Improved retrospectively gated in-vivo microCT for simultaneous assessment of lung function and anatomy in mice

Retrospective gating (RG) is a well established technique in preclinical computed tomography (CT) to assess 3D morphology of the lung. In RG additional angular projections are recorded typically by performing multiple rotations. Consequently, the projections are sorted according to the expansion state of the chest and those sets are then reconstructed separately. Thus, the breathing motion artefacts are suppressed at a cost of strongly elevated x-ray dose levels. Here we propose to use the entire raw data to assess lung function in addition to retrospectively gated 3D reconstruction that visualize anatomical structures of the lung. Using this novel RG based x-ray lung function approach (RG based XLF) on the example of the mdx mouse model of Duchenne muscle dystrophy (mdx) we accurately obtained both the 3D anatomical morphology of the lung and the thoracic bones as well as the functional temporal parameters of the lung. Thus, RG-based XLF will remove the necessity for separate acquisition procedures by being able to reproduce comparable lung function results in a single low dose CT scan.