Table 1.
Subject baseline characteristics at each site.
Fig 1.
Schematic overview of the proposed dense convolutional network (DN) architecture.
Table 2.
Computed QAT values from multiple radiologist verified thresholds and the PTM.
Fig 2.
Presented from a single case from the Site 1 examined at 12 months are representative images from A) the inspiratory CT scan and AT maps from B) a static threshold of -856HU, C) the personalized threshold method (PTM), D) the DN method (presented as probability map), and E) radiographic assessment by a trained radiologist.
The QAT for the whole 3D dataset is provided on the top right corner of each 2D image. The images are windowed between [–950, 150] for display purposes so that regions of AT are visible.
Fig 3.
Presented are Quantitative air trapping (QAT) results of the various methods from Site 1 cohort at the different examination times.
Fig 4.
A) Presented from a single case from the Site 2 cohort examined at 3 months are representative images from A) the inspiratory CT scan and the AT maps from the personalized threshold method (PTM), the DN method, and radiographic assessment by a trained radiologist. The QAT for the whole 3D dataset is provided on the top right corner of each 2D image. The images are windowed between [–950, 150] for display purposes so that regions of AT are visible. B) Quantitative air trapping (QAT) at different times by the various methods on the Site 2 cohort.
Table 3.
Mean and (standard deviation) of pulmonary function test and clinical CT scores.
Table 4.
Regression coefficient and (p-values) of pulmonary function tests and clinical CT scores using linear mixed-effects model.
Fig 5.
Presented are the results of the effect of deflation level on the expiratory CT scans in quantifying AT.
A) A representative image of the expiratory CT scan from a single case (from Patient 2*) from the Site 1 cohort examined at baseline and its corresponding simulated % of residual volume (RV) 2D images. The images are windowed between [–1000, –50] for display purposes so that regions of AT are visible. [·] represents the mean intensity within the whole lung region in HU. B) Patient characteristics table for the four cases considered in this study. C) Plot of average quantitative air trapping (QAT) difference VS the simulated % of RV for the PTM, and DN method.