Applied Study Of Coronal High-Resolution Computed Temography Image And Thin Coronal Section Specimen In The Middle Ear And Nearly Structures Of Temporal Bone

Objective:To observe morphology character and the adjacent relationship between the high-resolution computed tomography (HRCT) coronal images and thin coronal section slices specimens of all structures within the middle ear and its adjacent structures of the temporal bone. To discuss the anatomical features of HRCT images in the middle ear and its adjacent structure and accumulate Chinese ears coronal HRCT images anatomical data. In order to provide morphological basis and anatomical foundation for imaging diagnosis and surgical treatment of the auriculotemporal pathological changes.Methods:15(30sides) adult's skull specimens were fixed by 10% formalin, experimental specimens use the marked line which was perpendicular with the canthomeatal line(CML) as a basic line of coronal scanning, through using GE Hi-speed N X / i Sys # CT to scan, we can gain the thickness of 1.00 mm HRCT consecutive coronal scan images. After scaning the specimens, then removed brain tissues from the skull. Tissues (80 mm×80 mm×80 mm) were intercepted at the center of temporal bone, and routine decalcified, dehydrated, soaked in collodion, embedded and sliced into 1.00 mm continuous coronal pieces. Then six coronal sections were selected, such as through the anterior part of the head of malleus, the middle part of the head of malleus, 1/3 posterior part of the vertical segment of internal carotid artery, the middle of the transverse crest, the round window niche and the vertical segment of facial nerve (VSFN) and so on. Then some anatomy structures of middle ear and its near part were measured and localized. The data was dealed by SPSS software then get the conclusion.Results:The result of relative qualitative and quantitative investigation of the middle ear and nearly structures of six sections above-mentioned as follow.Through the anterior part head of malleus of coronal HRCT section. The distance from superior border of head of malleus to tegmen tympani was 3.54±1.42 mm( x±s, mm, the same as follow). The distance from wall head of malleus to ganglion geniculatum was 5.46±0.50 mm. The distance from ganglion geniculatum to cochlear was 1.45±0.31 mm. The distance from ganglion geniculatum to tegmen tympani was 3.46±1.52 mm. The distance from inferior border of cochlear to internal carotid canal was 2.96±1.14 mm.Through the middle part head of malleus of coronal HRCT section. The distance from short process of malleus to ganglion geniculatum was 7.40±0.65 mm. The distance from short process of malleus to cochlear was 6.68±0.69 mm. The distance from floor of tympanum to vertical segment of internal carotid artery was 2.42±1.00 mm. The distance from cochlear to medial wall of tympanic cavity was 1.64±0.34 mm.Through the 1/3 posterior part of the vertical segment of internal carotid artery of coronal HRCT section. The distance from labyrinthine segment of facial nerve to cochlear was 0.83±0.21 mm. The distance from labyrinthine segment of facial nerve to arcuate eminence was 4.68±1.32 mm. The distance from horizontal segment of facial nerve to cochlear was 2.83±0.84 mm. The distance from short crus of incus to horizontal segment of facial nerve was 3.08±0.37 mm.Through the middle transverse crest of coronal HRCT section. The length of the internal acoustic meatus left side was 11.85±1.65 mm,right side was 12.67±1.61 mm. The distance from the tip of scute to horizontal facial nerve was 5.57±1.28 mm. The distance from the tip of transverse crest to superior wall of internal acoustic meatus was 1.98±0.33 mm. The distance from the tip of transverse crest to inferior wall of internal acoustic meatus was 2.69±0.37 mm. The distance from lenticular process of incus to oval window was 3.35±0.23 mm. The distance from lenticular process of incus to horizontal facial nerve was 1.87±0.16 mm. The distance from horizontal facial nerve to lateral semicircular canal was 1.06±0.21 mm. The distance from lateral semicircular canal to medial wall of tympanic cavity was 1.26±0.30 mm. The distance from superior semicircular canal to arcuate eminence was 1.21±0.95 mm. The length of the internal acoustic meatus was shorter in the left ears than in the right ears, this difference was satistically significant(P<0.05).Through the round window niche of coronal HRCT section. The distance from facial recess to lateral semicircular canal was 1.96±0.80 mm. The exterior and interior diameter of facial recess was 1.36±0.20 mm. The depth of facial recess was 1.39±0.27 mm. The exterior and interior diameter of pyramidal recess was 1.40± 0.31 mm. The depth of pyramidal recess was 1.67±0.49 mm. The exterior and interior diameter of round window niche was(1.36±0.24)mm. The depth of round window niche was 1.54±0.25 mm. The distance from lateral semicircular canal to mastoid antrum left side was 1.47±0.42 mm,right side was 1.26±0.25 mm. The distance from inferior wall of tympanic cavity to region of jugular vein was 4.22±1.69 mm. The distance between lateral semicircular canal and mastoid antrum was shorter in the right ears than in the left ears, this difference was satistically significant(P<0.05).Through the vertical segment of facial nerve of coronal HRCT sections. The length of vertical segment of facial nerve was 14.71±1.86 mm. The distance from vertical segment of facial nerve to posterior semicircular canal was 3.66±0.61 mm. The distance from vertical segment of facial nerve to region of jugular vein was 7.27±1.53 mm. The distance from mastoid segment of facial nerve ex-stylomastoid foramen to lateral wall of mastoid process was 11.05±2.24 mm. The distance from superior semicircular canal to posterior semicircular canal was 4.65±0.76 mm.Conclusions:Compared with the temporal bone's HRCT coronal scan images and consecutive coronal celloidin slices specimens, we can clearly identify apiece subtle anatomical structures of middle ear and something else around it. The results of this study offer morphological basis and anatomical foundation for otology clinical diagnostic imaging and microsurgery treatment, and also enrich our knowledge about ear coronal HRCT images information for sectional anatomy.