Fig. 4

The dictionary learning results for a 63-year-old male diagnosed at baseline with GOLD 2 COPD and declared a fast progressor with ΔFEV₁/yr of -249 ml/yr. Representative axial slice of an expiratory CT scan acquired at baseline, its associated PRM map, the tPRM maps V^fSAD and χ^fSAD of PRM^fSAD, and their image patch probability maps from the dictionary learning model