[Radiodiagnostic techniques in gastroenteropathic neuroendocrine tumors]

Because of the technical advances made in computed tomography (CT) and magnetic resonance imaging (MRI), these techniques have become increasingly important in the management of patients with neuroendocrine tumors which, as shown by several published series, continue to pose a challenge even for radiologists highly experienced in these fascinating neoplasms. The development of multidetector CT, as well as high-gradient MRI and other advances in this modality, have improved the sensitivity of pancreatic islet tumor detection. The sensitivity of the two techniques seems to be similar, but comparison between the distinct imaging modalities and the different modes or stages of tumoral development is difficult. In carcinoid tumors, both CT and MRI are important to define the extension of metastatic disease and to evaluate treatment response. Both techniques, together with endoscopic ultrasonography, can be essential when identifying the source of a functioning pancreatic endocrine tumor. The results are directly related to the radiologist's interest and experience, the meticulousness with which the technique is performed, and the resolution of the distinct imaging methods. However, a combination of various techniques including functional localization and radioisotope use is usually required to detect these elusive lesions.