Example scans for a typical patient with operable chronic thromboembolic pulmonary hypertension. a) Perfusion (Q′) and b) ventilation (V′) lung scans. Example scans for a typical patient with operable chronic thromboembolic pulmonary hypertension. a) Perfusion (Q′) and b) ventilation (V′) lung scans. R: right; L: left; ANT: anterior; POST: posterior; LPO: left posterior oblique; RPO: right posterior oblique. c) Computed tomography pulmonary angiography scan. d) Pulmonary angiogram. David Jenkins Eur Respir Rev 2015;24:263-271 ©2015 by European Respiratory Society