Retrospective Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Radiol. Dec 28, 2015; 7(12): 501-508
Published online Dec 28, 2015. doi: 10.4329/wjr.v7.i12.501
Common bile duct diameter in an asymptomatic population: A magnetic resonance imaging study
Rong Peng, Ling Zhang, Xiao-Ming Zhang, Tian-Wu Chen, Lin Yang, Xiao-Hua Huang, Ze-Ming Zhang
Rong Peng, Ling Zhang, Ze-Ming Zhang, Department of Radiology, Medical Imaging Center, Panzhihua Central Hospital, Panzhihua 617000, Sichuan Province, China
Xiao-Ming Zhang, Tian-Wu Chen, Lin Yang, Xiao-Hua Huang, Sichuan Key Laboratory of Medical Imaging, Department of Radiology, Affiliated Hospital of North Sichuan Medical College, Nanchong 637000, Sichuan Province, China
Author contributions: Peng R and Zhang XM contributed equally to this work; Peng R, Zhang L, Zhang XM, Chen TW, Yang L, Huang XH and Zhang ZM designed research; Peng R, Zhang L and Zhang XM performed research; Peng R, Chen TW and Zhang ZM analyzed the data; Peng R and Zhang XM wrote the paper.
Institutional review board statement: This study was reviewed and approved by Ethics Committee of Affiliated Hospital of North Sichuan Medical College.
Informed consent statement: Through consideration by the Ethics Committee, the experimental design and the program of the study will not cause harm and risk to the subjects. Due to the retrospective nature of this study and the actual medical condition of Nanchong, it’s difficult to get informed consent from all patients involved in the study. The data collected were analyzed anonymously. So Ethics Committee of our Hospital waived the need for written informed consent from the all participants.
Conflict-of-interest statement: We have no financial relationships to disclose.
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: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Xiao-Ming Zhang, MD, PhD, Sichuan Key Laboratory of Medical Imaging, Department of Radiology, Affiliated Hospital of North Sichuan Medical College, Wenhua Road 63, Nanchong 637000, Sichuan Province, China. cjr.zhxm@vip.163.com
Telephone: +86-817-2262218 Fax: +86-817-2222856
Received: June 12, 2015
Peer-review started: June 15, 2015
First decision: October 21, 2015
Revised: November 11, 2015
Accepted: December 8, 2015
Article in press: December 11, 2015
Published online: December 28, 2015
Processing time: 198 Days and 10 Hours
Abstract

AIM: To measure the common bile duct (CBD) diameter by magnetic resonance cholangiopancreatography (MRCP) in a large asymptomatic population and analyze its some affecting factors.

METHODS: This study included 862 asymptomatic subjects who underwent MRCP. The CBD diameter was measured at its widest visible portion on regular end-expiration MRCP for all subjects. Among these 862 subjects, 221 volunteers also underwent end-inspiration MRCP to study the effect of respiration on the CBD diameter. The age, sex, respiration, body length, body weight, body mass index (BMI), portal vein diameter (PVD), length of the extrahepatic duct and CBD, cystic junction radial orientation and location were recorded. The subjects were divided into 7 groups according to age. All of the above factors were compared with the CBD diameter on end-expiration MRCP.

RESULTS: Among the 862 subjects, the CBD diameter was 4.13 ± 1.11 mm (range, 1.76-9.45 mm) and was correlated with age (r = 0.484; P < 0.05), with a dilation of 0.033 mm per year. The upper limit of the 95% reference range was 5.95 mm, resulting in a reasonable upper limit of 6 mm for the asymptomatic population. Respiration and other factors, including sex, body length, body weight, BMI, PVD, length of the extrahepatic duct and CBD, cystic junction radial orientation and location, were not related to the CBD diameter.

CONCLUSION: We established a reference range for the CBD diameter on MRCP for an asymptomatic population. The CBD diameter is correlated with age. Respiration did not affect the non-dilated CBD diameter.

Keywords: Adult; Biliary tract; Common bile duct; Magnetic resonance imaging

Core tip: We measured the common bile duct (CBD) diameter by magnetic resonance cholangiopancreatography (MRCP) for a large asymptomatic population and suggested the normal upper limit of the duct be set at 6 mm on MRCP. The CBD diameter was correlated with age, and gradually dilates 0.033 mm per year. Respiration didn’t effect on the non-dilated CBD diameter on MRCP. The significant changes of CBD diameter between inspiration and expiration may suggest a dilation of CBD.