Pre-clinical background
Sprague-Dawley rats are often used in pre-clinical trials involving inhalation medication for safety assessment and dose finding studies. These type of studies can become costly and there is always the issue of animal welfare.
Question
Can imaging be used to create a representative model of the rat’s respiratory system?
Imaging and segmentation
To address this question, a total of 11 Sprague-Dawley rats was selected with an average weight of 372g. The animals underwent static and dynamic micro CT scanning of the upper and lower respiratory system. From these images it was possible to segment the airway structure and measure the airway dimensions.
Segmentation of the tracheobronchial airways in the Sprague Dawley rat
By measuring also the upper airway using dynamic micro CT scanning it was possible to reconstruct a realistic model of the respiratory system of a Sprague Dawley rat. Also the lobar structure could be defined based on the CT images as depicted below.
Resulting average model of Sprague Dawley rat respiratory system
Conclusions
Micro CT scanning and segmentation methods are adequate tools to generate animal specific three dimensional models of the respiratory system. These models can be used in a later stage as a basis for flow and structural simulations.
Publication
Study of the variability in upper and lower airway morphology in Sprague-Dawley rats using modern micro-CT scan-based segmentation techniques.
De Backer JW, Vos WG, Burnell P, Verhulst SL, Salmon P, De Clerck N, De Backer W.
Anat Rec (Hoboken). 2009 May;292(5):720-7.
free article: download