Correlation of endolymphatic hydrops and perilymphatic enhancement with the clinical features of Ménière's disease.

OBJECTIVES: To use three-dimensional real inversion recovery (3D-real IR) MRI to investigate correlations between endolymphatic hydrops (EH) grades or the degree of perilymphatic enhancement (PE) and clinical features of Ménière's disease (MD), as previous findings have been inconsistent. METHODS: A total of 273 consecutive patients with definite unilateral MD were retrospectively enrolled from September 2020 to October 2021. All patients underwent 3D-real IR and 3D-T2WI 6 h after intravenous gadolinium injection. MD-related symptom duration and vertigo frequency were recorded. EH grades were evaluated, the signal intensity ratio (SIR) was measured, and correlations between clinical features and EH, PE were assessed respectively. RESULTS: The study included 123 males and 150 females, with a mean age of 53.0 years. A longer duration of vertigo was associated with higher cochlear EH grades, whereas the opposite was true for the duration of aural fullness. A longer time since vertigo onset was associated with higher vestibular EH grades; the opposite was true for the duration of individual vertigo attacks. The multiple regression analysis revealed that age, tinnitus duration, and vestibular EH were risk factors for SIR. Furthermore, the low-frequency hearing threshold (HT) was a risk factor for cochlear and vestibular EH, and the SIR. CONCLUSION: The EH grade and SIR (an indicator for the quantitative evaluation of PE) were correlated with clinical features and HT of MD; thus, imaging can be a valuable tool in planning individualised treatment. CLINICAL RELEVANCE STATEMENT: This study revealed that the grade of endolymphatic hydrops and degree of perilymphatic enhancement positively correlates with the length of time since onset of clinical symptoms and hearing thresholds in patients with Ménière's disease, facilitating the tailored treatment. KEY POINTS: • Relationships between 3-dimensional real inversion recovery features and clinical symptoms in Ménière's disease are unknown. • Symptom duration and hearing thresholds correlated with endolymphatic hydrops grades and degree of perilymphatic enhancement. • MRI features correlate with MD severity; thus, imaging is valuable for planning tailored treatment.

MRI can help differentiate Ménière's disease from other menieriform diseases.

It is difficult to distinguish other pathologies mimicking Ménière's disease (MD) clinically. This study aims to investigate the differences of imaging findings and features between MD and other menieriform diseases via intravenous gadolinium-enhanced magnetic resonance imaging (MRI). 426 patients with menieriform symptoms, including MD, vestibular migraine (VM), and vestibular schwannoma (VS), underwent 3D-FLAIR and 3D-T2WI MRI 6 h after the intravenous gadolinium injection. MR images were analyzed for inner ear morphology, perilymphatic enhancement (PE), EH and other abnormalities. EH was observed at a higher rate in MD patients (85.71%) than patients with other menieriform diseases (VM group = 14.75%, VS group = 37.50%). The prevalence of unilateral EH as well as both cochlear and vestibular EH showed significant differences between MD and VM groups. The prevalence of cochlear EH (I and II) and vestibular EH (II and III) was different between MD and VM groups. The prevalence of PE was higher in MD than VM group. The degrees of cochlear and vestibular hydrops were higher in the definite than probable MD group (P < 0.05). Using these imaging features, MRI can be used to help differentiate MD from other menieriform diseases.

[Effects of population density and culture volume on the growth and reproduction of Moina irrasa].

A laboratory experiment was conducted to study the effects of different population density (D1 : 100 ind x L(-1), D2 : 150 ind x L(-1), D3 : 300 ind x L(-1)) and culture volume (V1: 50 mL, V2 : 100 mL, V3 : 400 mL) on the growth and reproduction of Moina irrasa at 25 degrees C. At the same culture density, the body length of the M. irrasa females at their first pregnancy, the first brood, and the total offsprings per female decreased with the increase of culture volumes, while the sex ratio (male/female) of the offsprings was in adverse. At the same culture volumes, the total offsprings per female decreased with the increase of culture density. At D1 V1, the body length of the females at their first pregnancy (0.95 +/- 0.10 mm) and the total offsprings (171.3 +/- 19.8 ind) per female were the maximum. At D3V2, the sex ratio was the maximum (0.54 +/- 0.05). Culture density, culture volume, and their interactions significantly affected the total offsprings per female and the sex ratio (P < 0.001).