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Abdominal Imaging of
Liver
Chuan Lu
School of Radiology
Taishan Medical University
Anatomy
 Protocols and Normal
Ultrasound Findings
 Pathology

Anatomy of the Liver

The Liver occupies all of the
right hypochondrium, the
greater part of the epigastrium,
and left hypochondrium. The
ribs cover the greater part of the
right lobe .In the epigastric
region, the liver extends several
centimeters below the xiphoid
process. Most of the left lobe of
the liver is covered by the rib
cage.
Lobes of the Liver



Right lobe: The right lobe of the liver is the largest
of the liver’s lobes. It extends the left lobe by a
ratio of 6:1. It occupies the right hypochodrium.
Left lobe: The left lobe of the liver lies in the
epigastric and left hypochondriac region.
Caudate lobe: The caudate lobe is a small lobe
situated on the posterosuperior surface of the left
lobe opposite the tenth and eleventh thoracic
vertebrae .
Hepatic Nomenclature

Couinaud’s system of hepatic
nomenclature provides the anatomic basis
for hepatic surgical resection. By using this
system , the radiologist may be able to
precisely isolate the location of a lesion for
the surgical team

Couinaud’s hepatic segments divide the liver
into eight segments . The hepatic veins are the
longitudinal boundaries . The transverse plane
is defined by the right and left portal pedicles .
Hepatic Segmental Anatomy






The caudate lobe (segmentⅠ) is
situated posteriorly.
Segment Ⅰincludes the caudate
lobe.
Segment Ⅱand Ⅲ includes the
left superior and inferior lateral
segment.
Segment Ⅳa and Ⅳb includes
the medial segment of the left
lobe.
SegmentⅤ and Ⅵ are caudal to
the transverse plane .
Segments Ⅶ and Ⅷ are
cephalad to the transverse plane.
Superior anterior
segment (right lobe)
Caudate lobe
→
→
Inferior lateral
segment
→
Medial segment
→
Superior posterior
segment (left lobe)
→
Superior posterior
segment (left lobe)
Superior lateral
segment
Inferior anterior
segment (right lobe)
Anatomy of Liver : Glisson
system
Ultrasound can allow
us to visualize the
portal veins, hepatic
veins , intrahepatic
bile ducts .

The portal veins carry blood from the bowl to the liver, whereas the
hepatic veins drain the blood from the liver into the inferior venal cava .
The hepatic arteries carry oxygenated blood from the aorta to the liver.
The bile ducts transport bile ,manufactured in the liver , to the
duodenum.
Vascular Supply: The
Portal
veins
portal
venous
system is a reliable
indicator of various
ultrasonic tomographic
planes throughout the
liver.
Main portal vein
Right main portal vein
Left main portal vein




Intrahepatic Portal Vein Branches
Right anterior superior
left median superior
Right anterior inferior
left median inferior
Right posterior superior left anterior inferior
Right posterior inferior
left lateral superior
Vascular Supply: Hepatic veins
The hepatic veins are divided into three
components: right,middle,and left. The right
hepatic veins is the largest and enters the right
lateral
Distinguishing Characteristics of Hepatic
and Portal Veins

The best way to distinguish
the hepatic from the portal
vessels is to trace their
points of entry to the liver.
The hepatic vessels flow into
the inferior vena cava,
whereas the splenic veins
and superior mesenteric vein
join together to form the
portal venous system.
Distinguishing Characteristics of Hepatic
and Portal Veins

The walls of hepatic veins are thin-walled ,and the walls
of portal veins are brightly reflective veins



The hepatic veins are easily differentiated from
bile ducts and portal veins .
They are not surrounded by an echogenic wall
They originate close to the diaphragm , and can
be traced into the inferior vena cava
Sonographic Evaluation of the Liver

Evaluation of the hepatic structure is one of
the most important procedures in sonography
for many reasons. The normal , basiclly
homogenerous parenchyma of the liver
allows imaging of the neighboring anatomic
structures in the upper abdomen.
Sonographic Evaluation of The Liver



The system gain should be adjusted to
adequately penetrate the entire right lobe
of the liver as a smooth ,homogeneous
echo-texture pattern
The time gain compensation should be
adjusted to
balance the far-gain and the near-gain
echo signals.
The far time -gain control pods should
gradually be increased until the posterior


The appropriate transducer depends
on the patient’s body habitus and size
The average adult abdomen usually
requires a 3.5MHz





The basic instrumentation should be adjusted
in the following parameters :
Time gain compensation
Overall gain
Transducer frequency and type
Depth and focus
Longitudinal Scan Plane

The longitudinal ,or sagittal, scan offers an
excellent window to visualize the hepatic
structure . With the patient in full inspiration ,
the transducer may be swept under the costal
margin to record the liver parenchyma from
the anterior abdominal wall to the diaphragm.
Longitudinal Scan Plane




Scan Ⅰ
Scan Ⅱ
Scan Ⅲ
Scan Ⅳ,Ⅴ,Ⅵ
Longitudinal Scan Plane

Scan Ⅰ
The initial scan should be made slightly to the
left of the midline to record the left lobe of
the liver and the abdominal aorta. The left
hepatic and portal veins may be seen as
small circular structures in this view.
肝腹主动脉纵切声像图
Sagittal image of left lobe of liver, and aorta

The initial scan should be made slightly to the left of
the midline to record the left lobe of the liver and
the abdominal aorta. The left hepatic and portal
veins may be seen as small circular structures in
this view.
Sagital image of tip of left lobe of liver
The initial scan should be made slightly to the left of the midline to record the
left lobe of the liver and the abdominal aorta. The left hepatic and portal veins
may be seen as small circular structures in this view.
Sagittal image of left lobe of liver,
and aorta
The initial scan should be made slightly to the left of the midline to record the left lobe of the liver and the
abdominal aorta. The left hepatic and portal veins may be seen as small circular structures in this view.
SMA,CA
Longitudinal Scan Plane


Scan Ⅱ
As the sonographer scans at midline or slightly to the right of
midline , a larger segment of the left lobe and the inferior vena
cava may be seen posteriorly . In this view , it is useful to record
the inferior vena cana as it is dilated near the end of inspiration.
The left or midline hepatic vein may be imaged as it drain into
the inferior vena cava near the level of the diaghram. The area
of the portal hepatis is shown anterior to the inferior vena cava
as the superior mesenteric vein and splenic vein converge to
form the main portal vein. The common bile duct may be seen
just anterior to the main portal vein. The head of the pancreas
may be seen just inferior to the right lobe of the liver and main
portal vein and anterior to the inferior vena cava.
Sagittal image of left lobe of liver,
portal vein and inferior vena cava

The left or midline hepatic vein may be imaged as it drain into the
inferior vena cava near the level of the diaghram. The area of the
portal hepatis is shown anterior to the inferior vena cava
Normal IVC and Budd-Charis Syndrome
Longitudinal Scan Plane

Scan Ⅲ
The next image should be made slightly
lateral to this saggital plane to record part of
the right portal vein and right lobe of liver .
The caudate lobe is often seen in this view.
Sagittal image of gallbladder
Gallbladder and Biliary System


Normal size of
gallbladder:
7~9cm in length ;
3~4cm in width;
Wall thickness : 2~3mm
Normal size of bile ducts :
right /left intrahepatic
duct just to proximal
CHD: 2-3mm ；
CBD:≥8mm =dilated
Longitudinal Scan Plane

Scan Ⅳ,Ⅴ,Ⅵ
The nest three scans should be made in small increment through
the right lobe of the liver .
The last scan is usually made to show the right kidney and
lateral segment of the right lobe of the liver. The liver texture is
compared with the renal parenchyma. The normal liver
parenchyma should have a softer , more homogenerous
texture than the dense medulla and hypoechoic renal cortex.
Liver size may be measured from the tip of the liver to the
diaphragm . Generally this measurement is less than 15 cm,
with 15 to 20 cm representing the upper limits of normal.
Hepatomegaly is present when the liver measurement exceed 20
cm.
肝右肾纵切声像图
Sagittal image of liver /right kidney
The normal liver parenchyma should have a
softer , more homogenerous texture than the
dense medulla and hypoechoic renal cortex
The last scan is usually made to show the right kidney and
lateral segment of the right lobe of the liver. The liver texture
is compared with the renal parenchyma. The normal liver
parenchyma should have a softer , more homogenerous
texture than the dense medulla and hypoechoic renal cortex.
Transverse Scan Plane

Multiple transverse scans are made across the upper
abdomen to record specific areas of the liver. The
transducer should be angled in a steep cephalic
direction to be as parallel to the diaphragm as possible.

The patient should be in full inspiration to
maintain detail of the liver parenchyma ,
vascular architecture, and ductal structures
Transverse Scan Plane





Scan Ⅰ
Scan Ⅱ
Scan Ⅲ
Scan Ⅳ
Scan Ⅴ,Ⅵ
Transverse Scan Plane

Scan Ⅰ
The initial transverse scan is made with the
transducer under the costal margin at a steep
angel perpenducular to the diaphragm.
The patient should be in deep inspiration to
adequately record the dome of the liver. The
sonographer should identify the inferior vena cava
and three hepatic veins as they drain into the cava.
This pattern has sometimes been referred to as
“reindeer sign” or “Playboy bunny” sign.

The sonographer should identify the inferior vena
cava and three hepatic veins as they drain into
the cava. This pattern has sometimes been
referred to as “reindeer sign” or “Playboy bunny”
sign.
Transverse Scan Plane


Scan Ⅱ
The transducer is then directed slightly inferior to the
point described in scan Ⅰ to record the left portal
vein as it flows into the left lobe of the liver.
Transverse Scan Plane

Scan Ⅲ
The porta hepatis is seen as a tubular structure
within the central part of the liver. Sometimes the
left or right portal vein can be identified . The
caudate lobe may be seen just superior to the
porta hepatis ; thus , depending on the angel ,
either the caudate lobe is shown anterior to the
inferior vena cava, or as the transducer moves
inferior ,the porta hepatis is identified anterior to
the inferior vena cava.
Transverse Scan Plane

Scan Ⅳ
The fourth scan should show the right portal
vein as it divides into the anterior and
posterior segments of the right lobe of the
liver. The gallbladder may be seen in this
scan as an anechoic structure medial to the
right lobe and anterior to the right kidney.
肋缘下斜切声像图
The fourth scan should show the right portal vein as
it divides into the anterior and posterior segments
of the right lobe of the liver. The gallbladder may
be seen in this scan as an anechoic structure
medial to the right lobe and anterior to the right
kidney.
Transverse Scan Plane

Scan Ⅴ,Ⅵ
These two scans are made through the lower
segment of the right lobe of the liver . The
right kidney is the posterior border. Usually
intrahepatic vascular structures are not
identified in these views
肝脏右叶最大斜径



测量标准切面：以肝右
静脉和肝中静脉汇入下腔
静脉的右肋缘下肝脏斜切
面为标准测量切面
测量位置：测量点分别置
于肝右叶前、后缘之肝包
膜处，测量其最大 垂直
距离
正常参考值：12－14cm
Lateral Decubitus Scan Plane


Left Anterior Oblique
The left anterior oblique scan requires that the
patient roll slightly to the left . A 45-degree sponge
or pillow may be placed under the right hip to
support the patient.
This view allows better visualization of the lower right
lobe of the liver, usually diaplacing the duodenum
and transverse colon to the midline of the abdomen ,
out of the field of view. Transverse , oblique, or
longitudinal scans may be made in this position.
Lateral Decubitus Scan Plane

Lateral Decubitus Scan Plane


Measurement of main portal vein
1.0～1.5cm
“Fliying Bird Sign”
Common bile duct

Diameter <0.8cm
Sonographic Evaluation of The Liver





Adequate scanning technique demands that
each patient be examined with the following
assessment
The size of the liver in the longitudinal plane
The attenuation of the liver parenchyma
Liver texture
The presence of hepatic vascular structures,
ligaments ,and fissures
Pathology of the Live

Evaluation of the liver parenchyma
includes the assessment of its size ,
configuration, homogeneity , and contour.
The Normal attenuation of the liver parenchyma
Normal: Liver texture=homogeneous
Assessment of its size , configuration, homogeneity ,
and contour
Abnormal Liver texture-inhomogeneous :
The diffuse hepatic lesions
Assessment of its size , configuration, homogeneity ,
and contour.
Assessment of its size , configuration,
homogeneity , and contour
Assessment of its size , configuration, homogeneity ,
and contour
The size of the liver
The changes of the size and shape
Assessment of its size , configuration,
homogeneity , and contour
The changes of the hepatic contour
Assessment of its size , configuration,
homogeneity , and contour
The focal hepatic lesions

hyperechoic , hypoechoic, anechioc , mixed pattern
Assessment of its size , configuration,
homogeneity , and contour
The vascular disorganization
Assessment of its size , configuration, homogeneity ,
and contour
Dilated intrahepatic bile ducts
Pathology of the Live
Subsequent sections discuss the pathology of liver
disease in the following categories :
 Diffuse disease
 Hepatic Tumors
Benign disease
Malignant disease
 Abscess formation
 Functional disease
 Tranplantation
 Vascular problems
Pathology of the Live
Diffuse Fatty Infiltration
US
 increased sound attenuation =poor definition of
posterior aspect of liver ( bright liver)
 fine/coarsened hyperechogenicity
(compared with kidney)
 impaired visualization of borders of hepatic
vessels
 Attenuation of sound beam
Fatty Infiltration
increased sound attenuation
=poor definition of posterior
aspect of liver ( bright liver)
impaired visualization of
borders of hepatic vessels
Diffuse Fatty Infiltration—CT



Areas of lower attenuation than normal
portal vein/IVC density
Reversal of liver spleen density
relationship (liver density is normal 612HU greater than spleen)
Hyperdense intrahepatic vessels
Diffuse Fatty Infiltration—CT


Areas of lower attenuation than normal portal
vein/IVC density
Hyperdense intrahepatic vessels

Reversal of liver spleen density relationship (liver
density is normal 6-12HU greater than spleen)
Hepatic Cirrhosis
2
1




3
4
Surface irregularity
Increased echogenicity
Heterogeneous coarse echotexture
Ascites
Regenerating nodules
Regenerating nodules
Ascites
Portal hypertension
Heterogeneous coarse echotexture
Surface irregularity
Ascites
Decreased definition of walls of portal venules
Heterogeneous coarse echotexture
Surface irregularity
Ascites
Decreased definition of walls of portal venules
Ascites, even in very small qualities,
can cause a thick gallbladder wall
Ascites

Surface irregularity
Pathology of the Live
Focal Hepatic Disease
 Cystic Lesions
 Hepatic cysts may be congenital or
acquired ,solitary , or multiple. Patients are
often asymptomatic, except patients who
have large cysts , which can compress the
hepatic vasculature or ductal system.
Pathology of the Live
Focal Hepatic Disease
 Cystic Lesions within the liver include the following :
 Simple or congenital hepatic cysts
 Traumatic cysts
 Parasitic cysts
 Inflammatory cysts
 Polycystic disease
 Pseudo-cysts
Ultrasound Findings of Cystic
Lesions
On ultrasound examination the cyst walls are
thin , with well-defined borders, and
anechoic with distal posterior
enhancement.
Sonographic Features
Of hepatic cyst:
 No internal echoes
 Smooth borders
 Regular /irregular outline
 Acoustic enhancement

Septum may be seen
Hepatic cyst 1
Hepatic cyst
2
Hepatic cyst



Second most common benign hepatic
lesion(22%)
Acquired hepatic cyst: second to trauma,
inflammation , parasitic infection
Associated
tuberous necrosis
polycystic kidney disease(25-33%have liver cyst);
polycystic liver disease(50%have polycystic
kidney disease)
Polycystic liver
disease
Hepatic abscess



Types
pyogenic(88%)
amebic(10%)
fungal(2%)
Hepatic abscess-




Hypoechoic round lesion with well-defined –mildly
echogenic rim
Distal acoustic enhancement
Coarse clumpy debris /low-level echoes/fluid-debris level
Intensely echogenic reflections with reverberations




Hypoechoic round lesion with well-defined –mildly
echogenic rim
Distal acoustic enhancement
Coarse clumpy debris /low-level echoes/fluid-debris level
Intensely echogenic reflections with reverberations
Hepatic abscess-CT
Pathology of the Live

Hepatic Tumors
Benign disease
Malignant disease
Pathology of Liver



Primary Hepatic Carcinoma (PHC)
Metastases to liver
Hepatic hemangioma
Hepatocellular Carcinoma(HCC)
Primary Hepatic Carcinoma (PHC)




Etiology: cirrhosis, hepatitis B and C
infection and carcinogens
Solitary,
multifocal or
more rarely diffusely infiltrating
Hepatocellular Carcinoma(HCC)

Growth pattern:

solitary massive (27-59%):
 bulk in one (most often right) lobe with satellite
nodules
multifocal small nodular (15-25%):
 small foci of usually <2 cm (up to 5 cm) in both
hepatic lobes
diffuse microscopic infiltrating form (10-26%):
 tiny indistinct nodules closely resembling cirrhosis
Vascular supply: hepatic artery, portal vein in 6%



HCC








Metastases to: lung (most common = 8%), adrenal,
lymph nodes, bone
portal vein invasion (25-48%)
arterioportal shunting (4-63%)
invasion of hepatic vein (16%)/IVC (= Budd-Chiari
syndrome)
occasionally invasion of bile ducts
calcifications in ordinary HCC (2-25%); however,
common in fibrolamellar (30-40%) and sclerosing HCC
hepatomegaly and ascites
tumor fatty metamorphosis (2-17%)
Sonographic Features of HCC






86-99% sensitivity;
90-93% specificity;
65-94% accuracy;
Hyperechoic HCC(13%)due to fatty metamophosis
or marked dilatation of sinusoids
Hypoechoic HCC(26%)due to solid tumor
HCC of mixed echogenicity (61%)due to
nonliquefactive tumor necrosis

HCC of mixed echogenicity (61%)due to nonliquefactive
tumor necrosis
Hypoechoic HCC(26%)due to solid tumor

Hyperechoic HCC(13%)due to fatty
metamophosis or marked dilatation of sinusoids
Vascular supply: hepatic artery, portal vein in 6%
portal vein invasion (25-48%)
HCC- CT




sensitivity of 63% in cirrhosis, 80% without cirrhosis)
hypodense mass/rarely isodense/hyperdense in fatty
liver:
 dominant mass with satellite nodules
 mosaic pattern = multiple nodular areas with differing
attenuation on CECT (up to 63%)
 diffusely infiltrating neoplasm
encapsulated HCC = circular zone of radiolucency
surrounding the mass (12-67%)
False-positive: confluent fibrosis, regenerative nodule
Biphasic CECT:





enhancement during hepatic arterial phase (80%)
decreased attenuation during portal venous phase
with inhomogeneous areas of contrast accumulation
isodensity on delayed scans (10%)
thin contrast-enhancing capsule (50%) due to rapid
washout
wedge-shaped areas of decreased attenuation
(segmental/lobar perfusion defects due portal vein
occlusion by tumor thrombus)
Biphasic CECT:

enhancement during hepatic arterial phase
(80%)
Biphasic CECT:

decreased attenuation during portal venous phase
with inhomogeneous areas of contrast accumulation
Biphasic CECT:

isodensity on delayed scans (10%)
HCC- CT ：Unenhanced CT and Contrast enhanced CT

Unenhanced CT :hypodense mass/rarely isodense/hyperdense
in fatty liver
Biphasic CECT:

enhancement during hepatic arterial phase (80%)
Biphasic CECT:

decreased attenuation during portal venous
phase with inhomogeneous areas of contrast
accumulation
Biphasic CECT:

isodensity on delayed scans (10%)
After 1st TACE

Therapy of HCC: Interventional radiology - transcatheter
arterial chemoembolization(TACE)
After 2nd TACE

Therapy of HCC: Interventional radiology - transcatheter
arterial chemoembolization(TACE)
Metastases to liver






Organ of origin:
colon(42%); stomach(23%);
pancreas(21%); breast(14%); lung(13%)
Number : multiple(98%); solitary(2%)
“Bullseye”：An echogenic center with a
surrounding echopenic area
Echopenic : Less echogenic than the
surrounding liver
Echogenic More echogenic than the
surrounding liver
所指为肝内多发低回
声结节，呈
“Bullseye”：An echogenic center with a surrounding echopenic area
“牛眼征”
“Bullseye”：An echogenic center with a surrounding echopenic area
Metastases to liver
Metastases to liver
(bulls eye sign)
Hepatic hemangioma /
Cavernous hemangioma of liver


CH of the liver is composed of blood-filled
fairly large or tortuous vascular cavities
divided by thin, often incomplete, fibrous
septa and lined by a single layer of flat
endothelium
The blood flow in the vascular spaces is slow
and nondirectional which is predisposed to
thrombosis
Ultrasonic features of Hepatic hemangioma






Uniformly hyperechoic mass(60-70%)
Inhomogeneous hypoechoic mass (up to 40%)
Homogeneous(58-73%) /heterogeneous
May show acoustic enhancement(37-77%)
Unchanged in size/appearance(82)on 1-to-6 year
follow-up
No Doppler signals/signals with peak velocity of
<50cm/cm
。
Uniformly hyperechoic mass(60-70%)
Cavernous hemangioma of liver
Markedly hyperechoic lesion without dorsal
acoustic shadowing.
A slightly hypoechoic lesion with sharply delineated borders,
oval shape and no dorsal acoustic enhancement.

hypoechoic mass (up to 40%)
多发肝海绵状血管瘤
谢
谢