Arterial vs pancreatic phase: Which is the best choice in the evaluation of pancreatic endocrine tumours with multidetector computed tomography (MDCT)? [Fase arteriosa vs fase pancreatica: Qual'è la scelta migliore nella valutazione dei tumori endocrini pancreatici con TC multidetettore (MDCT)?]

PURPOSE: The aim of this study was to assess whether the pancreatic phase may replace the arterial phase in the evaluation of endocrine pancreatic tumours. MATERIALS AND METHODS: Twenty-nine endocrine pancreatic lesions with definitive morphological and immunohistochemical characterisation after surgical treatment (n=24) or fine-needle-aspiration cytology under endoscopic ultrasonography guidance (n=5) were retrospectively evaluated. All lesions were studied with triple-phase 16-row multidetector computed tomography (MDCT). Images obtained during each phase were separately interpreted by two senior radiologists experienced in pancreatic pathology and who were blinded to surgical results. Endocrine tumour and normal pancreas attenuation and the mean absolute tumour-to-gland attenuation difference were measured in each phase, and data were analysed with Student's t test. Visualisation of arterial vascular abnormalities and hypervascular liver metastases in the arterial and pancreatic phases and the diagnostic contribution of the two phases were compared. RESULTS: For both radiologists, the mean absolute tumour-to-gland attenuation difference was significantly higher (p<0.05) in the pancreatic phase (40+/-53 HU and 34+/-56 HU) than in the arterial phase (31+/-38 HU and 26+/-43 HU). There were no differences in the detection of arterial vascular abnormalities or hypervascular liver metastases in the two phases. The diagnostic contribution was higher in the pancreatic phase. CONCLUSIONS: In our experience, the pancreatic phase can replace the arterial phase in the evaluation of pancreatic endocrine tumours