MR Imaging of the Cochlear Modiolus after Intratympanic Administration of Gd-DTPA

Abstract

Purpose: We evaluated whether enhancement of the cochlear modiolus could be visualized 24 hours after intratympanic injection of gadolinium diethylenetriamine penta-acetic acid (Gd-DTPA) using a 3-dimensional real inversion recovery sequence combined with a 32-channel head coil at 3 tesla. Intratympanic injection of Gd-DTPA has been reported for visualizing endolymphatic hydrops in Meniere's disease, and its use has shown communication between the cochlear perilymph and cerebrospinal ‰uid in the internal auditory canal. Although the cochlear modiolus has been considered the route for this communication, this has not been conˆrmed through direct visualization of its enhancement.Materials and Methods: We qualitatively and quantitatively evaluated the presence of contrast enhancement in the modiolus in 19 patients with clinically suspected endolymphatic hydrops or hearing loss who underwent imaging as described above.Results: The contrast ratio (CR) between the cochlear modiolus and cerebellar white matter on the injected side was 1.09±1.23, and that on the non-injected side was -0.48± 0.38 (Pº0.01). In all subjects, the CR value was larger on the injected than non-injected side, and enhancement of the cochlear modiolus was also recognized visually.Conclusions: Intratympanic Gd-DTPA can be administered to visualize enhancement of the cochlear modiolus and may thereby reveal its functional anatomy.

Variability in the perilymphatic diffusion of gadolinium does not predict the outcome of intratympanic gentamicin in patients with ménière's disease

“…This canalicular system may play a role in the circulation of perilymph in the human cochlea, and from there to the vestibular structures. This fluid exchange pattern is compatible with the findings observed in humans by Kaway et al,33 who visualized increased enhancement of the cochlear modiolus after IT injection of Gad using 3D‐FLAIR turbo spin echo with real reconstruction sequence with high spatial resolution and a 32‐channel head coil at 3 T.…”

MRI With Intratympanic Gadolinium: Comparison Between Otoneurological and Radiological Investigation in Menière's Disease

“…One radiologist graded the hydrops in different parts of the vestibule ( Table 7 ). Contrast medium was observed in the internal auditory canal ( Figure 2 ), demonstrating a communication between CSF and cochlear perilymph as described by Naganawa ( 18 ) and Kawai ( 19 ).…”

Direct Entry of Gadolinium into the Vestibule Following Intratympanic Applications in Guinea Pigs and the Influence of Cochlear Implantation

“…It has previously been assumed that intratympanically applied gentamicin suppressed function of otolith organs and SCC with little effect on hearing by spreading locally from ST to the vestibule in the basal turn (Salt and Plontke 2005, Kawai et al 2010, Naganawa et al 2008, Nakashima et al 2000, Watanabe et al 1971. It was also assumed that to achieve this, the vestibular hair cells were more sensitive to the ototoxic influence of gentamicin than cochlear hair cells (Nakashima et al 2000, Chia et al 2004, BaggerSjoback et al 1990, Wanamaker et al 1998, Aran et al 1995.…”