We present unusual coronary-pulmonary collaterals in a 65-year-old CTEPH patient. Perfusion mapping of a dual-energy computed tomography (DECT) study revealed areas of right lung that were minimally perfused despite unilateral occlusion of the right pulmonary artery, leading to the discovery of coronary-pulmonary collaterals via invasive coronary angiography. Pulmonary thromboendarterectomy removed the clot en-bloc. Post-surgery DECT and catheterization confirmed restoration of pulmonary arterial circulation and excellent hemodynamic response. Here, suggestion of perfusion to a proximally obstructed lung with DECT helped to document the presence of rarely documented coronary-pulmonary artery collaterals.