砧骨发育不良的CT检查

Hypoplasia of incus: multiplane reformatted technique and CT findings

目的 :探讨砧骨多层螺旋CT多平面重组 (multi planarreformation ,MPR)技术和各种类型砧骨发育不良的CT特征。方法 :对 5 0例无耳症状、体征的志愿者行平行枕眶线扫描 ,应用轴位图像行以下多方位的MPR :①冠状位 ;②矢状位 ;③砧骨长轴位层面 ;④砧骨、锤骨同层显示层面。比较轴位和前三种位置整体显示砧骨形态的能力。在砧骨长轴位图像上测量砧骨的长度。异常组 ,砧骨发育异常 5 4例 86耳 ,2 7例行听骨链重建术。全部病例经电测听检查均表现有不同程度的传导性耳聋。结果 :正常组轴位、冠状位、矢状位均未能显示砧骨长轴位整体形态 ,砧骨长轴位MPR图像均直观显示了砧骨长轴整体形态。锤骨与砧骨长轴在同一层面显示 13例 ,2 2耳 ,在不同层面分别显示 37例 ,78耳。在砧骨长轴位MPR图像上 ,测量砧骨的长度为 6 .8mm± 0 .5mm。异常组 5 4例 ,砧骨长脚缺如 2 5例 ;砧骨长脚被软组织取代 9例 ,砧骨与镫骨之间的“L”型夹角消失 2 0例 ,其中 ,砧骨长脚与鼓室壁粘连 2例。结论 :利用MPR技术可得到与砧骨长轴层面平行的重组图像 ,可较完整的显示砧骨的大小、形态 ,准确评价砧骨的各种畸形和病变 ,为制定治疗方案提供科学依据。

Objective:To evaluate the technique of multi-planar reformation (MPR) for the incus with multi-slice spiral thin-section computed tomography (CT) and the CT features of hypoplasia of incus.Methods:CT scanning of temporal bone was undergone in 50 volunteers. Multiplan reformatted images were made, it include coronal MPR, sagittal MPR, oblique MPR that is parallel to incus and oblique MPR which shown incus and malleus in the same image,comparisons of ability to shown the full incus were done between all the MPR images. The measurements of the incus length were made in the oblique MPR that is parallel to the incus. CT findings were evaluated in 54 cases with hypoplasia of incus. Prosthetic ossicular reconstruction was made in 27 cases.Results:The whole incus cannot be shown in axial, coronal and sagittal MPR images;however, it is shown in oblique MPR image that is parallel to incus in all the cases, incus and malleus were seen in the same image in 13 cases (22 temporal bones), in difference images in 37 cases (78 temporal bones). The length of incus was 6.8mm±0.5mm. In the abnormal group, there is defects of the incus long process in 25 cases, bone tissue of the incus long process was replaced by soft tissue in 9 cases, no normal angle with the shape of“L' was shown between incus and stapes in 20 cases.Conclusion:MPR that is parallel to incus can be got from axial images.The shape, size and malformation of incus can be evaluated on this image. It is useful for treatment of malformation of incus.