Digestive System: Liver and Biliary Tract

1. Chapter 16 Digestive System:LiverandBiliary Tract

2. Digestive System • Consists of 2 tracts: • 1. alimentary tract (mouth, pharnyx, esophagus, stomach, large and small intestines) 2. accessory organs contributing to digestion (salivary glands, liver, pancreas, gallbladder, biliary tract) • Both contained in the abdominopelvic cavity which consists of 2 parts • 1. Abdominal cavity-large superior portion • 2. Pelvic cavity-smaller inferior

3. Abdominal Cavity Extends from diaphragm to superior aspect of pelvis • Stomach • Small & large intestines • Liver/Gallbladder • Spleen • Pancreas • Kidneys

4. Pelvic CavityLies within margins of pelvis • Rectum/Sigmoid • Urinary bladder • Reproductive organs

5. Peritoneum • The double-walled serousmembranous sac that encloses abdominopelvic cavity • 1.Parietal Peritoneum- outer portion in close contact with abdominal wall, undersurface diaphragm • 2. Visceral Peritoneum- inner portion-over or around organs • Space between 2 layers is peritoneal cavity

6. Parietal peritoneum (Adheres to abdominal wall) • Visceral peritoneum- (adheres to organs) • Peritoneal folds • Mesentary and Omentum • Folds caused by adherence of visceral layer of peritoneum • Supports organs in position

7. Retroperitoneum • Cavity behind peritoneum • Contains kidneys and pancreas

8. Liver

9. Liver • Largest gland in body • Takes up most of anterior RUQ • Produces 1-3 pints of bile per day

10. Liver (cont’d) • Falciform ligament divides liver into 2 major lobes • Right lobe • Left lobe • 2 minor lobes • Caudate lobe- part of right lobe -posterior • Quadrate lobe - “ inferior

11. Liver Physiologic Functions • Formation of bile • Bile: • Aids in digestion of fats • Helps to eliminate waste products of RBC’s collected from liver cells from bile ducts • Also stored in gallbladder

12. Liver has a dual blood supply • Portal vein (through portal system) • -carries blood from digestive system to be filtered by liver • 2. Hepatic artery • -supplies oxygenated blood from abdominal aorta

13. Portal System • Consists of veins arising from stomach, intestinal tract, gallbladder and spleen • Blood circulates through these organs rich in nutrients to liver where it is modified before returning to heart via hepatic veins

14. Biliary System(Excretory system of liver)

15. Biliary System • Consists of : 1. bile ducts 2. gallbladder 3. associated structures involved in production and transportation of bile

16. 2 Primary functions of biliary system: • Drain waste products from liver into duodenum • Help in digestion with controlled release of bile • Bile is greenish-yellow fluid (consisting of waste products, cholesterol, and bile salts) • - excreted from body as feces- gives feces its dark brown color.

17. Gall bladder • Serves as reservoir for bile from liver – 2oz. capacity (50 percent of bile 1st stored in gallbladder) • Concentrates bile • Helps to break down fats • when food eaten, gallbladder is activated by hormone cholecystokinin which stimulates contraction of gallbladder and releases stored bile into duodenum

18. Transportation of bile sequence • Liver cells secrete bile- collected by system of ducts flowing from liver through right and left hepatic ducts. • Hepatic ducts drain into common hepatic duct.

19. Transportation of bile sequence (cont’d) • Common hepatic duct joins with cystic duct from gallbladder to form: • Common bile duct -runs from liver then • Joins with or runs side by side withpancreatic duct into chamber known as • Hepatopancreatic ampulla (or ampulla or vater) • Empties into duodenum • Controlled by Spincter of Oddi (or spincter of hepatopancreatic ampulla)

20. Biliary Ducts Two main hepatic ducts join to form : • Common Hepatic duct • Unites with: • Cystic duct to form: Common bile duct • Which joins withpancreatic duct and empties into duodenum

21. Pancreas • Glandular organ • Head will be found within duodenal loop • Generally cannot be seen on radiographs

22. PancreasCont’d • Both an exocrine and endocrine gland • Endocrine- (Isle of Langerhans) produces glucagon and insulin to regulate sugar metabolism • Exocrine- secretes digestive enzymes that are conveyed through pancreatic duct- often times uniting with common bile duct to hepatopancreatic ampulla then to duodenum

23. Spleen • Not a part of digestive system • Belongs to lymphatic system • Produces lymphocytes • Stores and removes dead or dying RBC’s • Can be visualized on plain radiographs

24. Radiography of the Abdomen KUB Flat and upright 3-way abdomen (acute abdomen series - rule out free air, bowel obstruction, infections) • 1. AP • 2. AP upright or left-lateral decubitus (can’t stand) • 3.PA erect chest -to visualize free air under diaphragm

25. Positioning AP Abdomen • Pt. supine • CR at crest of ilium • Pt. centered at midline • kVp range - 70’s • Expose at end of full expiration

26. Shielding • 1. If gonads within 2 inches to primary x-ray field even with proper beam limitation • 2. Clinical objectives not compromised • 3. Pt has reasonable reproductive potential

27. Evaluation Criteria - Abdomen Radiograph • Symphysis pubis to upper abdomen • Vertebral column is centered • Pelvis, ribs, and hips equidistant • No rotation

28. Evaluation Criteria For Abdomen Radiograph cont’d • Markers must be visible • All soft tissue structures should be present • No motion • Variances in position must beindicated!

29. Structures Shown On Abdominal Radiography • Size and shape of liver • Spleen • Kidneys • Psoas muscles • Any intra-abdominal tumors, masses, or calcifications

30. Positioning Variants Of Abdomen Radiograph • Upright • Demonstrates free air under diaphragm • Air-fluid levels • Left Lateral Decubitus • Demonstrates air/fluid levels on non-ambulatory patient

31. Positioning Variants Of Abdomen Radiograph cont’d • Lateral Position • Demonstrates: • calcification in pre-vertebral space • aneurysms of aorta (if calcified)

32. Radiography of Biliary Tract & Gallbladder

33. Radiography Of Biliary Tract & Gallbladder(regular cholecystography) • Cholecystography (largely replaced by Ultrsound, CT, MRI, nuclear medicine) • Study of gallbladder • Oral contrast is used • Cholangiography • Study of biliary ducts • IV contrast is used • May be injected directly into ducts

34. Biliary Tract Examinations • Why perform? • Determine liver function • Patency and condition of ducts • Demonstrate concentrating and emptying ability of GB • Search for gallstones • Only those that contain calcium are visible

35. Cholelithiasis (gallstones) Cholecystitis (inflammation of gallbladder) Biliary neoplasia (tumor) Opacities or masses Biliary stenosis (abnormal narrowing) IndicationsforBiliary Tract Exam

36. ContraindicationsforBiliary Tract Exams • Allergy to contrast • Pyloric obstruction (blockage from stomach to duodenum) • Severe jaundice • Malabsorption • Liver dysfunction • Hepatocellular disease

37. Patient Prep • Fat-free meal evening before • Oral contrast taken 2 to 3 hours before evening meal • NPO after midnight until exam • Early morning appointment • Ensure that patient can, will, and did follow instructions

38. Gallbladder Exam(Cholecystography) • Obtain scout film • Full KUB or RUQ film • Determine contrast is in gallbladder and is visible • May include fluoroscopic examination • Post-fatty meal film may be obtained • Determines emptying ability of GB

39. Position of Gallbladder • RUQ • In hypersthenic pt. • Superior and lateral • In Asthenic • Inferior and nearer to spine

40. PA Projection • Patient prone recumbent or prone upright • Center 10x12 cassette at RUQ, level of the elbow • 70 - 80 kVp range • Exposure made at end of full expiration

41. PA Oblique Projection • LAO position • Pt rotated 15 - 40 degrees depending on body habitus • CR at level of elbow, between spine and midaxillary line 10x12 cassette

42. Rt. Lateral Decubitus • Position • Rt. Lateral recumbent • Central Ray • Directed horizontally to level of gallbladder • Good for non-ambulatory patients

43. Gall Bladder cont’d • Must be free of foreshortening or superimposition from itself and adjacent structures • Entire gallbladder must be visualized • No motion or rotation

44. Very rarely performed Used when patients cannot tolerate oral contrast Generally done in supine, and RPO positions Films taken at timed intervals - up to about 40 minutes after injection Tomography may be used Intravenous Cholangiography (IVC)

45. Percutaneous Transhepatic Cholangiography(performed preoperatively) • Percutaneous: any medical procedure where access to inner organs or other tissue is done via needle-puncture of the skin, rather than by scapel • Pt prepped for sterile procedure • Chiba (long) needle is placed into bile ducts • Contrast is injected under fluoro • AP Projections obtained • Biliary drainage or stone extraction may accompany this procedure

46. CholangiographyIntra-operative • Obtained during a cholecystectomy • Pt. prepped and draped for surgery • Examines patency of ducts during or after surgical removal of GB

47. Procedure for Operative Cholangiography • Obtain scout of RUQ when possible • A grid should be used • C-Arm may be used for a dynamic study • May need to rotate patient into RPO • Coordinate exposures w/anesthesiologist

48. T-Tube Cholangiography • Post-operative procedure- performed through T-tube left in common hepatic and common bile ducts • Determines patency (open) of biliary ducts after cholecystectomy, status of Spincter of oddi, residual or undetected stones

49. T-Tube Cholangiography (cont’d) Procedure: • Obtain scout of RUQ • Contrast will be injected into T-tube • Obtain AP and RPO films

50. Cholangiogram types Percutaneous Intraoperative T-Tube