CT perfusion imaging of pancreatic head mass Department of Radiology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University， Shanghai 200025, China Corresponding author: CHEN Ke-min, E-mail: keminchenrj @yahoo.com.cn Abstract Computed tomography (CT)-based assessment of tissue perfusion is now possible because of multidetector technology, and most scanners now include software for perfusion analysis. Perfusion CT is a clinical technique that can be used to provide regional maps and obtain quantitative measurements of various hemodynamic parameters on the basis of the linear relationship between CT enhancement and iodinated contrast material concentration. Pancreatic perfusion CT imaging has been applied to the normal tissue of pancreas, the pancreatic cancer, and the pancreatic endocrine tumors. Pancreatic adenocarcinoma is referred to as a hypovascular tumor and this is reflected by the small blood volume values and lower blood flow values in the tumor. In pancreatic endocrine tumors, values of blood volume and blood flow were higher in the tumors than normal pancreatic tissue, and blood flow was strongly correlated with MVD. Perfusion CT measurements are correlated with histoprognostic factors, such as proliferation index and WHO classification. There were some discrepancies in PS values of normal pancreatic tissue and pancreatic tumors between different studies, which perhaps because of the different perfusion CT models and the defect of this technique. To obtain more conclusive results as to the utility of this approach and its optimization, further studies in a larger patient population with use of different perfusion models are needed.