Hepatic Sonography: A “Whirlwind Tour” - SD

Hepatic Sonography: A Whirlwind Tour

I am Stephanie Wilson.
I'm an abdominal radiologist. I live in Calgary in Canada.
And today I'm going to discuss ultrasound of liver disease.
Today my presentation is entitled Hepatic Sonography,
a whirlwind tour.
I've called it that, as there's so much
to speak about in terms of the liver on ultrasound.
And this is a very focused presentation.
These are my disclosures.
I have research support from Lanius Medical Imaging
and I function in an advisory capacity
with both Phillips and Siemens.
In this presentation, I'm also going
to discuss the off-label use of FIN in the United States.
However, I'm a Canadian
and FIN is approved for use in Canada
and we use it routinely in our clinical work.

Learning Objectives

So the learning objectives of this presentation are not
to discuss the normal liver.
Rather we're going to show the sonographic features
of fatty and cirrhotic liver.
We're going to approach the role of sonography
and significant focal liver disease
and we're going to recognize the incredible contribution
of contrast enhanced ultrasound to liver imaging.

Cirrhosis

So let's start with cirrhosis.
So cirrhosis is the end stage manifestation
of chronic liver insult.
It's an irreversible process with liver fibrosis
and it parallels infection with viruses, hepatitis B
and hepatitis C,
therefore it has definite geographic predisposition.
Alcohol, autoimmune hepatitis
and primary biliary cirrhosis are other relatively common
etiologies in North America,
but worldwide infections with hepatitis B
and C are most important.
An interesting point is the increasing significant
of nash or non-alcoholic steatohepatitis
as a cause of cirrhosis.
Now, cirrhosis on ultrasound is recognized as something
that may create a normal picture.
So in other words, biopsy proven disease may be associated
with a normal sonogram.
However, this is not typically the case.
And so what I like to do is point out the things
that we do see.
So first of all, we can look at liver size and
although the acute alcoholic cirrhotic liver can be large
end stage cirrhosis in generally produces a small organ
lobar redistribution with increase in the size
of the left lateral lobe of the liver
and the caudate lobe are the most sensitive early
features of cirrhosis.
And of course parenchymal change creating both a course
and a nodular contour, are key
surface nodularity is best appreciated in the presence
of ascites but may be seen in other patients as well.

Sonographic Manifestations of Cirrhosis

So let's look at some of these manifestations.
So here's a subcostal oblique view looking at a patient
with lobar redistribution.
The arrows marked the main lobar fissure
and you can see the small right lobe deep
to the arrows in comparison
with the markedly enlarged left lateral
and left medial lobes.
This patient shows another form of lobar redistribution
with marked enlargement
of the caudate lobe shown here on a transverse image
and even more optimally on this longitudinal
or sagittal view.
Now, parenchymal change is variable in cirrhosis
and may consist of nodularity
or a cosing of the parenchyma as shown here and here
and here, although all of them have a different appearance,
this coarse knee would make us suspicious in all cases
of the presence of cirrhosis.
And on the third image,
we can appreciate also the marked surface irregularity
on the under aspect of the liver.
Now surface nodularity, as I commented,
is best seen in patients with ascites as here or here
and you can appreciate that it can create either small
nodules or large surface irregularity.
Now other gray scale manifestations
that we can see in patients with cirrhosis show as here
with strict of the hepatic veins
and color lucene on color doppler.

Complications of Cirrhosis: Portal Hypertension

Now complications of cirrhosis include portal hypertension
and on sonography we can appreciate this with evidence
of indirect signs mainly including splenomegaly and ascites.
In addition to that, the identification
of slen portal collaterals suggests
underlying portal hypertension.
So here's a patient where we can see on the sonogram a small
and coarse liver with obvious surface
modularity and ascites.
Now when we look at the spleen, we can see
that it is markedly enlarged.
Looking at the splenic hilum, we can see a tortuous mass
of vessels, in the hilar region.
And the addition of color doppler proves
that these are all vascular structures.
In this case, venous varis identification
of specific vessels is paralleled with the
diagnosis of portal hypertension including the left gastric
vein which runs off the cephalad border of the splenic vein,
and of course the easily identified
recanalize paraumbilical vein shown here on a sagittal view.

Pitfalls in Diagnosing Cirrhosis

Now what are some of the pitfalls when we're looking on gray
scale ultrasound at patients with possible cirrhosis?
So one is manifest in this 50-year-old woman who came
to the hospital with increased abdominal girth.
You can see on her initial CT scan
that she has very coarse liver parenchyma
and easily shown surface nodularity
CT scan confirms this appearance and on both ultrasound
and initial CT scan,
this patient was suspect to have cirrhosis.
Now while this is definitely a plausible explanation
for these findings, in the very rare circumstance we can
find patients who have metastasis,
most particularly from the breast, which masquerade
as cirrhosis, creating both parenchymal, non homogeneity
and a nodular liver.
So this pseudo cirrhosis appearance should always be kept in
mind and we should be suspicious always that everything
that appears to be cirrhosis may not in fact be.

Focal Liver Masses in Cirrhosis

So now when we consider the patient that has cirrhosis,
what is one of our major objectives?
It's the identification of focal liver masses.
And when we see these, we have
to consider hepatocellular carcinoma, both regenerative
and dysplastic nodules.
And of course, look for the incidental benign lesion
that can occur in any liver including one with cirrhosis.

Hepatocellular Carcinoma (HCC)

So let's talk first of all about hepatocellular carcinoma.
So this cancer is an enormous world health issue.
It's a malignant tumor of the hepatocytes
and there are 500,000 deaths conservatively estimated in the
world annually of critical importance in North America is
the hypothesis that fatty liver will take over from
hepatitis B
and C as the major cause of hepatoma in North America
by the year 2020.
Now, what are some of the facts
that we know about hepatocellular carcinoma?
We know that 5% of the patients
with cirrhosis will develop hepatocellular carcinoma
during their lifetime.
Now we also know that 60 to 90% of the patients that we see
with hepatocellular carcinoma have underlying cirrhosis.
Therefore, we know
that we can identify these populations as it correlates
with the geographic distribution of hepatitis B
and C infection.
And so surveillance
of these high risk populations is the key to finding new
and small tumors at the point when
they can still be treated.
Now hepatocellular carcinoma on ultrasound
or on imaging can appear as a solitary nodule.
It can appear as multifocal nodularity,
it can a pre-app appear as a big mass
or as a small mass with variable echogenicity.
We can also see hepatocellular carcinoma regrettably
as diffuse disease
and on we can also see surface nodularity which may rupture.
And so there's a propensity of these tumors as well
to invade the portal vein.

Sonographic Examples of HCC

So let's look at a few examples.
Here's a patient who on a surveillance scan shows a dumbbell
shaped hypo coic nodularity in the liver proven
hepatocellular carcinoma.
Another patient on a surveillance scan at presentation shows
multifocal hypo coic nodularity throughout the liver.
And another patient shows
with diffuse hypo coic infiltration
of the parenchyma a very,
very poor prognostic feature which appears in multiple
patients at the time that they are first seen.

Hemangioma-Like Nodules in Cirrhosis

Now let's look at the patient
that has the hemangioma like small lesion in the liver.
In a landmark publication by Elli
and his Italian colleagues,
they looked at almost 2000 patients
with newly diagnosed cirrhosis
and they found that of these nodules shown in these newly
diagnosed patients, 50%
of these echogenic nodules resembling hemangioma will turn
out to be hepatocellular carcinoma.
They looked at another population of almost 1700 patients
with known cirrhosis
and they documented that the new appearance
of an echogenic hemangioma like mass in this population
that all would be hepatocellular carcinoma.
So this is a very important take home point.
And right after I had read that article,
I saw this beautiful case.
So in October of 2003 we looked at a woman
with hepatitis C virus
and we called her surveillance scan normal
On her next surveillance scan, you can see
that she has a small echogenic nodule in her liver,
less than one centimeter in diameter.
And you can see that six months later this nodule has
doubled, almost tripled in size.
And this is then a proven hepatocellular carcinoma really
accentuating this marked importance
of these hemangioma like nodules in this population.
And so the take home message from this is to never diagnose
a hemangioma on ultrasound alone in a patient with cirrhosis
or known risk for hepatocellular carcinoma.
So let's look at a couple
of surveillance scan this one showing a small hypo coic
nodule in the liver and this one showing an even smaller
echogenic nodule.
So if we ask ourself on this surveillance ultrasound,
we see these two nodules,
which one should have contrast enhanced ultrasound?
And the answer of course is both
because both have a very high risk
of being an early hepatocellular carcinoma.

Contrast-Enhanced Ultrasound for HCC

So let's talk for a moment about contrast enhanced
ultrasound of the patient at risk
for hepatocellular carcinoma.
So what are we looking for?
Classic hepatocellular carcinoma shows arterial phase
hyper vascularity and portal venous phase washout.
Now there are many recognized variations including no high
vascularity in the arterial phase
and portal venous phase, late washout or weak washout
and in fact no washout at all.
So basically there are many variations
but the classic hyper vascularity
and washout is seen in about 80 to 85% of the population.
So let's look at that small hypo coic nodule
and from our still images you can see here
that the lesion is hypervascular in the arterial phase
and in the portal venous phase shows washout such
that it appears less enhanced than the adjacent parenchyma.
When we look at the small movie clip looking at that nodule,
we can see here all in spite of the fact
that the patient is breathing easily appreciate the
hypervascular nodule in the arterial phase.
And so this is rapid on the spot characterization
of an identified nodule on a surveillance scan.

Surveillance Challenges and Biopsy

So let's look at another surveillance situation.
This is a patient with severe end stage cirrhosis
who had multiple MR scans as a screening method.
So the surveillance MR scans were reported
as negative showing no nodules on the baseline scans
and no hyper vascularity in the arterial phase
with gadolinium.
So at one point along the course
of this patient's investigations,
the patient was sent for ultrasound.
Now in spite of the marked nodularity
of the liver on MR on the ultrasound exam, we don't see all
of that nodularity,
but we see instead one very dominant hypo
coic nodule in the liver.
Because of that we performed contrast enhanced ultrasound
and you can see that this nodule is in fact a
hypovascular nodule.
So this is not the classic appearance for HCC,
however we've learned that there are many variations.
And so if we have a nodule in the liver on gray scale
with a contrast enhanced enhancement variation,
we recommend biopsy.
This patient underwent ultrasound guided biopsy
and this is a confirmed well differentiated hepatocellular
carcinoma not visible on the EMR scan even in retrospect.

Comparison with CT and MR

Now this brings me to another very important topic
and that is how well does contrast enhanced ultrasound
correspond with CT and MR scan?
And so in our own publication from radiology, we found
that there was generally high agreement of
contrast enhanced ultrasound with CT
and MR especially in the arterial phase.
And that's beautifully shown in this patient
with a large hepatocellular carcinoma
with a higher grade of carcinoma shown
as the hypervascular nodule within the tumor on both the
ultrasound and the MR scan.

Other Presentations of HCC

So let's look at a bunch of other presenting features
of patients with hepatocellular carcinoma.
So here we can see a large
and heterogeneous mass proven HCC, another patient
with an even larger mass with the borders marked
by the arrows and a central scar like area marked
by an additional arrow.
Another patient with an echogenic large nodule
and ascites and another patient who's ruptured a surface
hepatocellular carcinoma.
Also within the presence of ascites another patient
with another surface tumor.
And these of course are always susceptible to both rupture
and hemorrhage with usually severe prognostic sequelae.

Vascular Invasion in HCC

Now, hepatocellular carcinoma is a unique tumor having a
propensity to invade the vessels around the tumor.
So here we can see a cirrhotic liver
with an obvious tumor posteriorly in the right lobe.
And you can see within the hepatic vein shown here a tumor
thrombus in the mid portion of the vein.
More commonly we see expansive thrombus in the portal vein
as we show here where the vein is both expanded
and filled with a softly echogenic mass.
When we look at the remainder
of the vein going into the left ascending branch,
we can see the entire intra hepatic portal vein is occluded
and expanded by the tumor.
Now when we look at this with doppler, you can see
that the color doppler shows profuse flow
within the portal vein.
And when we do a spectral waveform, we can see
that those are arterial signals arising from the vessels invading the portal vein.
And so of course this confirms
that this is malignant portal venous thrombosis
and this is just an ultimate CT scan confirming the thrombus
with the hyper vascularity in the portal vein.
So here are, it's a collection of all of the cases
that I've shown you showing the big spectrum, small,
large masses, solitary masses, multiple masses, echogenic
and hypo coic.
And all of these are hepatocellular carcinoma
emphasizing the marked variation in the
presentation of these tumors.

Fatty Liver

So let's leave, cirrhosis and hepatocellular carcinoma
and go on to talk about fatty liver.
So the normal liver has less than 5% content fat
and the fat that is present in the normal liver is never
within the hepatocytes.
Now in the patient who develops steatosis
or fatty liver, the amount of fat may increase
to 80% by weight.
And in this condition we have deposition
of fat globules within the hepatocytes.
This is associated with elevation
of the patient's liver function tests
and this is the most common indication for the performance
of the ultrasound scan.
Now the clinical significance
of fatty liver has changed over the years.
When I was a student
and in an early part of my career, we were taught
that fatty liver was totally reversible
and it was inconsequential
and that the hepatologist did not want
to be referred patients whom were noted
to have fatty liver on ultrasound.
However, over the time it's become recognized that patients
with fatty liver may go on
to develop chronic active inflammation of their liver
and that a significant percentage of patients
with fatty liver progress to cirrhosis
and the risk for hepatocellular carcinoma.
So this is obviously of critical importance in North America
where we have a general obesity
epidemic associated frequently with fatty liver.
And so what is recommended by the American Association
for the Study of liver disease is that patients
with fatty liver have to have monitoring with ultrasound
and serial liver enzymes.
And their general recommendation is
that your waist must be smaller than your hips
and that this is a formula for good health.
And although different health organizations in the world
recommend this in different ways, there is no other way
for a fatty liver to be reduced other than weight
reduction and exercise.

Sonography of Fatty Liver

Now what about sonography in the patient with fatty liver?
The sonography varies with the amount of fat
that's in the liver and also with the distribution,
within the liver parenchyma, whether it be diffuse or focal.
Now in the patient with diffuse fatty liver,
this is characterized basically as mild, moderate
or severe with severe fatty liver causing liver enlargement,
beam attenuation and poor definition
of deep structures including the diaphragm.
Now, with focal fatty liver we can have a geographic
pattern, a nodular pattern or a segmental fatty liver
and of course we can also have fatty sparing where parts
of the liver are fatty and other parts are normal.
All of these produce very specific
and quite identifiable features on ultrasound.

Diffuse Fatty Liver

So let's look at diffuse fatty liver first.
So here you can see the liver is bright.
The kidney appears more black than usual
and in a more severe example, the liver is bright
and you can see the attenuation
of the beam in the far field, with reduction
of visualization, of the deep structures.

Focal Fatty Liver

Here's another patient who has a type of focal fat
that is commonly identified
and that occurs in the anterior portion of segment four
adjacent to the falsy form ligament.
So here on a sagittal
and a transverse image, we can see this wedge shaped,
wedge-shaped area of increased echogenicity
and this kind of focal fat is generally
without clinical consequence.
Another typical appearance
for focal fat involves the portion of segment four anterior
to the portal venous bifurcation.
And this is another again, likely inconsequential appearance of focal fat in the liver.
Now focal fat may occur as a complication
of steroid ingestion
or as a complication of pregnancy as here
where we can see nodularity increased echogenicity in the
central portion of the liver.
And you can appreciate the unaltered course
of the hepatic vein within this fatty deposition.
This is another patient with focal fat within the parenchyma
and the lack of alteration of the course
or patency of the portal
and hepatic veins is characteristic of this diagnosis.
And if there's any question about whether we're looking at
focal fat or tumor masses on ultrasound,
then we can do different things including contrast enhanced
ultrasound or most often MR scan.
This is a patient who has interesting fat deposition along
the surface of the liver marked here by the arrows.
And this kind of appearance of the fat occurs
with tiano necrosis
and this always is found in diabetics
who have had insulin in infused with their dialate
and they develop this kind of toxic
fat deposition on the surface of the liver.

Liver Masses

So now we'll leave those diffuse liver processes
and talk the rest of our time on liver masses.
So there are many masses that we see in the liver
and we divide them in different ways in including
by their origin, those of hepatocyte origin
and those of non hepatocyte origin.
And so I've tried to look at them as
to whether they're significant or insignificant.
So considering the tumors of hepatocyte origin,
of course it's liver cell adenoma
and hepatocellular carcinoma which are most important
of the non hepatocyte origin masses.
This includes the insignificant he angio,
but it includes the significant masses, metastatic disease,
peripheral cholangio and biliary cystadenoma.
So we'll try to touch briefly on those lesions.

Interpreting Focal Liver Masses

So when we're interpreting a focal liver mass,
it's very important to do so with knowledge
of the patient's clinical history.
This must include in particular if the patient has any known
history of malignancy,
if they have any known chronic liver disease,
have they been tested for hepatitis B or hepatitis C
and do they have any history of hepatitis?
We have to know also if they have any symptoms referable
to their liver or if they're asymptomatic.
If we don't have these clinical information,
the interpretation is guarded.

Differentiation of Focal Nodular Hyperplasia (FNH) and Adenoma

So let's start with the differentiation
of focal nodular hyperplasia and adenoma.
Now, focal nodular hyperplasia is basically an insignificant
lesion, but it's differential diagnostic, features from adenoma
or so common that they have to be discussed together.
So they have the common clinical background
that they occur most often in asymptomatic young women.
They're most often incidentally detected
and they're characterized
by arterial face hyper vascularity on ultrasound
CT and MR scan.
However, without precise specific imaging,
they're often indeterminate.
So what do we know about focal nodular hyperplasia?
This is a hyperplastic liver growth rather than a
tumor and it develops in response to vascular insult.
Likely venous thrombosis on the constituents
of focal nodular hyperplasia are exactly the same
as normal liver, but they're disorganized
on baseline gray scale ultrasound.
These are very subtle tumors, often iso co to the liver
but producing contour bulge or vascular displacement.
Now contrast enhanced ultrasound is generally diagnostic
showing stellate vessels and centrifugal filling.
By comparison, hepatic adenoma is a much
more significant tumor.
It's less common than FNH
and it has a link to female sex hormones.
It's more common in women.
Adenomas are benign tumors
of the liver hepatocytes which are often large and solitary
and they may show blood fat and calcium as contents.
Now the reason that these are important is
that they have a definite risk of malignant transformation
and they also have a risk
of spontaneous rupture and hemorrhage.

Contrast-Enhanced Ultrasound: FNH vs. Adenoma

So let's look at the difference between contrast
on contrast enhanced ultrasound, adenoma and FNH.
So FNH is characterized in the arterial phase
by identification of stellate vessels,
a centrifugal filling pattern
and sustained enhancement in the portal venous phase
with a non enhancing scar.
Whereas hepatic adenoma shows a more chaotic
vascular pattern with centipede filling
and more variable enhancement in the portal venous phase
with 50% showing washout and they have no scar.
So here's a classic appearance
of FNH in an asymptomatic young woman.
So the upper left picture shows sagittal picture
of the left lobe of the liver with a rather bulbous contour
of the tip suggesting the possibility of a iso coic mass.
The subsequent frames are from the arterial phase
of contrast enhanced ultrasound
and you can see that the vascularity starts in the center
of the tumor, that there are central vessels.
And this proceeds to the middle bottom picture
where we have a homogeneously enhancing mass at the peak
of arterial phase enhancement.
The bottom right picture is a portal venous phase image
taken at about four minutes
and you can see that the mass stays enhanced
with a subtle non enhancing central scar.
When we look at this movie clip, you can see
that the mass is enhancing here
and when we use a MIP technique which tracks the vessels,
you can see that we can show the stellate vascularity
and the centrifugal filling of the tumor with ease.

So contrast this with another young woman who presents
with elevated liver function tests
and she has a similar sized mass in the superficial aspect
of her liver and her liver is large
and fatty so she has steatosis.
Now when we look at her still images, you can see
that her tumor has more chaotic vessels.
It's similarly homogeneously enhanced in the arterial phase
and it shows washout in the the portal venous phase.
Now when we look at the clip of this tumor though,
in contrast to the focal nodular hyperplasia, you can see
that the filling pattern is chaotic and diffuse
and that this tumor shows washout
in the portal venous phase.

Liver Metastases

So let's leave that and go on
to more significant liver masses
and that would include liver metastases.
So the incidence of liver metastases varies with the type
of tumor and the stage and initial detection.
However, at autopsy, as many as 50% of patients
who die from their cancer have liver metastases, many
of them undiagnosed.
Now the primary tumors, that are most likely
to metastasize to the liver are listed in order
with the gallbladder, colon and stomach
and pancreas leading the way ahead
of the very common tumors from the breast and lung.
Now these metastases are in general terms bloodborne
and in the United States the incidence of
of metastases is at least 20 times the incidence
of hepatocellular carcinoma.

Ultrasound Features of Metastases

Now when we consider ultrasound of these lesions,
let's take some of the rules that we take to heart.
So first of all, the identification of a hypo coic halo
around a liver mass on ultrasound is a very highly specific
sign for significant liver pathology.
And that's because most of these turn out
to be metastatic disease, greater than the number
that have hepatocellular carcinoma
and infrequent FNH will have a halo as well.
But nonetheless, we can never assume anything is benign.
We must confirm all masses with a hypo coic halo.
So here are some such lesions
where here we can see a mixed echogenic mass
with a well-defined hypo coic halo.
Another patient again with an echogenic mass
with a well-defined hypo colo
and here diffuse disease with hypo colos
around all of the tumors.

So when we're looking at liver metastases,
what do we have to consider?
Well most often these present focal liver masses,
however, they can also have a geographic
or a diffuse distribution which is much more difficult than
the focal liver mass.
Now the morphology of the liver metastases,
they may be echogenic, they may be hypo coic,
they may show a target appearance, they may be calcified,
they may be cystic, and they may be diffuse.
And so we have to look at all of those patterns recognizing
that there are cell types that associate
with our observations.

Diffuse Metastatic Disease

So here's a young patient who presents
with a diffuse grossly abnormal liver.
This is diffuse metastatic disease biopsy proven
as small cell carcinoma from the lung.
Here's a pitfall.
Another patient presents
to our emergency department feeling unwell.
And when we look at this liver, what's our first thought?
We don't see discrete masses.
We see rather very, very coarse parenchyma
and it would be very tempting to call this patient
as having cirrhosis.
However, we can see on CT scan
that this is instead diffuse infiltration
of the liver with tumor.
Another patient with small cell carcinoma of the lung.

Indeterminate Masses and Contrast-Enhanced Ultrasound

Now let's look at another patient.
This is a patient who presents for a CT scan.
The patient is feeling unwell
and we can see a small low attenuation mass in the portal.
Venous phase CT scan, this is indeterminate.
So the patient is sent for ultrasound
and we can see a slightly expansive mass
but also with an indeterminate appearance on the
ultrasound scan.
However, if we add contrast enhanced ultrasound, we can show
that the mass is hypervascular in the arterial phase
and has rapid complete washout.
So what is this indeterminate on CT
and baseline ultrasound hypervascular in the arterial phase
with rapid washout.
So this allows us to suggest a malignant tumor.
This is biopsied in its metastatic colon cancer
and the patient is subsequently found
to have a sigmoid car carcinoma.
So if we look at this clip, we can see on the clip
that the mass enhances hypervascular very rapidly.
And then within the time limit of this clip, which is 22nd,
you can see that the mass has been hypervascular
and is now rapidly washing out.

So what do we know from this?
Well, we know that metastases on ultrasound in contrast
to their appearance on CT generally show hyper vascularity
in the arterial phase.
This is a transiently observed phenomenon in
that washout is rapid and complete.
And so this rapid timing of washout is discriminatory
between malignant tumors in
that hepatocellular carcinoma washes out
slowly and in completely.

Hypoechoic Metastases

So let's go on to look at some of the specific morphology
of the tumors.
So hypo coic metastases have got several primaries
that we should consider including the very common tumors
from the lung and the breast.
Tumors from the pancreas, esophagus
and stomach again generally produce hypo coic metastases
as do both melanoma and lymphoma.
What do these tumors have in common?
They're often hypovascular with a cellularity
with little stroma.
And so here's a patient with a lung primary
with multiple small hypo tumors in the liver.
This is absolutely suggestive
and virtually diagnosed agnostic alone
of metastatic liver disease.
Another patient with HIV lymphoma, hypo coic masses in the liver, very, very suggestive
of malignancy and never to be ignored on a sonographic scan.

So if we see patients
that have these hypo coic masses like this,
this is very easy for us to suggest
that this would be metastatic disease.

Geographic Pattern of Metastases

So now let's look at this patient
who has got an area in the liver that's very black
and then alternates with almost a very straight border,
with echogenic liver and then another area that's black.
So when we look at that, what's the
first thought in my mind?
The first thought in my mind is could this be some
kind of unusual fatty infiltration
with a geographic pattern?
However, when we look at the CT scan, it's more compelling
and this is of course a geographic pattern
of metastatic infiltration.
And this is a patient with metastatic carcinoma
of the prostate, which infrequently involves the liver.

Echogenic Metastases

So let's go on to echogenic metastases.
Echogenic tumors tend very often
to have a gastrointestinal tract origin
and of course we've already talked about the fact
that they can also be representative
of hepatocellular carcinoma.
Echogenic tumors include all
of the highly vascular primaries including renal cell
carcinoma, carcinoid, tumor choriocarcinoma,
and eyelet cell carcinoma.
And these of course may mimic hemangioma
unless they have that very,
very telltale hypo coic halo as here.
So this is a young man
with multiple small echogenic masses in his liver,
and this is metastatic choriocarcinoma from the testicle.

Calcified Metastases

So calcified metastases are relatively uncommon,
but they include origins from mucinous gut primaries from
all of the bony tumors including osteogenic sarcoma
and chondro sarcoma as well as the neuroendocrine,
neuroblastoma and ovarian tumors.
And so when we look at these tumors,
they can have punctate calcifications
as the lesion does on the right
or a discreet shadowing focus as the tumor on the left.

Cystic Metastases

Now what about cystic metastases?
These are unfortunately more tricky than they might,
you might like them to be in
that the differentiation from the ubiquitous benign hepatic
cyst can be difficult.
If we see septations nodules
and fluid fluid levels, it's more easy,
however, they can be quite hard.
So here's a patient who has a multi septated cystic mass in
the liver, which is a proven cystic metastatic lesion.
And this most unusual looking mass with a small nodule,
which was enhancing on contrast enhanced ultrasound.
This is a patient with metastatic lung disease.
The one on the left is from a metastatic UMM SK tumor.

Now when we're looking at these cystic metastases, we have
to always consider stromal tumors, just tumors,
renal cell carcinoma, and neuroendocrine tumors.
So here we have an echogenic mass with a cystic center
and merely at site suggest to me a carcinoid primary.

Stromal Tumors and GIST

Now when we're considering these stromal tumors, we have
to recognize that these are highly vascular tumors
that can outstrip their blood supply.
So here's a patient who has a surveillance scan showing a
small hemangioma like echogenic nodule on day one.
Six months later when the patient returns, you can see
that the mass is many, many times larger
and now completely cystic with a shaggy thick outer border.
And this is a metastatic gist.
Tumor from the jejunum will end with biliary cystadenoma,
a rare neoplasm of the biliary epithelium,
which has variable malignant potential.
We see this most often in women.
These tumors have a tendency to recur
and on sonography they appear appear as a liver cyst
with vascular septations and septal or mural nodules.
So here you can see a very nice example
where we have a cystic mass in the liver
with these thickened nodular septations,
which correspond exactly
with the pathologic specimen in this patient
with a recurrent BIU cystadenoma.

Conclusion

So in conclusion, ultrasound is an excellent modality
for liver surveillance in chronic liver disease.
It has both high spatial and temporal resolution
and when it's used in conjunction with contrast,
enhanced ultrasound provides both a sensitive
and accurate diagnosis of focal liver disease.
Thank you.