Comparison of multidetector-row computed tomography findings of IgG4-related sclerosing cholangitis and cholangiocarcinoma Poster No.: C-0245 Congress: ECR 2014 Type: Scientific Exhibit Authors: M. Yata, K. Suzuki, N. Furuhashi, K. Kawakami, Y. Kawai, S. Naganawa; Nagoya/JP Keywords: Biliary Tract / Gallbladder, CT, Diagnostic procedure, Cancer, Inflammation DOI: 10.1594/ecr2014/C-0245 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 15
Aims and objectives Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) is a systemic immune-mediated condition that is now being recognized with increasing frequency. IgG4-RD is characterized by elevations in serum IgG4 concentrations, a lymphoplasmacytic infiltrate composed of IgG4-positive plasma cells, storiform fibrosis, and obliterative phlebitis [1, 2]. IgG4-RD can involve multiple organs such as the salivary glands, breast, lungs, pancreas, biliary tree, kidneys, lymph nodes, aorta, prostate, and so on [3]. IgG4-related sclerosing cholangitis (IgG4-SC) is a biliary lesion of IgG4-RD [4] and is more common in elderly men [5]. Patients frequently have obstructive jaundice due to bile duct stricture, but steroid therapy is effective [6]. IgG4-SC shows various cholangiographic features similar to those of cholangiocarcinoma (CCA) [7, 8]. Although IgG4-SC can often be difficult to distinguish from CCA, making an accurate differential diagnosis is important for avoiding unnecessary surgery of IgG4-SC. The aim of this study is to compare multidetector-row computed tomography (MDCT) findings between cases of IgG4-SC and CCA. Methods and materials <Patients> We retrospectively recruited consecutive patients with IgG4-SC from September 2003 to May 2012 and CCA from October 2009 to October 2012 in multiphase contrast enhanced CT database. IgG4-SC was diagnosed according to the clinical diagnostic criteria of Japan Biliary Association (2012) [9] and/or Mayo Clinic's HISORt criteria [6]. CCA was histopathologically diagnosed on surgical specimen. The patients who had biliary drainage tube were excluded. And the patients who were histopathologically diagnosed with intraductal papillary neoplasm of the bile duct were excluded from CCA. Thus, the present study examined 28 patients with IgG4-SC (24 men, 4 women; mean age, 68 years; age range, 52-86 years), and 33 patients with CCA (20 men, 13 women; mean age, 71 years; age range, 34-85 years). <CT image acquisition> CT scan was performed using 16-slice (IgG4-SC; n=5, CCA; n=0) and 64-slice multisection CT systems (IgG4-SC; n=23, CCA; n=33) (Aquilion, Toshiba Medical Systems, Tokyo, Japan). Non-ionic contrast material (2-2.5 ml/kg) with an iodine concentration of 300 mgi/ml was injected through the peripheral venous line for 30 s (with an upper limit of 5 ml/s), and a saline flush was injected at a fixed rate of 5 ml/s Page 2 of 15
immediately after contrast material injection. After unenhanced images were acquired, all patients underwent arterial phase and portal phase imaging. Delayed phase images were also acquired (IgG4-SC; n=24, CCA; n=33). Individualized scan delays were determined using the automatic bolus-tracking method (SureStart, Toshiba). Average scan delays from the injection of contrast material to the start of arterial phase, portal phase, and delayed phase imaging were 40, 65, and 240 s, respectively, for 16-channel multisection CT; and 44, 70, and 240 s for 64-channel multisection CT. Unenhanced images were reconstructed with a 5 mm section thickness at 5 mm intervals. Contrast-enhanced images were reconstructed with a 2 mm section thickness at 2mm intervals, and coronal reformatted images were also generated with a 2 mm section thickness at 2 mm intervals. <CT image analysis> Two radiologists (4 and 16 years of experience) who had no knowledge of the clinical information evaluated the following CT findings by consensus (Table 1 on page 4). Table 1: Assessment items References: Nagoya University Graduate School of Medicine - Nagoya/JP The frequencies of the findings were compared among IgG4-SC and CCA. And the sensitivity and specificity of the findings in IgG4-SC were calculated. Another radiologist (3 years of experience) measured the biliary lesions (Table 2 on page 5). Page 3 of 15
Table 2: Measurement items References: Nagoya University Graduate School of Medicine - Nagoya/JP <Statistical Analyses> Assessment items from (a) to (j) were analyzed with chi-square test and measurement items from (k) to (q) were analyzed with Student's t test, Welch's t test, or Mann-Whitney U-test. And statistical significance was set at p # 0.05. Images for this section: Page 4 of 15
Table 1: Assessment items Table 2: Measurement items Page 5 of 15
Results The results of CT findings are summarized in Table 3 on page 8. Table 3: CT findings of the biliary lesions from (a) to (h) References: Nagoya University Graduate School of Medicine - Nagoya/JP Compared with CCA, IgG4-SC was significantly more frequently associated with (a) lesion of lower common bile duct (Fig. 1 on page 9), (b) wall thickening only (Fig. 2 on page 10), (c) concentric wall thickening (Fig. 3 on page 11), (d) smooth outer margin (Fig. 2 on page 10), (g) funnel-shaped dilatation of the proximal bile duct (Fig. 1 on page 9). The results of contrast enhancement are summarized in Table 4 on page 8. Table 4: CT findings about contrast enhancement of the biliary wall (i,j) References: Nagoya University Graduate School of Medicine - Nagoya/JP Page 6 of 15
(i) Single-layered contrast enhancement, and (j) homogeneous attenuation were significantly higher in IgG4-SC than CCA (Fig. 4 on page 12). Of those mentioned above, the specificities more than 80% were (a) lesion of lower common bile duct, (d) smooth outer margin, (g) funnel-shaped dilatation of the proximal bile duct, (j) homogeneous attenuation in the arterial phase. And the sensitivity of (i) single-layered contrast enhancement in the arterial phase was 100 %. With regard to CCA, the specificities when the biliary wall showed two-layered contrast enhancement in the arterial phase were also 100 % (Fig. 5 on page 13). The results of measurement are summarized in Table 5 on page 8. Table 5: Measurement of size of the biliary lesion from (k) to (n), and dilated bile duct diameter (o,p) References: Nagoya University Graduate School of Medicine - Nagoya/JP (k) Length of the biliary lesions was longer in IgG4-SC than in CCA. On the other hand, (o) diameter of the dilated proximal common bile duct, and (p) diameter of the dilated proximal intrahepatic bile duct were smaller in IgG4-SC than in CCA. The results of attenuation values are summarized in Table 6 on page 9. Table 6: Attenuation values of the biliary wall (Hounsfield Unit: HU) (q,r) Page 7 of 15
References: Nagoya University Graduate School of Medicine - Nagoya/JP (q) When the biliary wall showed single-layered contrast enhancement, there was no significant difference in attenuation values in all phase. (r) With regard to IgG4SC, no patients showed two-layered contrast enhancement in the arterial phase and delayed phase and only one patient showed two-layered contrast enhancement in the portal phase. On the other hand, 13 patients with CCA showed two-layered contrast enhancement (Fig. 5 on page 13). Images for this section: Table 3: CT findings of the biliary lesions from (a) to (h) Table 4: CT findings about contrast enhancement of the biliary wall (i,j) Page 8 of 15
Table 5: Measurement of size of the biliary lesion from (k) to (n), and dilated bile duct diameter (o,p) Table 6: Attenuation values of the biliary wall (Hounsfield Unit: HU) (q,r) Page 9 of 15
Fig. 1: A 59-year-old man with IgG4-SC. Coronal CT image in the arterial phase shows the thickening of the lower common bile duct wall and funnel-shaped dilatation of the proximal bile duct (arrow). Page 10 of 15
Fig. 2: A 70-year-old man with IgG4-SC. Coronal CT image in the arterial phase shows the biliary wall thickening without mass formation and smooth outer margin (arrow). Page 11 of 15
Fig. 3: A 74-year-old man with IgG4-SC. Axial CT image in the portal phase shows concentric wall thickening (arrow). Fig. 4: A 61-year-old man with IgG4-SC. Axial CT images in the arterial phase (a), portal phase (b), and delayed phase (c) show single-layer enhancement and homogeneous attenuation (arrow). Page 12 of 15
Fig. 5: A 34-year-old woman with CCA. Axial CT images in the arterial phase (a), portal phase (b), and delayed phase (c) show two-layered contrast enhancement. The inner side shows high attenuation (arrow), and the outer side shows low attenuation (arrow head) mainly in the arterial phase. Page 13 of 15
Conclusion There are a number of CT findings which are useful in differentiating between IgG4-SC and CCA. Especially, (a) lesion of lower common bile duct, (d) smooth outer margin, (g) funnel-shaped dilatation of the proximal bile duct, and (j) homogeneous attenuation in the arterial phase can help suspect IgG4-SC. On the other hand, two-layered contrast enhancement can help suspect CCA. It is important to keep those things in mind when differentiating IgG4-SC from CCA in CT images. Personal information References 1. Zen Y, Nakanuma Y. IgG4-Related Disease: A Cross-sectional Study of 114 Cases. Am J Surg Pathol 2010; 34: 1812-19. 2. Deshpande V, Zen Y, Chan JK, et al. Consensus statement on the pathology of IgG4related disease. Modern Pathology 2012; 25: 1181-92. 3. Khosroshahi A, Stone JH. A clinical overview of IgG4-related systemic disease. Current Opinion in Rheumatology 2011; 23: 57-66. 4. Takuma K, Kamisawa T, Igarashi Y. Autoimmune pancreatitis and IgG4-related sclerosing cholangitis. Current Opinion in Rheumatology 2011; 23: 80-87. 5. Nakazawa T, Ohara H, Sano H, et al. Clinical Differences Between Primary Sclerosing Cholangitis and Sclerosing Cholangitis With Autoimmune Pancreatitis. Pancreas 2005; 30: 20-25. 6. Ghazale A, Chari ST, Zhang L, et al. Immunoglobulin G4-Associated Cholangitis: Clinical Profile and Response to Therapy. Gastroenterology 2008; 134: 706-15. 7. Hamano H, Kawa S, Uehara T, et al. Immunoglobulin G4-related lymphoplasmacytic sclerosing cholangitis that mimics infiltrating hilar cholangiocarcinoma: part of a spectrum of autoimmune pancreatitis? Gastrointestinal Endoscopy 2005; 62: 152-57. 8. Arikawa S, Uchida M, Kunou Y, et al. Comparison of sclerosing cholangitis with autoimmune pancreatitis and infiltrative extrahepatic cholangiocarcinoma: multidetectorrow computed tomography findings. Jpn J Radiol 2010; 28: 205-13. Page 14 of 15
9. Ohara H, Okazaki K, Tsubouchi H, et al. Clinical diagnostic criteria of IgG4-related sclerosing cholangitis 2012. J Hepatobiliary Pancreat Sci 2012; 19: 536-42. Page 15 of 15