Time Course for Measuring Endolymphatic Size in Healthy Volunteers Following Intravenous Administration of Gadoteridol

Abstract

Purpose: We developed semi-quantitative methods to measure endolymphatic size on images obtained 4 hours after intravenous administration of single-dose gadolinium-based contrast medium (IV-SD-GBCM) and found little variation in results between observers. We used the methods to measure the size of the endolymph in healthy volunteers at various times after IV-SD-GBCM and attempted to determine the optimal timing for the evaluation.Methods: In 8 healthy male volunteers, we obtained heavily T 2 -weighted 3-dimensional fluid-attenuated inversion recovery (hT 2 W-3D-FLAIR) images 1.5, 3, 4.5, and 6 hours after IV-SD-GBCM as positive perilymph images (PPI) as well as acquiring positive endolymph images (PEI) and magnetic resonance cisternography (MRC). To evaluate the endolymph, we generated 2 kinds of processed images (HYDROPS-Mi2 and HY-DROPS2-Mi2) by subtracting PEI or MRC from PPI as previously proposed. We semiquantitatively measured the ratio of the area of the endolymph (%EL) to that of total lymph on the 2 kinds of generated images for the cochlea and vestibule according to the previously proposed method. We analyzed statistics to evaluate the change in %EL over time and used analysis of variance (ANOVA) for a 2 © 4 repeated-measures design to assess difference in image type. We adopted 5% as a significance level.Results: The %EL was significantly larger at 1.5 hours after IV-SD-GBCM than at 3, 4.5, and 6 hours in both the cochlea and vestibule for both kinds of generated images. Between 4.5 and 6 hours, the %EL plateaued for both the cochlea and vestibule, and the 2 kinds of generated images did not differ significantly.Conclusion: A delay of 1.5 hours after IV-SD-GBCM is not sufficient to evaluate endolymphatic size. The %EL plateaus between 4.5 and 6 hours. These data might be valuable for further clinical studies.

Visualization of endolymphatic hydrops with MR imaging in patients with Ménière’s disease and related pathologies: current status of its methods and clinical significance

“…Advantages and disadvantages of the IV-Gd and IT-Gd methods are summarized in Table 1 [9,31,56,57]. The typical scan parameters used recently with the IV-Gd method 4 h after IV-SD-GBCM are shown in Table 2 [58,59].…”

Imaging of Endolymphatic Hydrops in 10 Minutes: A New Strategy to Reduce Scan Time to One Third

“…13 We employed a constant value of 0.04 according to a recent study. 14 We transferred MR images by CD-ROM to an iMac personal computer (Apple Computer, Inc., Cupertino, CA, USA) with a free DICOM viewer (OsiriX image software, ver. 5.8 32 bit; downloadable at http://www.osirix-viewer.com/ index.html), which allowed easy pixel-by-pixel multiplication between the image series in a few seconds.…”

Improved HYDROPS: Imaging of Endolymphatic Hydrops after Intravenous Administration of Gadolinium

“…It might be also possible to widen the appropriate scan time window for the endolymphatic hydrops evaluation, which is currently between 3–6 hours. 11 The PPI is also expected to be a tool to evaluate the glymphatic system by analyzing the enhancement of the cerebrospinal fluid and the fluid in the perivascular space of the basal ganglia. 12 The increased sensitivity of the PPI to low concentrations of GBCA in fluid might be useful for the evaluation of the glymphatic system.…”