Brief Article
Copyright ©2010 Baishideng. All rights reserved.
World J Gastroenterol. Jul 7, 2010; 16(25): 3196-3201
Published online Jul 7, 2010. doi: 10.3748/wjg.v16.i25.3196
Role of diffusion-weighted magnetic resonance imaging in the diagnosis of extrahepatic cholangiocarcinoma
Xing-Yu Cui, Hong-Wei Chen
Xing-Yu Cui, Hong-Wei Chen, Department of Radiology, Wuxi People’s Hospital, Nanjing Medical University, Wuxi 214023, Jiangsu Province, China
Author contributions: Cui XY designed and performed the research, analyzed data and wrote the manuscript; Chen HW revised the paper.
Correspondence to: Hong-Wei Chen, Chief Physician, Department of Radiology, Wuxi People’s Hospital, Nanjing Medical University, Wuxi 214023, Jiangsu Province, China. chw6312@163.com
Telephone: +86-510-85350232 Fax: +86-510-85350232
Received: January 4, 2010
Revised: March 17, 2010
Accepted: March 24, 2010
Published online: July 7, 2010
Abstract

AIM: To determine the clinical value of diffusion-weighted imaging (DWI) for the diagnosis of extrahepatic cholangiocarcinoma (EHCC) by comparing the diagnostic sensitivity of DWI and magnetic resonance cholangiopancreatography (MRCP).

METHODS: Magnetic resonance imaging examination was performed in 56 patients with suspected EHCC. T1-weighted imaging, T2-weighted imaging, MRCP and DWI sequence, DWI using single-shot spin-echo echo-planar imaging sequence with different b values (100, 300, 500, 800 and 1000 s/mm2), were performed. All cases were further confirmed by surgery or histopathological diagnosis. Two radiologists jointly performed the analysis of the DWI and MRCP images. Apparent diffusion coefficient (ADC) value and signal-noise ratio were calculated for EHCC. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value were tested using DWI with a b value of 500 s/mm2 and MRCP images, respectively.

RESULTS: Histopathological diagnosis confirmed that among the 56 cases, 35 were EHCC (20 hilar and 15 distal extrahepatic), 16 were cholangitis, and 5 were calculus of bile duct. Thirty-three out of the 35 EHCC cases were detected by DWI. EHCC exhibited differential levels of high signal intensity in DWI and low signal intensity in the ADC map. The mean value for ADC was (1.31 ± 0.29) × 10-3 mm2/s. The detection rate of EHCC was significantly higher by DWI (94.3%) than by MRCP (74.3%) (P < 0.05). There was a significant difference in sensitivity (94.3% vs 74.3%), specificity (100% vs 71.4%), accuracy (96.4% vs 73.2%), positive predictive value (100% vs 81.3%), and negative predictive value (91.3% vs 62.5%) between DWI and MRCP in diagnosing EHCC.

CONCLUSION: DWI has a high sensitivity for the detection of EHCC as it shows the EHCC lesion more unambiguously than MRCP does. DWI can also provide additional clinically important information in EHCC patients when added to routine bile duct MR imaging protocols.

Keywords: Diffusion magnetic resonance imaging; Cholangiocarcinoma; Magnetic resonance imaging; Magnetic resonance cholangiopancreatography