听骨链螺旋CT三维表面遮盖显示技术的临床应用

目的 探讨听小骨螺旋CT三维表面遮盖显示技术(SSD)的临床应用价值及相关的技术要点。资料与方法 对43例患者进行螺旋高分辨率CT扫描，利用密集放大的重建图像，采用手动编辑，先移去听小骨周围的骨质，仅保留听小骨，用经编辑的轴位图像进行SSD三维成像。结果 40侧正常耳的听小骨三维SSD显示了听小骨的细微结构，还反映了听小骨之间的关系。病变听小骨的三维SSD重建图像与轴位图像的表现基本相符；慢性中耳炎25耳中，22耳进行了听小骨SSD成像，10耳见有骨质破坏；先天性外、中耳畸形16耳均见有听小骨发育不良；外伤后听力下降5耳中，1耳锤砧关节脱位和1耳并有移位的锤骨骨折在听小骨三维SSD成像直观地显示。结论 螺旋CT扫描和三维SSD有利于听小骨的显示和病变的诊断。

Evaluation of Spiral CT SSD Technique in Observing Ossicular Chain

Objective To evaluate shaded surface display (SSD) with spiral CT scanning in observing ossicular chain, to discuss its technical points. Materials and Methods High resolution spiral CT scanning was performed in 43 patients and SSD reformation was carried out. Overlapping slices were calculated at 0.2mm thickness. Segmentation was manually done with 3D software. Bony structure around the ossicular chain was extracted and only ossicular chain was reserved. SSD reformation was conducted by using edited axial images.Results SSD could clearly show the fine structures and anatomical relationship of the ossicular chain in all 40 normal ears. For the demonstration of the diseased ossicular chain, SSD was in accord with the axial image. Of 25 ears with chronic otitis media, SSD was performed in 22, of which bony destruction was demonstrated in 10. Dysplasia of ossicular chain was seen in 16 ears with congenital malformations. Ossicular chain fracture was demonst rated in 2 out of 5 injured ears.Conclusion SSD with spiral CT scanning is a useful technique for observing ossicular chain.