Comparison between high-resolution 3D-IR with real reconstruction and 3D-flair sequences in the assessment of endolymphatic hydrops in 3 tesla.

BACKGROUND: The main sequences used to assess degree of endolymphatic hydrops (EH) are the 3D- inversion-recovery (IR) with real reconstruction and the 3D- fluid-attenuated inversion recovery (FLAIR). OBJECTIVES: The purpose of this study is to describe and compare both sequences. MATERIAL AND METHODS: Forty-two consecutive patients diagnosed with probable or definite Ménièr´s disease were referred for hydrops MR examination. Vestibular and cochlear EH in both sequences were read by two independent radiologists, unaware of the patient's clinical status. The primary study endpoint was the concordance in the hydrops detection and severity with both imaging sequences. This was assessed using the Cohen's kappa Κ statistic for disease grading and Pearson Χ2 test to test the difference in detection rates of hydrops. Statistical significance was defined as two-sided p < .05. RESULTS: We obtained an excellent overall concordance, with a kappa of 0.821, (p < .001) when comparing hydrops detection. The degree of concordance is higher in vestibular hydrops than in cochlear hydrops. The 3D-IR sequence detected more hydrops than the 3D FLAIR, (62 vs. 39.5%, p < .03). CONCLUSION: The 3D-IR sequence seems to be superior to the 3D-FLAIR for the assessment of EH. Significance: The 3D-IR sequence should be considered as a standalone parameter for a shorter and optimized EH magnetic resonance imaging protocol.

Detailed MR imaging assessment of endolymphatic hydrops in patients with SLC26A4 mutations.

OBJECTIVE: Mutations in SLC26A4 represent the second most common mutations in deafness patients. The majority of patients with SLC26A4 mutations have a large vestibular aqueduct (LVA). Recently, some reports showed the presence of endolymphatic hydrops (ELH) in patients with LVA on the basis of high-resolution enhanced 3T-MRI. However, detailed evaluation has not been performed. We provide the first report on ELH in LVA patients with biallelic SLC26A4 mutations. In this study, we focused on 1) the findings of ELH in LVA patients with biallelic SLC26A4 mutations, and 2) the findings of the endolymphatic duct (ED) and endolymphatic sac (ES) by using two different gadodimide (Gd) enhancement methods. SUBJECTS AND METHODS: Five patients with SLC26A4 mutations underwent enhanced 3T-MRI using the intratympanic (IT) or intravenous (IV) injection of Gd for the diagnosis ELH. RESULTS: All of the patients had ELH in at least one ear. ELH was identified in the vestibule (8/10 ears) as well as in the cochlea (7/10 ears). With regard to the ED and ES, all ears for which MRI was performed with an IT injection of Gd had black areas in the ES or VA or both; however, all of the ears receiving an IV injection had no black areas and were well enhanced. CONCLUSIONS: A majority of the patients had severe ELH in the cochleo-vestibular endolymph, with two different patterns observed in the MRI findings of the ED and ES.

Assessment of endolymphatic hydrops and otolith function in patients with Ménière's disease.

Ménière's disease is associated with hydrops of the inner ear endolymphatic space, and histopathologically, the cochlea and vestibule are usually involved. We used gadolinium-enhanced magnetic resonance imaging and measured cervical and ocular vestibular evoked myogenic potentials and the gain in the utricular induced linear vestibulo-ocular reflex to test the hypothesis that vestibular hydrops in Ménière's disease patients is associated with otolith organ dysfunction. We evaluated 21 patients diagnosed with unilateral definitive Ménière's disease using gadolinium magnetic resonance imaging to detect endolymphatic hydrops in the cochlea and vestibule. Cervical and ocular vestibular evoked myogenic potentials and the gain in utricular induced linear vestibulo-ocular reflex during eccentric rotation were measured to assess otolith organ function. For eccentric rotation, patients were rotated while displaced from the axis of rotation, while linear acceleration stimulated the utricle and induced the vestibulo-ocular reflex. Magnetic resonance imaging revealed vestibular hydrops in 14 of 20 patients (70%). Among the 14 patients, ten (71%) had abnormal cervical and three (21%) had abnormal ocular vestibular evoked myogenic potentials. Four patients (4/21, 19%) had abnormal linear vestibulo-ocular reflexes, three of whom also had abnormal ocular vestibular evoked myogenic potentials. Overall, 16 of 17 patients had normal linear vestibulo-ocular reflexes and normal ocular vestibular evoked myogenic potentials. Vestibular endolymphatic hydrops in Ménière's disease patients caused otolith organ dysfunction, mainly in the saccule. The number of Ménière's disease patients with abnormal ocular vestibular evoked myogenic potentials was low (19%), and they also had abnormal utricular induced linear vestibulo-ocular reflexes.

Vestibular pneumolabyrinth: why assessment with temporal bone computed tomography utilizing dynamic focal spot mode is important for the diagnosis.

We present an interesting and relatively uncommon case of vestibular pneumolabyrinth in a young child post-trauma. His initial clinical exam and imaging studies of the head and cervical spine were negative. He subsequently developed nystagmus and a dedicated temporal bone study demonstrated a subtle fracture and vestibular pneumolabyrinth. Temporal bone fractures can be difficult to appreciate, and therefore, associated findings of fluid in the middle ear, stapes dislocation, or vestibular pneumolabyrinth must be carefully evaluated. Temporal bone computed tomography is a high resolution study, utilizing dynamic focal spot mode which leads to increased sampling and resolution, thereby reducing aliasing artifacts but a longer scan time and increased radiation dose. CT head and cervical spine normally obtained without using this technique leads to aliasing artifacts where even the normal endolymph in the inner ear structures appear hypodense mimicking pneumolabyrinth, thereby obscuring true pneumolabyrinth. It is important to be aware of this finding and technique-related artifact, if a temporal bone injury is suspected, to ensure an earlier diagnosis and optimum management.

Assessment of the reuniting duct by three-dimensional CT rendering.

CONCLUSION: The rendering strategy sometimes induces misunderstanding of the image. We demonstrated a more accurate image of the bony groove of the reuniting duct using three-dimensional (3D) cone beam CT image, which was less affected by artifacts created by the rendering effect. OBJECTIVE: To obtain a suitable image of the groove of the reuniting duct for future morphological study. MATERIALS AND METHODS: The grooves of reuniting ducts in 10 healthy human subjects were analyzed by cone beam CT in comparison with a cadaver study. RESULTS: We could obtain more accurate 3D CT images of the bony groove in human subjects by checking the landmarks of 3D CT images.

Assessment of changes in cochlear function with pneumolabyrinth after middle ear trauma.

OBJECTIVE: To describe a case of pneumolabyrinth secondary to tympanic membrane/ossicular trauma and the subsequent recovery of sensorineural hearing loss managed with conservative measures. PATIENTS: A 15-year-old boy presented to an outside hospital with signs and symptoms of acute hearing loss, vertigo, and tinnitus after penetrating injury to his right tympanic membrane. In addition, computed tomography demonstrated air density within the vestibule. INTERVENTIONS: The patient was managed conservatively with bed rest, avoidance of straining, corticosteroids, and antibiotics. MAIN OUTCOME MEASURES: Computed tomography, audiologic testing. RESULTS: Patient recovered near-normal hearing subjectively. There was closure of the air-bone gap (