Sammanfattning
Techniques able to detect impairments in the distal human lung are lacking. Since inhaled nanoparticles are predominantly deposited in the acini, their deposition can be used to derive structural properties of the region. In
theory, structural enlargements in the distal lung imply that less inhaled nanoparticles deposit there. This rationale is the basis of the airspace dimension assessment (AiDA) method.
The research presented in this thesis aimed to evaluate and characterize this new method for the measurement of distal lung structure. The objective was to do so by comparing the AiDA method with other lung structure and lung function measuring techniques as well as with background variables. AiDA measurements were carried out with nearly 800 individuals in four different studies. From these, distal airspace radii (rAiDA) were calculated, along with a second index: zero seconds recovery R0.The AiDA method was benchmarked against magnetic resonance imaging (MRI) with hyperpolarized gas, with 23 healthy individuals and compared to computed tomography (CT) variables and standard pulmonary function tests (PFTs) in a population-based cohort with 695 subjects. The method was also evaluated as a tool to detect lung changes in an occupational group exposed to high loads of air pollution (with 28 welders and 17 controls), and AiDA indices were evaluated as parameters that can explain observed discrepancies between modeled and measured respiratory tract particle deposition in a group of 17 healthy participants.
The measured rAiDA were correlated with lung microstructure measurements obtained with MRI with hyperpolarized gas and rAiDA were on average larger in subjects with emphysema detected with CT, in comparison with healthy participants. The AiDA indices explained variance that no other PFTs captured, but there was no average difference between the occupational group and controls measurable with the AiDA method. The rAiDA were correlated with the difference between measured and modeled respiratory tract particle deposition. Moreover, rAiDA increased with age, but the inter-subject variability was large in all age groups.
The results demonstrated that the AiDA method has potential to characterize distal lung structure and may serve as a new, non-invasive tool for clinical examination of human lungs. However, the R0 index needs to be further
evaluated. In the future, controlled clinical trials are necessary to evaluate the method’s sensitivity to different lung conditions.
theory, structural enlargements in the distal lung imply that less inhaled nanoparticles deposit there. This rationale is the basis of the airspace dimension assessment (AiDA) method.
The research presented in this thesis aimed to evaluate and characterize this new method for the measurement of distal lung structure. The objective was to do so by comparing the AiDA method with other lung structure and lung function measuring techniques as well as with background variables. AiDA measurements were carried out with nearly 800 individuals in four different studies. From these, distal airspace radii (rAiDA) were calculated, along with a second index: zero seconds recovery R0.The AiDA method was benchmarked against magnetic resonance imaging (MRI) with hyperpolarized gas, with 23 healthy individuals and compared to computed tomography (CT) variables and standard pulmonary function tests (PFTs) in a population-based cohort with 695 subjects. The method was also evaluated as a tool to detect lung changes in an occupational group exposed to high loads of air pollution (with 28 welders and 17 controls), and AiDA indices were evaluated as parameters that can explain observed discrepancies between modeled and measured respiratory tract particle deposition in a group of 17 healthy participants.
The measured rAiDA were correlated with lung microstructure measurements obtained with MRI with hyperpolarized gas and rAiDA were on average larger in subjects with emphysema detected with CT, in comparison with healthy participants. The AiDA indices explained variance that no other PFTs captured, but there was no average difference between the occupational group and controls measurable with the AiDA method. The rAiDA were correlated with the difference between measured and modeled respiratory tract particle deposition. Moreover, rAiDA increased with age, but the inter-subject variability was large in all age groups.
The results demonstrated that the AiDA method has potential to characterize distal lung structure and may serve as a new, non-invasive tool for clinical examination of human lungs. However, the R0 index needs to be further
evaluated. In the future, controlled clinical trials are necessary to evaluate the method’s sensitivity to different lung conditions.
| Originalspråk | engelska |
|---|---|
| Kvalifikation | Doktor |
| Tilldelande institution |
|
| Tilldelningsdatum | 2023 mars 17 |
| Förlag | |
| ISBN (tryckt) | 978-91-8039-539-7 |
| ISBN (elektroniskt) | 978-91-8039-538-0 |
| Status | Published - 2023 feb. 21 |
Bibliografisk information
Defence detailsDate: 2023-03-17
Time: 09:15
Place: Lecture Hall Stora hörsalen, IKDC, Sölvegatan 26, Faculty of Engineering LTH, Lund University, Lund.
External reviewer(s)
Name: Sigsgaard, Torben
Title: Prof.
Affiliation: Aarhus University, Denmark.
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Ämnesklassifikation (UKÄ)
- Lungmedicin och allergi
- Miljömedicin och yrkesmedicin
