IMAGING ANATOMY OF LIVER BY DR RAVINDRA BANGAR DNB RESIDENT RADIODIGNOSIS KMIO BANGLORE

1. Dr Ravindra Bangar ,
DNB Resident KMIO.
Moderators-
Dr. Raghuram
Dr.Jaipal

2.  Embryology
 Gross anatomy
 Blood supply
 USG anatomy
 CT anatomy
 MRI anatomy
 Other modalities
 Conclusion

3.  During the third week of fetal life, the liver
primordium appears as an outgrowth of
endodermal epithelium at the distal end of
the foregut, known as the hepatic
diverticulum or liver bud .
 Penetrate the septum transversum, which is
the mesodermal plate.
 Connection between the hepatic
diverticulum and the distal foregut
narrows, thus forming the bile duct.
 Kupffer cells and connective tissue cells of
the liver are derived from the mesoderm of
the septum transversum.

5.  Largest solid organ in the human body
 Weight - 1.2 to 1.4kg
 Span - 13 to 15.5cm .more than 15.5cm
 considered as hepatomegaly
 Location - Right hypochondrium and part of
 Epigastrium
 Surfaces of the liver
Diaphragmatic surface
Visceral surface

6.  Divided into 2 anatomical regions:
1.Diaphragmatic surface:
Smooth and dome-shaped surface
Inferior to diaphragm
Separated from diaphragm by subphrenic recess
and from posterior organs {kidney and suprarenal
glands} by hepatorenal recess
Covered by peritoneum except On the posterior
surface of liver is a region not invested in
peritoneum this is the bare area

8.  Covered by visceral peritoneum except porta
hepatis and gall bladder bed.
 The visceral surface is related to:
 Right side of the stomach i.e. gastric and pyloric areas
 Superior part of the duodenum i.e. duodenal area
 Lesser omentum
 Gall bladder
 Right colic flexure
and right transverse colon ; colic area
 Right kidney
and suprarenal gland; Renal area

10.  Couinaud divided the liver into a functional left and
right lobe by a main portal scissurae containing the
middle hepatic vein.
 This is known as CANTLIE'S LINE.
 Cantlie's line runs from the middle of the gallbladder
fossa anteriorly to the inferior vena cava posteriorly.

11.  8 segments
 Have their own blood
supply lymphatics and
billiary drainage.
 Right,middle and left
hepatic veins divide
liver longitudinally
into 4 segments.
 Each of these
segments is further
divided transversly by
an imaginary plane
passing thorugh right
and left main portal
pedicles.

12.  Right hepatic vein divides the right lobe into
anterior and posterior segments.
 Middle hepatic vein divides the liver into right
and left lobes (or right and left hemiliver).
This plane runs from the inferior vena cava to
the gallbladder fossa.
 Left hepatic vein divides the left lobe into a
medial and lateral part.

13.  Portal vein divides the liver into upper and
lower segments.
 The left and right portal veins branch
superiorly and inferiorly to project into the
center of each segment.

14.  Because of this division into self-contained
units, each segment can be resected without
damaging those remaining. For the liver to
remain viable, resections must proceed along
the vessels that define the peripheries of
these segments. This means, that resection-
lines parallel to the hepatic veins.

15. ◦ BLOOD SUPPLY
 2/3 FROM PORTAL VEIN
 1/3 FROM HEPATIC ARTERY
◦ VENOUS DRAINAGE
 HEPATIC VEINS (3)
◦ CAUDATE LOBE is considered autonomous

16.  Caudate lobe derives its arterial supply from
both the right and left hepatic arteries and
both the portal veins and its venous blood
drains directly into the IVC.
 Right lobe segments are supplied by right
portal vein and right hepatic artery.
 Left lobe segments by left portal vein and left
hepatic artery.

17.  Common Hepatic artery
 Branch of coeliac artery
 In 18.5% patient it arise from SMA

19.  Two most common variations are origin of
the left hepatic artery from the left gastric
artery and origin of all or some right hepatic
artery branches from the superior mesenteric
artery.

24.  The major portal veins are intrasegmental
(within the segment), while the major hepatic
veins are intersegmental (between the
segments).
 The intrahepatic portal triads, consisting of
branches of the portal vein, hepatic
arteries, and bile ducts, course through the
central portions of the hepatic segments.
 The portal vein is 7 to 10 cm long and 0.8
to1.4 cm in diameter and is without valves

25.  Right hepatic vein which lies between the
right anterior and posterior hepatic
segments, drains segments V, VI, and VII
 Middle hepatic vein which lies in the
interlobar plane, drains primarily segments
IV, V, and VIII
 Left hepatic vein which courses in the sagittal
plane between the medial and lateral
segments of the left lobe, drains segments II
and III.

26.  Riedels lobe
◦ Extension of tip of right lobe
inferiorly
◦ May be mistaken for
pathological hepatomegaly
 Lobar agenesis/ atrophy
◦ Absence of supplying
vasculature / dilated bile ducts
◦ Differentiate from atrophy

28.  Limited role
 Demostrate-
 hepatomegaly
 calcification

29.  Initial imaging modality for suspected liver
pathology.
 Position-Supine or left decubitus
 Transducer-convex(3.5-5Mhz)
 Approach-Subcostal
Xiphisternal
Intercostal

30.  Normal liver is fine homogeneous
 Either hypo echoic or isoechoic compared to
normal renal cortex
 Hypoechoic compared to spleen

31. CAUDATE LOBE SAGG VEIW-
ARROWS FISSURE FOR LIG
VENOSUM

34. SAGGITAL IMAGE OF PORTA HEPATIS SHOWING
CBD & MAIN PORTAL VEIN ENCLOSED IN THE
HEPATODUODENAL LIGAMENT

36.  Normal liver is homogenous and has density
higher than spleen .
 Normal liver parenchyma – 40-80 HU
 8-10 HU greater than spleen

37. Dual phase study
◦ Arterial (20sec)
◦ Portal (60 sec)
Triphasic study
o Early arterial phase(20sec)
o Portal venous phase(60sec)
o delayed phase(180)

46.  Primarily MRI has evolved as problem solving
for liver lesions
 It has higher contrast resolution ,multiplanar
capability and lacks ionizing radiation

47. ◦ Liver parenchyma appears homogenous on both T1
and T2.
◦ Moderate signal intensity on T1 Wi similar to
pancreas but hyperintense to spleen and kidneys
o On T2 Wi liver appears dark and is hypointense to
spleen

49. A comprehensive MRI liver protocol
T1 weighted images
T2 weighted images
T1Post contrast(Triphasic studies as CT)
STIR
DWI(Mainly used in tumor imaging and assessing treatment
response in tumors)

50. These can improve lesion detection & characterization
ECF agents like gadolinium chelates such as Gd-DTPA &
Gd-DOTA help in detection of hypervascular metastases
or small hepatocellular lesions
Reticuloendothelial agents like supermagnetic iron oxide
particles coated with dextran, ferumoxides etc function as
T2 relaxation promoters lowering normal signal of RES
containing tissue
Hepatobiliary agents like Mn-DPDP, Gd-EOB-DTPA & Gd-
BOPTA which increase the signal intensity of normal liver
& hepatocyte containing lesions on T1W images

51.  Approach-Femoral artery
 Contrast is injected in coeliac axis and SMA
or one or more of their branches
 To study vascular anatomy and
hemodynamics
 In order to select proper angiointerventional
treatment.

53.  Lacks anatomical specificity but good global view
 Tc-sulphur colloid/ albumin colloid – which targets
reticuloendothelial system.(to differentiate adenoma
and FNH ,FNH lesions show uptake indicating intramural
kupffer cells this is not seen in adenoma)
 If hemangioma is suspected , Tc 99 labelled RBC are
used instead.(lesion appear as hot spot ,as after
radioisotope inj. increase in blood pool activity in
hemangioma as compared to surrounding normal liver)
 Colloid particle size – 0.01- 1 microns
 Injected intravenously

54.  The ability of FDG-PET to estimate metabolic
rates make it potentially valuable tool for
monitoring therapy.
 Highly sensitive for detecting hepatic
metastasis.