Imaging Study And Application Of Inner Ear With Magnetic Resonance Hydrography Technique

Objective:To probe into the advantage and disadvantage of the three kinds of post-processing method of Magnetic resonance hydrography(MRH)technology, i.e. Mutiplanar reformatibn(MPR), Maximum intensity 1 rojection(MIP) and Volume rendering(VR). Thus choose simple reasonable and effective scanning sequence and best post-processing method for different reasons SNHL, to offer the objective imaging basis for clinic non-invasive evaluation of inner ear. Methods:we performed high-resolution three-dimensional turbo spin echo T2 weighted image (3D TSE T2WI) axial scanning with 3D TSE T2WI and then performed bilateral oblique plan sagittal scanning with 3D TSE T2WI to 80 normal adults and 45 clinically suspected SNHL patients of inner ear. Then performed T1WI axial scanning to 45 patients, if we found abnormal in T1WI, we must performed enhanced T1WI scanning to them.After the data acquisition we transmitted them to the workstation for 2 or 3-dimensional reconstruction in MPR, MIP and VR by ViewForum. The ability of MPR, MIP and VR to showing and measuring anatomic structures in inner ear was studied. Results:(1) Subtle anatomical structure of cochleovestibular nerve, facial nerve and inner ear membrane labyrinth could be clearly shown in 160 ears of 80 eases. (2) There were post-procession-related differences in three semicircular canal height and diameter of uppe,lateral semicircular canal, VR, MIP image quality difference was statistically significant, the ability of VR,MIP and MPR display the structure of inner and neural is differences and statistically significant; (3) In 45 cases,9 cases were found to be abnormal by using MRI (positive rate abnalout 20%). There were 7 kinds of diseases in these cases. Amongthese abnormal cases, a congenital abnormality-large vestibular aqueduct (3 cases) was the most common disease happened in children. Conclusion:(1) MRI can intuitively and three-dimensionally display the refined structures of the membranous labyrinth. It can not be replaced by other methods. (2) MRH is a reliable imaging method for diagnosing sensorineural hearing loss as it is helpful in finding its causes. (3) Compared with the several methods of post-processing, MPR is good to observe the endolymphatic labyrinth and nerves of the labyrinth, VR technology displayed image quality is higher and it is the best way to generally evaluate the inner ear.