Optical Coherence Tomography (OCT) for Time-Resolved Imaging of Alveolar Dynamics in Mechanically Ventilated Rats

Schnabel, Christian; Gaertner, Maria; Koch, Edmund

doi:10.3390/app7030287

Cited by 3 publications

(4 citation statements)

References 10 publications

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“…The experimentally obtained axial resolution of Δz ¼ 11.6 μm in air (Δz ¼ 8.7 μm in tissue) is measured by means of the reflection of a glass plate and corresponds approximately to the one achieved with the scanner head without endoscope. 73 The lateral resolution is measured by telecentric OCT imaging of the USAF resolution test target and amounts to Δx ¼ 17.5 μm [cf. Fig.…”

Section: Eoct Scanner Performancementioning

confidence: 99%

In vivo imaging in the oral cavity by endoscopic optical coherence tomography

et al. 2018

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The common way to diagnose hard and soft tissue irregularities in the oral cavity is initially the visual inspection by an experienced dentist followed by further medical examinations, such as radiological imaging and/or histopathological investigation. For the diagnosis of oral hard and soft tissues, the detection of early transformations is mostly hampered by poor visual access, low specificity of the diagnosis techniques, and/or limited feasibility of frequent screenings. Therefore, optical noninvasive diagnosis of oral tissue is promising to improve the accuracy of oral screening. Considering this demand, a rigid handheld endoscopic scanner was developed for optical coherence tomography (OCT). The novelty is the usage of a commercially near-infrared endoscope with fitting optics in combination with an established spectral-domain OCT system of our workgroup. By reaching a high spatial resolution, in vivo images of anterior and especially posterior dental and mucosal tissues were obtained from the oral cavity of two volunteers. The convincing image quality of the endoscopic OCT device is particularly obvious for the imaging of different regions of the human soft palate with highly scattering fibrous layer and capillary network within the lamina propria.

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Section: Eoct Scanner Performancementioning

confidence: 99%

In vivo imaging in the oral cavity by endoscopic optical coherence tomography

et al. 2018

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“…The biological meaning of the proposed test is to provide the lung TOC to enhance facilities of the follow-up OCT of ex vivo lungs and to prove that a short time vaping may help in the future to improve significantly endoscopic optical modalities for lung studying, including endoscopic OCT [24,32]. TOC allows for increased resolution and improved imaging of lung tissues using OCT and many other optical techniques [57].…”

Section: Resultsmentioning

confidence: 99%

“…To increase the contrast of OCT images, Kohlfaerber et al used a microscopic resolution OCT (mOCT) with temporal tissue fluctuation (dynamic mOCT) for visualizing the morphological and functional micro-anatomy of the airways in vivo [23]. Schnabel et al compared three tissue optical clearing (TOC) methods to track the lung bio-distribution of hUC-MSCs labeled with the tdTomato fluorescent protein [24]. The direct detection of the tdTomato cells was only possible using the CUBIC clearing protocol, which resulted in highly transparent lungs and allowed for studying the interaction of the hUC-MSCs with cells in the host's lung.…”

Section: Introductionmentioning

confidence: 99%

Multimodal Diagnostics of Changes in Rat Lungs after Vaping

Yanina,

Genin,

Genina

et al. 2023

Diagnostics

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(1) Background: The use of electronic cigarettes has become widespread in recent years. The use of e-cigarettes leads to milder pathological conditions compared to traditional cigarette smoking. Nevertheless, e-liquid vaping can cause morphological changes in lung tissue, which affects and impairs gas exchange. This work studied the changes in morphological and optical properties of lung tissue under the action of an e-liquid aerosol. To do this, we implemented the “passive smoking” model and created the specified concentration of aerosol of the glycerol/propylene glycol mixture in the chamber with the animal. (2) Methods: In ex vivo studies, the lungs of Wistar rats are placed in the e-liquid for 1 h. For in vivo studies, Wistar rats were exposed to the e-liquid vapor in an aerosol administration chamber. After that, lung tissue samples were examined ex vivo using optical coherence tomography (OCT) and spectrometry with an integrating sphere. Absorption and reduced scattering coefficients were estimated for the control and experimental groups. Histological sections were made according to the standard protocol, followed by hematoxylin and eosin staining. (3) Results: Exposure to e-liquid in ex vivo and aerosol in in vivo studies was found to result in the optical clearing of lung tissue. Histological examination of the lung samples showed areas of emphysematous expansion of the alveoli, thickening of the alveolar septa, and the phenomenon of plasma permeation, which is less pronounced in in vivo studies than for the exposure of e-liquid ex vivo. E-liquid aerosol application allows for an increased resolution and improved imaging of lung tissues using OCT. Spectral studies showed significant differences between the control group and the ex vivo group in the spectral range of water absorption. It can be associated with dehydration of lung tissue owing to the hyperosmotic properties of glycerol and propylene glycol, which are the main components of e-liquids. (4) Conclusions: A decrease in the volume of air in lung tissue and higher packing of its structure under e-liquid vaping causes a better contrast of OCT images compared to intact lung tissue.

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“…These dynamic processes may occur at different time scales and are investigated in two papers of the special issue. C. Schnabel et al [13] use OCT to investigate the rather fast alveolar dynamics in an in vivo animal model. On the other hand, O. Thouvenin et al [14] use full field OCT in combination with dynamic, mechanical, and molecular contrast with the aim of providing tissue-and disease-specific information on a microscopic level and improving the sensitivity/specificity of disease diagnosis.…”

Section: Introductionmentioning

confidence: 99%