OBJECTIVE To compare the ability of ultra-high-resolution CT(U-HRCT)and multi-slice spiral CT(MSCT)to display key vocal transmission structures in the middle ear.METHODS Subjects with normal middle ear structures who underwent 0.1 mm layer thickness U-HRCT and 0.625 mm layer thickness MSCT scans at the same time in Beijing Friendship Hospital affiliated to Capital Medical University from December 2019 to August 2024 were retrospectively enrolled.Two experienced head and neck radiologists reconstruct standard transsectional,coronal images based on the thinnest layer thickness.According to the 5-point method,16 key sound transmission structures of the middle ear,including malleus,incus and stapes,as well as joints,ligaments and tendons,were evaluated for image quality scoring.The standard deviation(SD)value,signal noise ratio(SNR),and contrast noise ratio(CNR)of bone in the malleus region and intratympanic gas were measured and calculated on the two examination images.RESULTS Thirty patients(47 sides)with normal middle ear structure were included,including 18 males and 12 females.The two physicians compared the results of U-HRCT in showing malleus head,malleus neck,malleus handle,incus body,long process,and short process,5 points accounted for 100%,and the 5-point scores of incudomalleolar joint space,incudostapedial joint space,stapes footplate and annular ligament were 100%,98.29%,75.83%and 77.83%,respectively,which were significantly higher than those of MSCT(P<0.001).In addition,U-HRCT showed higher scores for lenticular process,stapes head,anterior arch of stapes,posterior arch of stapes,annular ligament,stapes muscle,and tendo musculi tensoris tympani than MSCT(P<0.001),and the lenticular process showed a 100%display rate.There was no significant difference in the SNR between the two groups(P>0.05),but the SD value of the malleus in U-HRCT was 161.6±36.4,which was significantly lower than that in MSCT(297.8±128.1),and the difference was statistically significant(P<0.001).CONCLUSION U-HRCT can clearly visualize the key sound transmission structures of the middle ear,and its visualization ability is significantly better than that of MSCT.

Objective:To summarize the clinical features and postoperative efficacy of patients with oval window atresia accompanied by facial nerve aberration.Methods:The clinical data of patients with congenital middle ear malformation with facial nerve aberration admitted to our hospital from January 2015 to March 2023 were retrospectively analyzed. There were 97 cases (133 ears) in total. Among them, 39 patients (44 ears) had complete follow-up data, including 27 male patients and 12 females, aged 7-48 years old, with an average age of 17.8 years old. Of these, 14 cases (16 ears) were patients combined with facial nerve aberration, and 25 cases (28 ears) were without facial nerve aberration. The results of imaging examination, pure-tone audiometry, selection of surgical strategy, intraoperative findings and postoperative hearing improvement were summarized and analyzed. The malformations of malleus, incus, stapes, oval window and facial nerve were recorded. Prism 9 software was used to statistically analyze the mean bone conductance and air-bone gap of patients before and after surgery.Results:All the 14 patients (16 ears) with middle ear malformation accompanied by facial nerve aberration and oval window atresia showed poor hearing and no facial palsy since childhood. High resolution CT (HRCT) examination of temporal bone, pure tone audiometry and Gelle test were performed before surgery. The malformations of malleus, incus, stapes, oval window and facial nerve were recorded. Preoperative high-resolution CT (HRCT) examination of temporal bone found 12 ears with 4 or more deformities, accounting for 75.00%, in the group of patients with facial nerve malformation. The preoperative average bone conductive threshold was (15.3±10.4) dB and the average air-bone gap was (46.3±10.6) dB in pure-tone audiometry (0.5, 1, 2, 4kHz). According to the different degrees of facial nerve and ossicle malformation, we performed three different hearing reconstruction strategies for the 14 patients (16 ears) with facial nerve aberration and oval window atresia, including 7 ears of incus bypass artificial stape implantation, 7 ears of Malleostapedotomy (MS) and 2 ears of Malleus-cochlear-prothesis (MCP). After 3 months to 18 months of follow-up, all patients showed no facial paralysis. The postoperative mean bone conductive threshold was (15.7±7.9) dB and air-bone gap was (19.8±8.5) dB. There were significant differences in mean air-bone gap before and after operation ( t=7.766, P<0.05), and there was no significant difference between the mean bone conductive threshold before and after surgery ( t=0.225, P=0.824). There was no significant difference of mean reduction of air-bone gap between patients with and without facial nerve aberration ( t=1.412, P=0.165). There was no significant difference between the three hearing reconstruction strategies. There was no significant displacement of the Piston examined by U-HRCT. Conclusion:For patients of middle ear malformation whose facial nerve cover the oval window partially, incus bypass artificial stape implantation or Malleostapedotomy (MS) can be selected according to the specific condition of auditory ossis malformation, and for patients whose facial nerve completely covers the oval window area, Malleus-cochlear-prothesis (MCP) can be selected. Three types of stapes surgery are safe and reliable for patients with oval window atresia accompanied by facial nerve aberration. There was no significant difference in efficacy between them. Preoperative HRCT assessment of middle ear malformation is effective. There is no significant difference of surgical effect with or without facial nerve aberration. The U-HRCT can be used to evaluate the middle ear malformation before surgery and the Piston implantation status after surgery. Due to the risks of surgery, those who do not want to undergo surgery can choose artificial hearing AIDS, such as hearing aid, vibrating soundbridge, bone bridge or bone-anchored hearing aid.