scholarly journals High Resolution and Labeling Free Studying the 3D Microstructure of the Pars Tensa-Annulus Unit of Mice

Author(s):  
Jian-Ping Wu ◽  
Xiaojie Yang ◽  
Yilin Wang ◽  
Ben Swift ◽  
Robert Adamson ◽  
...  

Hearing loss is a serious illness affecting people’s normal life enormously. The acoustic properties of a tympanic membrane play an important role in hearing, and highly depend on its geometry, composition, microstructure and connection to the surrounding annulus. While the conical geometry of the tympanic membrane is critical to the sound propagation in the auditory system, it presents significant challenges to the study of the 3D microstructure of the tympanic membrane using traditional 2D imaging techniques. To date, most of our knowledge about the 3D microstructure and composition of tympanic membranes is built from 2D microscopic studies, which precludes an accurate understanding of the 3D microstructure, acoustic behaviors and biology of the tissue. Although the tympanic membrane has been reported to contain elastic fibers, the morphological characteristic of the elastic fibers and the spatial arrangement of the elastic fibers with the predominant collagen fibers have not been shown in images. We have developed a 3D imaging technique for the three-dimensional examination of the microstructure of the full thickness of the tympanic membranes in mice without requiring tissue dehydration and stain. We have also used this imaging technique to study the 3D arrangement of the collagen and elastic fibrillar network with the capillaries and cells in the pars tensa-annulus unit at a status close to the native. The most striking findings in the study are the discovery of the 3D form of the elastic and collagen network, and the close spatial relationships between the elastic fibers and the elongated fibroblasts in the tympanic membranes. The 3D imaging technique has enabled to show the 3D waveform contour of the collagen and elastic scaffold in the conical tympanic membrane. Given the close relationship among the acoustic properties, composition, 3D microstructure and geometry of tympanic membranes, the findings may advance the understanding of the structure—acoustic functionality of the tympanic membrane. The knowledge will also be very helpful in the development of advanced cellular therapeutic technologies and 3D printing techniques to restore damaged tympanic membranes to a status close to the native.

1989 ◽  
Vol 98 (10) ◽  
pp. 761-766 ◽  
Author(s):  
Richard A. Chole ◽  
Kevin Kodama

The purpose of this study was to determine whether anatomic differences in the tympanic membranes of various species could explain differences in the propensity to form aural cholesteatomas and retraction pockets. Tympanic membranes from humans, dogs, cats, rabbits, guinea pigs, rats, gerbils, and mice were examined histologically. The pars flaccida and pars tensa varied greatly among the species studied. The guinea pig's pars flaccida was very small and had a thin lamina propria. In contrast, the lamina propria of the rabbit and cat pars flaccida were thick. The amount of collagen, elastin, mast cells, and macrophages varied widely. The human and gerbilline tympanic membranes were anatomically dissimilar; for example, the human pars flaccida and pars tensa contained more and denser collagen than did those of the gerbil. The presence of macrophages or mast cells did not correlate with the propensity to develop cholesteatomas. Therefore, anatomic differences among these species do not explain why some develop aural cholesteatomas and others do not.


Author(s):  
Neil Rowlands ◽  
Jeff Price ◽  
Michael Kersker ◽  
Seichi Suzuki ◽  
Steve Young ◽  
...  

Three-dimensional (3D) microstructure visualization on the electron microscope requires that the sample be tilted to different positions to collect a series of projections. This tilting should be performed rapidly for on-line stereo viewing and precisely for off-line tomographic reconstruction. Usually a projection series is collected using mechanical stage tilt alone. The stereo pairs must be viewed off-line and the 60 to 120 tomographic projections must be aligned with fiduciary markers or digital correlation methods. The delay in viewing stereo pairs and the alignment problems in tomographic reconstruction could be eliminated or improved by tilting the beam if such tilt could be accomplished without image translation.A microscope capable of beam tilt with simultaneous image shift to eliminate tilt-induced translation has been investigated for 3D imaging of thick (1 μm) biologic specimens. By tilting the beam above and through the specimen and bringing it back below the specimen, a brightfield image with a projection angle corresponding to the beam tilt angle can be recorded (Fig. 1a).


2018 ◽  
Vol 2018 (1) ◽  
pp. 151-156
Author(s):  
Scott Geffert ◽  
Daniel Hausdorf ◽  
Joseph Coscia ◽  
Oi-Cheong Lee ◽  
Dahee Han ◽  
...  

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 354
Author(s):  
Walid Mnasri ◽  
Mahsa Parvizian ◽  
Souad Ammar-Merah

Current biomedical imaging techniques are crucial for the diagnosis of various diseases. Each imaging technique uses specific probes that, although each one has its own merits, do not encompass all the functionalities required for comprehensive imaging (sensitivity, non-invasiveness, etc.). Bimodal imaging methods are therefore rapidly becoming an important topic in advanced healthcare. This bimodality can be achieved by successive image acquisitions involving different and independent probes, one for each mode, with the risk of artifacts. It can be also achieved simultaneously by using a single probe combining a complete set of physical and chemical characteristics, in order to record complementary views of the same biological object at the same time. In this scenario, and focusing on bimodal magnetic resonance imaging (MRI) and optical imaging (OI), probes can be engineered by the attachment, more or less covalently, of a contrast agent (CA) to an organic or inorganic dye, or by designing single objects containing both the optical emitter and MRI-active dipole. If in the first type of system, there is frequent concern that at some point the dye may dissociate from the magnetic dipole, it may not in the second type. This review aims to present a summary of current activity relating to this kind of dual probes, with a special emphasis on lanthanide-based luminescent nano-objects.


1995 ◽  
Vol 109 (6) ◽  
pp. 495-498 ◽  
Author(s):  
H. L. Tay ◽  
R. P. Mills

AbstractA prospective study on the dynamics of tympanic membrane atelectasis during the treatment for glue ear was performed in a sample of 115 ears of 83 children aged between one and 11 years. The progression in the degree of pars tensa atelectasis was analysed in relation to six potentially relevant factors. Multivariate analysis showed that the factor with the most predictive value on the progression of the pars tensa retraction was the grade of atelectasis at initial detection (p<0.0001). The use of grommets did not have any significant influence on the outcome grade of atelectasis. There was an association between previous grommet insertion and localized retractions in the inferior segment of the pars tensa (P<0.0001). However, localized retractions in the postero-superior quadrant were not associated with previous grommet insertion (P<0.02). Although the hearing thresholds of atelectatic ears were significantly worse than normal ears especially at 4 kHz (p<0.006), the difference was less than 5 dB.


1994 ◽  
Vol 12 (4) ◽  
pp. 545-551 ◽  
Author(s):  
William H. Perman ◽  
Elisabeth M. Heiberg ◽  
Joseph Grunz ◽  
Virginia M. Herrmann ◽  
Christina G. Janney

2021 ◽  
Author(s):  
Eva Chatzinikolaou ◽  
Kleoniki Keklikoglou

Micro-computed tomography (micro-CT) is a high-resolution 3D-imaging technique which is now increasingly applied in biological studies focusing on taxonomy and functional morphology. The creation of virtual representations of specimens can increase availability of otherwise underexploited and inaccessible samples. This protocol aims to standardise micro-CT scanning procedures for embryos and juveniles of the marine gastropod species Hexaplex trunculus.


2012 ◽  
Vol 129 ◽  
pp. 271-285 ◽  
Author(s):  
Wei Yan ◽  
Jia-Dong Xu ◽  
Gao Wei ◽  
Li Fu ◽  
Hua-Bing He

Author(s):  
Kuofeng Hung ◽  
Andy Wai Kan Yeung ◽  
Ray Tanaka ◽  
Michael M. Bornstein

The increasing use of three-dimensional (3D) imaging techniques in dental medicine has boosted the development and use of artificial intelligence (AI) systems for various clinical problems. Cone beam computed tomography (CBCT) and intraoral/facial scans are potential sources of image data to develop 3D image-based AI systems for automated diagnosis, treatment planning, and prediction of treatment outcome. This review focuses on current developments and performance of AI for 3D imaging in dentomaxillofacial radiology (DMFR) as well as intraoral and facial scanning. In DMFR, machine learning-based algorithms proposed in the literature focus on three main applications, including automated diagnosis of dental and maxillofacial diseases, localization of anatomical landmarks for orthodontic and orthognathic treatment planning, and general improvement of image quality. Automatic recognition of teeth and diagnosis of facial deformations using AI systems based on intraoral and facial scanning will very likely be a field of increased interest in the future. The review is aimed at providing dental practitioners and interested colleagues in healthcare with a comprehensive understanding of the current trend of AI developments in the field of 3D imaging in dental medicine.


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