Objective To investigate the CT imaging features of solid pseudopapillary tumor of the pancreas (SPTP) and to improve the preoperative diagnostic accuracy. Methods A retrospective analysis was performed on the CT manifestations of 21 cases of SPTP confirmed by pathology and surgery. Results In the 21 cases of SPTP, 19 were young and middle-aged female (range: 9～29 years old). The lesions were located in the pancreatic head and neck in 13 cases, and in the pancreatic body and tail in 4 cases each. The maximum diameter of tumor was 3 ～ 15 cm (mean 7.5cm). CT showed a single, round-like, cystic and solid mass in the pancreas. Eighteen cases had a complete capsule, and 3 cases had poorly defined margin with surrounding tissue. 5 cases of tumor were encapsulated or appeared scattered calcification in the center, only 1 case had pancreatic duct dilation (about 5mm in diameter), and no patient had bile duct changes. After enhanced scanning, the tumor capsule and the solid part were mildly to moderately enhanced during arterial phase, and they were significantly enhanced during portal venous phase and equilibrium phase. The cystic part was not enhanced, but the capsule was significantly enhanced. Conclusions CT manifestations of solid pseudopapillary tumor of the pancreas have certain characteristics, and when combined with clinical and imaging manifestations, accurate diagnosis generally can be made.

Objective To analyze atypical 64-slice spiral CT imaging finings of pancreatic cancer and to improve the ability to identify CT manifestations of pancreatic cancer. Methods A retrospective analysis was performed on the atypical 64-slice spiral CT imaging findings of 12 eases of pancreatic cancer confirmed by pathology after surgery. Results All the twelve cases were pancreatic ductal adenocarcinoma.Among them, 7 cases were moderately differentiated ductal adenocarcinoma, 1 case was well-differentiated ductal adenocarcinoma, 1 case was mucinous adenocarcinoma, 3 cases were adenosquamous carcinoma. Among 8 cases with ductal adenocarcinoma, the lesions were located in the pancreatic head and (or) uncinate process in 7 cases, and in the pancreatic neck of 1 case. Tumors were expressed as isodense or low-density or cysticsolid lesions, the masses showed no enhancement in the enhanced scanning phase. Tumors were clearly exogenous or exogenous tendencies in 5 cases. Five cases had no distal pancreatic duct dilation, 2 patients had common bile duct and intrahepatic biliary dilation, and only 1 patient had atrophy of distal pancreas. There was one case of mucinous carcinoma, plain CT scan showed a cystic lesion in head of pancreas about 5cm in diameter, the solid part below the cystic lesion was slightly enhamced in the enhanced scanning phase and the body and tail pancreatic duct was moderately dilated (7 mm). There was no common bile duct and adjacent blood vessels invasion. Among 3 cases of adenosquamous carcinoma, lesions were located in the pancreatic head of 2 cases and in pancreatic body of 1 case. The maximal diameter of mass ranged 3.0 cm ～ 4.5 cm.Cystic necrotic area was observed within the lesions in 3 cases in enhanced pancreatic parenchymal phase of CT scan. Distal pancreatic duct were mildly dilated (4 ～ 5 mm) in 3 cases. There was no common bile duct and intrahepatic bile duct dilation. Conclusions Pancreatic cancer may show atypical CT imaging findings and great cautions are needed for differential diagnosis.

Objective To investigate the ability of different standards on the evaluation of vascular invasion of pancreatic carcinoma. Methods The MSCT imagings of 56 cases of pancreatic carcinoma confirmed by surgery were analyzed retrospectively. The vascular invasion degrees of 5 large vessels around the pancreas were evaluated according to Loyer classification standard, Lu classification standard and the Changhai standard, the surgical result was used as the gold standard. The accuracy of different standards was evaluated, and the Kappa coefficient were calculated. Results The accuracy, sensitivity, specificity, positive predictive value and negative predictive value of Loyer classification standard were 86.79%, 86.27%, 86.90%, 59.46% and 96.60%, respectively, and the Kappa coefficient was 0.623. The accuracy, sensitivity, specificity, positive predictive value and negative predictive value of Lu classification standard were 93.21%, 84.31%, 95.20%, 79.63% and 96.46%, respectively, and the Kappa coefficient was 0.777. The accuracy, sensitivity, specificity, positive predictive value and negative predictive value of Changhai standard were 95.36%, 84.31%, 97.82%, 89.58% and 96.55%, respectively. The Kappa coefficient was 0.841. Conclusions The Changhai standard was feasible to evaluate the vascular invasion of pancreatic carcinoma.