title: MR volumetric assessment of endolymphatic hydrops.
abstract: OBJECTIVE
  We aimed to volumetrically quantify endolymph and perilymph spaces of the inner ear in order to establish a methodological basis for further investigations into the pathophysiology and therapeutic monitoring of Menière's disease.
  
  
  METHODS
  Sixteen patients (eight females, aged 38-71 years) with definite unilateral Menière's disease were included in this study. Magnetic resonance (MR) cisternography with a T2-SPACE sequence was combined with a Real reconstruction inversion recovery (Real-IR) sequence for delineation of inner ear fluid spaces. Machine learning and automated local thresholding segmentation algorithms were applied for three-dimensional (3D) reconstruction and volumetric quantification of endolymphatic hydrops. Test-retest reliability was assessed by the intra-class coefficient; correlation of cochlear endolymph volume ratio with hearing function was assessed by the Pearson correlation coefficient.
  
  
  RESULTS
  Endolymph volume ratios could be reliably measured in all patients, with a mean (range) value of 15% (2-25) for the cochlea and 28% (12-40) for the vestibulum. Test-retest reliability was excellent, with an intra-class coefficient of 0.99. Cochlear endolymphatic hydrops was significantly correlated with hearing loss (r = 0.747, p = 0.001).
  
  
  CONCLUSIONS
  MR imaging after local contrast application and image processing, including machine learning and automated local thresholding, enable the volumetric quantification of endolymphatic hydrops. This allows for a quantitative assessment of the effect of therapeutic interventions on endolymphatic hydrops.
  
  
  CONCLUSIONS
  • Endolymphatic hydrops is the pathological hallmark of Menière's disease. • Endolymphatic hydrops can be visualized by locally enhanced ultra-high-resolution MR imaging. • Computer-aided image processing enables quantification of endolymphatic hydrops. • Endolymphatic hydrops correlates with hearing loss in patients with Menière's disease. • Therapeutic trials in Menière's disease can be monitored with this quantitative approach.
authors.affiliation: Department of Otorhinolaryngology Head and Neck Surgery, Grosshadern Medical Centre, University of Munich, Marchioninistr. 15, 81377, Munich, Germany, rguerkov@med.uni-muenchen.de.
authors.forename: R
authors.initials: R
authors.lastname: Gürkov
authors.forename: A
authors.initials: A
authors.lastname: Berman
authors.forename: O
authors.initials: O
authors.lastname: Dietrich
authors.forename: W
authors.initials: W
authors.lastname: Flatz
authors.forename: C
authors.initials: C
authors.lastname: Jerin
authors.forename: E
authors.initials: E
authors.lastname: Krause
authors.forename: D
authors.initials: D
authors.lastname: Keeser
authors.forename: B
authors.initials: B
authors.lastname: Ertl-Wagner
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D007758:Ear, Inner / Q000473:pathology*; D018159:Endolymphatic Hydrops / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results