This document discusses the imaging of bile ducts and causes of lower biliary obstruction. It covers the normal biliary anatomy, various imaging modalities used including ultrasound, CT, MRI, ERCP and their appearances. It describes the classification, appearances and algorithms for evaluating obstructive jaundice and discusses specific conditions like choledocholithiasis, cholangiocarcinoma, pancreatic carcinoma and post-surgical complications.

1. IMAGING OF BILE DUCT DR.SUDHEER HEGDE CONSULTANT RADIOLOGIST DEPARTMENT OF RADIOLOGY COLUMBIA ASIA HOSPITALS Courtesy : Dr.Shalini Govil

2. NORMAL ANATOMY cross-sectional and cholangiographic CAUSES OF LOWER BILIARY OBSTRUCTION APPEARANCES ON DIFFERENT IMAGING MODALITIES ALGORITHM FOR OBSTRUCTIVE JAUNDICE

3. BILIARY ANATOMY

4. IMAGING MODALITIES Ultrasound - transabdominal, EUS, intraductal Cholangiography - invasive : ERCP / PTC - non-invasive : MR Cholangiography CT Cholangiography - minIP and maxIP Cross Sectional - spiral CT / MRI as part of MRC/CTC Non-invasive biliary package – MRC with spiral CT DSA Biliary Scintigraphy

5. BILIARY ANATOMY - Cholangiogram

6. Ultrasound biliary tract

7. BILIARY ANATOMY - CT right hepatic duct

8. common hepatic duct / common duct at the hilum BILIARY ANATOMY - CT

9. supra-pancreatic common duct in the lesser omentum BILIARY ANATOMY - CT

10. BILIARY ANATOMY - CT intra-pancreatic common duct

11. BILIARY ANATOMY - CT intra-pancreatic common duct

12. MRCP

13. EUS – bile duct calculi

14. CAUSES OF LOWER BILIARY OBSTRUCTION CLASSIFICATION BY LEVEL OF OBSTRUCTION Intrapancreatic - choledocholithiasis, chronic pancreatitis, pancreatic carcinoma Suprapancreatic – cholangiocarcinoma, metastatic adenopathy, choledochal cyst Intraluminal – tumour – HCC/CC, blood, stone, worm, hydatid

15. ULTRASONOGRAPHY Signs of Biliary Dilatation: Parallel Channel sign – IHBD > 2mm CBD > 6mm Post Fatty Meal Sonography CBD size increase of 2mm Post Cholecystectomy No compensatory dilatation of CBD CBD > 10mm

16. CHOLANGIOGRAPHY Invasive (ERCP / PTC) - High spatial resolution Possible therapeutic options Complication rate (2-3%) Non-invasive CT Cholangiogram - with IV contrast (maxIP) bilirubin > 2mg% - ineffective - without IV contrast (minIP) MR Cholangiogram

17. MR CHOLANGIOGRAPHY Breath-hold (HASTE, RARE) Non-breath-hold (IRTSE) Bile appears bright on heavily T2W images Mapping of biliary tree proximal to obstruction Contraindicated in presence of aneurysm clips, cardiac pacemakers.

18. MR CHOLANGIOGRAPHY SENSITIVITY SPECIFICITY Biliary Obstruction 91 – 100% 100% Level of Obstruction 91 – 100% 100% Choledocholithiasis 81 – 100% 85 – 100% (2mm)

19. MR CHOLANGIOGRAPHY

20. ERC MRC CTC THERAPY + - - SECTIONAL - + + IMAGING ANGIOGRAM - + +

21. CT / MRI Extraductal information – mass, nodes, ascites, metastases, biliary cirrhosis, portal hypertension and varices CT / MR angiography – for tumour resectability: periampullary, pancreatic, GB and hilar carcinomas.

22. CTC MRC

23. ERCP

24. MR/CT CHOLANGIOGRAPHY visualisation of the proximal biliary tree involvement of CHD, confluence, RHD, LHD, second order ducts SECTIONAL IMAGES nodes, liver metastases, ascites, peritoneal metastases, hilar vessel involvement

25. PANCREATIC / PERIAMPULLARY CARCINOMA US – Double duct sign (CBD & PD dilated) - Mass (+) - Ca Pancreas(95%) –US guided FNAC - Mass (– )-Perimpullary Ca – ERC with Biopsy Spiral CT - 80% accuracy(resectability) Endoscopic US – local extent of disease.

26. Periampullary Carcinoma

27. Periampullary Carcinoma

28. Ca pancreas double duct sign

29. ALGORITHM for OBSTRUCTIVE JAUNDICE ULTRASOUND BILIARY DILATATION MASS+ MR (MRC, MRA) or CT (CTC + CTA) or MRC + CT + CTA STENT or SURGERY ? STRICTURE ? CALCULUS (intact bile duct) (THERAPEUTIC) ERC CALCULUS+ MASS -

30. RESECTABILITY CRITERIA Involvement of encasing the portal vein, distal superior mesenteric vein. Involvement of CBD and PD (both ducts) Unilateral vascular invasion with contralateral biliary involvement Metastases Helical CT - 60% Accuracy

31. Pancreatic adenocarcinoma encasing the portal vein, distal superior mesenteric vein. Intraluminal filling defect suggestive of a thrombus is seen in the superior mesenteric vein

32. THANK YOU

33. CHOLANGIOCARCINOMA Intraductal ultrasound bile duct wall thickening - carcinoma vs inflammation semicircular, eccentric, asymmetric wall thickening notched outer margin rigid, papillary inner margin heterogeneous echoes

34. NON SURGICAL THERAPEUTIC DRAINAGE Low Obstruction – ERCP with Stent Placement Cholangitis – Drainage (Nasobiliary/PTBD)

35. PTBD with STENT PLACEMENT ERC with STENT

36. DISTAL CHOLANGIOCARCINOMA

37. GB CARCINOMA

38. PRIMARY SCLEROSING CHOLANGITIS US extrahepatic and intrahepatic ductal wall thickening CHOLANGIOGRAPHY pruned tree appearance multifocal strictures pseudodiverticulae PSC-like cholangitis – AIDS cholangitis NON INVASIVE CHOLANGIOGRAM PREFERABLE

39. PRIMARY SCLEROSING CHOLANGITIS

41. HYDATID CYSTS

42. CHOLEDOCHAL CYST US / NON INVASIVE CHOLANGIOGRAPHY - Todani type - abnormal pancreatico biliary junction

43. CHOLEDOCHAL CYST

44. CHOLEDOCHAL CYST

45. ABERRANT BILE DUCTS non invasive cholangiogram – prior to laproscopic cholecystectomy MRC HIGH DIAGNOSTIC CT C ACCURACY MRC 0.5 T – SUBOPTIMAL VISUALISATION OF NORMAL CALIBER DUCTS

46. MRC CTC

47. POST SURGICAL COMPLICATIONS Retained calculi – T tube Cholangiogram / ERCP Biliary leak Biliary stenosis/stricture

50. BILE LEAKS Site of Leak T-Tube Cholangiogram ERCP with sphincterotomy / Stent Scintigram Infected Biloma US / CT – pigtail drainage

51. T – TUBE cholangiogram BILE LEAKS

52. POST SURGICAL STRICTURE BILIARY ENTERIC ANASTAMOSIS POST CHOLECYSTECTOMY US – biliary dilatation aerobilia MR / CT with Cholangiogram – level of obstruction HIDA Scan – assess patency

53. POST-SURGICAL STRICTURES BISMUTH CLASSIFICATION

54. ERC MRC

55. BISMUTH type 5 STRICTURE ANASTAMOTIC STRICTURE

56. GALL STONE associated obstructions GALL STONE ILEUS Rigler’s triad - air in the biliary tree small bowel obstruction ectopic gall stone MIRIZZI SYNDROME

57. GALL STONE ILEUS