolymphatic hydrops (EH) in patients with Meniere's disease (MD) using MRI. The aim of the present study was to optimize a sensitive technique generating strong contrast enhancement from minimum gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) while reliably detecting EH in the inner ear, including the apex.
Materials and methods: All imaging was performed using a 3.0 T MR system 24 h after intratympanic injection of low-dose Gd-DTPA. Heavily T2-weighted 3-dimensional fluid-attenuated inversion recovery reconstructed with magnitude and zero-filled interpolation (hT2W-FLAIR-ZFI) was optimized and validated in phantom studies and compared with medium inversion time inversion recovery imaging with magnitude reconstruction (MIIRMR). The following parameters were used in hT2W-FLAIR-ZFI: repetition time 14,000 ms, echo time 663 ms, inversion time 2900 ms, flip angle 120°, echo train length 271, and field of view 166 × 196 mm2.
Results: MRI obtained using hT2W-FLAIR-MZFI yielded high-quality images with sharper and smoother borders between the endolymph and perilymph and a higher signal intensity ratio and more homogenous perilymph enhancement than those generated with MIIRMR (p < 0.01). There were predominantly grade II EHs in the cochleae and grade III EHs in the vestibule in definite MD. EH was detected in the apex of 11/16 ipsilateral ears, 3/16 contralateral ears in unilateral definite MD and 3/6 ears in bilateral MD.
Conclusions: The novel hT2W-FLAIR-MZFI technique is sensitive and demonstrates strong and homogenous enhancement by minimum Gd-DTPA in the inner ear, including the apex, and yields high-quality images with sharp borders between the endolymph and perilymph.
Keywords: Endolymphatic hydrops; Enhancement; Image reconstruction; MRI; Meniere’s disease.
© 2021. The Author(s).