Clinical Research
Copyright ©2005 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 14, 2005; 11(14): 2142-2147
Published online Apr 14, 2005. doi: 10.3748/wjg.v11.i14.2142
Value of CT in the diagnosis and management of gallstone ileus
Chih-Yung Yu, Chang-Chyi Lin, Rong-Yaun Shyu, Chung-Bao Hsieh, Hurng-Sheng Wu, Yeu-Sheng Tyan, Jen-I Hwang, Chang-Hsien Liou, Wei-Chou Chang, Cheng-Yu Chen
Chih-Yung Yu, Chang-Hsien Liou, Wei-Chou Chang, Cheng-Yu Chen, Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, China
Chang-Chyi Lin, Rong-Yaun Shyu, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, China
Chung-Bao Hsieh, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, China
Hurng-Sheng Wu, Department of Surgery, Show-Chwan Memorial Hospital, Changhua, Taiwan, China
Yeu-Sheng Tyan, Department of Radiology, Chung Shan Medical University Hospital, Taichung, Taiwan, China
Jen-I Hwang, Department of Radiology, Taichung Veterans General Hospital, Taichung, Taiwan, China
Author contributions: All authors contributed equally to the work.
Correspondence to: Dr. Chih-Yung Yu, Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, No 325, Sec. 2, Cheng-Gung Road, 114 Nei-Hu, Taipei, Taiwan, China. jefcyyu@ms24.hinet.net
Telephone: +886-2-87927247 Fax: +886-2-87927245
Received: September 21, 2004
Revised: September 22, 2004
Accepted: November 29, 2004
Published online: April 14, 2005
Abstract

AIM: To retrospectively establish the diagnostic criteria of gallstone ileus on CT, and to prospectively apply these criteria to determine the diagnostic accuracy of CT to confirm or exclude gallstone ileus in patients who presented with acute small bowel obstruction (SBO). Another purpose was to ascertain whether the size of ectopic gallstones would affect treatment strategy.

METHODS: Fourteen CT scans in cases of proved gallstone ileus were evaluated retrospectively by two radiologists for the presence or absence of previously reported CT findings to establish the diagnostic criteria. These criteria were applied in a prospective contrast enhanced CT study of 165 patients with acute SBO, which included those 14 cases of gallstone ileus. The hard copy images of 165 CT studies were reviewed by a different group of two radiologists but without previous knowledge of the patient’s final diagnosis. All CT data were further analyzed to determine the diagnostic accuracy of gallstone ileus when using CT in prospective evaluation of acute SBO. The size of ectopic gallstone on CT was correlated with the clinical course.

RESULTS: The diagnostic criteria of gallstone ileus on CT were established retrospectively, which included: (1) SBO; (2) ectopic gallstone; either rim-calcified or total-calcified; (3) abnormal gall bladder with complete air collection, presence of air-fluid level, or fluid accumulation with irregular wall. Prospectively, CT confirmed the diagnosis in 13 cases of gallstone ileus with these three criteria. Only one false negative case could be identified. The remaining 151 patients are true negative cases and no false positive case could be disclosed. The overall sensitivity, specificity and accuracy of CT in diagnosing gallstone ileus were 93%, 100%; and 99%, respectively. Surgical exploration was performed in 13 patients of gallstone ileus with ectopic stones sized larger than 3 cm. One patient recovered uneventfully following conservative treatment with an ectopic stone sized 2 cm in the long axis.

CONCLUSION: Contrast enhanced CT imaging offered crucial evidence not only for the diagnosis of gallstone ileus but also for decision making in management strategy.

Keywords: CT, Gallstone ileus