3. Liver techniqueLiver technique
Always clear 2-3 cmAlways clear 2-3 cm
beyond the margin ofbeyond the margin of
any organ to avoidany organ to avoid
exophytic or adjacentexophytic or adjacent
masses.masses.
6. Sonographically theSonographically the
vessels seen visiblevessels seen visible
within the liverwithin the liver
parenchyma are hepaticparenchyma are hepatic
and portal veins.and portal veins.
Hepatic arteries and bileHepatic arteries and bile
ducts not seen unlessducts not seen unless
abnormally dilated butabnormally dilated but
seen in porta hepatis.seen in porta hepatis.
7. Portal veinsPortal veins
Echogenic (bright) wallsEchogenic (bright) walls
- used for evaluation- used for evaluation
of evaluation of liverof evaluation of liver
parenchyma.parenchyma.
Enter the liver through portaEnter the liver through porta
hepatis.hepatis.
Largest portal vein divide inLargest portal vein divide in
the middle of liver.the middle of liver.
More horizontally oriented.More horizontally oriented.
Pass within lobes andPass within lobes and
segments.segments.
Flow into liver.Flow into liver.
9. Hepatic veinsHepatic veins
Imperceptible margins.Imperceptible margins.
Enlarge toward the IVC.Enlarge toward the IVC.
More vertically oriented.More vertically oriented.
Umbrella configuration.Umbrella configuration.
Runs between lobes andRuns between lobes and
segments.segments.
Used as anatomic divider ofUsed as anatomic divider of
the liver.the liver.
Flow out the liverFlow out the liver
10. Transverse liver scanTransverse liver scan
Anatomic landmarkAnatomic landmark
Upper: large hepatic veinsUpper: large hepatic veins
joint IVCjoint IVC
Mid: large central portal veinsMid: large central portal veins
(left higher than right).(left higher than right).
Lower:Lower:
-No large veins.-No large veins.
-Falciform ligament-Falciform ligament
-Ligamentum teres.-Ligamentum teres.
11. Ligamentum teresLigamentum teres
Obliterated fetal reminant ofObliterated fetal reminant of
the umbilical vein in thethe umbilical vein in the
fissure for ligamentum teres.fissure for ligamentum teres.
Joins the umbilical segmentJoins the umbilical segment
of the left portal vein.of the left portal vein.
May recanalize in portalMay recanalize in portal
hypertension.hypertension.
Not to be mistaken for aNot to be mistaken for a
mass or calcium.mass or calcium.
Divides left lobe.Divides left lobe.
12. Ligamentum venosumLigamentum venosum
The obliterated fetalThe obliterated fetal
reminant of ductusreminant of ductus
venosus.venosus.
Lie within fissure forLie within fissure for
ligamentum venosus.ligamentum venosus.
Does not recanalize inDoes not recanalize in
adults.adults.
Separates the left lobeSeparates the left lobe
from caudate lobe.from caudate lobe.
13. Caudate lobeCaudate lobe
Caudate means tail.Caudate means tail.
Functionally autonomous segment, spared inFunctionally autonomous segment, spared in
liver diseases.liver diseases.
Blood supply from RT and LT portal vein.Blood supply from RT and LT portal vein.
Dian direct to IVC.Dian direct to IVC.
Pseudomass.Pseudomass.
14. Enlarged caudate lobeEnlarged caudate lobe
Caudate is enlarged whenCaudate is enlarged when
the caudate to right lobethe caudate to right lobe
ratio is > 0.65ratio is > 0.65
15. Hepatic and portal veinsHepatic and portal veins
Basis of modern lobar andBasis of modern lobar and
segmental anatomy.segmental anatomy.
Hepatic veins drainHepatic veins drain
peripherallyperipherally
-Interlobar,-Interlobar,
intersegmental.intersegmental.
-Used as dividers.-Used as dividers.
Portal veins feed centrally.Portal veins feed centrally.
-Intralobar,-Intralobar,
intrasegmentalintrasegmental
-Used to name-Used to name
segments.segments.
16. Hepatic veins (anatomic dividers)Hepatic veins (anatomic dividers)
MHV divide the liverMHV divide the liver
into right and left lobes.into right and left lobes.
RHV divide the rightRHV divide the right
lobe into anterior andlobe into anterior and
posterior segments.posterior segments.
LHV divide the left lobeLHV divide the left lobe
into medial and lateralinto medial and lateral
segments (cranially).segments (cranially).
17. Portal vein define segmentsPortal vein define segments
Feed the segments.Feed the segments.
Define the segments.Define the segments.
Name the segments.Name the segments.
18. Division of main portal veinDivision of main portal vein
On coronal scan dividesOn coronal scan divides
the liver into superiorthe liver into superior
and inferior.and inferior.
On axial scan divides theOn axial scan divides the
liver into anterior andliver into anterior and
posterior.posterior.
19. Anatomic liver segmentsAnatomic liver segments
caudate lobecaudate lobe Segment ISegment I
Lateral segment left lobeLateral segment left lobe
superiorsuperior
SegmentSegment IIII
Lateral segment left lobeLateral segment left lobe
inferiorinferior
SegmentSegment IIIIII
Medial segment left lobeMedial segment left lobe SegmentSegment IVIV
Anterior segment rightAnterior segment right
lobe inferiorlobe inferior
SegmentSegment VV
Posterior segment rightPosterior segment right
lobe inferiorlobe inferior
SegmentSegment VIVI
Posterior segment rightPosterior segment right
lobe superiorlobe superior
SegmentSegment
VIIVII
Anterior segment rightAnterior segment right
lobe superiorlobe superior
SegmentSegment
VIIIVIII
20.
21. Main portal vein: normal dopplerMain portal vein: normal doppler
Continuous, forward flow.Continuous, forward flow.
Low velocity (15-28 cm/sec.)Low velocity (15-28 cm/sec.)
Hepatopetal flow.Hepatopetal flow.
Undulating patternUndulating pattern
-Respiratory variation-Respiratory variation
-Increase flow on inspiration.-Increase flow on inspiration.
May reflect cardiac variation.May reflect cardiac variation.
Slightly turbulent.Slightly turbulent.
Location between two capillaryLocation between two capillary
beds (mesenteric & hepatic).beds (mesenteric & hepatic).
22. Normal portal venous flow directionNormal portal venous flow direction
and waveform. Drawing at topand waveform. Drawing at top
illustrates that the direction of flow inillustrates that the direction of flow in
normal portal veins is antegrade, ornormal portal veins is antegrade, or
hepatopetal, which corresponds to ahepatopetal, which corresponds to a
waveform above the baseline atwaveform above the baseline at
spectral Doppler US. Normal phasicityspectral Doppler US. Normal phasicity
may range from low (bottom left) tomay range from low (bottom left) to
high (bottom right). Abnormally lowhigh (bottom right). Abnormally low
phasicity results in a nonphasicphasicity results in a nonphasic
waveform, whereas abnormally highwaveform, whereas abnormally high
phasicity results in a pulsatilephasicity results in a pulsatile
waveform. The PI is used to quantifywaveform. The PI is used to quantify
pulsatility. Normal phasicity results in apulsatility. Normal phasicity results in a
PI greater than 0.5.PI greater than 0.5.
23. Main portal vein: abnormal dopplerMain portal vein: abnormal doppler
Pulsatile flow is abnormalPulsatile flow is abnormal
- May resemble HV pulsatility.- May resemble HV pulsatility.
- Increase right heart pressure.- Increase right heart pressure.
- Transmitted pressure through- Transmitted pressure through
intrahepatic sinusoids.intrahepatic sinusoids.
- Tricuspid regurgitation.- Tricuspid regurgitation.
- Moderate to sever right heart- Moderate to sever right heart
failure, pericarditis.failure, pericarditis.
Exception: child, young persons.Exception: child, young persons.
24. Spectral Doppler US imageSpectral Doppler US image
shows a pulsatile waveformshows a pulsatile waveform
with flow reversal in the rightwith flow reversal in the right
portal vein. The waveformportal vein. The waveform
may be systematicallymay be systematically
characterized ascharacterized as
predominantly antegrade,predominantly antegrade,
pulsatile, biphasic-pulsatile, biphasic-
bidirectional, and di-bidirectional, and di-
inflectional.inflectional.
25. Slow portal venous flow. SpectralSlow portal venous flow. Spectral
Doppler US image shows slowDoppler US image shows slow
flow in the main portal vein. Slowflow in the main portal vein. Slow
portal venous flow is aportal venous flow is a
consequence of portalconsequence of portal
hypertension. In this case, the peakhypertension. In this case, the peak
velocity is 9.0 cm/sec, which isvelocity is 9.0 cm/sec, which is
well below the lower limit ofwell below the lower limit of
normal (16–40 cm/sec). Althoughnormal (16–40 cm/sec). Although
portal hypertension may cause aportal hypertension may cause a
pulsatile-appearing waveform aspulsatile-appearing waveform as
seen in this case, the slow flowseen in this case, the slow flow
helps differentiate this conditionhelps differentiate this condition
from hyperpulsatile high-velocityfrom hyperpulsatile high-velocity
states such as CHF and tricuspidstates such as CHF and tricuspid
regurgitation.regurgitation.
26. Normal and abnormal portalNormal and abnormal portal
venous phasicity. Images show avenous phasicity. Images show a
spectrum of increasing pulsatilityspectrum of increasing pulsatility
(bottom to top). Note that(bottom to top). Note that
increasing pulsatility correspondsincreasing pulsatility corresponds
to a decrease in the calculated PI.to a decrease in the calculated PI.
Although normal phasicity rangesAlthough normal phasicity ranges
widely in the portal veins, the PIwidely in the portal veins, the PI
should be greater than 0.5 (middleshould be greater than 0.5 (middle
and bottom). When the PI is lessand bottom). When the PI is less
than 0.5 (top), the waveform maythan 0.5 (top), the waveform may
be called pulsatile; this is anbe called pulsatile; this is an
abnormal finding.abnormal finding.
27. Hepatofugal portal venousHepatofugal portal venous
flow. Spectral Doppler USflow. Spectral Doppler US
image shows retrogradeimage shows retrograde
(hepatofugal) flow in the(hepatofugal) flow in the
main portal vein, a findingmain portal vein, a finding
that appears blue on thethat appears blue on the
color Doppler US image andcolor Doppler US image and
is displayed below theis displayed below the
baseline on the spectralbaseline on the spectral
waveform. Hepatofugal flowwaveform. Hepatofugal flow
is due to severe portalis due to severe portal
hypertension from any cause.hypertension from any cause.
28.
29. Hepatic artery: normal dopplerHepatic artery: normal doppler
Rapid systolicRapid systolic
accelerationacceleration
Continuous forward flowContinuous forward flow
throughout cardiac cyclethroughout cardiac cycle
- Low impedance.- Low impedance.
Same direction as MPV.Same direction as MPV.
RI = 0.5-0.7RI = 0.5-0.7
30. Schematics show a spectrum ofSchematics show a spectrum of
increasing hepatic arterialincreasing hepatic arterial
resistance (bottom to top). Theresistance (bottom to top). The
hepatic artery normally has lowhepatic artery normally has low
resistance (RI = 0.55–0.7) (middle).resistance (RI = 0.55–0.7) (middle).
Resistance below this rangeResistance below this range
(bottom) is abnormal. Similarly,(bottom) is abnormal. Similarly,
any resistance above this rangeany resistance above this range
(top) may also be abnormal. High(top) may also be abnormal. High
resistance is less specific for diseaseresistance is less specific for disease
than is low resistance.than is low resistance.
31.
32. Hepatic veins: normal dopplerHepatic veins: normal doppler
Toward IVC and heart.Toward IVC and heart.
Away from transducerAway from transducer
(blue).(blue).
Characteristic pulsatileCharacteristic pulsatile
flow.flow.
33. Diagram illustrates normal hepaticDiagram illustrates normal hepatic
venous flow direction and waveform.venous flow direction and waveform.
The direction of normal flow isThe direction of normal flow is
predominantly antegrade, whichpredominantly antegrade, which
corresponds to a waveform that iscorresponds to a waveform that is
mostly below the baseline at spectralmostly below the baseline at spectral
Doppler US. The term triphasic, whichDoppler US. The term triphasic, which
refers to therefers to the aa,, SS, and, and DD inflectioninflection
points, is commonly used to describepoints, is commonly used to describe
the shape of this waveform; accordingthe shape of this waveform; according
to D.A.M., however, this term is ato D.A.M., however, this term is a
misnomer, and the termmisnomer, and the term tetrainflectionaltetrainflectional
is more accurate, since it includes theis more accurate, since it includes the vv
wave and avoids inaccurate phasewave and avoids inaccurate phase
quantification. Normal hepatic venousquantification. Normal hepatic venous
waveforms may be biphasic (bottomwaveforms may be biphasic (bottom
left) or tetraphasic (bottom right).left) or tetraphasic (bottom right).
34. Hepatic veins: normal dopplerHepatic veins: normal doppler
Reflects respiratory phases.Reflects respiratory phases.
Reflects variations in centralReflects variations in central
venous pressure transmittedvenous pressure transmitted
from RV.from RV.
Reflect compliance of liverReflect compliance of liver
parenchyma.parenchyma.
Triphasic pattern.Triphasic pattern.
Deep respiration or valsalvaDeep respiration or valsalva
reduce pulsatility of wavereduce pulsatility of wave
form in normals.form in normals.
35. Hepatic veins: abnormal dopplerHepatic veins: abnormal doppler
Non triphasic flowNon triphasic flow
- Elevated right heart- Elevated right heart
pressure.pressure.
Decrease pulsatility orDecrease pulsatility or
amplitude of phasicamplitude of phasic
oscillation.oscillation.
- Loss or reversed phase.- Loss or reversed phase.
Monophasic abnormal.Monophasic abnormal.
- Flattened wave form.- Flattened wave form.
- Resemble PV flow.- Resemble PV flow.
- Stiff, non compliant liver.- Stiff, non compliant liver.
36. Decreased hepatic venous phasicity.Decreased hepatic venous phasicity.
Diagrams illustrate varying degrees ofDiagrams illustrate varying degrees of
severity of decreased phasicity in theseverity of decreased phasicity in the
hepatic vein. Farrant and Meire (5) firsthepatic vein. Farrant and Meire (5) first
described a subjective scale fordescribed a subjective scale for
quantifying abnormally decreasedquantifying abnormally decreased
phasicity in the hepatic veins, a findingphasicity in the hepatic veins, a finding
that is most commonly seen inthat is most commonly seen in
cirrhosis. The key to understanding thiscirrhosis. The key to understanding this
scale lies in observing the position ofscale lies in observing the position of
thethe aa wave relative to the baseline andwave relative to the baseline and
peak negativepeak negative SS wave excursion. As thewave excursion. As the
distance between thedistance between the aa wave and peakwave and peak
negative excursion decreases, phasicitynegative excursion decreases, phasicity
is more severely decreased.is more severely decreased.
42. Fatty liverFatty liver
Posterior soundPosterior sound
attenuation.attenuation.
Enlarged liver.Enlarged liver.
Tend to have fineTend to have fine
homogeneoushomogeneous
echotexture.echotexture.
44. Liver cirrhosisLiver cirrhosis
Fatty fibrotic patternFatty fibrotic pattern
- Heterogeneous texture- Heterogeneous texture
(coarse).(coarse).
- Almost no posterior- Almost no posterior
attenuation.attenuation.
Shrunken liver.Shrunken liver.
Nodular surface.Nodular surface.
Elevated caudate to rightElevated caudate to right
lobe ratio (> 0.73 has 99%lobe ratio (> 0.73 has 99%
specificity for cirrhosis).specificity for cirrhosis).
45. Liver cirrhosisLiver cirrhosis
Accounts for > 90% of allAccounts for > 90% of all
portal hypertension.portal hypertension.
Distorted liver architecture.Distorted liver architecture.
- Fibrosis.- Fibrosis.
- Regenerating nodules.- Regenerating nodules.
- Distorted vascular- Distorted vascular
channelschannels
46. Portal hypertensionPortal hypertension
Increase hepaticIncrease hepatic
resistance.resistance.
Increase portal venousIncrease portal venous
pressure.pressure.
Eventually decreaseEventually decrease
portal flow.portal flow.
Reversed portal flowReversed portal flow
prognostication for riskprognostication for risk
of hemorrhage.of hemorrhage.
50. Doppler in portal hypertensionDoppler in portal hypertension
Portal vein:Portal vein:
- Loss or respiratory- Loss or respiratory
variation.variation.
- Decrease velocity of MPV.- Decrease velocity of MPV.
- Hepatofugal (reversed) flow.- Hepatofugal (reversed) flow.
Hepatic veins:Hepatic veins:
- Loss of normal pulsatility.- Loss of normal pulsatility.
- Non triphasic flow.- Non triphasic flow.
- Flattened wave.- Flattened wave.
Hepatic arteries:Hepatic arteries:
- Enlarged hepatic arteries.- Enlarged hepatic arteries.
51. Focal liver massesFocal liver masses
US is excellent in detecting focal liver lesions.US is excellent in detecting focal liver lesions.
US is specific for liver cysts > 1 cm.US is specific for liver cysts > 1 cm.
Not good in differentiating among pathologic entities.Not good in differentiating among pathologic entities.
No good in distinguishing between benign andNo good in distinguishing between benign and
malignant lesions.malignant lesions.
Triphasic study of the lesions by CT and MRI areTriphasic study of the lesions by CT and MRI are
excellent.excellent.
US is very helpful in diagnosis, follow up and guidanceUS is very helpful in diagnosis, follow up and guidance
biopsy.biopsy.