Role of diffusion-weighted magnetic resonance imaging in the diagnosis of extrahepatic cholangiocarcinoma
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.
SourceAvailable from: Dalia Z. Zidan[Show abstract] [Hide abstract]
ABSTRACT: Purpose To investigate the added value of diffusion-weighted imaging (DWI) to magnetic resonance cholangiopancreatography (MRCP) in differentiating benign from malignant extrahepatic biliary strictures. Methods Magnetic resonance examination including, T2-weighted imaging, MRCP and DWI using different b-values (0,500,800 s/mm2) were performed in 38 patients with suspicious extrahepatic biliary strictures. Apparent diffusion coefficient (ADC) value was calculated. The signal intensity of the lesions on DWI using b = 500 and 800 s/mm2 was examined. Analysis of the DWI and MRCP images for the cause of the extrahepatic biliary stricutre was performed. Patients were further confirmed by histopathological diagnosis and follow up. Sensitivity, specificity, accuracy, positive predictive and negative predictive values were calculated for both the MRCP images and DWI. Results Of the 38 cases, 23 cases had malignant extrahepatic biliary strictures and 15 had benign strictures. DWI detected 21 out of the 23 malignant biliary strictures and 14 out of 15 benign biliary strictures. Malignant strictures more frequently appeared hyperintense than benign strictures on DWI using b-values of 500 and 800 s/mm2. There was a significant difference in sensitivity (91.3% vs. 73%), specificity (93.3% vs. 64.7%), accuracy (92.1% vs. 73.6%), positive predictive value (95.4% vs. 81%), and negative predictive value (87.5% vs. 64.7%) between DWI and MRCP in differentiating biliary strictures. Conclusion Combined evaluation using DWI added to MRCP improves the differentiation of malignant from benign extrahepatic biliary strictures.12/2013; 44(4):719–726. DOI:10.1016/j.ejrnm.2013.09.005
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ABSTRACT: To determine the value of adding diffusion-weighted imaging (DWI) to conventional magnetic resonance cholangiopancreatography (MRCP) for differentiating benign from malignant distal biliary strictures. Two independent readers reviewed three image sets (1: MRCP alone; 2: MRCP and DWI combined; and 3: MRCP, DWI, and contrast-enhanced T1-weighted imaging [T1WI] combined) of 60 patients with suspected distal biliary strictures and rated the probability of malignancy. Diagnostic performance and accuracy were compared using the receiver operating characteristic (ROC) curves and McNemar two-tailed test. κ coefficients were calculated to assess the interobserver agreement. The Az value and accuracy improved significantly after additional review of DWI for both readers: Az = 0.780 vs. 0.916 (P = 0.003) for Reader 1 and 0.784 vs. 0.853 (P = 0.037) for Reader 2; accuracy = 69% vs. 93% for Reader 1 (P < 0.001) and 57% vs. 85% for Reader 2 (P = 0.002). No significant difference in the Az values and accuracy was found between MRCP and DWI combined, and MRCP, DWI, and contrast-enhanced T1WI combined (P > 0.050). There was substantial interobserver agreement in all three image sets (κ = 0.695-0.732). The addition of DWI to MRCP significantly improved diagnostic accuracy in the characterization of distal biliary strictures. J. Magn. Reson. Imaging 2013. © 2013 Wiley Periodicals, Inc.Journal of Magnetic Resonance Imaging 06/2014; 39(6). DOI:10.1002/jmri.24304 · 2.57 Impact Factor
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ABSTRACT: Purpose To assess the benefit of adding diffusion-weighted (DW) imaging to gadoxetic acid-enhanced magnetic resonance (MR) imaging and MR cholangiopancreatography in the preoperative evaluation of hilar cholangiocarcinoma. Materials and Methods The institutional review board approved this retrospective study and waived the requirement for informed consent. The study included 52 patients (36 men, 16 women; mean age, 63.4 years) with surgically confirmed hilar cholangiocarcinoma who underwent gadoxetic acid-enhanced MR imaging and DW imaging at 3.0 T between August 2010 and December 2011. Two observers independently reviewed two image sets-a gadoxetic acid set, including images from MR cholangiopancreatography, and a combined gadoxetic acid set and DW imaging set-to evaluate the tumor involvement of each biliary confluence and vascular and liver invasion by using receiver operating characteristic (ROC) curve analysis. Results For each observer, area under the ROC curve (Az) values for tumor involvement of the biliary confluence were 0.965 and 0.957 for the gadoxetic acid set and 0.980 and 0.975 for the combined set, respectively (P > .05). For detecting 105 biliary confluences with tumor involvement, the sensitivities with the combined set (97.1% [102 of 105] and 98.1% [103 of 105]) were higher than those with the gadoxetic acid set (91.4% [96 of 105] for both observers) (P = .029 and P = .016), although the specificities were similar with both image sets (P > .05). For the detection of liver invasion, the combined set (75.0% [15 of 20] for both observers) yielded better sensitivity than the gadoxetic acid set (50.0% [10 of 20] and 45.0% [nine of 20]) (P = .016 and P = .031). For evaluation of vascular invasion, the two image sets showed similar diagnostic performance. Conclusion In the preoperative evaluation of hilar cholangiocarcinoma, the addition of DW imaging to gadoxetic acid-enhanced MR imaging could improve sensitivity in the evaluation of tumor extent along the bile duct and liver invasion. © RSNA, 2013 Online supplemental material is available for this article .Radiology 10/2013; 270(3):130009. DOI:10.1148/radiol.13130009 · 6.21 Impact Factor