Pulmonary embolism ( PE) is a blockage of the main artery of the lung or one of its branches by a substance that has travelled from elsewhere in the body through the bloodstream (embolism). Usually this is due to embolism of a thrombus (blood clot) from the deep veins in the legs, a process termed venous thromboembolism.

An Enchondroma is a cartilage cyst found in the bone marrow. Typically, enchondroma is discovered on a X-ray scan. Enchondromas have a characteristic appearance on Magnetic Resonance Imaging ( MRI) as well. They have also been reported to cause increased uptake on PET examination.