Tsutomu Nakashima1, Masaaki Teranishi1, Makoto Sugiura1, Michihiko Sone1, Hideo Hayashi1, Shinji Naganawa2

1Department of Otorhinolaryngology, Nagoya University, Nagoya, Japan/2Department of Radiology, Nagoya University, Nagoya, Japan

■ OBJECTIVE: Image diagnosis of endolymphatic hydrops may be a key to understanding inner ear diseases such as Meniere’s disease or fluctuating sensorineural hearing loss. We have reported on the  visualization of endolymphatic hydrops in patients with Meniere’s disease (Laryngoscope 117: March 2007). In the present study, we attempted to obtain clearer endolymphatic space images.

■ METHODS: Gadodiamide hydrate was diluted with saline (v/v 1:7 or 1:15). The diluted gadodiamide hydrate was injected intratympanically through the tympanic membrane using a 23 G needle and a 1 mL syringe. Magnetic resonance (MR) imaging was performed with a 3 Tesla MR unit (Trio, Siemens). Three-dimensional fluid-attenuated inversion recovery (FLAIR) and 3-D real imaging recovery (IR) were performed. The subjects for this study included 20 patients with various inner ear diseases, such as Meniere’s disease, idiopathic sudden sensorineural hearing loss, fluctuating hearing loss without vertigo, episodic vertigo without hearing loss, enlarged vestibular aqueduct. The protocol of this study was approved by the Ethics Review Committee of our university.

■ RESULTS: Endolymphatic hydrops was observed in patients with Meniere’s disease or fluctuating hearing loss without vertigo. In a patient with an enlarged vestibular aqueduct, the gadolinium, which was administered intratympanically after hearing deterioration, was observed in the enlarged endolymphatic sac. In this patient, the gadolinium moved into the endolymphatic space from the perilymphatic space, and rupture of Reissner’s membrane was suspected. Three-dimensional real IR allowed visualization of the endolymphatic space even in the apical turn. No adverse effects of the intratympanic injection of gadolinium were observed.