Virtual MPR From Multi-slice Computed Tomography: An Application Of Stapes

The second part:THE OPTIMUM IMAGE OF SHOWING THE STAPES BY MSCTObjectiveBy comparing the display on the stapes from conventional axial, coronal, oblique ofstapes MPR, MIP images, evaluating the quality of different thickness of recombinant withthe oblique MPR, MIP image, and measuring anatomical structures from oblique of stapesMPR images, this part of the study aims to explore the best way to show the wholestructure and optimization of reconstruction slice thickness.Methods52cases (104ears,27males and25females, age:5-63years old, average age:34.5years old) diagnosed of tinnitus, headache, dizziness were examined in our hospital duringSeptember2012to May2013. Patients were scanned by MSCT to gain axis and coronalimages, and the images were post-processed to show oblique MPR and MIP imagereconstruction of stape. The stapes of the conventional axis level, the oblique MPR andMIP were observed; The oblique MPR and MIP images of different thickness wereevaluated, and the date were analysed by SPSS16.0statistical software. The best way andslice thickness to display the overall structure of the stapes in MSCT were explored. Therelevant anatomical structures from oblique of stapes MPR images were meausured, andthe results were analyzed and compared between different sides and with the publishedcadaver data.Results1.In conventional axial and coronal images,only a part of stapes can be displayedwith direct scan,and the whole body of stapes can be displayed with MPR.The displayrate of foot plate of stapes in oblique MIP image is lower than that of stapes oblique MPRimages.2. The optimum image of showing the overall structure of the stapes is obliqueMPR images with the thickness of0.6mm.3.the relevant anatomical structures can be measured in the oblique MPR images of stapes from MSCT: the height of stapes: theLongitudinal diameter of obturator: left(1.73±0.29）mm, right（1.70±0.23）mm; thehorizontal diameter of obturator: left（1.54±0.30）mm, right（1.58±0.26）mm; the angle ofincudostapedial joint: left（84.18±13.38）°,right（82.79±13.24）°; the width of forefoot ofstapes: left（3.31±0.22）mm, right（3.34±0.27）mm; the width of posterior crus of stapes:left（3.31±0.22）mm, right（3.34±0.27）mm.ConclusionsThe optimum images of showing the overall structure of the stapes is oblique MPRimages with the thickness of0.6mm, and the relevant anatomical structures can bemeasured in the images so as to provide theoretical basis for the clinic and to guide theoperation. The second part:THE EVALUATIONOF THE STAPES LESIONS IN PATIENTSWITH CHRONIC SUPPURATIVE OTITIS MEDIA BY MSCTObjectiveTo explore the evaluation of the stapes lesions in patients with chronic suppurativeotitis media by Multi-slice computed tomography.Methods62cases(62ears)with chronic suppurative otitis media underwent multi-slicecomputed tomography scanning before the operation, and the axial, coronal images as wellas MPR were analysed，CT images were observed above, statistical chronic otitis mediaand cholesteatoma formation, the number of cases involving the stapes, the number ofcases confirmed by surgery, and calculate the positive rate, false positive rate, negative rate,false negative rate CT diagnosis and compared with intraoperative findings in order toexplore the accuracy of Multi-slice computed tomography with regard to displaying thestapes lesions in patients with chronic suppurative otitis media. CT diagnosis rate iscalculated as follows: compliance rate=(CT diagnostic positive number+CT diagnosisnegative number)/total number of cases.Results1.The coincidence rate of displaying the structural and morphological abnormalitiesof stapes in the axial and coronal images is39.6%(19/48).2. The coincidence rate ofdisplaying the structural and morphological abnormalities of stapes in the oblique MPRimages is81.3%(39/48).3. The normal or partial structure of stapes was seen during thesurgery in8.3%(4/48) patients with no stapes showed in Multi-slice computedtomography.ConclusionsThe oblique MPR images were superior in displaying the structural and morphologyof the stapes than the conventional axial and coronal images in patients with chronicsuppurative otitis media. The coincidence rate between the oblique MPR images and theoperation was high. However, there were some errors in showing the stapes packaged bygranulomatous tissue.