Inclusion Criteria:  patient with pathohistologically proven localized or metastatic PDAC; patient aged 18 or older, male or female, who can provide written informed consent for this study; patient with complete clinical data.  Exclusion Criteria:  patient age < 18 years; patient with other active cancer; patient with PDAC under the treatment blocking NT receptors; pregnant or lactating women; patient who cannot stay on PET/CT camera for app. 90 minutes; patient who cannot stand MRI; patient simultaneously participating in another clinical trial; patient with HIV, HCV, HVB infection or other serious chronic infection patient with serious mental, neurological, cardiovascular, respiratory and other system diseases; patient with liver and kidney function (GFR less than 50 ml/min) disease; patient with severe severe refractory mental disorder.