64排螺旋CT仿真内镜对中耳解剖结构的三维显示

Virtual endoscopy 3-D findings of the middle ear based on 64-detector spiral CT data

目的探讨64排螺旋CT仿真内窥镜、听骨链三维重建及镫骨前后脚斜面重建对中耳正常解剖结构显示情况。方法33例66耳行颞骨64排螺旋CT扫描,正常者35耳。所有33例均行颞骨64排螺旋CT容积扫描检查。将骨算法及软组织算法重建的轴位数据重建图像传至GE Advantage工作站。35耳均行中耳CTVE成像,听骨链SSD三维重建,镫骨前后脚进行斜轴位重建,与解剖及冠、轴位图像进行对照。结果CTVE100%(35/35)清晰显示听骨链的结构,鼓室各壁结构,下鼓室、鼓室上隐窝及鼓窦,砧镫关节、镫骨脚板及面神经骨管的位置;100%(35/35)显示面神经骨管;68.6%(24/35)清晰显示镫骨前脚,74.3%(26/35)清晰显示镫骨后脚;65.7%(23/35)清晰显示面隐窝,82.8%(29/35)显示鼓室天盖。锤骨前、上韧带、砧骨后韧带CTVE的分辨率较低,显示情况仅分别为8.6%(3/35)、8.6%(3/35)及11.4%(4/35)。镫骨肌显示率为0。CTVE对后鼓室细微结构的显示:20%(7/35)显示岬小桥,8.6%(3/35)显示岬下脚,8.6%(3/35)显示茎突隆起。听骨链的SSD重建及镫骨前后脚的斜轴位重建对听骨链的显示:100%(35/35)清晰显示听小骨各结构,尤其是完全显示了镫骨前后脚及脚板。结论64排螺旋CT中耳CTVE可以清晰显示大部分中耳的正常解剖细节,使各结构更立体、清晰。听骨链SSD及镫骨前后脚的斜轴位重建,可以整体显示听骨链的情况。64排螺旋CT中耳的CTVE、听骨链SSD及镫骨前后脚斜轴位重建图像清晰、立体,耗时不长,可以用于临床常规使用。

Objective To assess the value of 64-detector spiral CT for the virtual endoscopy （VE） of normal middle ear and the three-dimensional reconstruction of ossicular chain.Methods 33 subjects were examined by 64-detector spiral CT.The obtained data was transferred to GE Advantage Workstation via an internal Dicom network for post-processing. CTVE, SSD of ossicular chain and the oblique reconstruction of stapes were processed on 35 ears,and were compared with anatomy and coronal and axial CT film.Results The structures of handle and head of malleus,body and long limb of incus, body and limbs of of stapes, promontory, fossa of round window, oval window, auditory tube, hypotympanon, epitympanic recess ,pyramidal eminence and horizontal semicircular canal were clearly displayed in 100%（35/35）. CTVE showed the location of incudostapesial joint, base of stapes and facial nerve tube in 100%（35/35）. CTVE clearly showed the anterior limb of stapes in 68.6%（24/35）, the posterior limb of stapes in 74.3%（26/35）. CTVE had a low differentiation for the ligament of mallus and incus. CTVE showed the facial recess in 65.7%（23/35）.CTVE showed the ponticulus and subiculum of retrotympanium in 8.6%（3/35）,respectively.The representation of SSD of ossicular chain and oblique reconstruction of stapes： The SSD of normal ossiular chain showed all the structures of ossicles in 100% （35/35）, especially the anterior and posterior limbs and base of stapes.Conclusion CTVE can clearly and threedimensionally show most structures of normal middle ear. SSD of ossicular chain and the oblique reconstruction of stapes can wholely show the ossicular chain. The imaging of CTVE, SSD of ossicular chain and reconstruction of stapes of 64-detector spiral CT is clear and tridimensional with a short time, and can be applied in clinical examination.