1. The Liver

2. The liver Powerhouse- Largest parenchymal organ
many metabolic activities-storehouse for glycogen and secretes bile
Largest parenchymal organ
Its bulky mass displaces gas- filled components of the digestive system
Provides an acoustic window for visualization of upper abdominal and upper retroperitoneal structures
Glissons capsule surrounds the liver-strong connective tissue

3. Liver structures Portal veins Hepatic veins Hepatic arteries
Flow returning to liver
Hepatic veins
Flow returning to IVC
Hepatic arteries
Flow supplying liver-CA
Hepatic ducts
bile
Ligaments
Secure the liver
Fissures
Anatomical divisions
On ultrasound images these structures help divide the liver into easily recognizable segments
Provide anatomical landmarks

4. Location Occupies a major portion of the right hypochondrium
Extends medially into the epigastrium
Laterally into the left hypochondrium
Superiorly it reaches the dome of the diaphragm
Posteriorly it borders the bony lumbar region of the muscular posterior abdominal wall
The bulk of the liver lies beneath the right costal margin

5. Location continued
Superior surface,anterior surface and a portion of the posterior surface are in contact with the diaphragm
Anterior surface

6. Boundaries
Anterosuperior surface fits snuggly into the dome of the diaphragm
Separated from the overlying pleural cavities and pericardium
Thin edge of the superior surface of the left lobe reaches level of the 5th rib on full expiration
The anterosuperior surface is closest to the anterolateral abdominal wall and is palpable when the organ is enlarged
Largely covered by the peritoneum of the greater sac
The Bare area on the posterior surface is in direct contact with the diaphragm

7. Posterior liver surface
Posterior surface of the liver outlines the boundaries of the bare area
The bare area is not separated from the diaphragm by the peritoneal cavity

8. Bare area IVC courses through it to the right of the median plane
Lies between leaflets of anterior inferior and posterior superior coronary ligaments
Rt kidney and adrenal lie lateral and inferior
Surrounded by ligaments

9. Bare area significance
The bare area is clinically important as it represents a site where infection can spread from the abdominal cavity into the thoracic cavity
None peritoneal surface,in direct contact with the diaphragm

10. Sagittal scan plane-Bare area
Longitudinal section of right kidney and adrenal gland in contact with bare area
Anterior kidney surface separated from posterior liver by Morrison’s pouch(a peritoneal space)

11. Bare area

12. Right posterosuperior surface
Major relations-
right posterior fibers of the diaphragm
upper posterior abdominal wall,
right kidney and adrenal gland
Bony and muscular posterior abdominal wall protects the posterior surface
Inferior segment of this surface communicates with
right lumbar paracolic gutter
visceral surface of liver
The inferior margin is the border between the anterior aspect and the visceral surface

13. Transverse scan plane of liver
Axial section of the diaphragmatic undersurface and posterosuperior liver surface

14. Diaphragmatic surface
Smooth and convex- liver conforms to the cavity of the inferior surface of the diaphragm
Largely separated from the diaphragm by part of the peritoneal cavity called the subphrenic recess
Superior part of the liver is covered with peritoneum except at the bare area

15. Posterior surface con’t
H-shaped group of deep fissures and fossae
Crossbar of the H – is the porta hepatis
LT sagittal limbs-deep fissures-ligamentum teres and venosum
Rt sagittal limbs-fossae for gallbladder and IVC

16. Inferior (visceral) surface
Rests on upper abdominal organs
Not on a horizontal plane
Lies at 45Degrees
Marked by indentations from the organs in contact with its surface
Rt Lobe related to:
Duodenum
Right colic flexure
Right kidney and adrenal gland
Gallbladder
Lt lobe related to:
Stomach
Colon

17. Indentations Rt sided indentations- Hepatic flexure-colon
Right kidney , adrenal gland
Duodenum
Gallbladder
Lt sided indentations-
Gastric
Posteriorly- marked by groove that surrounds the IVC

18. Lobes of the liver Functionally divided into right and left lobes
Also known as hemilivers
This plane is known as the main lobar fissure
passes through the gallbladder fossa and fossa for the IVC
Liver is also divided by 3 hepatic veins
And right and left portal veins and its branches

19. Liver relationships
Refer to page 121 fig 6-13I

20. Right lobe Lies close to anterolateral abdominal wall
Related to undersurface of diaphragm
Along the RT midaxillary line from 7th -11th ribs
Divided into anterior and posterior portions

21. Right lobe-relationships
Anterior to-
Hepatic flexure
Rt kidney and adrenal gland
Descending duodenum,
Diaphragm
Posterior to-
6-10th ribs
Superior to-
Rt kidney
Inferior to-
Diaphragm
Medial to-
Rt lateral abdominal wall
Rt lateral to AO
Falciform ligament
Lt lobe liv

22. Left lobe Closely related to the undersurface of the diaphragm
Varies in size and shape
May extend deeply into the LUQ
Free inferior margin related to the stomach
Frequently lies anterior to pancreas body,SV and SA
Divided into medial and lateral lobes

23. LL relationships

24. Left lobe Anterior to- Posterior to- Superior to- stomach, EGJ SV,SA
Pancreas body/tail
Caudate lobe
Diaphragm
Spine
Posterior to-
xiphoid process
7th and 8th costal cartilages
Superior to-
Stomach,
Bowel
Lt Kidney and adrenal gland

25. Lt lobe con’t Inferior to- Medial to- Lt lateral to- Diaphragm Stomach
Spleen
Lt lateral abdominal wall
Lt lateral to-
IVC
Rt lobe liver,
Falciform ligament
Fissure for ligamentum teres
Lt medial lobe
Spine

26. Left medial lobe(inferior liver surface)
Anterior to-
Porta hepatis,
Pyloris
Duodenum
Transverse colon
GDA
Posterior to-
Anterior liver margin
Superior to-
RT kidney and adrenal gland
Medial to- GB
Rt lateral to-
Fissure for ligamentum teres
Lt lateral lobe

27. Transverse scan plane Midepigastrium
Falciform ligament appears in short axis demarcating lateral border of medial left lobe

28. Sagittal scan plane-LL
Longitudinal section of left inferior margin of the left hepatic lobe

29. Caudate lobe Smallest lobe Related to posterior abdominal wall
Covered by peritoneum of lesser sac
Anterior boundary –
left portal vein
Posterior boundary-
IVC
Lateral margin projects into superior recess of lesser sac(omental bursa)
Caudad border forms cephalad margin of foramen of winslow

30. Caudate lobe Anterior to- Posterior to- Superior to- Inferior to-
Diaphragm
Posterior to-
Porta hepatis,
Fissure for ligamentum venosum
Lt lobe liver
Superior to- SV
Inferior to-
diaphragm
Medial to-
IVC
Rt lateral to- AO

31. Caudate lobe relationships
Page 202 Curry

32. Ligaments of the liver Teres- Obliterated Lt umbilical vein-(prenatal)
Also known as Round ligament
Connecting the Lt branch of PV to the umbilicus-
Runs in the free edge of falciform ligament-
In utero it carried blood from the placenta to the fetus

33. Coronary ligaments Coronary ligament-
peritoneum reflection from diaphragm to the anterosuperior liver surface
Surrounds bare area
Converges posterolaterally to form right triangular ligament

34. Falciform ligament
Attaches the liver to the diaphragm and the anterior abdominal wall
Fold of peritoneum-divides RT and Lt lobes-along with the grooves for ligamentum venosum and teres
Continues as the LT triangular ligament to the left
And the coronary ligament to the right

35. Falciform and Venosum Ligaments

36. Ligamentum Venosum
Remnant of the ductus venosus of the fetal circulation
Attached to the left branch of the portal vein within the porta hepatis
It may be continuous with the round ligament
Lies within a fissure on the inferior surface of the liver between caudate and Lt lobe

37. Ligamentum venosum The ductus venosus(red)
Becomes ligamentum venosum after birth
Connects umbilical V to IVC in utero

38. Parasagittal scan plane
Right of the midline
Caudate lobe posterior to left lobe
Longitudinal section of ligamentum venosum

39. Peritoneal divisions continued
Greater sac-
Also called abdominal cavity
encloses most of the abdominal organs:the enclosed organs are intraperitoneal
Lesser omentum-
also called gastrohepatic omentum or small omentum
double layer-from liver to stomach
Greater omentum-
also called gastrocolic omentum
large fold of peritoneum
extends from stomach
passes anteriorly to colon and small intestine
Subphrenic recess-
Small space between visceral peritoneum of liver and parietal peritoneum of diaphragm
Part of greater and lesser sac

40. Peritoneal divisions Epiploic Foramen of Winslow- Lesser sac –
Also called omental foramen and epiploic foramen
opening between the greater sac of the peritoneal cavity in the abdomen(which encloses the abdominal organs) and lesser sac
Lesser sac –
bordered anteriorly by the stomach,
posteriorly by the pancreas and part of transverse colon
also called- omental bursa

41. Liver Divisions by Hepatic veins
Drain blood from segments and lobes of the liver
Located interlobar and intersegmental
Drain into IVC
Separate and drain:
RHV-anterior and posterior segment of RL
LHV-medial and lateral segment of LL
MHV-RL and medial LL

42. Intrahepatic Portal veins
Course within hepatic lobes and segments
intersegmental
Supply liver with blood from GI tract for processing
intrasegmental
Left and right branches are formed by the intraabdominal main portal vein

43. Portal veins

44. Porta Hepatis Enclosed in the free margin of the lesser omentum
The most obvious structure at the porta hepatis is the hepatic portal vein
The portal vein is formed behind the neck of the pancreas,courses obliquely toward liver
At the porta hepatis,portal vein is posterior to the hepatic arteries and ducts

45. Porta Hepatis
lateral
medial

46. Portal triad Portal vein Hepatic artery Bile duct
Hepatic ducts are anterior to PV and RT lateral to hepatic arteries
Abundance of triads throughout liver parenchyma
Portals have echogenic walls
Contained in the hepatoduodenal ligament from the Rt free edge of lesser omentum

47. Mickey mouse sign of Portal Triad
Rt lateral
medial

48. Couinaud’s segments(kwee-no)

49. Couinaud’s segmental anatomy
Diagnostic and surgical importance
Provides the basis for surgical resection
Diagnostic designation of lesions on US and CT
Based on venous anatomy-
Both hepatic and portals divide the liver
Segments are defined by the portal venous branches that lead into them
And by the hepatic veins that separate them
Each segment can be resected without damaging the others

50. Segments-clockwise rotation
Segment 1-caudate lobe
Segments 2 and 3-lateral left lobe
Segments 4a and 4b-medial left lobe
Segment 5 and 8-anterior right lobe
Segments 6 and 7-posterior right lobe

51. Portal vein divisions
Portal veins divide the liver into upper and lower portions
Left and right portal veins branch superiorly and inferiorly to project into centre of each segment

52. Hepatic vein divisions
RHV-divides the RT lobe into anterior and posterior segments
MHV-divides the liver into RT and LT lobes or hemilivers
This plane runs from IVC to GB fossa
LHV-divides LT lobe into a medial and lateral part

53. Couinaud’s segmental anatomy
In the centre of
each segment there
is a branch of :
Portal vein
Hepatic artery
Bile duct
In the periphery of
each segment there is:
Vascular outflow
through hepatic veins