Nagy Naguib Naeem Naguib MD, MSc, Presenter: Nothing to Disclose

Ahmed Fathy Emam MBBCh, Abstract Co-Author: Nothing to Disclose

Nour-Eldin Abdelrehim Nour-Eldin MD, MSc, Abstract Co-Author: Nothing to Disclose

Tatjana Gruber-Rouh, Abstract Co-Author: Nothing to Disclose

Boris Bodelle MD, Abstract Co-Author: Nothing to Disclose

Marc Harth, Abstract Co-Author: Nothing to Disclose

Thomas Lehnert MD, Abstract Co-Author: Nothing to Disclose

Thomas Josef Vogl MD, PhD, Abstract Co-Author: Nothing to Disclose

To assess the reproducibility of the volumetric assessment of the inner ear using three dimensional (3D) reconstruction of the high resolution MR-Imaging (HR-MRI) sequences.

The study was retrospectively performed on 50 patients (F=27, M=23) with a mean age of 53.3 years. Patients were referred for MRI due to different disorders of the inner ear. HR-MRI was performed using a T2-weighted SPACE sequence with 0.6 mm slice thickness. 3D reconstructions were performed using Advantage Workstation. Assessed were the volumes of both inner ears together, of each side alone, of the cochlea & of the vestibular system. All volume measurements were performed twice. To avoid possible Bias the time interval between both measurements was 1 year & the previous results were not accessible during the second evaluation (blinded). The agreement between both results was tested using intra-class correlation (ICC) test.

For the first assessment the mean volume of both inner ears together was 1.01 cm3 +/-0.13 (Range: 0.69–1.33), of each inner ear alone 0.5 cm3 +/-0.07 (Range: 0.32–0.71), of the cochlea 0.17 cm3 +/-0.024 (Range: 0.13–0.23) & of the vestibular system 0.33 cm3 +/-0.06 (Range: 0.19-0.49). For the second assessment the mean volume of both inner ears together was 0.99 cm3 +/-0.11 (Range: 0.79–1.27), of each inner ear alone 0.5 cm3 +/-0.06 (Range: 0.38–0.66), of the cochlea 0.17 cm3 +/-0.025 (Range: 0.13–0.26) & of the vestibular system 0.33 cm3 +/-0.05 (Range: 0.23-0.45). ICC analysis showed a statistically significant (p<0.0001) excellent agreement for volumetric assessment of both inner ears together (ICC-Coefficient=0.82, Confidence Interval (CI) 95%) and of the cochlea (ICC-Coefficient=0.88, CI 95%). A statistically significant (p<0.0001) substantial agreement for volumetric assessment of each side alone (ICC-Coefficient=0.79, CI 95%) and of the vestibular system (ICC-Coefficient=0.7, CI 95%) was noted.

Volumetric assessment of the inner ear using 3D reconstruction of HR-MRI is a reproducible method with statistically significant excellent agreement for volumetric assessment of both sides together and cochlea and substantial agreement for each side alone and vestibular system.

The reproducibility of the volumetric assessment makes it possible to introduce 3D volume assessment of the inner ear as one of the MRI assessment parameters for patients presenting with inner ear disorders.

Naguib, N, Emam, A, Nour-Eldin, N, Gruber-Rouh, T, Bodelle, B, Harth, M, Lehnert, T, Vogl, T, Reproducibility of Volumetric Assessment of the Inner Ear using Three Dimensional Reconstruction of the High Resolution MRI Sequence.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14014817.html