Definition of Airway Composition Within Gamma Camera Images

3D In Silico Modeling of the Human Respiratory System for Inhaled Drug Delivery and Imaging Analysis

“…If such data are to be used as published, what does a modeler do when faced with a conundrum; namely, when the dimensions of the individual airways after being compiled into a network have a product that may appear aphysical? This has been already demonstrated by Martonen et al 48 for symmetric Weibel 49,50 morphologies. Indeed, that result lead to the development of the reflection technique, because we fully recognize the value of the rare morphometric data obtained in clinical research and wish to use it.…”

“…Indeed, that result lead to the development of the reflection technique, because we fully recognize the value of the rare morphometric data obtained in clinical research and wish to use it. Accordingly, the aforementioned demonstration 48 that the Weibel morphology was aphysical when compared to real scintigraphy data lead to the development of a theoretical lung model by Martonen et al 51 that was, by design, applicable to clinical studies at McMaster University (Canada). In any event, we have evolved another technique that is not based on reflection, yet still uses morphometric data as originally published.…”

Airway Identification Within Planar Gamma Camera Images Using Computer Models of Lung Morphology

“…Previous studies have shown that morphologies based on simplified idealized models are aphysical and are therefore limited in their effectiveness with scintigraphy protocols (18,20,21). For an accurate assessment of airway distributions, a morphology has been developed such that the airway networks are confined within mathematically defined boundaries representing lung surfaces.…”

“…Then a partition delineating the different regions was superimposed on the computer simulations to distinguish airways in each respective region. This is an extension over previous efforts (18,19) in which 2-D computer simulations were used to model the airway structure. This 3-D approach overcomes the limitation of 2-D models in accurately simulating the actual shape of the lung, the same limitation that planar images suffer from fully representing the distribution of aerosol deposited in the lung.…”

Human Lung Morphology Models for Particle Deposition Studies

“…Many of the mathematical models reported in the literature that describe PM deposition use Weibel's model A morphology (Weibel, 1963), which assumes the airways of the lung to be a symmetric dichotomously branching system. However, computer simulations of that morphology have shown it to lack realism when compared to scintigraphy images (Martonen et al, 1994a). Therefore, new morphological models were created using planar gamma camera and 3-D single-photon emission computed tomography (SPEC T) images as guides (Martonen et al, 1997.…”