[Grading of pancreatic neuroendocrine neoplasms with imaging: an update]

Imaging evaluation of pancreatic neuroendocrine neoplasms is developing with the updating of pathological grading. Tumor size, blood perfusion and apparent diffusion coefficient(ADC)value are the most commonly used imaging indicators for the evaluation of the malignancy of pancreatic neuroendocrine neoplasms, as well as other imaging characteristics representing the tumor invasiveness. Dual-probe imaging with SSR-PET and FDG-PET can further improve the accuracy of diagnosis and classification of pancreatic neuroendocrine neoplasms, and provide further information for the tumor treatment and prognosis. Quantitative analysis including texture analysis and radiomics is also a new topic in the research of pancreatic neuroendocrine neoplasms. The combination of morphology, functional imaging and quantitative analysis may contribute to the non-invasive evaluation of the malignancy of pancreatic neuroendocrine neoplasms.