紧张部内陷袋胆脂瘤高分辨率CT征象分析

High resolution CT features of acquired primary pars tensa cholesteatoma

目的 分析紧张部内陷袋胆脂瘤的高分辨率CT(HRCT)征象,为影像诊断提供依据。方法 回顾性分析经临床及病理证实的36例(36耳)紧张部内陷袋胆脂瘤患者HRCT资料,采用多平面重组(MPR)技术重建标准轴位及冠状位图像,由2位主任医师对病变形态特点、累及部位、听小骨破坏情况、周围骨结构改变和乳突气化程度等影像征象进行分析。结果 36例紧张部胆脂瘤均表现为起源于中后鼓室的软组织密度灶,其中6例呈局限团块状,15例呈团片状,15例呈弥漫团块状;病变累及中下鼓室36例,上鼓室21例,乳突腔9例,上鼓室前隐窝7例,鼓室窦28例,面神经隐窝25例;1例听小骨完整,6例锤骨头破坏,17例锤骨柄破坏,14例砧骨体破坏,35例砧骨长脚破坏,11例砧骨短脚破坏,23例镫骨头破坏,21例镫骨前后弓破坏,30例听小骨外移;2例水平半规管破坏,3例面神经管椎曲段破坏,17例面神经管水平段破坏,2例面神经管垂直段破坏,5例盾板明显破坏,13例盾板毛糙,18例盾板完整,5例鼓窦入口扩大,5例乳突腔边缘骨质硬化;乳突气化程度分级为0级17例,1级10例,2级9例,3级0例。结论 紧张部内陷袋胆脂瘤HRCT特征为中后鼓室软组织密度灶伴听小骨外移及破坏,听小骨破坏以砧骨长脚与镫骨板上结构多见。

Objective To analyze the high resolution CT(HRCT) features of pars tensa cholesteatoma in order to provide reference for imaging diagnosis of the disease. Methods HRCT data of 36 patients(36 ears) with pars tensa cholesteatoma confirmed by clinic and pathology were retrospectively analyzed. MPR technique was used to reconstruct the standard axial and coronal images. The morphological characteristics of the lesions, lesion range, destruction of the auditory ossicles, changes in the periphery bone structure and degree of mastoid cells were analyzed by two chief physicians. Results All 36 cases presented soft-tissue originating from the tympanic cavity, 6 of which were limited masses, 15 patchy and 15 diffuse masses. All lesions were located in mesotympanum and hypotympanum, including 21 in attic, 9 in mastoid cavity, 7 in anterior epitympanic recess, 28 in tympanic sinus and 25 in facial recess. One case had normal ossicular chain, 6 disruptions of the head of malleus, 17 disruptions of the handle of malleus, 14 disruptions of the body of incus, 35 disruptions of the long limb of incus, 11 disruptions of the short limb of incus, 23 disruptions of the head of stapes, 21 disruptions of the anterior and posterior crus of stapes, and 30 cases of external displacement of ossicular chain. Two cases had horizontal semicircular canal destruction, 3 pyramid segment destruction of facial canal, 17 horizontal segment destruction of facial canal, 2 vertical segment destruction of facial canal, 5 obvious destruction of scutal shield, 13 rough scutal shield, 18 complete scutal shield, 5 drum sinus entrance enlargement, 5 sclerosis of the bony borders of the mastoid cavity. The development of the mastoid cells was classified as grade 0 in 17 cases, grade 1 in 10 cases, grade 2 in 9 cases, and grade 3 in 0 case. Conclusion Pars tensa cholesteatomas are located in the tympanic cavity, which cause ossicular chain to displace laterally. The destruction of ossicular chain is mainly observed in the long limb of incus and stapes superstructure.