Retrospective Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 7, 2016; 22(13): 3621-3631
Published online Apr 7, 2016. doi: 10.3748/wjg.v22.i13.3621
Proposal of a computed tomography classification for hepatic alveolar echinococcosis
Tilmann Graeter, Wolfgang Kratzer, Suemeyra Oeztuerk, Mark Martin Haenle, Richard Andrew Mason, Andreas Hillenbrand, Thomas Kull, Thomas F Barth, Peter Kern, Beate Gruener
Tilmann Graeter, Department of Diagnostic and Interventional Radiology, University Hospital Ulm, 89081 Ulm, Germany
Wolfgang Kratzer, Suemeyra Oeztuerk, Mark Martin Haenle, Department of Internal Medicine I, University Hospital Ulm, 89081 Ulm, Germany
Richard Andrew Mason, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, 10601 East Boulevard, Cleveland, OH 44106, United States
Andreas Hillenbrand, Department of General- and Visceral Surgery, University Hospital Ulm, 89081 Ulm, Germany
Thomas Kull, Department of Nuclear Medicine, University Hospital Ulm, 89081 Ulm, Germany
Thomas F Barth, Institute of Pathology, University Hospital Ulm, 89081 Ulm, Germany
Peter Kern, Ulm University, WHO Informal Working Group on Echinococcosis, Comprehensive Infectious Diseases Center, 89081 Ulm, Germany
Beate Gruener, Section of Infectious Diseases and Clinical Immunology, Comprehensive Infectious Diseases Center Ulm, 89081 Ulm, Germany
Author contributions: Graeter T, Kratzer W, Kern P and Gruener B designed the research; Graeter T, Haenle MM, Hillenbrand A, Kull T and Gruener B performed the research; Graeter T, Kratzer W, Oeztuerk S, Mason RA and Barth TF analyzed the data; and Graeter T and Kratzer W wrote the paper.
Institutional review board statement: The study was reviewed and approved by the local ethics committee of university of Ulm.
Informed consent statement: Because of retrospective and anonymous character of this study the need for informed consent was waived by the institutional review board.
Conflict-of-interest statement: The authors declare that there are no conflicts of interest.
Data sharing statement: No additional data are available.
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:
Correspondence to: Wolfgang Kratzer, MD, Professor, Department of Internal Medicine I, University Hospital Ulm, Albert-Einstein-Allee 23, 89081 Ulm, Germany.
Telephone: +49-731-50044730 Fax: +49-731-50044620
Received: September 21, 2015
Peer-review started: September 23, 2015
First decision: October 15, 2015
Revised: October 30, 2015
Accepted: December 30, 2015
Article in press: December 30, 2015
Published online: April 7, 2016

AIM: To establish a computed tomography (CT)-morphological classification for hepatic alveolar echinococcosis was the aim of the study.

METHODS: The CT morphology of hepatic lesions in 228 patients with confirmed alveolar echinococcosis (AE) drawn from the Echinococcus Databank of the University Hospital of Ulm was reviewed retrospectively. For this reason, CT datasets of combined positron emission tomography (PET)-CT examinations were evaluated. The diagnosis of AE was made in patients with unequivocal seropositivity; positive histological findings following diagnostic puncture or partial resection of the liver; and/or findings typical for AE at either ultrasonography, CT, magnetic resonance imaging or PET-CT. The CT-morphological findings were grouped into the new classification scheme.

RESULTS: Within the classification a lesion was dedicated to one out of five “primary morphologies” as well as to one out of six “patterns of calcification”. “primary morphology” and “pattern of calcification” are primarily focussed on separately from each other and combined, whereas the “primary morphology” V is not further characterized by a “pattern of calcification”. Based on the five primary morphologies, further descriptive sub-criteria were appended to types I-III. An analysis of the calcification pattern in relation to the primary morphology revealed the exclusive association of the central calcification with type IV primary morphology. Similarly, certain calcification patterns exhibited a clear predominance for other primary morphologies, which underscores the delimitation of the individual primary morphological types from each other. These relationships in terms of calcification patterns extend into the primary morphological sub-criteria, demonstrating the clear subordination of those criteria.

CONCLUSION: The proposed CT-morphological classification (EMUC-CT) is intended to facilitate the recognition and interpretation of lesions in hepatic alveolar echinococcosis. This could help to interpret different clinical courses better and shall assist in the context of scientific studies to improve the comparability of CT findings.

Keywords: Hepatic alveolar echinococcosis, Diagnosis, Echinococcus multilocularis, Classification, Computed tomography, Alveolar echinococcosis

Core tip: Computed tomography (CT), mostly combined with positron emission tomography, provides one of the most important diagnostic tools in suspected alveolar echinococcosis. Aim of the study was to establish a new CT-classification based on a large patient collective with confirmed hepatic alveolar echinococcosis. The Echinococcosis Multilocularis Ulm Classification-CT presented in this paper is intended to facilitate the recognition and interpretation of hepatic lesions in alveolar echinococcosis based on CT-morphological criteria. It can also be used to more objectively interpret different clinical courses and enhance the comparability of CT findings in the context of scientific studies.