Visualization of Endolymphatic Hydrops after Intratympanic Injection of Gd-DTPA: Comparison of 2D and 3D Real Inversion Recovery Imaging

Abstract

Endolymphatic hydrops of Ménière's disease has been visualized after intratympanic injection of gadopentetate dimeglumine (Gd-DTPA) using a 3-dimensional (3D) inversion-recovery sequence with real reconstruction (3D real IR). This technique enables differentiation of bone and endo- and perilymph space on a single image but requires 15 min of scan time. Therefore, we compared it with 2D real IR, which is faster. We investigated 10 ears in 9 patients with suspected Ménière's disease. Twenty-four hours after intratympanic administration of 8-fold diluted Gd-DTPA, we obtained 3D and 2D real IR images as well as magnetic resonance (MR) cisternography at 3 tesla. Three radiologists independently graded the degree of endolymphatic hydrops according to previously proposed criteria. Contrast-to-noise ratio (CNR) between peri- and endolymph was measured. We could evaluate the degree of endolymphatic hydrops in 9 cochleas and 10 vestibules but not in a tenth cochlea, which was too faintly enhanced on both 2D and 3D real IR. Grading of all evaluated cochleas and vestibules agreed completely among the 3 radiologists. Evaluation on 2D real IR and 3D real IR also agreed completely. Mean CNR was significantly higher on 3D than 2D real IR (P<0.05), and CNR on both correlated significantly (r = 0.872). Endolymphatic hydrops in Ménière's disease can be evaluated with 2D as well as 3D real IR and in a shorter scan time.