Objective:To investigate the imaging features of pancreatic hypervascular tumors in computed tomography (CT) and magnetic resonance imaging (MRI) examinations.Methods:The retrospective and descriptive study was conducted. The clinicopathological data of 53 patients with pancreatic hypervascular tumors who were admitted to two medical centers, including 32 cases in the Affiliated Hospital of Medical School, Ningbo University and 21 cases in the First Affiliated Hospital of Naval Medical University, from March 2007 to February 2021 were collected. There were 21 males and 32 females, aged (48±23)years. Of the 53 patients, there were 19 cases with pancreatic neuroendocrine tumor (PNET), 9 cases with pancreatic metastasis from renal cell carcinoma (PRCC), 8 cases with solid pseudopapillary tumors of pancreas (SPTP), 7 cases with intrapancreatic accessory spleen (IPAS), 6 cases with serous cystadenoma of pancreas (SCP) and 4 cases with aneurysms. All the 53 patients underwent CT and MRI. Observation indicators: (1) imaging feature of PNET; (2) imaging feature of PRCC; (3) imaging feature of SPTP; (4) imaging feature of IPAS; (5) imaging feature of SCP; (6) imaging feature of aneurysms. Measurement data with normal distribution were represented as Mean±SD, and measurement data with skewed distribution were represented as M(range). Count data were described as absolute numbers. Results:(1) Imaging feature of PNET: of the 19 cases with PNET, there were 1 case with Von Hippel-Lindau disease (VHLD), 8 cases with multiple endocrine neoplasia type 1 (MEN1) and 10 cases with neuroendocrine tumor (NET). Of the 19 cases, 16 cases had single tumor and 3 cases had 2 tumors, 9 cases had tumor located at head of pancreas and 10 cases had tumor located at body and tail of pancreas. Morphology of tumors in the 19 cases were mostly round or elliptical, with some shallow lobes and clear boundary. There were 4 cases with cluster-like calcifications in the center of tumors and 15 cases with no cluster-like calcification in the center of tumors. The tumor diameter of 19 cases was (26.7±10.3)mm. Of the 19 cases, 1 case underwent pancreatic atrophy and segmental expansion of the main pancreatic duct and 18 cases underwent no pancreatic atrophy or segmental expansion of the main pancreatic duct, 2 cases underwent dilated bile ducts and 17 cases underwent no dilated bile ducts. The enhance-ment mode of imaging examination of PNET was wash in and wash out. (2) Imaging feature of PRCC: Of the 9 cases with PRCC, 2 cases had single tumor and 7 cases had multiple tumors. Of the 2 cases with single tumor, 1 case had tumor located at neck of pancreas and 1 case had tumor located at body and tail of pancreas. All the 7 cases with multiple tumors had tumor located at head, neck, body and tail of pancreas. Morphology of tumors in the 9 cases were round or quasi-circular, with clear boundary. The tumor diameter were (18.0±5.0)mm of the 2 cases with single tumor and 2.0-50.0 mm of the 7 cases with multiple tumors, respectively. Of the 9 cases, 2 cases underwent pancreatic ducts dilatation and 7 cases underwent no pancreatic ducts dilatation. The enhancement mode of imaging examination of PRCC was wash in and wash out. (3) Imaging feature of SPTP: all 8 cases with SPTP had single tumor, including 4 cases with tumor located at head of pancreas and 4 cases with tumor located at body and tail of pancreas. Morphology of tumors in the 8 cases were lobulated with clear boundary. Of the 8 cases, there were 2 cases with no calcifications of tumors and 6 cases with calcification of tumors, 2 cases with no cystic necrosis of tumors and 6 cases with cystic necrosis of tumors, 3 cases with no bleeding in the tumors and 5 cases with bleeding in the tumors. The tumor diameter of 8 cases was (51.6±11.8)mm. All the 8 cases were negative for pancreatic ducts dilatation, but the adjacent organs were compressed and moved. The enhancement mode of imaging examination of SPTP was asymptotic enhancement. (4) Imaging feature of IPAS: all the 7 cases with IPAS had single tumor located at tail of pancreas. Morphology of tumors in the 7 cases were round or quasi-circular shape with clear boundary. Of the 7 cases, 1 case with solid-cystic and uneven density tumor was epidermoid cyst in the accessory spleen of the tail of the pancreas, and 6 cases had solid and uniform density tumors. The tumor diameter of 7 cases was (25.5±8.5)mm. All the 7 cases were negative for pancreatic ducts dilatation and the surrounding structures of pancreatic ducts were clear. The enhancement mode of imaging examination of IPAS was asymptotic enhancement. (5) Imaging feature of SCP: all 6 cases with SCP had single tumor, including 1 case with tumor located at neck of pancreas and 5 cases with tumor located at body and tail of pancreas. Morphology of tumors in the 6 cases were round or quasi-circular, with clear boundary. Of the 6 cases, 2 cases had cystic tumors and 4 cases had solid tumors. The tumor diameter of 6 cases was (35.5±15.4)mm. Of the 6 cases, 2 cases were positive for pancreatic ducts dilatation and 4 cases were negative for pancreatic ducts dilatation. The enhancement mode of imaging examination of SCP was wash in and wash out. (6) Imaging feature of aneurysms: all the 4 cases with aneurysms had single tumor, including 1 case with tumor located at body of pancreas and 3 cases with tumor located at tail of pancreas. One case with tumor located at body of pancreas was superior duodenal aneurysm and 3 cases with tumor located at tail of pancreas were splenic aneurysms. Morphology of tumors in the 4 cases were round, with clear boundary. Of the 4 cases, 1 case was negative for tumor marginal calcification and 3 cases were positive for tumor marginal calcification. The tumor diameter of 4 cases was (11.3±2.5)mm. All the 4 cases were negative for pancreatic ducts dilatation. The enhance-ment mode of imaging examination of aneurysms was wash in and wash out.Conclusions:The imaging features of pancreatic hypervascular tumors in CT and MRI examinations show diversity. The enhancement mode of imaging examination of PNET, PRCC, SCP and aneurysms is wash in and wash out. The enhancement mode of imaging examination of SPTP and IPAS is asymptotic enhancement.

Balancing the risks and benefits of organophosphate pesticides(OPs)on human and environmental health relies partly on their accurate measurement.A highly sensitive fluorescence anti-quenching multi-residue bio-barcode immunoassay was developed to detect OPs(triazophos,parathion,and chlorpyrifos)in apples,turnips,cabbages,and rice.Gold nanoparticles were functionalized with monoclonal antibodies against the tested OPs.DNA oligonucleotides were complementarily hybridized with an RNA fluorescent label for signal amplification.The detection signals were generated by DNA-RNA hybridization and ribonuclease H dissociation of the fluorophore.The resulting fluorescence signal en-ables multiplexed quantification of triazophos,parathion,and chlorpyrifos residues over the concen-tration range of 0.01-25,0.01-50,and 0.1-50 ng/mL with limits of detection of 0.014,0.011,and 0.126 ng/mL,respectively.The mean recovery ranged between 80.3％and 110.8％with relative standard deviations of 7.3％-17.6％,which correlate well with results obtained by liquid chromatography-tandem mass spectrometry(LC-MS/MS).The proposed bio-barcode immunoassay is stable,reproducible and reliable,and is able to detect low residual levels of multi-residue OPs in agricultural products.