|
Records |
Links |
|
Author |
Vinchurkar, S.; De Backer, L.; Vos, W.; Van Holsbeke, C.; de Backer, J.; de Backer, W. |
![find record details (via OpenURL) openurl](img/xref.gif)
|
|
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
A case series on lung deposition analysis of inhaled medication using functional imaging based computational fluid dynamics in asthmatic patients : effect of upper airway morphology and comparison with in vivo data |
Type |
A1 Journal article |
|
Year |
2012 |
Publication |
Inhalation Toxicology |
Abbreviated Journal |
Inhal Toxicol |
|
|
Volume |
24 |
Issue |
2 |
Pages |
81-88 |
|
|
Keywords |
A1 Journal article; Pharmacology. Therapy; Biophysics and Biomedical Physics; Condensed Matter Theory (CMT); Laboratory Experimental Medicine and Pediatrics (LEMP) |
|
|
Abstract |
Context: Asthma affects 20 million Americans resulting in an economic burden of approximately $18 billion in the US alone (Allergies and Asthma Foundation 2000; National Center for Environmental Health (NCEH) 1999). Research studies based on differences in patient-specific airway morphology for asthma and the associated effect on deposition of inhaled aerosols are currently not available in the literature. Therefore, the role of morphological variations such as upper airway (extrathoracic) occlusion is not well documented. Objective: Functional imaging based computational fluid dynamics (CFD) of the respiratory airways for five asthmatic subjects is performed in this study using computed tomography (CT) based patient-specific airway models and boundary conditions. Methods: CT scans for 5 asthma patients were used to reconstruct 3D lung models using segmentation software. An averaged inhalation profile and patient-specific lobar flow distribution were used to perform the simulation. The simulations were used to obtain deposition for BDP/Formoterol (R) HFA pMDI in the patient-specific airway models. Results: The lung deposition obtained using CFD was in excellent agreement with available in vivo data using the same product. Specifically, CFD resulted in 30% lung deposition, whereas in vivo lung deposition was reported to be approximately 31%. Conclusion: It was concluded that a combination of patient-specific airway models and lobar boundary conditions can be used to obtain accurate lung deposition estimates. Lower lung deposition can be expected for patients with higher extrathoracic resistance. Novel respiratory drug delivery devices need to accommodate population subgroups based on these morphological and anatomical differences in addition to subject age. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
|
|
Language |
|
Wos |
000299744800001 |
Publication Date |
2012-01-20 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0895-8378;1091-7691; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
1.751 |
Times cited |
36 |
Open Access |
|
|
|
Notes |
; ; |
Approved |
Most recent IF: 1.751; 2012 IF: 1.894 |
|
|
Call Number |
UA @ lucian @ c:irua:96238 |
Serial |
286 |
|
Permanent link to this record |
|
|
|
|
Author |
De Backer, L.A.; Vos, W.G.; Salgado, R.; de Backer, J.W.; Devolder, A.; Verhulst, S.L.; Claes, R.; Germonpré, P.R.; de Backer, W.A. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
|
|
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Functional imaging using computer methods to compare the effect of salbutamol and ipratropium bromide in patient-specific airway models of COPD |
Type |
A1 Journal article |
|
Year |
2011 |
Publication |
International journal of chronic obstructive pulmonary disease |
Abbreviated Journal |
Int J Chronic Obstr |
|
|
Volume |
6 |
Issue |
|
Pages |
637-646 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Vision lab; Laboratory Experimental Medicine and Pediatrics (LEMP) |
|
|
Abstract |
Background: Salbutamol and ipratropium bromide improve lung function in patients with chronic obstructive pulmonary disease (COPD). However, their bronchodilating effect has not yet been compared in the central and distal airways. Functional imaging using computational fluid dynamics offers the possibility of making such a comparison. The objective of this study was to assess the effects of salbutamol and ipratropium bromide on the geometry and computational fluid dynamics-based resistance of the central and distal airways.Methods: Five patients with Global Initiative for Chronic Obstructive Lung Disease Stage III COPD were randomized to a single dose of salbutamol or ipratropium bromide in a crossover manner with a 1-week interval between treatments. Patients underwent lung function testing and a multislice computed tomography scan of the thorax that was used for functional imaging. Two hours after dosing, the patients again underwent lung function tests and repeat computed tomography.Results: Lung function parameters, including forced expiratory volume in 1 second, vital capacity, overall airway resistance, and specific airway resistance, changed significantly after administration of each product. On functional imaging, the bronchodilating effect was greater in the distal airways, with a corresponding drop in airway resistance, compared with the central airways. Salbutamol and ipratropium bromide were equally effective at first glance when looking at lung function tests, but when viewed in more detail with functional imaging, hyporesponsiveness could be shown for salbutamol in one patient. Salbutamol was more effective in the other patients.Conclusion: This pilot study gives an innovative insight into the modes of action of salbutamol and ipratropium bromide in patients with COPD, using the new techniques of functional imaging and computational fluid dynamics. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000208709800068 |
Publication Date |
2011-11-28 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1178-2005; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.157 |
Times cited |
25 |
Open Access |
|
|
|
Notes |
; ; |
Approved |
Most recent IF: 3.157; 2011 IF: NA |
|
|
Call Number |
UA @ lucian @ c:irua:93165 |
Serial |
1300 |
|
Permanent link to this record |
|
|
|
|
Author |
Vos, W.; de Backer, J.; Poli, G.; De Volder, A.; Ghys, L.; Van Holsbeke, C.; Vinchurkar, S.; De Backer, L.; de Backer, W. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
|
|
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Novel functional imaging of changes in small airways of patients treated with extrafine beclomethasone/formoterol |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
Respiration |
Abbreviated Journal |
Respiration |
|
|
Volume |
86 |
Issue |
5 |
Pages |
393-401 |
|
|
Keywords |
A1 Journal article; Biophysics and Biomedical Physics; Condensed Matter Theory (CMT); Laboratory Experimental Medicine and Pediatrics (LEMP) |
|
|
Abstract |
Background: Inhaled formulations using extrafine particles of long-acting beta(2)-agonists and corticosteroids were developed to optimize asthma treatment. Findings that these combinations reach and treat smaller airways more effectively are predominantly based on general non-specific outcomes with little information on regional characteristics. Objectives: This study aims to assess long-term effects of extrafine beclomethasone/formoterol on small airways of asthmatic patients using novel functional imaging methods. Methods: Twenty-four stable asthma patients were subdivided into three groups (steroid naive, n = 7; partially controlled, n = 6; well controlled, n = 11). Current treatment was switched to a fixed combination of extrafine beclomethasone/formoterol (Foster (R); Chiesi Pharmaceuticals, Parma, Italy). Patients underwent lung function evaluation and thorax high-resolution computerized tomography (HRCT) scan. Local airway resistance was obtained from computational fluid dynamics (CFD). Results: After 6 months, the entire population showed improvement in pre-bronchodilation imaging parameters, including small airway volume (p = 0.0007), resistance (p = 0.011), and asthma control score (p = 0.016). Changes in small airway volume correlated with changes in asthma control score (p = 0.004). Forced expiratory volume in 1 s (p = 0.044) and exhaled nitric oxide (p = 0.040) also improved. Functional imaging provided more detail and clinical relevance compared to lung function tests, especially in the well-controlled group where only functional imaging parameters showed significant improvement, while the correlation with asthma control score remained. Conclusions: Extrafine beclomethasone/formoterol results in a significant reduction of small airway obstruction, detectable by functional imaging (HRCT/CFD). Changes in imaging parameters correlated significantly with clinically relevant improvements. This indicates that functional imaging is a useful tool for sensitive assessment of changes in the respiratory system after asthma treatment. Copyright (C) 2013 S. Karger AG, Basel |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
Basel |
Editor |
|
|
|
Language |
|
Wos |
000329046200006 |
Publication Date |
2013-04-12 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1423-0356;0025-7931; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
2.772 |
Times cited |
30 |
Open Access |
|
|
|
Notes |
; ; |
Approved |
Most recent IF: 2.772; 2013 IF: 2.924 |
|
|
Call Number |
UA @ lucian @ c:irua:113762 |
Serial |
2376 |
|
Permanent link to this record |
|
|
|
|
Author |
De Backer, L.A.; Vos, W.; de Backer, J.; Van Holsbeke, C.; Vinchurkar, S.; de Backer, W. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
|
|
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
The acute effect of budesonide/formoterol in COPD : a multi-slice computed tomography and lung function study |
Type |
A1 Journal article |
|
Year |
2012 |
Publication |
European Respiratory Journal |
Abbreviated Journal |
Eur Respir J |
|
|
Volume |
40 |
Issue |
2 |
Pages |
298-305 |
|
|
Keywords |
A1 Journal article; Biophysics and Biomedical Physics; Condensed Matter Theory (CMT); Laboratory Experimental Medicine and Pediatrics (LEMP) |
|
|
Abstract |
The Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification of chronic obstructive pulmonary disease (COPD) does not always match with other clinical disease descriptors such as exacerbation frequency and quality of life, indicating that forced expiratory volume in 1 s (FEV1) is not a perfect descriptor of the disease. The aim of this study was to find out whether changes in airway geometry after inhalation of the most commonly used inhalation therapy in severe COPD can more adequately be described with an image-based approach than with spirometry. 10 COPD GOLD stage III patients were assessed in a double-blind crossover study. Airway volumes were analysed using segmentation of multi-slice computed tomography (MSCT) images; airway resistance was determined using computational fluid dynamics (CFD). Distal airway volume significantly increased (p=0.011) in patients 4 h after receiving a budesonide/formoterol combination from 9.6+/-4.67 cm(3) to 10.14+/-4.81 cm(3). Also CFD-determined airway resistance significantly decreased (p=0.047) from 0.051+/-0.021 kPa.s.L-1 to 0.043+/- 0.019 kPa.s.L-1. None of the lung function parameters showed a significant change. Only functional residual capacity (FRC) showed a trend to decline (p=0.056). Only the image-based parameters were able to predict the visit at which the combination product was administered. This study showed that imaging is a sensitive, complementary tool to describe changes in airway structure. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
Copenhagen |
Editor |
|
|
|
Language |
|
Wos |
000307291700006 |
Publication Date |
2011-12-20 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0903-1936;1399-3003; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
10.569 |
Times cited |
37 |
Open Access |
|
|
|
Notes |
; ; |
Approved |
Most recent IF: 10.569; 2012 IF: 6.355 |
|
|
Call Number |
UA @ lucian @ c:irua:101113 |
Serial |
3568 |
|
Permanent link to this record |
|
|
|
|
Author |
De Backer, L.; Vos, W.; Dieriks, B.; Daems, D.; Verhulst, S.; Vinchurkar, S.; Ides, K.; de Backer, J.; Germonpré, P.; de Backer, W. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
|
|
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
The effects of long-term noninvasive ventilation in hypercapnic COPD patients : a randomized controlled pilot study |
Type |
A1 Journal article |
|
Year |
2011 |
Publication |
International journal of chronic obstructive pulmonary disease |
Abbreviated Journal |
Int J Chronic Obstr |
|
|
Volume |
6 |
Issue |
|
Pages |
615-624 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Laboratory Experimental Medicine and Pediatrics (LEMP) |
|
|
Abstract |
Introduction: Noninvasive ventilation (NIV) is a well-established treatment for acute-on-chronic respiratory failure in hypercapnic COPD patients. Less is known about the effects of a long-term treatment with NIV in hypercapnic COPD patients and about the factors that may predict response in terms of improved oxygenation and lowered CO2 retention.Methods: In this study, we randomized 15 patients to a routine pharmacological treatment (n = 5, age 66 [standard deviation ± 6] years, FEV1 30.5 [±5.1] %pred, PaO2 65 [±6] mmHg, PaCO2 52.4 [±6.0] mmHg) or to a routine treatment and NIV (using the Synchrony BiPAP device [Respironics, Inc, Murrsville, PA]) (n = 10, age 65 [±7] years, FEV1 29.5 [±9.0] %pred, PaO2 59 [±13] mmHg, PaCO2 55.4 [±7.7] mmHg) for 6 months. We looked at arterial blood gasses, lung function parameters and performed a low-dose computed tomography of the thorax, which was later used for segmentation (providing lobe and airway volumes, iVlobe and iVaw) and post-processing with computer methods (providing airway resistance, iRaw) giving overall a functional image of the separate airways and lobes.Results: In both groups there was a nonsignificant change in FEV1 (NIV group 29.5 [9.0] to 38.5 [14.6] %pred, control group 30.5 [5.1] to 36.8 [8.7] mmHg). PaCO2 dropped significantly only in the NIV group (NIV: 55.4 [7.7] → 44.5 [4.70], P = 0.0076; control: 52.4 [6.0] → 47.6 [8.2], NS). Patients actively treated with NIV developed a more inhomogeneous redistribution of mass flow than control patients. Subsequent analysis indicated that in NIV-treated patients that improve their blood gases, mass flow was also redistributed towards areas with higher vessel density and less emphysema, indicating that flow was redistributed towards areas with better perfusion. There was a highly significant correlation between the % increase in mass flow towards lobes with a blood vessel density of >9% and the increase in PaO2. Improved ventilation–perfusion match and recruitment of previously occluded small airways can explain the improvement in blood gases.Conclusion: We can conclude that in hypercapnic COPD patients treated with long-term NIV over 6 months, a mass flow redistribution occurs, providing a better ventilation–perfusion match and hence better blood gases and lung function. Control patients improve homogeneously in iVaw and iRaw, without improvement in gas exchange since there is no improved ventilation/perfusion ratio or increased alveolar ventilation. These differences in response can be detected through functional imaging, which gives a more detailed report on regional lung volumes and resistances than classical lung function tests do. Possibly only patients with localized small airway disease are good candidates for long-term NIV treatment. To confirm this and to see if better arterial blood gases also lead to better health related quality of life and longer survival, we have to study a larger population. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000208709800066 |
Publication Date |
2011-11-18 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1178-2005; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.157 |
Times cited |
28 |
Open Access |
|
|
|
Notes |
; ; |
Approved |
Most recent IF: 3.157; 2011 IF: NA |
|
|
Call Number |
UA @ lucian @ c:irua:93164 |
Serial |
866 |
|
Permanent link to this record |