Patient with COPD, left heart failure and small tumour. Patient with COPD, left heart failure and small tumour. On the left; upper row frontal slice of ventilation SPECT showing uneven distribution of ventilation with central deposition of Technegas typical for COPD. Middle row corresponding perfusion SPECT image and lower row corresponding CT image. Blue arrow on CT image shows thickening of the airway wall typical of COPD. In the middle transversal slices of ventilation SPECT upper row, with corresponding perfusion SPECT in the middle row. On CT image in lower row small tumour (1 cm) is visualised. Aligning both modalities small perfusion defect is observed in this area (arrow). On the right column; sagittal slice upper row presents Fusion ventilation SPECT/CT, middle row with corresponding fusion perfusion SPECT/CT slice that shows antigravitational redistribution os perfusion, typical for left heart failure (violet arrow) not visible on CT nor ventilation (non segmental mismatch). Marika Bajc breathe 2012;9:48-60 ©2012 by European Respiratory Society