Magnetic resonance imaging of endolymphatic hydrops: a comparison of methods with and without gadolinium-based contrast agent administration

In the evaluation of endolymphatic hydrops (EH) using magnetic resonance (MR) imaging, hybrid of reversed image of positive endolymph signal and native image of perilymph signal multiplied with heavily T2-weighted MR cisternography (HYDROPS-Mi2) imaging with the intravenous administration of a gadolinium-based contrast agent (IV-GBCA) has been utilized. Recently, MR cisternography (MRC) without GBCA has been proposed as a potential alternative method. However, the feasibility of EH evaluation by MRC without GBCA has not been established. The present study aimed to compare HYDROPS-Mi2 imaging with IV-GBCA to MRC without IV-GBCA for the evaluation of EH. In 40 ears of 20 patients with clinically suspected EH, MRC at pre-IV-GBCA and HYDROPS-Mi2 images from 4 h post-IV-GBCA were analyzed. The saccular height on the MRC (SH-MRC) was measured. The percentage of the volume of the endolymphatic space within the whole lymphatic space of the vestibule on the HYDROPS-Mi2 image (%EL(volume)-HYD) was measured. The correlation between the SH-MRC and %EL(volume)-HYD was calculated. The receiver operating characteristic (ROC) of the SH-MRC and %EL(volume)-HYD for the clinical diagnosis of EH was evaluated. The Spearman’s rank correlation coefficient between the SH-MRC and %EL(volume)-HYD was 0.102. The areas under the ROC curve were 0.570 for the SH-MRC, and 0.926 for the %EL(volume)-HYD. In conclusion, there was no significant correlation between the MRC without IV-GBCA and the HYDOROPS-Mi2 with IV-GBCA in the evaluation of EH.