Visualization of endolymphatic hydrops after intratympanic injection of GD-DTPA: Comparison of 2D and 3D real inversion recovery imaging

Abstract

Purpose: Endolymphatic hydrops of Meá nieà re's disease has been visualized after in-tratympanic injection of gadopentetate dimeglumine (Gd-DTPA) using a 3-dimensional (3D) inversion-recovery sequence with real reconstruction (3D real IR). This technique enables diŠerentiation 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. Materials and Methods: We investigated 10 ears in 9 patients with suspected Meá nieà re's disease. Twenty-four hours after intratympanic administration of 8-fold diluted Gd-DT-PA, we obtained 3D and 2D real IR images as well as magnetic resonance (MR) cistern-ography 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. Results: 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). Conclusion: Endolymphatic hydrops in Meá nieà re's disease can be evaluated with 2D as well as 3D real IR and in a shorter scan time.