VEGFA and cancer: The purpose of this study was to quantitatively evaluate 16-slice spiral CT perfusion imaging to describe the blood patterns of benign and malignant pulmonary nodules and to investigate the relationship between CT perfusion imaging and tumor angiogenesis and vascular endothelial growth factor (VEGF) expression in patients with benign and malignant pulmonary nodules, and the differential diagnosis between benign and malignant pulmonary nodules by using perfusion imaging of 16-slice spiral CT.