A comparison of imaging techniques for the localisation of gastro-enteropancreatic neuroendocrine tumours.

Imaging techniques are used to locate gastro-enteropancreatic endocrine tumours. Extracorporeal ultrasound (US), computerised tomography (CT scans), magnetic resonance imaging and positron emission tomography have sensitivities of 20-40%. Angiography is not very sensitive, but is useful for stimulation tests. Transhepatic portal venous sampling is valuable in specific situations. Endoscopic US, peroperative procedures and somatostatin scintigraphy can be highly sensitive. The latter can detect extrapancreatic tumours and metastatic foci over the whole body. For sporadic tumours, US and CT scans remain the most common initial procedures. For multiple endocrine tumours, complex procedures plus stimulation tests may be needed to identify the origin of the hormone secretion.