scholarly journals Phase-contrast X-ray tomography resolves the terminal bronchioles in free-breathing mice

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Kian Shaker ◽  
Ilian Häggmark ◽  
Jakob Reichmann ◽  
Marie Arsenian-Henriksson ◽  
Hans M. Hertz
Keyword(s):  
Mechanical Ventilation ◽  
Longitudinal Studies ◽  
Phase Contrast ◽  
Free Breathing ◽  
Lung Parenchyma ◽  
Tracheobronchial Tree ◽  
X Ray ◽  
Prospective Gating ◽  
Natural Breathing ◽  
Gated Imaging

AbstractPhase-contrast X-ray lung imaging has broken new ground in preclinical respiratory research by improving contrast at air/tissue interfaces. To minimize blur from respiratory motion, intubation and mechanical ventilation is commonly employed for end-inspiration gated imaging at synchrotrons and in the laboratory. Inevitably, the prospect of ventilation induced lung injury (VILI) renders mechanical ventilation a confounding factor in respiratory studies of animal models. Here we demonstrate proof-of-principle 3D imaging of the tracheobronchial tree in free-breathing mice without mechanical ventilation at radiation levels compatible with longitudinal studies. We use a prospective gating approach for end-expiration propagation-based phase-contrast X-ray imaging where the natural breathing of the mouse dictates the acquisition flow. We achieve intrapulmonary spatial resolution in the 30-μm-range, sufficient for resolving terminal bronchioles in the 60-μm-range distinguished from the surrounding lung parenchyma. These results should enable non-invasive longitudinal studies of native state murine airways for translational lung disease research in the laboratory.

scholarly journals A proof-of principal study using phase-contrast imaging for the detection of large airway pathologies after lung transplantation

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Stephan Umkehrer ◽  
Carmela Morrone ◽  
Julien Dinkel ◽  
Laura Aigner ◽  
Maximilian F. Reiser ◽  
...  
Keyword(s):  
Lung Transplantation ◽  
Phase Contrast ◽  
Small Animal ◽  
Lung Parenchyma ◽  
Dark Field ◽  
Contrast Imaging ◽  
X Ray ◽  
Contrast Mechanism ◽  
Contrast Information

Abstract In this study we aim to evaluate the assessment of bronchial pathologies in a murine model of lung transplantation with grating-based X-ray interferometry in vivo. Imaging was performed using a dedicated grating-based small-animal X-ray dark-field and phase-contrast scanner. While the contrast modality of the dark-field signal already showed several promising applications for diagnosing various types of pulmonary diseases, the phase-shifting contrast mechanism of the phase contrast has not yet been evaluated in vivo. For this purpose, qualitative analysis of phase-contrast images was performed and revealed pathologies due to previous lung transplantation, such as unilateral bronchial stenosis or bronchial truncation. Dependent lung parenchyma showed a strong loss in dark-field and absorption signal intensity, possibly caused by several post transplantational pathologies such as atelectasis, pleural effusion, or pulmonary infiltrates. With this study, we are able to show that bronchial pathologies can be visualized in vivo using conventional X-ray imaging when phase-contrast information is analysed. Absorption and dark-field images can be used to quantify the severity of lack of ventilation in the affected lung.

Influence of Lung Aeration on Pulmonary Concentrations of Nebulized and Intravenous Amikacin in Ventilated Piglets with Severe Bronchopneumonia

2002 ◽  
Vol 97 (1) ◽  
pp. 199-206 ◽  
Author(s):  
Marilia Elman ◽  
Ivan Goldstein ◽  
Charles-Hugo Marquette ◽  
Fréderic Wallet ◽  
Gilles Lenaour ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Mechanical Ventilation ◽  
Intravenous Administration ◽  
Porcine Model ◽  
Lung Parenchyma ◽  
Tracheobronchial Tree ◽  
Lung Deposition ◽  
Equivalent Dose ◽  
Intravenous Injections ◽  
Lung Aeration

Background Pulmonary concentrations of aminoglycosides administered intravenously are usually low in the infected lung parenchyma. Nebulization represents an alternative to increase pulmonary concentrations, although the obstruction of bronchioles by purulent plugs may impair lung deposition by decreasing lung aeration. Methods An experimental bronchopneumonia was induced in anesthetized piglets by inoculating lower lobes with a suspension of 10(6) cfu/ml Escherichia coli. After 24 h of mechanical ventilation, 7 animals received two intravenous injections of 15 mg/kg amikacin, and 11 animals received two nebulizations of 40 mg/kg amikacin at 24-h intervals. One hour following the second administration, animals were killed, and multiple lung specimens were sampled for assessing amikacin pulmonary concentrations and quantifying lung aeration on histologic sections. Results Thirty-eight percent of the nebulized amikacin (15 mg/kg) reached the tracheobronchial tree. Amikacin pulmonary concentrations were always higher after nebulization than after intravenous administration, decreased with the extension of parenchymal infection, and were significantly influenced by lung aeration: 197 +/- 165 versus 6 +/- 5 microg/g in lung segments with focal bronchopneumonia (P = 0.03), 40 +/- 62 versus 5 +/- 3 microg/g in lung segments with confluent bronchopneumonia (P = 0.001), 18 +/- 7 versus 7 +/- 4 microg/g in lung segments with lung aeration of 30% or less, and 65 +/- 9 versus 2 +/- 3 microg/g in lung segments with lung aeration of 50% or more. Conclusions In a porcine model of severe bronchopneumonia, the nebulization of amikacin provided 3-30 times higher pulmonary concentrations than the intravenous administration of an equivalent dose. The greater the lung aeration, the higher were the amikacin pulmonary concentrations found in the infected lung segments.

scholarly journals Effective segmentation of fresh post-mortem murine lung parenchyma in phase contrast X-ray tomographic microscopy images

2017 ◽  
Vol 849 ◽  
pp. 012006 ◽  
Author(s):  
Ioannis Vogiatzis Oikonomidis ◽  
Tiziana P Cremona ◽  
Goran Lovric ◽  
Filippo Arcadu ◽  
Marco Stampanoni ◽  
...  
Keyword(s):  
Phase Contrast ◽  
Lung Parenchyma ◽  
Post Mortem ◽  
Murine Lung ◽  
X Ray ◽  
Microscopy Images

Image Quality Analysis of X-ray Grating Interferometer Using Integrating-bucket Method

2020 ◽  
Vol 64 (2) ◽  
pp. 20503-1-20503-5
Author(s):  
Faiz Wali ◽  
Shenghao Wang ◽  
Ji Li ◽  
Jianheng Huang ◽  
Yaohu Lei ◽  
...  
Keyword(s):  
Image Quality ◽  
Phase Contrast ◽  
Quality Analysis ◽  
Phase Contrast Imaging ◽  
Phase Image ◽  
Contrast Imaging ◽  
High Quality ◽  
Image Quality Analysis ◽  
X Ray ◽  
Grating Interferometer

Abstract Grating-based x-ray phase-contrast imaging has the potential to enhance image quality and provide inner structure details non-destructively. In this work, using grating-based x-ray phase-contrast imaging system and employing integrating-bucket method, the quantitative expressions of signal-to-noise ratios due to photon statistics and mechanical error are analyzed in detail. Photon statistical noise and mechanical error are the main sources affecting the image noise in x-ray grating interferometry. Integrating-bucket method is a new phase extraction method translated to x-ray grating interferometry; hence, its image quality analysis would be of great importance to get high-quality phase image. The authors’ conclusions provide an alternate method to get high-quality refraction signal using grating interferometer, and hence increases applicability of grating interferometry in preclinical and clinical usage.

Numerical analysis of shift error in X-ray phase contrast imaging for large field of view

2017 ◽  
Vol 34 (1) ◽  
pp. 8
Author(s):  
Jianheng Huang ◽  
Yaohu Lei ◽  
Xin Liu ◽  
Jinchuan Guo ◽  
Ji Li ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Phase Contrast ◽  
Field Of View ◽  
Phase Contrast Imaging ◽  
Large Field ◽  
Contrast Imaging ◽  
X Ray
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