Problem To non-invasively measure in-vivo human inner ear by MRI and measure the geometry of vestibule by the reconstructed 3D model of inner ear for further diagnosis of large vestibular aqueduct syndrome (LVAS). Methods 3-T MR scanner, MAGNETOM Trio made by Siemens, was utilized. The TR/TE for MR imaging of 7 patients was 5.65/2.6 ms and the voxel size was 0.5 mm X 0.5 mm X 0.5 mm for single slice of 48 slices. The configuration of semicircular canals, vestibule and cochlea could be detected by threshold. The 3D geometry of inner ear was then computed based on the thickness of slice. Results The surface area and volume of semicircular canals for 7 normal ears were 217.85 square mm and 63.56 cubic mm; of vestibule were 105.88 square mm and 56.36 cubic mm; of cochlea were 171.84 square mm and 81.29 cubic mm respectively. The variation of volumes of vestibule and cochlea could be quantified non-invasively. The correlation between the volume and the level of LVAS will be analyzed once the number of volunteer reaches a statistically significant level. Conclusion The variation for the geometry of vestibule could be measured non-invasively. The grade of LVAS can be assessed by the obtained 3D model of semi-circular canal, vestibule and cochlea. Significance According to the 3D model, the geometry of inner ear can be measured, and the syndrome can be revealed directly to help clinical diagnosis of LVAS more accurately.
Marching Cubes and Histogram Pyramids for 3D Medical Visualization
