Evaluation of the usefulness of three-dimensional optical coherence tomography in a guinea pig model of endolymphatic hydrops induced by surgical obliteration of the endolymphatic duct

Abstract

Abstract. Optical coherence tomography (OCT) has advanced significantly over the past two decades and is currently used extensively to monitor the internal structures of organs, particularly in ophthalmology and dermatology. We used ethylenediamine tetra-acetic acid (EDTA) to decalcify the bony walls of the cochlea and investigated the inner structures by deep penetration of light into the cochlear tissue using OCT on a guinea pig model of endolymphatic hydrops (EH), induced by surgical obliteration of the endolymphatic duct. The structural and functional changes associated with EH were identified using OCT and auditory brainstem response tests, respectively. We also evaluated structural alterations in the cochlea using three-dimensional reconstruction of the OCT images, which clearly showed physical changes in the cochlear structures. Furthermore, we found significant anatomical variations in the EH model and conducted graphical analysis by strial atrophy for comparison. The physical changes included damage to and flattening of the organ of Corti-evidence of Reissner's membrane distention-and thinning of the lateral wall. These results indicate that observation of EDTA-decalcified cochlea using OCT is significant in examination of gradual changes in the cochlear structures that are otherwise not depicted by hematoxylin and eosin staining.

Bio-Photonic Detection and Quantitative Evaluation Method for the Progression of Dental Caries Using Optical Frequency-Domain Imaging Method

“…Optical coherence tomography (OCT) is a rapidly advancing optical frequency-domain imaging modality, which can provide non-invasive high-resolution cross-sectional images of dental tissues and various biological tissues [4]. This near-infrared (NIR) biomedical imaging method provides images with high axial and lateral resolutions (i.e., below 8 μm and 15 μm, respectively) [5,6], and, furthermore, OCT has been widely used in different medical applications such as ophthalmology [7,8], dermatology [9], and otolaryngology [10,11]. The methods currently in use for the detection of dental caries such as radiography, microradiography, and X-rays do not provide sufficient resolution, sensitivity, and contrast compared to OCT. Radiography is the most frequently applied inspection method in dentistry with a resolution of 50 μm, which is comparatively lower than the resolution of OCT.…”

Optical Inspection and Morphological Analysis of Diospyros kaki Plant Leaves for the Detection of Circular Leaf Spot Disease

“…Although the transmission depth of OCT is limited, it offers a high level of sensitivity when capturing depth-resolved images with a high signal-to-noise ratio. Thus, OCT is widely applied in various fields such as ophthalmology [ 11 , 12 ], dentistry [ 13 ], otolaryngology [ 14 ], and inspection of industrial defects [ 15 ]. Recently, OCT has become a prominent imaging modality in the field of agriculture.…”

Vasopressin induces endolymphatic hydrops in mouse inner ear, as evaluated with repeated 9.4 T MRI

“…Techniques to directly detect structural alterations associated with EH in vivo are not yet available, however, ultra-high imaging techniques for the use on small animals and pathological specimens have been developed including micro CT (Chihara et al, 2013, Lane et al, 2004, MR microscopy (Lane et al, 2005, Pettit et al, 2002 and optical coherence tomography (OCT) (Kakigiet al, 2013, Cho et al, 2015. These approaches avoid tissue destruction inherent to histological preparation using standard light microscopy.…”