scholarly journals In Vivo Computed Tomography as a Research Tool to Investigate Asthma and COPD: Where Do We Stand?

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Gaël Dournes ◽  
Michel Montaudon ◽  
Patrick Berger ◽  
François Laurent
Keyword(s):  
Computed Tomography ◽  
Quantitative Research ◽  
Three Dimensional ◽  
Lung Parenchyma ◽  
Airway Disease ◽  
Bronchial Tree ◽  
Research Tool ◽  
Airway Wall ◽  
Clinical Tool

Computed tomography (CT) is a clinical tool widely used to assess and followup asthma and chonic obstructive pulmonary disease (COPD) in humans. Strong efforts have been made the last decade to improve this technique as a quantitative research tool. Using semiautomatic softwares, quantification of airway wall thickness, lumen area, and bronchial wall density are available from large to intermediate conductive airways. Skeletonization of the bronchial tree can be built to assess its three-dimensional geometry. Lung parenchyma density can be analysed as a surrogate of small airway disease and emphysema. Since resident cells involve airway wall and lung parenchyma abnormalities, CT provides an accurate and reliable research tool to assess their role in vivo. This litterature review highlights the most recent advances made to assess asthma and COPD with CT, and also their drawbacks and the place of CT in clarifying the complex physiopathology of both diseases.

scholarly journals Distinct functions of tissue-resident and circulating memory Th2 cells in allergic airway disease

2020 ◽  
Author(s):  
Rod A. Rahimi ◽  
Keshav Nepal ◽  
Murat Cetinbas ◽  
Ruslan I. Sadreyev ◽  
Andrew D. Luster
Keyword(s):  
Allergic Asthma ◽  
Allergic Airway Inflammation ◽  
Lung Parenchyma ◽  
Airway Disease ◽  
Gene Signature ◽  
Allergic Airway Disease ◽  
Transcriptional Analysis ◽  
Th2 Cells ◽  
Redundant Functions

ABSTRACTMemory CD4+ T helper type 2 (Th2) cells are critical in driving allergic asthma pathogenesis, yet the mechanisms whereby tissue-resident memory Th2 cells (Th2 Trm) and circulating memory Th2 cells collaborate in vivo remain unclear. Here, using a house dust mite (HDM) model of allergic asthma and parabiosis, we demonstrate that Th2 Trm and circulating memory Th2 cells perform non-redundant functions in vivo. Upon HDM re-challenge, circulating memory Th2 cells trafficked into the lung parenchyma and ignited perivascular inflammation to promote eosinophil and CD4+ T cell recruitment. In contrast, Th2 Trm proliferated near airways and promoted mucus metaplasia, airway hyper-responsiveness, and airway eosinophil activation. Transcriptional analysis revealed that Th2 Trm and circulating memory Th2 cells share a core Th2 gene signature, but also exhibit distinct transcriptional profiles. Specifically, Th2 Trm express a tissue adaptation signature, including genes involved in regulating and interacting with extracellular matrix. Our findings demonstrate that Th2 Trm and circulating memory Th2 cells are functionally and transcriptionally distinct subsets with unique roles in promoting allergic airway disease.SUMMARYHow memory Th2 cell subsets orchestrate allergic airway inflammation remains unclear. Rahimi et al. use a murine model of allergic asthma and parabiosis to demonstrate that tissue-resident and circulating memory Th2 cells are functionally distinct subsets with unique roles in promoting allergic airway disease.

scholarly journals Synchrotron-based dynamic computed tomography of tissue motion for regional lung function measurement

2012 ◽  
Vol 9 (74) ◽  
pp. 2213-2224 ◽  
Author(s):  
Stephen Dubsky ◽  
Stuart B. Hooper ◽  
Karen K. W. Siu ◽  
Andreas Fouras
Keyword(s):  
Computed Tomography ◽  
Lung Function ◽  
Ct Scanning ◽  
Bronchial Tree ◽  
Dynamic Computed Tomography ◽  
Lung Inflation ◽  
Regional Dynamics ◽  
Lung Expansion ◽  
Regional Lung

During breathing, lung inflation is a dynamic process involving a balance of mechanical factors, including trans-pulmonary pressure gradients, tissue compliance and airway resistance. Current techniques lack the capacity for dynamic measurement of ventilation in vivo at sufficient spatial and temporal resolution to allow the spatio-temporal patterns of ventilation to be precisely defined. As a result, little is known of the regional dynamics of lung inflation, in either health or disease. Using fast synchrotron-based imaging (up to 60 frames s −1 ), we have combined dynamic computed tomography (CT) with cross-correlation velocimetry to measure regional time constants and expansion within the mammalian lung in vivo . Additionally, our new technique provides estimation of the airflow distribution throughout the bronchial tree during the ventilation cycle. Measurements of lung expansion and airflow in mice and rabbit pups are shown to agree with independent measures. The ability to measure lung function at a regional level will provide invaluable information for studies into normal and pathological lung dynamics, and may provide new pathways for diagnosis of regional lung diseases. Although proof-of-concept data were acquired on a synchrotron, the methodology developed potentially lends itself to clinical CT scanning and therefore offers translational research opportunities.

Electronic Speckle Pattern Interferometry of the Vibrating Larynx

1995 ◽  
Vol 104 (1) ◽  
pp. 5-12 ◽  
Author(s):  
Glendon M. Gardner ◽  
Michelle Conerty ◽  
James Castracane ◽  
Steven M. Parnes
Keyword(s):  
Real Time ◽  
Quantitative Research ◽  
Speckle Pattern ◽  
Three Dimensional ◽  
Vocal Folds ◽  
Digital Data ◽  
Electronic Speckle Pattern Interferometry ◽  
Clinical Tool ◽  
Digital Hardware ◽  
Laser Holography

Laser holography is a technique that creates a three-dimensional image of a static object. This technique can be applied to the analysis of vibrating structures. Electronic speckle pattern interferometry uses a laser for illumination of the vibrating object and solid state detectors and digital hardware technology for capturing and processing the image in real time. This was performed on a human cadaver larynx and is the first time an interferogram of vibrating vocal cords has ever been obtained. Dark and bright interference fringes are seen that represent the vibratory motion of the vocal folds. These are presented in still photos as well as real-time on videotape. This method can provide advantages over current techniques of laryngeal study: it is sensitive to motion in the vertical dimension, and the digital data can be quantitatively analyzed. Application of this technique to study the larynx should eventually be a valuable clinical tool and provide quantitative research data.

Three-dimensional reconstruction based on images from spiral high-resolution computed tomography of the temporal bone: anatomy and clinical application

2005 ◽  
Vol 119 (9) ◽  
pp. 693-698 ◽  
Author(s):  
Beom-Cho Jun ◽  
Sun-Wha Song ◽  
Ju-Eun Cho ◽  
Chan-Soon Park ◽  
Dong-Hee Lee ◽  
...  
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
3D Reconstruction ◽  
Temporal Bone ◽  
Three Dimensional ◽  
Image Data ◽  
Computer Assisted ◽  
Surface Rendering ◽  
High Resolution Computed Tomography

The aim of this study was to investigate the usefulness of a three-dimensional (3D) reconstruction of computed tomography (CT) images in determining the anatomy and topographic relationship between various important structures. Using 40 ears from 20 patients with various otological diseases, a 3D reconstruction based on the image data from spiral high-resolution CT was performed by segmentation, volume-rendering and surface-rendering algorithms on a personal computer. The 3D display of the middle and inner ear structures was demonstrated in detail. Computer-assisted measurements, many of which could not be easily measured in vivo, of the reconstructed structures provided accurate anatomic details that improved the surgeon’s understanding of spatial relationships. A 3D reconstruction of temporal bone CT might be useful for education and increasing understanding of the anatomical structures of the temporal bone. However, it will be necessary to confirm the correlation between the 3D reconstructed images and histological sections through a validation study.

Three-Dimensional Imaging of the Hypopharynx and Larynx by Means of Helical (Spiral) Computed Tomography

1995 ◽  
Vol 104 (6) ◽  
pp. 425-431 ◽  
Author(s):  
Paul M. Silverman ◽  
Andrew S. Zeiberg ◽  
Thomas R. Troost ◽  
Roy B. Sessions ◽  
Robert K. Zeman
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Imaging Technique ◽  
Three Dimensional ◽  
Upper Airway ◽  
Spiral Ct ◽  
Airway Disease ◽  
Independent Review ◽  
Ct Technology ◽  
Conventional Ct

A new computed tomography (CT) technology, helical (spiral) CT, allows the entire neck to be imaged in only 30 seconds. Although multiplanar and three-dimensional (3-D) imaging could be performed with conventional CT, the volumetric acquisition provided by helical (spiral) CT allows significantly improved quality and easier reconstruction for more applications. These 3-D models show an airway appearance similar to that obtained with laryngography. Independent review of the 3-D images in 12 patients with lesions by two radiologists and one otolaryngologist was performed to assess 1) image quality, 2) ability to judge lesion extent, and 3) assistance in understanding the lesion compared to that provided by routine axial scans. Rating scores of 1 to 5 were assigned, with 5 representing the best quality or greatest value. The results showed that both groups scored image quality equally: 4.7. Lesion extent for the radiologists was 2.6, while the otolaryngologist's ranking was 3.7 (p < .01). In assisting understanding of lesions versus axial scans, radiologists ranked 3-D images 2.1, while the otolaryngologist ranked them 3.1 (p < .01). In summary, 3-D models provide a complementary imaging technique in understanding upper airway disease.

Percutaneous Tibial Fracture Reduction Using Computed Tomography Imaging, Computer Modelling and 3D Printed Alignment Constructs: A Cadaveric Study

2019 ◽  
Vol 32 (02) ◽  
pp. 139-148 ◽  
Author(s):  
John Davies ◽  
Albert Lynch
Keyword(s):  
Computed Tomography ◽  
Tibial Fracture ◽  
Computer Modelling ◽  
Three Dimensional ◽  
Joint Angles ◽  
In Vivo Evaluation ◽  
Minimally Invasive Osteosynthesis ◽  
Diaphyseal Fractures ◽  
3D Printed

Objective The main aim of this study was to evaluate a percutaneous method of bone alignment using a diaphyseal tibial fracture model. Materials and Methods Mid-shaft diaphyseal fractures were created in 12 large-breed canine tibiae. Interaction pins were inserted into the proximal and distal bone segments. Computed tomography scans of the fractured tibiae and pins were imported into three-dimensional (3D) modelling software and the fractures were virtually reduced. A multi-component 3D printed alignment jig was created that encompassed the pins in their aligned configuration. Orthogonal radiographs were taken after alignment jig application. Intact and post-alignment tibial lengths and joint angles were compared. Rotational alignment was subjectively evaluated. Results Post-alignment tibial lengths differed on the mediolateral and craniocaudal radiographs by an average of 1.55 and 1.43% respectively. Post-alignment mechanical medial proximal tibial angle, mechanical medial distal tibial angle and mechanical caudal proximal tibial angle had an average difference of 1.67°, 1.92° and 2.17° respectively. Differences in tibial length and joint angles were not significant (p > 0.05). Clinical Significance While in vivo evaluation is necessary, this technique to align diaphyseal fractures percutaneously using computer modelling and 3D printing is technically feasible and may facilitate the clinical use of minimally invasive osteosynthesis techniques.

Abstract 029: Photoacoustic Imaging - Novel In Vivo Quantification of Placental Hypoxia in a Mouse Model of Hypertensive Pregnancy

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Liliya M Yamaleyeva ◽  
Tiffaney Bledsoe ◽  
K. Bridget Brosnihan
Keyword(s):  
Nitric Oxide ◽  
Body Weight ◽  
Photoacoustic Imaging ◽  
Three Dimensional ◽  
Tissue Oxygen Saturation ◽  
Clinical Tool ◽  
Maternal Body ◽  
Nitric Oxide Inhibitor ◽  
Nitric Oxide Deficiency

Placental hypoxia/ischemia induces abnormal maternal and neonatal outcomes including preeclampsia and intrauterine growth restriction (IUGR). The ability to accurately determine placental oxygenation in a non-invasive way and in real-time is highly important during pregnancy as it may allow for the early diagnosis of IUGR and preeclampsia. Photoacoustic imaging (PA) is a novel preclinical and emerging clinical tool that combines optical contrast of photoacoustic laser technology with high spatial resolution of ultrasound. PA measures tissue oxygen saturation (sO2) that reflects differences in absorption spectra for oxygenated and deoxygenated hemoglobin. By using photoacoustic features of VEVO LAZR high resolution ultrasound system (VisualSonics) in a three-dimensional mode we investigated the sensitivity and accuracy of PA for placental oxygenation in C57Bl/6 mice at day 14 of gestation. Furthermore, since nitric oxide deficiency is associated with upregulation of circulatory hypoxia markers, C57Bl/6 mice were chronically treated with the nitric oxide inhibitor, L-NAME via osmotic minipumps (50 mg/kg/day; days 13 to 18 of gestation). The comparisons between scanned vs. not scanned uteroplacental units showed that PA had no effect on fetal (scanned: 0.028±0.001 vs. not scanned: 0.03±0.001 g/maternal body weight; p>0.05) or placental (scanned: 0.002±0.003 vs. not scanned: 0.002±0.002 g/maternal body weight; p>0.05) weights in C57Bl/6 mice. Changing inhaled O2 from 100- to 20% resulted on average in 12.5% reduction in total placental sO2. Systolic blood pressures were higher in L-NAME-treated vs. C57Bl/6 mice (215.8±0.8 vs. sham 99.3±4.4 mmHg; p<0.05). L-NAME infusion decreased sO2 in all areas of the placenta: labyrinth (73.6±0.97 vs. 58.6±3.4%, p<0.05), mesometrial triangle (63.0±2.0 vs. 48.9±1.0%, p<0.05), and total placenta (68.2±1.7 vs. 54.4±2.2%, p<0.05). Placental labyrinth had higher sO2 vs. mesometrial triangle area in both L-NAME infused (58.6±3.4 vs. 48.9±1.0%, p<0.05) and in C57Bl/6 (73.6±0.97 vs. 63.0±2.0%, p<0.05) mice reflecting elaborate branching morphology of the labyrinth. Our data suggest that PA imaging can detect regional differences in placental sO2 non-invasively and at different physiological states.

scholarly journals Morphological and functional properties of the conducting human airways investigated by in vivo computed tomography and in vitro MRI

2018 ◽  
Vol 124 (2) ◽  
pp. 400-413 ◽  
Author(s):  
Tristan Van de Moortele ◽  
Christine H. Wendt ◽  
Filippo Coletti
Keyword(s):  
Computed Tomography ◽  
Structure Function ◽  
Transverse Velocity ◽  
Three Dimensional ◽  
Diameter Ratio ◽  
Secondary Flows ◽  
Axial Component ◽  
Branch Diameter ◽  
Seven Generations

The accurate representation of the human airway anatomy is crucial for understanding and modeling the structure-function relationship in both healthy and diseased lungs. The present knowledge in this area is based on morphometric studies of excised lung casts, partially complemented by in vivo studies in which computed tomography (CT) was used on a small number of subjects. In the present study, we analyzed CT scans of a cohort of healthy subjects and obtained comprehensive morphometric information down to the seventh generation of bronchial branching, including airway diameter, length, branching angle, and rotation angle. Although some of the geometric parameters (such as the child-to-parent branch diameter ratio) are found to be in line with accepted values, for others (such as the branch length-to-diameter ratio) our findings challenge the common assumptions. We also evaluated several metrics of self-similarity, including the fractal dimension of the airway tree. Additionally, we used phase-contrast magnetic resonance imaging (MRI) to obtain the volumetric flow field in the three-dimensional-printed airway model of one of the subjects during steady inhalation. This is used to relate structural and functional parameters and, in particular, to close the power-law relationship between branch flow rate and diameter. The diameter exponent is found to be significantly lower than in the usually assumed Poiseuille regime, which we attribute to the strong secondary (i.e., transverse) velocity component. The strength of the secondary velocity with respect to the axial component exceeds the levels found in idealized airway models and persists within the first seven generations. NEW & NOTEWORTHY We performed a comprehensive computed tomography-based study of the conductive airway morphology in normal human subjects, including branch diameter, length, and mutual angles. We found significant departure from classic homothetic relationships. We also carried out MRI measurements of the three-dimensional inspiratory flow in an anatomy-based model and directly assessed structure-function relationships that have so far been assumed. We found that strong secondary flows (i.e., transverse velocity components) persist through the first seven generations of bronchial branching.

scholarly journals Distinct functions of tissue-resident and circulating memory Th2 cells in allergic airway disease

2020 ◽  
Vol 217 (9) ◽  
Author(s):  
Rod A. Rahimi ◽  
Keshav Nepal ◽  
Murat Cetinbas ◽  
Ruslan I. Sadreyev ◽  
Andrew D. Luster
Keyword(s):  
Allergic Asthma ◽  
Lung Parenchyma ◽  
Airway Disease ◽  
Gene Signature ◽  
Allergic Airway Disease ◽  
Transcriptional Analysis ◽  
Th2 Cells ◽  
Perivascular Inflammation

Memory CD4+ T helper type 2 (Th2) cells drive allergic asthma, yet the mechanisms whereby tissue-resident memory Th2 (Th2 Trm) cells and circulating memory Th2 cells collaborate in vivo remain unclear. Using a house dust mite (HDM) model of allergic asthma and parabiosis, we demonstrate that Th2 Trm cells and circulating memory Th2 cells perform nonredundant functions. Upon HDM rechallenge, circulating memory Th2 cells trafficked into the lung parenchyma and ignited perivascular inflammation to promote eosinophil and CD4+ T cell recruitment. In contrast, Th2 Trm cells proliferated near airways and induced mucus metaplasia, airway hyperresponsiveness, and airway eosinophil activation. Transcriptional analysis revealed that Th2 Trm cells and circulating memory Th2 cells share a core Th2 gene signature but also exhibit distinct transcriptional profiles. Th2 Trm cells express a tissue-adaptation signature, including genes involved in regulating and interacting with extracellular matrix. Our findings demonstrate that Th2 Trm cells and circulating memory Th2 cells are functionally and transcriptionally distinct subsets with unique roles in promoting allergic airway disease.

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