Study Of Reconstructing The Sagittal Images And Correlative Measurements For The Vestibular Aqueduct By MPR Using Multislice CT

Purpose To reconstruct the sagittal images of the vstibular aqueduct with multi-slice CT(MSCT)isotropic scanning by using multiplanar reformation (MPR).To measure the midpoint width,external opening width and length of the vstibular aqueduct,establish normative measurements and explore their discipline.Materials and methods Collecting 197 cases(101 men,96 women),394 ears.Age range 3 months to 82 years.We classified the cases into four groups by age:infant group,children group,adolescent group and adult group.Examining the temporal bone with multislice CT isotropic scanning and postprocessing the source images by using MPR in multislice CT.Analyzing the measurements we used SPSS(Statistics Package for Social Science)13.0 for windows.T-test was applied between sex,between groups and between laterity.Between groups we used one-way ANOVA.The demonstrating ratio for the panograma of the vestibular aqueduct and measuring ratio were tested with X~2 test.Statistical significance was assigned to a probability level of less than 0.05.Results1.The reconstucted sagittal images of the vstibular aqueduct by multislice CT with MPR was better in showing and measuring the vestibular aqueduct.the ratio of the sagittal images for showing,demonstrating the whole and measuring were respectively:97.7%,74.5%and 86%.About 25.5%of the long axes for the vestibular aqueduct didn't parallel to the sagittal plane of body.2.Whether between sex or between laterity,the analysis of the parameters for the vestibular aqueduct had no statistical significance(p＞0.05).between groups the statistical significance of the external opening width and length was shown(p＜0.05). That of the midpoint width didn't appeared(p＞0.05).3.The normative distribution for the vestibular aqueduct midpoint width was: 0.49～0.89mm.the length and external opening width for the infant group,the children group and 9-year -later group were respectively:1.38～6.04mm,2.88～7.57mm;3.33～8.30mm.0.50～0.90mm,0.56～0.96mm,0.54～1.12mm.Conclusion:1.For the first time,the approach with multislice CT isotropic scanning and MPR post-processing created the sagittal images,which could better show and measure the vstibular aqueduct.About 25.5%of the long axes for the vestibular aqueduct didn't parallel to the sagittal plane of body.2.The normative data of the vestibular aqueduct midpoint width,the length and external opening width for the vstibular aqueduct were established on sagittal reformats.3.In the meantime,we foud that:(1)The statistical result verified that postnatal development of the vestibular aqueduct was correct.(2)The length and the external opening could better show postnatal development of the vestibular aqueduct.(3)The midpoint width didn't altered or changed so little that we could not detect after coming to the world.(4)Our results rejected that the vstibular aqueduct developed maturely until three or four years old.it maybe grew up around nine years old.(5)The midpoint width was more suitable than the length or external openin width for the diagnostic parameter of the vestibular aqueduct dilatation. (6)The vestibular aqueduct with midpoint widths of 1.0 or greater should be considered enlargement.