Inclusion Criteria  Patients with resectable pancreatic cancer underwent ultrasound examination before surgery Conventional ultrasound can clearly show pancreatic space-occupying lesions and the elastic measurements show good images The patient agrees to receive ultrasound elasticity examination and signs informed consent All patients had no history of radiotherapy or chemotherapy before ultrasound examination All clinical case data and auxiliary examination data are complete and accessible.  Exclusion Criteria  Ultrasound evaluation was not performed before ultrasound-guided needle biopsy Conventional ultrasound could not clearly show pancreatic space-occupying lesions or poor elastic measurement images Patients who refuse to accept examination or give up treatment Patients receiving neoadjuvant chemotherapy or radiotherapy before ultrasound examination Incomplete clinical data and auxiliary examination data.