Computerized assessment of the mastoid air cell system

Isono, Michio; Murata, Kiyotaka; Azuma, Hiroji; Ishikawa, Masahiro; Ito, Akihiko

doi:10.1016/s0385-8146(98)00055-8

Cited by 29 publications

(23 citation statements)

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“…The developed equations show that this is true only true for ears derived from a population where the tympanum/MACS ratio of effective blood perfusion (related to surface area) per unit volume, M, is less than 1. Geometrical considerations show that the surface area per unit volume ratio of the MACS is much greater than that for the tympanum, and consequently, if M<1, blood perfusion per unit surface area must be much less for the MACS when compared to the tympanum [1,14,[37][38][39].…”

Section: Discussionmentioning

confidence: 99%

The mastoid as a functional rate-limiter of middle ear pressure change

Doyle

2007

International Journal of Pediatric Otorhinolaryngology

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Section: Discussionmentioning

confidence: 99%

The mastoid as a functional rate-limiter of middle ear pressure change

Doyle

2007

International Journal of Pediatric Otorhinolaryngology

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“…Computed tomography (CT)-based estimates for surface areas of pneumatized spaces within the temporal bone range from 74.78 to 330.01 cm 2 (Park et al, 2000;Swarts et al, 2010). CT-based volumes of normal mastoid air cell systems range from 1.61 mL (cm 3 ) to 20.25 cm 3 (Isono et al, 1999;Aktas and Kutlu, 2000;Park et al, 2000;Luntz et al, 2001;Pata et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

Ontogenetic Change in Temporal Bone Pneumatization in Humans

Hill

2011

The Anatomical Record

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Pneumatization of the temporal bone is often included in descriptions of fossils and as a phylogenetic marker, but a number of questions about the evolution, growth, and development of the trait remain. Many studies have analyzed temporal bone pneumatization from a clinical perspective, but a systematic quantification of normal development of pneumatized spaces has not been conducted. In this study, ontogenetic change in the size and organization of temporal bone pneumatization is analyzed in a cross-sectional sample of humans. High resolution computed tomography scans of the temporal bone were acquired from a cross-sectional sample of humans (N ¼ 28). Bone volume fractions, anisotropy, trabecular number, trabecular thickness, surface area, and volume were analyzed to provide information about the organization and size of pneumatized spaces across ontogeny. The results indicate that there are general and region-specific patterns of ontogenetic changes in the organization of pneumatized spaces. These changes reflect the transition from nonpneumatized bone to pneumatized bone. It also demonstrates that those regions that are pneumatized early in ontogeny (such as the mastoid antrum) continue to remodel after the initial period of pneumatization. The dynamic nature of temporal bone pneumatization over ontogeny suggests that this character requires careful consideration when used as a character for phylogenetic analyses. These results demonstrate the importance of comparing individuals from similar developmental stages, especially when completing quantitative analyses of the extent of pneumatization or organization of the spaces. Anat Rec, 294:1103Rec, 294: -1115Rec, 294: , 2011. V V C 2011 Wiley-Liss, Inc.

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“…An alternative is to scan the mastoid bone through X-ray computed tomography (CT), and consider the walls of the mastoid air cell system as a surrogate to the very thin mucosa invisible on clinical CT scans. The volume of gas occupied within the mastoid air cells, also important to estimate when investigating how well a mastoid is pneumatized, is though easier to estimate using X-ray CT and has been reported in several studies [84,17,37,48,54,64,77,88].…”

Section: Forewordmentioning

confidence: 99%

“…In terms of research, CT scanning is a greattool for gaining knowledge about the anatomy of the ear in both normal and pathological cases, thus enabling more in depth understanding of the physiology governing the temporal bone. More related to the mastoid, several studies have used CT as the main modality [37,46,64,79,80,88]. A clinical CT scan of a patient's head, as well as a clinical CT scan of a temporal bone specimen alone, are illustrated in Fig.…”

Section: Clinical X-ray Ct Scannermentioning

confidence: 99%

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Structural properties of the mastoid using image analysis and visualization

Cros¹

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Volume rendering of a 3D shape analysis where medial balls are fitting the mastoid air cell system of a human temporal bone specimen, overlaid over a manually cropped version of the original data. The different colours represent the different size classes: from very small in dark blue to vary large in purple. The bone is rendered with a modified transfer function so as to reveal the micro-channels.Copyright © 2017 Olivier Cros, unless otherwise noted. AbstractThe mastoid, located in the temporal bone, houses an air cell system whose cells have a variation in size that can go far below current conventional clinical CT scanner resolution. Therefore, the mastoid air cell system is only partially represented in a clinical CT scan. Where the conventional clinical CT scanner lacks level of minute details, micro-CT scanning provides an overwhelming amount of fine details. The temporal bone being one of the most complex in the human body, visualization of micro-CT scanning of this bone awakens the curiosity of the experimenter, especially with the correct visualization settings.This thesis first presents a statistical analysis determining the surface area to volume ratio of the mastoid air cell system of human temporal bone, from micro-CT scanning using methods previously applied for conventional clinical CT scans. The study compared current results with previous studies, with successive downsampling the data down to a resolution found in conventional clinical CT scans. The results from the statistical analysis showed that all the small mastoid air cells, that cannot be detected in conventional clinical CT scans, do heavily contribute to the estimation of the surface area, and in consequence to the estimation of the surface area to volume ratio by a factor of about 2.6. Such a result further strengthens the idea of the mastoid to play an active role in pressure regulation and gas exchange.Discovery of micro-channels through specific use of a non-traditional transfer function was then reported, where a qualitative and a quantitative preanalysis were performed and reported. To gain more knowledge about these micro-channels, a local structure tensor analysis was applied where structures are described in terms of planar, tubular, or isotropic structures. The results from this structural tensor analysis suggest these micro-channels to potentially be part of a more complex framework, which hypothetically would provide a separate blood supply for the mucosa lining the mastoid air cell system.The knowledge gained from analysing the micro-channels as locally providing blood to the mucosa, led to the consideration of how inflammation of the mucosa could impact the pneumatization of the mastoid air cell system. Though very primitive, a 3D shape analysis of the mastoid air cell system was carried out. The mastoid air cell system was first represented in a compact form through a medial axis, from which medial balls could be used. The medial balls, representative of how large the mastoid air cells can be locally, were used in two co...

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Computerized assessment of the mastoid air cell system

Cited by 29 publications

References 4 publications

The mastoid as a functional rate-limiter of middle ear pressure change

The mastoid as a functional rate-limiter of middle ear pressure change

Ontogenetic Change in Temporal Bone Pneumatization in Humans

Structural properties of the mastoid using image analysis and visualization

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