title: Simple Estimation of the Endolymphatic Volume Ratio after Intravenous Administration of a Single-dose of Gadolinium Contrast.
abstract: OBJECTIVE
  To evaluate the feasibility of a simple estimation for the endolymphatic volume ratio (endolymph volume/total lymph volume = %ELvolume) from an area ratio obtained from only one slice (%EL1slice) or from three slices (%EL3slices). The %ELvolume,calculated from a time-consuming measurement on all magnetic resonance (MR) slices, was compared to the %EL1sliceand the %EL3slices.
  
  
  METHODS
  In 40 ears of 20 patients with a clinical suspicion of endolymphatic hydrops, MR imaging was performed 4 hours after intravenous administration of a single dose of gadolinium-based contrast material (IV-SD-GBCM). Using previously reported HYDROPS2-Mi2 MR imaging, the %ELvolumevalues in the cochlea and the vestibule were measured separately by two observers. The correlations between the %EL1sliceor the %EL3slicesand the %ELvolumevalues were evaluated.
  
  
  RESULTS
  A strong linear correlation was observed between the %ELvolumeand the %EL3slicesor the %EL1slicein the cochlea. The Pearson correlation coefficient (r) was 0.968 (3 slices) and 0.965 (1 slice) for observer A, and 0.968 (3 slices) and 0.964 (1 slice) for observer B (P < 0.001, for all). A strong linear correlation was also observed between the %ELvolumeand the %EL3slicesor the %EL1slicein the vestibule. The Pearson correlation coefficient (r) was 0.980 (3 slices) and 0.953 (1 slice) for observer A, and 0.979 (3 slices) and 0.952 (1 slice) for observer B (P < 0.001, for all). The high intra-class correlation coefficients (0.991-0.997) between the endolymph volume ratios by two observers were observed in both the cochlea and the vestibule for values of the %ELvolume, the %EL3slicesand the %EL1slice.
  
  
  CONCLUSIONS
  The %ELvolumemight be easily estimated from the %EL3slicesor the %EL1slice.
authors.affiliation: Department of Radiology, Nagoya University Graduate School of Medicine.
authors.forename: Shinji
authors.initials: S
authors.lastname: Naganawa
authors.forename: Mai
authors.initials: M
authors.lastname: Kanou
authors.forename: Toshio
authors.initials: T
authors.lastname: Ohashi
authors.forename: Kayao
authors.initials: K
authors.lastname: Kuno
authors.forename: Michihiko
authors.initials: M
authors.lastname: Sone
mesh_terms: D061605:Administration, Intravenous; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003051:Cochlea / Q000000981:diagnostic imaging; D003287:Contrast Media / Q000008:administration & dosage*; D003937:Diagnosis, Differential; D004710:Endolymph / Q000000981:diagnostic imaging*; D018159:Endolymphatic Hydrops / Q000000981:diagnostic imaging; D005240:Feasibility Studies; D005260:Female; D005682:Gadolinium / Q000008:administration & dosage; D006571:Heterocyclic Compounds / Q000008:administration & dosage*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008196:Lymph / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008575:Meniere Disease / Q000000981:diagnostic imaging; D008875:Middle Aged; D009942:Organometallic Compounds / Q000008:administration & dosage*; D014722:Vestibule, Labyrinth / Q000000981:diagnostic imaging
chemical_list: D003287:Contrast Media; D006571:Heterocyclic Compounds; D009942:Organometallic Compounds; C062402:gadoteridol; D005682:Gadolinium