Endolymphatic Sac Assessed by 3D Cone Beam CT in Ménière Disease

Abstract

Objective: The poster introduces new 3D Cone-beam CT (CBCT) images of endolymphatic sac (ELS). The volume rendering provides realistic image of ELS in relation to the semicircular canal, enabling one to assess location, size, and shape preoperatively. The results are compared with operative findings to confirm clinical values of the new imaging technology. Method: The 3D Cone-beam CT images of the 12 patients with Ménière diseases who underwent an endolymphatic mastoid shunt operation between 2008 and 2011 were obtained at our hospital. We assessed location, size, and shape of the ELS. The results of preoperative assessments were compared with the operational findings. Results: First we present clear and sharp 3D pictures of ELS and the semicircular canal using volume rendering incomparable to conventional CT. In 11 patients, the ELS was located exactly along the Donaldson line. In one patient, it was located inferiorly to the line. Size of the ELS was moderate in 6 patients, small in 5, and exceedingly small in 1. Cross section of the sac was circular in 3 patients, oval and flat in 8, and unverified in 1 because the size was too small. The above findings agree with the operational findings closely. Conclusion: In 3D Cone-beam CT, we could get more informative and better quality images than in conventional CT. Thanks to the preoperative realistic 3D images of ELS and the semicircular canal, we could perform the sac operation more safely and easily. Imaging information thus obtained may help deepen the understanding of Ménière’s disease.