The purpose of this study is
1. to determine whether the perfusion parameters in the normal pancreas and the pancreas
cancer (adenocarcinoma or neuroendocrine tumor) are different on perfusion CT
2. to determine whether initial perfusion parameters as well as perfusion parameter change
in pancreas adenocarcinoma before and after chemotherapy are different between
chemotherapy response group (CR, PR according to RECIST 1.1) and non response group (SD,
PD according to RECIST 1.1).