乳突气化容积：超高分辨率CT三维重建

中耳气体总量取决于连接中耳和鼻咽的咽鼓管的气体交换和中耳及通过中耳粘膜的血容量之间的交换。中耳气化程度指残留于中耳腔的气体总量多于进入中耳腔的气体 ,从而使中耳呈气体样密度。最重要的是中耳为负压时可对抗中耳气体失衡时负的生物学效应。当负压大于鼓膜的内部张力时 ,则鼓膜朝向里。中耳的负压程度取决于通过咽鼓管和粘膜的气体多少以及乳突气化大小。该作者对 6 9例 (138耳 )正常颞骨乳突进行了测量 ,获得乳突气化全部容积的尽可能精确的数值。所有的病人均行颞骨 CT检查 (中耳无病变 )。层厚 10 mm,间隔 0 .5 mm。图像经过工…     

颞骨HRCT三维重建测量乳突气房表面积与容积的临床意义

目的 通过颞骨HRCT三维重建测量乳突气房表面积(SA)、容积(V),以揭示健康气化型乳突气房SA、V、表面积容积比(SA/V)的参考值范围及特征,为进一步乳突气房功能研究、生理建模及功能重建提供依据.方法 回顾性分析2016年1月-2017年6月广州市红十字会医院108例(216耳)乳突气化型成年患者的颞骨HRCT资...     

Evaluation of the mastoid air cell system by high resolution computed tomography: three-dimensional multiplanar volume rendering technique

The mastoid air cell system is an important contributor to the pathophysiology of middle-ear inflammatory disease. The mastoid cavity is not only an air reservoir, but also an active space for gas exchange. Various methods of temporal bone imaging have been designed to investigate mastoid pneumatization. In this study, we examined 100 normal temporal bones for the evaluation of mastoid pneumatization. Mastoid air cell systems were measured by reconstructed axial and coronal high resolution computed tomography (HRCT) images. The reconstructions were made by a three-dimensional multiplanar volume rendering (3D MPVR) technique. The mean volume of the mastoid air cell pneumatization was 7.9 cm(3) (4.0-14.0 cm(3), SD = 2.3 cm(3)). The ears were allocated to the groups with respect to measured mastoid air cell pneumatization. Twenty-eight per cent of the ears have small pneumatization with an air cell system not exceeding 6 cm(3). Fifty-two per cent had an air cell system between six and 10 cm(3), and 20 per cent had an air cell system exceeding 10 cm(3). With its excellent imaging quality and the ability to eliminate bone and soft tissue, HRCT is the best method for evaluating the mastoid air cell system. The 3D MPVR technique must be used to measure the temporal bone/mastoid pneumatization for the best results.     

Evaluation of mastoid air cell system by three-dimensional reconstruction using sagittal tomography of the temporal bone

The mastoid air cell system has been recognized as an important contributor to the pathophysiology of middle ear inflammatory diseases. Various methods of temporal bone imaging have been designed to investigate the correlation between middle ear disease and mastoid pneumatization. In this study, the mastoid air cell system was reconstructed three-dimensionally from sagittal tomographic images of the temporal bone on X-ray films, using a personal computer to evaluate the mastoid pneumatization in a total of 29 patients with chronic otitis media, adhesive otitis media, adhesive-type cholesteatoma, attic cholesteatoma and cholesterol granuloma, and in five normal subjects as controls. Reconstructed three-dimensional images of the mastoid air cell system and its volume were analyzed. The reconstructed images were helpful in recognizing the three-dimensional solid appearance of the mastoid air cell system. The volume of the reconstructed mastoid air cell system was significantly reduced compared with that in the controls in each of the patient groups. Mastoid pneumatization in the patients with adhesive-type cholesteatoma was significantly suppressed compared with that in the adhesive otitis media patients. Interestingly, the adhesive otitis media group showed cell development at the tip of mastoid process, whereas the group of adhesive-type cholesteatoma did not, suggesting a difference in the pathophysiology in the two diseases. We found that three-dimensional reconstruction of the temporal bone using sagittal tomographic images was useful in evaluating the state of mastoid air cell system development in individual cases and in investigating the pathophysiology in middle ear disease.     

Computerized assessment of the mastoid air cell system

There have been many arguments on the development of pneumatization of temporal bone. However, a technique for direct volume measurement from high resolution computed tomography has never been reported. The aim of this paper is to develop a technique by using digital image processing to measure the volume of the mastoid air cell system. Forty three ears of 26 healthy subjects (13 males and 13 females) without a history of chronic or exudative otitis media, clear signs of Meniere's disease, severe sensorineural hearing impairment or malformation of temporal bone were eligible for enrolment in this study. Using a digital image processing technique, only the black air cells and tympanic cavity on the CT films are easily selected. Then, after image processing, only areas of these extracted black pneumatized parts are calculated. Consequently, the volume of pneumatized parts of temporal bone could be calculated separately as total volume and as partial volume that divided by several CT planes. The average volume of pneumatization in 43 temporal bones was 5.97 ml. However, since the volume of pneumatization in the temporal bone has traditionally been estimated by analyzing areas on X-ray films, the new method described in this study is significant for its ability to directly measure the volume of pneumatization in the temporal bone.     

The causes of asymmetry of the mastoid air cell system

Starting from age 2 up to 7 years, 79 otherwise healthy children underwent nine tympanometric tests. At the age of 7, mastoid X-rays were obtained and the air cell areas measured by planimetry. The mean area was 8.4 cm2, with a left-right mean difference of 1.57 cm2. The children could be divided into three groups: (1) the ears with the smallest cell system associated with abnormal tympanograms (i.e. 'agreement'); (2) the ears with the largest cell system associated with abnormal tympanograms (i.e. 'disagreement'); (3) children with symmetrical cell systems and tympanograms. Significant majority of children showed 'agreement'. The results indicate that the size of the mastoid air cell system is determined by the degree of pathological involvement of the middle ear during childhood.     

Anthropological study of the mastoid air cell system in Pakistani races

This is an anthropological study of the development of the mastoid process in the four ethnic groups of Pakistani races: Turko-Iranian, Indo-Aryan, Scytho-Dravidian, and Aryo-Dravidian. Cephalometric studies have established that the majority of Pakistanis are brachio to ultra-brachiocephalic (Cephalic Index 82-x). Radiological evaluation of normal mastoids and their planimetric measurements show that the mastoid process is smaller (Av: 10.24 sq.cm. +/- 0.8) than the Caucasian Western races (Av: 12-15 sq.cm.). Neither combined approach tympanoplasty, nor mastoid obliteration technique may be required, nor technically possible in a small mastoid. Natural epithelization of a small 'peanut size' mastoidectomy cavity does not justify these procedures. A modified radical mastoidectomy and tympanoplasty reconstruction provides a satisfactory result in chronic discharging ears.     

Management of the mastoid air cell system in chronic otitis media

The influence of the Mastoid Air Cell System in Chronic Otitis Media is subject to much speculation. Does a mastoidectomy influence the surgical results following chronic inflammatory ear surgery? An understanding of the pathology associated within the mastoid air cell system is necessary before a discussion of the need for a mastoidectomy can be presented. Most mastoid air cell systems are sclerotic in chronic otitis media patients. The report summarizes one author's experiences with the influence of mastoidectomy upon surgical reconstruction for chronic inflammatory diseases of the ear. Emphasis is directed toward the eustachian tube rather than the mastoid air cell system.     

Measurement of surface area in human mastoid air cell system

The total surface areas of human mastoid air cells were measured using digital CT scans. Using 24 normal ears, the lining of the mastoid air cells was digitally scanned, traced and analysed. The mean surface area of the mastoid air cell system was 167.0 cm2 and ranged from 74.78 to 330.01 cm2. The volume was also measured, the mean being 10.43 cm3 ranging from 6.25 to 20.52 cm3. The correlation coefficient between surface area and volume was 0.95. These results indicate that well pneumatized mastoid air cells serve to provide an extremely large surface area in the temporal bone which in normal mastoid air cells is proportional to the volume.