正常中耳腔的CT仿真内窥镜技术

目的：探讨正常听骨链的CT仿真内窥镜(CTVE)成像技术方法及其对中耳结构显示程度。方法：15例无中耳疾病的健康人，层厚1mm、螺距1．0轴位薄层扫描，骨算法、0．1～0．2mm间隔重建，行CTVE成像，观察正常听骨链的情况。结果：采用CTVE技术，对锤骨、砧骨及锤砧关节及砧镫关节的显示率均能清晰的显示，砧镫关节呈“L”形。但镫骨底板和镫骨的前、后脚显示欠佳，约有1／3可以显示。结论：CTVE成像技术能很好地显示中耳腔内部的听骨链立体结构，特别是可以部分显示镫骨底板，该技术将在活体上对中耳腔形态及功能的研究有重要意义。     

15例成年国人颞骨内部结构CT解剖学

目的:研究成年国人颞骨内部解剖结构的CT重建图像,为临床耳显微外科及神经外科手术提供解剖学依据。方法:15名健康志愿者应用Picker5000螺旋CT机,平行于听眦线扫描,应用VoxelQ工作站进行多层面重建(multi planar reconstruction,MPR),表面遮盖重建(surface shaded display,SSD)及仿真内窥镜成像(CT virtual endoscopy,CTVE),多角度旋转观察颞骨内部解剖结构。结果:MPR能在不同切面显示耳蜗、半规管、内耳道及面神经管垂直段等结构,显示率为100%;SSD能清晰显示颞骨重要的骨性结构,如内耳门、颈静脉孔等,冠状位切割后的SSD图像能生动地显示锤骨、砧骨的立体形态及空间关系;CTVE可模仿内窥镜从外耳向中耳移动,清晰显示骨性外耳道、鼓室内侧壁及听骨链等结构。结论:MPR可行多方位重建,有助于耳颞部病变的全面了解,是轴位CT良好的补充;SSD、CTVE可准确、立体的观察颞骨内部解剖结构,对临床诊断、手术方案的设计、医学教学等具有指导意义。     

婴幼儿耳部低剂量CT三维成像研究

目的探讨低剂量CT在婴幼儿内、中耳容积再现（VR）重建中应用价值。方法 60例被怀疑耳部疾病患儿,其中男性36例,女性24例,年龄15天～3岁。分为常规剂量组和低剂量组,各随机选择30例CT诊断解剖结构正常、临床检查未见异常的健侧耳为研究对象。常规剂量组男性17例,女性13例,平均年龄为1岁8个月;低剂量组男性19例,女性11例,平均年龄为1岁5个月。用75mAs（常规剂量组）和15mAs（低剂量组）的剂量分别扫描婴幼儿颞骨,行VR重建,比较不同剂量对骨迷路和听骨链三维结构再现能力的影响。结果 60例中除镫骨板、镫骨脚和半规管外,其余结构均100%完整再现。常规剂量组中,镫骨脚、镫骨板的完整再现率分别为63.3%（19/30）、26.7%（8/30）,完整再现率最低的半规管为上半规管73.3%（22/30）;低剂量组中,镫骨脚、镫骨板的完整再现率分别为60.0%（18/30）和26.7%（8/30）,完整再现率最低的半规管为外半规管70.0%（21/30）。两组图像上述部位完整再现率比较差异均无统计学意义（P〉0.05）。结论 15mAs为目前颞骨CT扫描的最低剂量值,能获得理想的婴幼儿骨迷路和听骨链三维图像,可应用于临床。     

24孕周胎儿标本听小骨3.0 T MR影像的解剖形态观察

目的探讨24孕周胎儿标本听小骨3.0 T MR影像的解剖形态。方法以1具24孕周流产胎儿冷冻标本为研究对象, 女性, 发育指标正常, 双顶径62 mm, 头围22.3 cm, 腹围18.9 cm, 身长27.5 cm, 体质量580 g。使用西门子3.0 T MR对胎儿标本的双侧颞骨进行扫描, 获取中耳的各向同性薄层MR断层图像。选取山东大学解剖教研室胎儿标本库中的1具25孕周发育指标正常的女性胎儿标本的颞骨CT扫描图像, 以及1例来山东省妇幼保健院就诊的发育正常的2岁儿童颞骨CT图像, 将CT图像与24孕周流产胎儿的MRI进行形态结构对照。观察项目:观察胎儿听小骨的MRI信号特点;比较CT图像与MRI对听小骨的显示效果;经多向调整多平面重组(MPR), 分别显示锤骨、砧骨、镫骨及相关结构的典型断层解剖形态, 标识重要解剖结构;通过最大密度投影(MIP)重组对听骨链进行三维显示。结果 (1)MRI信号特点:胎儿听小骨在MR T2WI上显示为低信号, 其中骨化完全部分呈明显低信号、未完全骨化部分为较低信号;中耳鼓室中充满羊水, 表现为均匀T2WI高信号, 在羊水信号衬托下, 听小骨可清晰...     

食管胃静脉曲张供血与分流血管CT三维成像研究

目的:应用64层螺旋CT肝门静脉成像(CTPV)技术,探讨食管胃静脉曲张供血血管与分流血管解剖特征.方法:收集并分析我院64层螺旋CT肝门静脉成像及胃镜检查证实的食管胃静脉曲张50例.先常规平扫,后三期增强扫描,二维重建方法采用MIP、VR、MPR.结果:本组50例,食管静脉曲张几乎全部由胃左静脉供血,单纯南胃左静脉前支供血57.8%(26例),伴有食管旁静脉曲张82.2%(37例);胃底静脉曲张由单纯胃左静脉供血61.1%(22例),由胃短、胃后静脉供血11.1%(4例),由胃短、胃后、胃左静脉双蕈供血27.8%(10例).脾/胃-肾静脉分流20%(10例).结论:64层螺旋CT肝门静脉成像能立体、清晰地显示食管胃静脉曲张的供血与分流血管,对临床选择治疗方案具有重要价值.     

CT仿真内镜与多平面重建对垂体瘤患者蝶窦显示情况的比较

目的:比较CT仿真内镜(CT virtual endoscopy,简称CTVE)与CT多平面重建(multiplannar reconstruction,MPR)对垂体瘤患者蝶窦、鞍底的显示情况.方法:在119例垂体瘤经蝶手术中,对术前常规垂体CT检查数据分别进行MPR及CTVE重建,对两者显示的蝶窦情况进行比较.结果:在蝶窦表面解剖结构:蝶窦开口、蝶窦中隔、鞍底形状、斜坡凹陷、颈内动脉隆起、视神经管隆起方面,CTVE与MPR的显示率无明显差别,CTVE对颈内动脉视神经隐窝的显示率优于MPR,CTVE所提供的为三维图像,MPR提供的为二维图像.在显示深部解剖标志:斜坡松质骨、蝶窦壁厚度方面MPR明显优于CTVE.结论:CTVE能显示蝶窦浅表解剖结构的三维图像,可做为经蝶垂体瘤手术的术前了解蝶窦三维解剖结构的一种方法.     

中耳畸形对圆窗激振听力补偿性能影响的数值分析

目的研究中耳畸形对圆窗激振性能的影响,为圆窗激振式人工中耳的优化提供理论支持。方法构建包含两腔不对称的非螺旋耳蜗的人耳有限元模型,并与实验数据进行对比,验证模型的可靠性。基于该模型,通过改变相应组织的材料属性,分别模拟听骨链固定、听骨链融合、听小骨缺损3种中耳畸形对圆窗激振性能的影响。结果中耳畸形主要影响圆窗激振式人工中耳的低频性能,听骨链固定和听骨链融合对圆窗激振起恶化效果。镫骨固定对圆窗激振补偿性能的影响最大,恶化量高达47.93 dB;听小骨缺损可提高圆窗激振的性能,最大改善量为6.24 dB。结论中耳畸形对圆窗激振的低频性能有影响,临床植入圆窗激振式人工中耳时需要针对性地提高其作动器的输出量。     

翼腭窝区的高分辨力CT三维重建

目的:探讨高分辨力CT(HRCT)三维重建技术在翼腭窝区的应用价值,为临床该区疾病诊断及手术方案设计提供影像解剖学资料。方法:对10例健康志愿者行HRCT扫描后,利用多平面重组(MPR)和遮盖表面显示法(SSD)三维重建技术显示翼腭窝区骨性结构。结果:HRCT扫描及MPR重建图像清晰显示翼腭窝及其通道在横断面、冠状面及矢状面上的形态特征,SSD重建图像能满意显示翼腭窝区骨性结构的立体解剖及与周围结构的空间位置关系。结论:HRCT轴位扫描与MPR、SSD相结合可直观、立体、清晰地显示翼腭窝区结构。     

CT仿真内窥镜技术在肝门静脉变异分析中的应用

目的探讨CT仿真内窥镜(CTvirtual endoscopy,CTVE)在精确区分肝门静脉变异类型中的应用价值。方法对CT门静脉血管成像(CTportal angiology,CTPA)病例中筛选出MIP、VR显示为肝门静脉主干3分叉的15例病人和右支主干显示为3分叉的17例病人用CTVE分析。重点分析3分叉处的管腔结构,例如肝门静脉主干处,右前支-左支(RAPV-LPV)短共干或者是右前支-右后支(RAPV-RPPV)短共干很容易被误认为主干3分叉。以评价CTVE在分辨短共干与3分叉中的价值,纠正原始方法观察分支的欠缺。结果肝门静脉主干3分叉中60%(9例)经CTVE分析为短RAPV-LPV共干或短RAPV-RPPV共干。17例右支主干3分叉中,35%(6例)为右支主干先分出右后上支,然后分为右后下支和右前支,12%(2例)例为正常解剖(I型变异)。经CTVE分析后,32例病人只有47%(15例)是真正3分叉,阳性率仅为0.47,统计学有显著差异。结论由于短共干分支外观上极易与真正3分叉混淆,而CTVE可以真实显示腔内分叉的顺序,从而清晰鉴别3分叉与短共干。此方法可用于肝门静脉解剖的研究,纠正原始方法的不足,获得更加准确的数据。     

CT仿真内镜显示鞍底神经血管及其解剖标志的临床意义

目的探讨CT仿真内镜(CT virtual endoscopy,CTVE)显示鞍底深部血管神经及其表面解剖标志在经蝶手术中的应用价值。方法 128例垂体瘤经蝶手术中,利用Navigator Guide软件对术前垂体CT检查数据进行蝶窦CTVE重建,了解CTVE对鞍底血管、神经及其解剖标志的显示情况。结果 CTVE能以三维图像的形式显示颈内动脉隆起、视神经管隆起、视神经管-颈内动脉隐窝,三者的显示率分别为:43.4%(111例)、37.5%(96例)、57.0%(146例)。通过传输函数设计技术(transfer functions),CTVE能透视显示出增强的颈内动脉100%(256例),可观察到有43.8%(112例)中隔附着于颈内动脉的浅面。通过动态调高观察阈值,CTVE能显示视神经管99.6%(255例),可观察到约17.3%(44例)中隔附着于视神经管表面。结论在经蝶手术中,术前CTVE能以三维图像的形式显示鞍底深部血管、神经及其解剖标志;术中能指导对上述鞍底血管、神经的辨认及鞍底骨窗形成。     

Multidetector row CT demonstration of inner and middle ear structures

The aim of this study is to evaluate the anatomical details of the inner ear and middle ear, using multidetector row CT. Temporal bone CT scans were obtained using 16-detector row CT scanner (Lightspeed 16, General Electric Medical Systems, Milwaukee, WI) in 30 patients with dizziness, vertigo, or hearing loss. The three-dimensional (3D) images were reconstructed with volume rendering techniques. The 3D images were reviewed by two radiologists and scored by using a three-point quality rating for qualitative assessment of the 23 representative structures of the middle and inner ear. The malleus, incus, and facial nerve canal were identified in all patients. The incudomalleolar joint appeared fused in all patients. The stapes were seen clearly in 27 (90%) of 30 patients except in three patients. Among the three remaining patients, there was one who had effusions in the middle ear cavity. Another patient had left cholesteatoma. The third patient had normal middle ear cavity. The cochlea and the three semicircular canals (anterior, posterior, and lateral) were well demonstrated in 29 (97%) of 30 patients except for one old woman with osteoporosis. Sixteen-detector row CT imaging of temporal bone with advanced 3D reformation yields state-of-the-art anatomical details of the temporal region useful to address anatomical localization issues and ease conceptual structural learning.     

An unusual stapes

We present a case of a highly unusual stapes in the presence of a normal external ear. The stapes exhibits rudimentary anterior crus with abnormally shaped posterior crus that attached to the mid-portion of a fixed, rudimentary footplate. To our knowledge, this anomaly has not been previously documented. We review the embryological cause that may be contributing to the development of this congenitally abnormal stapes superstructure. This is to highlight the importance of the knowledge of the anatomy of the stapes and its variations especially to the otologists.No sources of financial support/funding are associated with this paper.     

Micro-CT of the human ossicular chain: Statistical shape modeling and implications for otologic surgery

The ossicular chain is a middle ear structure consisting of the small incus, malleus and stapes bones, which transmit tympanic membrane vibrations caused by sound to the inner ear. Despite being shown to be highly variable in shape, there are very few morphological studies of the ossicles. The objective of this study was to use a large sample of cadaveric ossicles to create a set of three-dimensional models and study their statistical variance. Thirty-three cadaveric temporal bone samples were scanned using micro-computed tomography (μCT) and segmented. Statistical shape models (SSMs) were then made for each ossicle to demonstrate the divergence of morphological features. Results revealed that ossicles were most likely to vary in overall size, but that more specific feature variability was found at the manubrium of the malleus, the long process and lenticular process of the incus, and the crura and footplate of the stapes. By analyzing samples as whole ossicular chains, it was revealed that when fixed at the malleus, changes along the chain resulted in a wide variety of final stapes positions. This is the first known study to create high-quality, three-dimensional SSMs of the human ossicles. This information can be used to guide otological surgical training and planning, inform ossicular prosthesis development, and assist with other ossicular studies and applications by improving automated segmentation algorithms. All models have been made publicly available.     

Three-Dimensional Finite Element Modeling of Human Ear for Sound Transmission

An accurate, comprehensive finite element model of the human ear can provide better understanding of sound transmission, and can be used for assessing the influence of diseases on hearing and the treatment of hearing loss. In this study, we proposed a three-dimensional finite element model of the human ear that included the external ear canal, tympanic membrane (eardrum), ossicular bones, middle ear suspensory ligaments/muscles, and middle ear cavity. This model was constructed based on a complete set of histological section images of a left ear temporal bone. The finite element (FE) model of the human ear was validated by comparing model-predicted ossicular movements at the stapes footplate and tympanic membrane with published experimental measurements on human temporal bones. The FE model was employed to predict the effects of eardrum thickness and stiffness, incudostapedial joint material, and cochlear load on acoustic-mechanical transmission through the human ossicular chain. The acoustic-structural coupled FE analysis between the ear canal air column and middle ear ossicles was also conducted and the results revealed that the peak responses of both tympanic membrane and stapes footplate occurred between 3000 and 4000 Hz.