Differentiation of pulmonary artery sarcoma from pulmonary embolus utilizing 128-slice dual source prospective cardiac-gated computed tomography scan

Abstract

Primary pulmonary artery sarcoma is a rare malignancy with poor prognosis that frequently presents with symptoms of PA obstruction, pulmonary arterial hypertension, and right ventricular failure. More frequently seen extensive thromboembolic disease presents similarly, which can delay definitive imaging diagnosis and management. Magnetic resonance imaging (MRI) is highly specific for identifying PA sarcomas because the tumor enhances with gadolinium contrast more than bland thrombus. Chest computed tomography (CT) scan findings such as a low-attenuation filling defect occupying the entire luminal diameter of the main or proximal PA, an expansion of any segment of the pulmonary artery with an extensive intraluminal filling defect, or extraluminal extension can also help differentiate pulmonary artery sarcomas from pulmonary artery thromboembolism. As much as delayed phase contrast enhancement has helped in differentiating between benign and malignant mass lesions, visualization of a low attenuation filling defect within a pulmonary artery on contrast-enhanced cardiac CT studies can further suggest malignancy, such as pulmonary artery sarcoma, if the lesion demonstrates enhancement throughout the delayed phase.