Diagnostic Advances
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Radiol. Sep 28, 2015; 7(9): 220-235
Published online Sep 28, 2015. doi: 10.4329/wjr.v7.i9.220
Role of computed tomography angiography in detection and staging of small bowel carcinoid tumors
David Bonekamp, Siva P Raman, Karen M Horton, Elliot K Fishman
David Bonekamp, Siva P Raman, Karen M Horton, Elliot K Fishman, the Russell H. Morgan Department of Radiology and Radiological Science, the Johns Hopkins Medical Institutions, Baltimore, MD 21287, United States
Author contributions: Bonekamp D and Fishman EK made the conception of study; Fishman EK acquired the data; Bonekamp D drafted up the manuscript; all the authors analyzed the imaging studies, revised the paper and made the final approval.
Conflict-of-interest statement: All the author have no conflict of interest.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Elliot K Fishman, MD, Professor, the Russell H. Morgan Department of Radiology and Radiological Science, the Johns Hopkins Medical Institutions, 601 N. Caroline Street, JHOC 3140C, Baltimore, MD 21287, United States. efishman@jhmi.edu
Telephone: +1-410-9555173 Fax: +1-410-6140341
Received: May 4, 2015
Peer-review started: May 5, 2015
First decision: June 3, 2015
Revised: June 18, 2015
Accepted: August 4, 2015
Article in press: August 7, 2015
Published online: September 28, 2015
Abstract

Small-bowel carcinoid tumors are the most common form (42%) of gastrointestinal carcinoids, which by themselves comprise 70% of neuroendocrine tumors. Although primary small bowel neoplasms are overall rare (3%-6% of all gastrointestinal neoplasms), carcinoids still represent the second most common (20%-30%) primary small-bowel malignancy after small bowel adenocarcinoma. Their imaging evaluation is often challenging. State-of-the-art high-resolution multiphasic computed tomography together with advanced postprocessing methods provides an excellent tool for their depiction. The manifold interactive parameter choices however require knowledge of when to use which technique. Here, we discuss the imaging appearance and evaluation of duodenal, jejunal and ileal carcinoid tumors, including the imaging features of the primary tumor, locoregional mesenteric nodal metastases, and distant metastatic disease. A protocol for optimal lesion detection is presented, including the use of computed tomography enterography, volume acquisition, computed tomography angiography and three-dimensional mapping. Imaging findings are illustrated with a series of challenging cases which illustrate the spectrum of possible disease in the small bowel and mesentery, the range of possible appearances in the bowel itself on multiphase data and extraluminal findings such as the desmoplastic reaction in mesentery and hypervascular liver metastases. Typical imaging pitfalls and pearls are illustrated.

Keywords: Small bowel carcinoid, Multidetector computed tomography, Multiplanar analysis, Volume rendered technique, Maximum intensity projection, Surface shading technique

Core tip: Small-bowel carcinoid tumors are neuroendocrine tumors and represent most common form of gastrointestinal carcinoids. Although primary small bowel neoplasms are overall rare, carcinoids still represent the second most common primary small-bowel malignancy. State-of-the-art high-resolution multiphasic computed tomography with advanced postprocessing methods provides an excellent tool to overcome the challenges of their depiction. Here, we discuss their imaging appearance, focusing on the primary tumor, locoregional mesenteric nodal metastases, and distant metastatic disease. Guidance for imaging protocol selection is given. Imaging findings are illustrated with a series of challenging cases which illustrate the spectrum of disease. Typical imaging pitfalls and pearls are illustrated.