scholarly journals Quantifying Regional Lung Deformation Using Four-Dimensional Computed Tomography: A Comparison of Conventional and Oscillatory Ventilation

2020 ◽  
Vol 11 ◽  
Author(s):  
Jacob Herrmann ◽  
Sarah E. Gerard ◽  
Wei Shao ◽  
Monica L. Hawley ◽  
Joseph M. Reinhardt ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Oscillatory Ventilation ◽  
Regional Lung ◽  
Lung Deformation

Setting Mean Airway Pressure during High-frequency Oscillatory Ventilation According to the Static Pressure–Volume Curve in Surfactant-deficient Lung Injury

2003 ◽  
Vol 99 (6) ◽  
pp. 1313-1322 ◽  
Author(s):  
Thomas Luecke ◽  
Juergen P. Meinhardt ◽  
Peter Herrmann ◽  
Gerald Weisser ◽  
Paolo Pelosi ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Lung Volume ◽  
High Frequency ◽  
Airway Pressure ◽  
Static Pressure ◽  
High Frequency Oscillatory Ventilation ◽  
Mean Airway Pressure ◽  
Oscillatory Ventilation ◽  
Hemodynamic Variables ◽  
High Frequency Oscillatory

Background Numerous studies suggest setting positive end-expiratory pressure during conventional ventilation according to the static pressure-volume (P-V) curve, whereas data on how to adjust mean airway pressure (P(aw)) during high-frequency oscillatory ventilation (HFOV) are still scarce. The aims of the current study were to (1) examine the respiratory and hemodynamic effects of setting P(aw) during HFOV according to the static P-V curve, (2) assess the effect of increasing and decreasing P(aw) on slice volumes and aeration patterns at the lung apex and base using computed tomography, and (3) study the suitability of the P-V curve to set P(aw) by comparing computed tomography findings during HFOV with those obtained during recording of the static P-V curve at comparable pressures. Methods Saline lung lavage was performed in seven adult pigs. P-V curves were obtained with computed tomography scanning at each volume step at the lung apex and base. The lower inflection point (Pflex) was determined, and HFOV was started with P(aw) set at Pflex. The pigs were provided five 1-h cycles of HFOV. P(aw), first set at Pflex, was increased to 1.5 times Pflex (termed 1.5 Pflex(inc)) and 2 Pflex and decreased thereafter to 1.5 times Pflex and Pflex (termed 1.5 Pflex(dec) and Pflex(dec)). Hourly measurements of respiratory and hemodynamic variables as well as computed tomography scans at the apex and base were made. Results High-frequency oscillatory ventilation at a P(aw) of 1.5 Pflex(inc) reestablished preinjury arterial oxygen tension values. Further increase in P(aw) did not change oxygenation, but it decreased oxygen delivery as a result of decreased cardiac output. No differences in respiratory or hemodynamic variables were observed when comparing HFOV at corresponding P(aw) during increasing and decreasing P(aw). Variation in total slice lung volume (TLVs) was far less than expected from the static P-V curve. Overdistended lung volume was constant and less than 3% of TLVs. TLVs values during HFOV at Pflex, 1.5 Pflex(inc), and 2 Pflex were significantly greater than TLVs values at corresponding tracheal pressures on the inflation limb of the static P-V curve and located near the deflation limb. In contrast, TLVs values during HFOV at decreasing P(aw) (i.e., 1.5 Pflex(dec) and Pflex(dec)) were not significantly greater than corresponding TLV on the deflation limb of the static P-V curves. The marked hysteresis observed during static P-V curve recordings was absent during HFOV. Conclusions High-frequency oscillatory ventilation using P(aw) set according to a static P-V curve results in effective lung recruitment, and slice lung volumes during HFOV are equal to those from the deflation limb of the static P-V curve at equivalent pressures.

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.

scholarly journals Three-dimensional characterization of regional lung deformation

2011 ◽  
Vol 44 (13) ◽  
pp. 2489-2495 ◽  
Author(s):  
Ryan Amelon ◽  
Kunlin Cao ◽  
Kai Ding ◽  
Gary E. Christensen ◽  
Joseph M. Reinhardt ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Regional Lung ◽  
Lung Deformation

scholarly journals In vivo imaging of canine lung deformation: effects of posture, pneumonectomy, and inhaled erythropoietin

2020 ◽  
Vol 128 (5) ◽  
pp. 1093-1105
Author(s):  
Cuneyt Yilmaz ◽  
D. Merrill Dane ◽  
Nicholas J. Tustison ◽  
Gang Song ◽  
James C. Gee ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Mechanical Properties ◽  
Uniform Distribution ◽  
In Vivo Imaging ◽  
Growth Promoter ◽  
Lung Growth ◽  
Image Deformation ◽  
Large Animals ◽  
Lung Deformation

Mechanical stresses on the lung impose the major stimuli for lung growth. We used computed tomography to image deformation of the lung in relation to posture, loss of lung units, and inhalational delivery of the growth promoter erythropoietin. Following loss of one lung in adult large animals, the remaining lung expanded and grew while retaining near-normal mechanical properties. Inhalation of erythropoietin promoted more uniform distribution of blood volume within the remaining lung.

scholarly journals Regional Lung Recruitability During Pneumoperitoneum Depends on Chest Wall Elastance – A Mechanical and Computed Tomography Analysis in Rats

2018 ◽  
Vol 9 ◽  
Author(s):  
Lucia Comuzzi ◽  
Mariana B. de Abreu ◽  
Gabriel C. Motta-Ribeiro ◽  
Renata T. Okuro ◽  
Thiago Barboza ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Chest Wall ◽  
Regional Lung ◽  
Chest Wall Elastance ◽  
Tomography Analysis

Regional lung volume changes during high-frequency oscillatory ventilation*

2010 ◽  
Vol 11 (5) ◽  
pp. 610-615 ◽  
Author(s):  
Gerhard K. Wolf ◽  
Bartłomiej Grychtol ◽  
Inez Frerichs ◽  
David Zurakowski ◽  
John H. Arnold
Keyword(s):  
Lung Volume ◽  
High Frequency ◽  
High Frequency Oscillatory Ventilation ◽  
Volume Changes ◽  
Oscillatory Ventilation ◽  
Regional Lung ◽  
High Frequency Oscillatory

scholarly journals Quantitative computed tomography determined regional lung mechanics in normal nonsmokers, normal smokers and metastatic sarcoma subjects

PLoS ONE ◽  
2017 ◽  
Vol 12 (7) ◽  
pp. e0179812 ◽  
Author(s):  
Jiwoong Choi ◽  
Eric A. Hoffman ◽  
Ching-Long Lin ◽  
Mohammed M. Milhem ◽  
Jean Tessier ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Quantitative Computed Tomography ◽  
Lung Mechanics ◽  
Regional Lung ◽  
Metastatic Sarcoma

Comparison Of Computed Tomography Techniques To Measure Regional Lung Strain

2011 ◽  
Author(s):  
Tyler Wellman ◽  
Tilo Winkler ◽  
Eduardo L.V. Costa ◽  
Guido Musch ◽  
R Scott Harris ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Regional Lung ◽  
Lung Strain
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