Fulminant (Acute) Liver Failure US and Correlative Imaging - HD

Introduction

Hello, my name is Mindy Harrow.
I'm a radiologist
and I work in Philadelphia in Pennsylvania at the Einstein
Healthcare Network.
And it is my pleasure today to speak with you about
fulminant liver failure.

The outline for my talk today is as follows.
First, we'll talk about the definition of
what this entity actually is, something about the incidents
and causes as well as the clinical features.
There are three types of acute liver failure,
which is very important for imaging that,
and we will discuss those as well as far as imaging goes.
Much of this, in fact most of it is done by ultrasound
with some CT and occasionally some MR.
And we'll show some examples.
In addition to general, imaging of acute liver failure,
we'll also touch upon some specific clinical situations
and etiologies for which imaging is very helpful as well
as some other minor issues.

Definition of Acute Liver Failure

Fulminant liver failure is the traditional name
for the entity that we'll be discussing,
but of late it has been changed
and is now known as an umbrella term of acute liver failure,
which is how we will refer to it for this talk.
The entity is the sudden onset
of hepatic encephalopathy in an otherwise healthy person.
So quite a dramatic event
because it is liver failure, it is typically associated
with coagulopathy, jaundice,
and may very rapidly progress to multi-organ system failure.

The subcategories of acute liver failure have to do
with the interval between the onset of jaundice
and encephalopathy.
This can be very, very rapid
and that would be the hyperacute stage which occurs within
one week of the incident, whether, whatever that might be
that causes the liver failure.
These patients, as sick as they may be,
and they are very, very sick,
generally have a better outcome.
Patients who are referred to in the acute phase
of acute liver failure generally present within the first
three to four weeks of the inciting cause.
Subacute is the category in which this occurs within three
months of the inciting cause.

Incidence and Mortality

How common is this entity, which perhaps you may
or may not have even seen a patient of.
There is no specific medical code or registry
or surveillance system, so it is a little bit difficult
and there are only estimates.
These estimates come from centers which have liver
transplant programs
because many of these patients are transferred
to such centers for their care
and often for liver transplants.
And so all of the information we have comes from
single hospital reports.
The estimates are between
twenty three hundred and twenty eight hundred
of new cases in the United States per year.
The overall annual death rate is 0.1%,
which actually is fairly significant
for this relatively rare entity
and it counts for 6% of all liver related deaths.
In addition, for a fairly uncommon entity, it accounts
for 6% of adult liver transplants.

Causes of Acute Liver Failure

As far as the causes, what we're talking about this acute
fulminant liver failure, that is the final common pathway
for many etiologies.
And the inciting cause has a lot to do
with the geographic location of the patient
and the time period of their, liver failure.
In the United States, drugs
and toxins are the most common etiologies for fulminant.
Acute liver failure. Accounting for nearly 60% of those
acetaminophen is the most common drug that we know of.
Many are considered idiosyncratic, which
of course just means we don't know what caused it.
And mushrooms, wild mushrooms are also a cause
and the rest of the world viruses are a more common cause
of, acute fulminant liver failure.
There are a whole laundry list of other causes, the some
of them relatively rare as you can see here, various,
entities, which cause
just ischemic hepatocellular injury can cause
fulminant liver failure as well as fatty liver of pregnancy
and Wilson's disease.
There are various miscellaneous causes as you can see,
which we'll also discuss a few of these
and of them, autoimmune hepatitis
is probably somewhat more common than many of the others,
and people think that may be the etiology for some
of the idiosyncratic causes.
We just are unable to prove it.
Indeterminate causes include primary graft non-function
in liver transplant patients.

As I said, again, acetaminophen is the most common cause
of fulminant liver failure in the United States
and also the most common cause of hyperacute liver failure.

Outcomes and Clinical Management

What kinds of outcomes do these patients have?
Well, this is the, this is the issue here in the short term,
three weeks from the diagnosis,
there is about two thirds survival, which means one third
of patients will die in this time period
if they need a liver transplant.
This usually is rapidly apparent
and occurs within a few days of admission
and death often occurs within a week
of admission when it's going to happen.
Overall, about 64%
of these patients will survive without a liver transplant.
This is a very, very serious illness
and survival does not necessarily mean
that their liver is in good shape.
It just means they survive.
The acute phase of those patients
who receive a liver transplant,
the survival rate at one year is in the 74 to 84% range.
If you know about liver transplants,
this is actually lower than, than in the United States
because these patients are
so sick when they receive their liver transplants.
The key thing for the clinical physicians caring
for these patients is to make a very as rapid
as possible determination of whether to list the patient
for a liver transplant.
If medical therapy is true prolonged, the patient may,
become, may not become suitable for a transplant.
They may be so sick
because of multi-organ failure and sepsis.
There is an association, for in, in the United States
for liver disease and they have a whole set of guidelines
for these patients in terms of diagnosis,
evaluation and monitoring.
As you can see here, if you look down the list of things
that they consider
or do for these patients, you'll notice
that there is no specific imaging recommendation.
That does not mean that these patients aren't imaged.
I can guarantee you they all are
and there are specific things that we need to look for,
but it's not on the ex on this, on this list,

Clinical Features

what are the clinical features of these patients?
As I said, these are patients who are going
to become jaundiced
and rapidly progressed to encephalopathy the all
of the functions of the liver or called into question here
and therefore they have metabolic issues, hypoglycemia,
lactic acidosis, coagulopathy, et cetera.
Encephalopathy ensues.
The lungs are affected
with acute respiratory distress syndrome,
high output heart failure.
There is suppression of bone marrow, acute renal failure
and a variety of other issues.
These, as I said, again, these are very, very sick patients.
They're in the intensive care unit
and they require, rapid
and aggressive kind of care.

A Patient Story

Before we turn to the imaging,
I'll actually tell you the story of a, one of the patients.
I, I happened to see a patient who had,
survived her hyperacute liver failure
and had a liver transplant.
She was waiting some, about six months later,
she was at our institution there for some reason
to see her doctor and I happened to say hello
and we were sitting and talking and this is the story
that she told me, just so that you understand
what happens to these patients.
She started to feel unwell one day, thought it was some sort
of GI distress or maybe something that she ate.
And as the day progressed, she started
to feel worse and worse.
By the evening she decided, she felt unwell enough
that she went to her local community
hospital emergency room.
She went there with one of her family members
and she remembers being in the emergency room.
The next thing she remembers is some number
of days later she woke up in the intensive care unit
of my hospital, a different hospital having
received a liver transplant.
That's exactly what happened.
And it, it was an overwhelmingly psychological burden
for her as well as a health burden
and it just to explain the, the severity
of these kinds of patients' illness.

Imaging in Acute Liver Failure

So as I mentioned, there are no specific guidelines
for imaging these patients,
but in general the vast majority
of them will receive some type of imaging
and that imaging often will be only ultrasound.
The reason for this is they are so sick,
they're in intensive care units
and we can bring the ultrasound to the bedside.
They may not be well enough to even be brought to
a CT scanner or an MR scanner.

What is the purpose of doing imaging in these patients?
One of the major things that we need to evaluate them for
is whether the appearance of the liver is that
of acute disease or chronic disease.
Now as you'll see in acute in hyperacute situations,
the liver may be fairly normal
but we are very good at figuring out in general if it's
chronic disease and, and you'll see what happens.
The pathology of acute liver failure is
that there is massive necrosis of the liver
and the whole liver essentially collapses if you will.
Often there are small islands of normal liver left behind
and those can go on
and have regenerating nodules in those areas.
Regular cirrhosis has lots of fibrosis
and also has some regenerating nodules.
But it's the fibrosis
and the nodular contour that is characteristic
so very hyperacute liver failure, just collapse of the liver
but it may seem normal to us on imaging cirrhosis.
Most people know what that looks like.
Fibrosis and regenerating nodules.
We need to also look at the hepatic vasculature,
particularly in terms of portal vein thrombosis
and the possibility of what may be needed
for transplantation.
And while most of these patients, there's nothing
that we can say regarding imaging as far as the etiology.
There are a few subcategories in which ultrasound
or imaging in general can suggest an etiology
and that's very important in the
hyperacute stage.

The liver may be essentially normal on ultrasound and CT.
In patients who present in the acute phase slightly later
the liver may begin to look somewhat abnormal.
There could be areas
that are relatively hypoechoic on ultrasound
and hypodense on CT.
These are felt to be the areas of necrosis.
The echogenic areas which stand out a bit
and are higher density on CT,
are probably the normal liver tissue
when patients are presenting in the more subacute phase,
several weeks or even a month.
Along in their symptoms again there will be hypoechoic
or hypodense areas of necrosis
and more well-defined areas that are echogenic
or hyperdense on CT representing islands of regeneration.

Hyperacute Phase

Let's turn now to the hyperacute liver phase.
Those patients who present within one week
of the inciting etiology in these patients,
the liver contour is smooth.
There are generally no findings yet
of portal hypertension such as splenomegaly.
The portal vein hopefully will be open
and though we do doppler there are no specific
doppler findings.
The liver echogenicity is usually normal
or could be slightly heterogeneous which is clearly
very nonspecific.
One thing that you may commonly see, again nonspecific
but the gallbladder may be quite small,
there are not much bile in the gallbladder
and the wall may be emus.
If you look at the kidneys, which you should do,
they can be enlarged and there may be a trace of ascites.
So overall, nothing specific but again smooth contour
and often relatively normal echogenicity at this stage.

Ultrasound and other modalities are very accurate
to distinguish hyperacute liver failure,
fulminant liver failure from cirrhosis
'cause cirrhosis will look completely different
and fulminant liver failure in the hyperacute stage looks
relatively normal with just minor findings.

Examples in Hyperacute Phase

Let's turn to some of these examples.
This was a patient who was admitted in acute hyperacute
liver failure secondary to acetaminophen.
She was 44 years old and one day
after this ultrasound she had a liver transplant which
showed at least 50% hepatocyte necrosis.
This is what her liver looked like.
I think we'd all admit
that the liver parenchyma here looks quite
homogeneous and normal.
The contour of the liver was smooth notice if you will.
The gallbladder not very distended
for an obviously fasting patient and has emus wall.
The doppler was unremarkable.
Normal portal flow, normal hepatic arterial flow,
a fairly innocuous looking ultrasound
but this patient needed a transplant one day later.

Here is a second patient acute liver failure
of unknown etiology in the hyperacute phase.
The explan on this patient a day
or two later showed submassive necrosis and some steatosis.
In this situation though, here is the liver,
small gallbladder again poorly distended.
This is the spleen.
So this liver was overall a little bit more echogenic than
the spleen but not enlarged, homogeneous
and had a smooth contour with normal portal flow.
So the important thing is we would not mistake
this for cirrhosis.
This is clearly not a chronic liver disease
and that's very crucial information for the clinicians.

Turning now to a patient
with acute liver failure now out about a week it was thought
that this patient had her liver failure due
to having taken some green tea extract from a herbal source.
This liver is a bit different.
This one is beginning to look somewhat abnormal.
Most of the liver if you look here is relatively hypoechoic
and the portal triads stand out a bit.
This area right here is a little bit more echogenic again,
here's another image, hypoechoic hypoechoic
and this is the spleen in comparison.
So if you look carefully though,
you might think the echogenic areas are a nodule or a mass.
Those are probably the normal islands of of liver
and the rest of the liver is hypoechoic.
Still normal size smooth contour.
Again this explan showed submassive necrosis
of relatively small liver.

This patient we was found
to have acute liver failure secondary
to autoimmune hepatitis.
The liver was small, this was within a week
to two if you will.
Again, some areas of echogenic liver.
Other areas hypoechoic with the bright portal triads and,
and already it's starting to be a little bit heterogeneous.
You can see compared
to the spleen which is actually now larger than the liver,
the liver has shrunk considerably.

Another patient came
and was found to have autoimmune hepatitis
and acute liver failure.
Had abnormal liver function studies.
As you can see, this patient was a little bit different.
The patient presented with jaundice
but no encephalopathy
or other organ failure, so not quite into the really
fulminant liver range and if you will,
the ultrasound was a little bit different.
This liver was large
as you can see it was a little bit echogenic
but quite homogeneous and a smooth cont.
There was ascites.
The gallbladder was small and the wall was thick.
This patient fortunately had an excellent response
to steroid therapy, which is the treatment
for autoimmune hepatitis and improved.
Did not need a liver transplant.
She came back to US three years later
for a routine abdominal sonogram
at which point the appearance of her liver
and spleen looked perfectly normal
as was her liver function.
So this is sort of went down the other pathway,
didn't quite go to the the fulminant stage
and was able to recover with steroids.

Autoimmune Hepatitis as a Cause

As I mentioned, autoimmune hepatitis,
is a cause of acute liver failure.
It may be a more common cause than we have known about
and sometimes it's difficult to make the diagnosis
because the antibodies
and levels may just not really be high enough
to determine it.
The imaging is the, is similar to the other causes
and the outcomes
as you can see can go in two different pathways.
The severe or fulminant patients may go on
to a liver transplant.
Those that are not quite as severe respond well
to corticosteroids.
The problem here is that you need to make the decision about
who gets the steroids and who does not.
If the patient is in fulminant liver failure
and looks like they need a transplant,
giving the corticosteroids may actually give them a poor
outcome after their liver transplant
because it predisposes them to sepsis
and they do not do as well.

Acute Phase

Turning now to patients who present in the acute stage
of fulminant acute liver failure.
So those are patients within one to four weeks
of the initial symptoms in this group.
When you initially image them,
you may see an abnormal appearance of the liver.
The contour can vary from finely nodular
to significantly nodular.
There may be a moderate to large volume of ascites.
Varice may be seen.
The liver can be quite small
and you saw that in some of the acute patients
and there's can be mild to moderate splenomegaly
by the time you get to this stage ultrasound
and the other modalities,
perform less well in distinguishing the patient from
cirrhosis because you're facing a patient
who you may never have seen before with a nodular contour
and ascites and the first inclination would be,
ah, this is cirrhosis.
So you have to be very careful.

Examples in Acute Phase

This patient had a unknown dietary supplement which was
thought to have caused her liver failure.
She had no prior liver disease
and came in quite sick with new encephalopathy.
If you look at the liver, it was small,
normal-ish in size, clearly heterogeneous areas
of hypoechoic and hyper coic liver.
Over on this image you can see even more large geographic
hypoechoic and hyper coic areas.
Her initial doppler was fairly normal.
Hepatic arterial velocities may be a little bit higher than
than usual, but good portal flow.
She was admitted to the ICU and monitored
and treated one day, one week later.
So now about three weeks
after the initial symptoms,
she had a significant clinical deterioration.
We were asked to re-image
and you can see now a significant amount
of ascites pleural effusion.
The liver is even maybe a little bit smaller
and the contour as you can see here, especially the contour
of the liver is now becoming wavy and minimally nodular.
This is in comparison to the spleen.
There's ascites around the spleen
and there's also a left pleural effusion.
Definitely a change in appearance of the liver.
The doppler had also changed a little bit.
The hepatic arterial velocities were even higher,
most likely reflecting the fact
that though there was portal flow,
there was less portal flow getting in.
So concomitant arterial flow had increased.
We were able to actually see a paraumbilical vein varix open
up and this patient
who had gone into acute liver failure had nephro magaly.
It was bilateral but certainly no hydro necrosis.
The patient went on rapidly and
and received a liver transplant
and this is what the liver that came out of her looked like.
You can see that the entire right lobe had
a very nodular contour.
Just looking at it, you might think it's cirrhosis
but the left lobe was relatively spared
and what we're looking at is,
and this is the pathology of it,
that the purple little purple cells are all the areas
of necrosis and this is an island of more normal liver
surrounded by all of this necrosis.
So the lumps and bumps on the surface, there are the islands
of the somewhat more normal or regenerating liver
and everything else around it has an acrost and collapsed.

This was a, a, a woman who came in again,
acute liver failure of unknown etiology
with approximately one to two weeks of symptoms,
very abnormal liver function studies.
She happened to have a CT and an ultrasound right
before she had had the CT and that's why they did it.
She had undergone a liver biopsy
and there was a very small per hepatic hematoma here,
no big hematoma in the liver.
The liver was maybe a little bit heterogeneous.
All of this gray around the enhancing
vascular structures is periportal edema.
Her ultrasound showed even better than the CT,
a wavy minimally nodular contour.
You can see this is the little hematoma
that she had kind of hypoechoic, not terribly heterogeneous.
She had an liver transplant two days later
with a small liver
and a significant amount of necrosis
with some very mild evolving fibrosis.

The liver nodularity
and fulminant liver failure correlates
with the length of the illness.
The longer the patient is sick.
So as you get into the late acute phase
and the subacute phase,
the liver nodularity becomes greater and greater.
Initially it may be fine and diffuse
and then it becomes very macro nodular.
The key thing here is that this nodularity is not due
to cirrhosis and this is crucial if you are,
if you are presented with a patient
and the clinicians tell you the patient is in acute liver
failure and you come across a nodular contour,
you might do not immediately say this is cirrhosis,
just report it as a nodular contour.
The problem here is
that if they think the patient has underlying chronic liver
disease and cirrhosis, the transplant priority
for the patient will be lower.
If it's just acute liver failure with submassive necrosis,
they will be higher on the list.
Remember again, the pathology for these patients
who are in the later stages are alternating areas of focal
and confluent regenerating nodules mixed
with areas of necrosis.
The key thing here is these patients do not have significant
fibrosis and given these large islands of regeneration, we,
we really don't know whether those patients might have a
greater potential for overall regeneration
and not need a transplant.
That's a hard thing to be able to study.

There is in addition
to cirrhosis another there is a differential
of nodule livers which aren't cirrhotic to keep in mind.
Metastasis can cause this treated metastasis sarcoidosis,
bud Chiari and pseudo peritoneal.
So these are other etiologies to keep in mind
for a nodular contour that is not cirrhosis.

Let's look at some of these patients.
This was a patient who came into us through one
of our other community hospitals
and the initial imaging if you look back at it was
interpreted as cirrhosis.
This is the appearance of the liver.
It was small, clearly a nodular contour, very heterogeneous,
high highish velocities in the hepatic artery.
Normal portal venous flow.
The patient also had CT
and these are the non-contrast arterial and delayed phases
and it was also interpreted as cirrhosis.
You can see the liver contour is nodular.
There is atrophy of the liver
and it's not strange that somebody would think of it
as cirrhosis, which is
so much more common than acute fulminant liver failure.

Here's another patient who had acute liver failure
of unknown etiology.
We first imaged the patient somewhere in the acute range
when they presented in the two to three weeks
after the initial insult.
The liver had a very abnormal appearance.
Ill-defined areas of increased echogenicity alternating
with hypo coic areas
and if you look with high frequency, the contour
of the liver is nodular Around the portal triads,
there's increased echogenicity and this is periportal edema.
The patient had a contrast CT
and you can see there are large ill-defined areas,
somewhat confluent that are hypodense
and other areas slightly more eco.
Hypo hyperdense.
Two weeks later the patient was still with us
and more imaging was done with both ultrasound and CT
and this shows exactly what can happen very, very rapidly.
Remember again, these areas are probably the normal areas
of liver, slightly ill-defined by the two weeks later.
The echogenic areas are now much more discreet, rounded
and lobulated alternating
with hypo coic areas the liver has shrunk even more
and the contour is extremely nodular, well visualized
because of all of the ascites around it.
On CT, again,
you can see the higher density nodules correspond
to the hyper dense.
No hyper echogenic nodules on ultrasound
with alternating low density areas and ascites.
Essentially the low density areas
and the low echogenicity areas are the necrotic regions in
this patient and the spleen is getting bigger and bigger.
There are small pleural effusions as well.
There was no cirrhosis when this patient went on
to liver transplant.

Studies on Imaging

There are not a lot of studies
that look at these patients, but this is one of them.
Not too long ago in the clinical literature in which they
just retrospectively reviewed their 46 patients
who presented with acute fulminant liver failure.
Most of the imaging in these patients was ultrasound.
The next most common imaging study was CT.
The majority of them had some abnormality,
but the majority of those abnormalities
were pretty non-specific.
Ascites was probably the most common thing.
As you can see here, A few patients had hepato ugal flow.
There was a chunk of patients about a quarter
who had a nodular surface
and as we've learned those are going to be the patients
who had a longer range of symptoms.
The etiologies in their group are, as you can see here,
with acetaminophen being the most common.
Though there were quite a number of idiopathic
and other etiologies
and most of the patients had necrosis on their explants.
The conclusion of the paper was that imaging
and explan pathology depend very much on the timing
of presentation and obviously when the transplant is done,
again they found what is in the literature
that acetaminophen toxic patients are the most common
to present in the hyperacute stage,
will have a relatively normal liver
and often proceed quite rapidly to transplant.

Specific Etiologies

Now let's turn to some other very specific etiologies
of acute liver failure and see what they look like.

Primary Graft Non-Function

This is a patient who received a liver transplant,
had had chronic liver disease, got their liver transplant
and we do an immediate post-transplant imaging study.
On that the liver looked fine in gray scale.
The arterial wave forms were a bit high resistance,
which is not uncommon.
The velocities were low normal
as you can see at 43 centimeters per second.
We always image the splenic artery
as an internal control which had a much higher velocity
and lower resistive index.
We had trouble finding intrahepatic arterial flow
and we're just able to get little spikes of flow.
We sometimes see that when the liver is quite emus.
So we were not initially concerned by the second day,
when the patient was not doing well
and the liver enzymes were becoming increasingly abnormal.
We had increasing difficulty finding arterial flow.
You can see in this CIC clip the little blips
of the hepatic artery right near the, the portal vein there
so we could see it in color.
It was very high resistance flow as you can see,
on the images on the left
and we had increasing trouble finding hepatic
arterial flow in the liver.
Otherwise the liver looked fine and the portal
and hepatic venous flow was also fine.
As the day progressed, the patient worsened.
We were asked to image again by now we were having
lower velocities,
high resistance arterial flow in the liver.
It was very difficult to find the arterial flow again
compared to the splenic artery
and now the liver was starting to subtly appear abnormal.
As you can see, there is increasing bright echogenicity
around the portal.
Triads, there was some pleural fluid
and slightly more ascites
and this is a syne clip of the liver that allows you to see
brighter echoes around the portal veins consistent
with periportal edema.
So nothing very specific
but what was happening was the patient was clinically
deteriorating dramatically
and this was, felt to be primary graft failure.
The patient needed an urgent re-transplant
and received one within a day
and on the explan,
there was hepato canicular cholestasis,
focal ductal cholestasis as has been described in primary
graft non-function function.

This is a very uncommon thing.
Fortunately, that's thought to be some type
of humeral antibody mediated rejection.
Essentially it is the acute onset of liver failure
without hepatic arterial thrombosis
immediately after liver failure.
Liver transplant.
So it's a very specific group of patients, those
who receive a liver transplant
and essentially immediate liver failure.
They have encephalopathy et cetera.
Just as the other patients who come in have it
and they have multi-organ failure,
typically they die if they're unable
to be trans re transplanted.

Hepatic Artery Thrombosis

This isn't is in distinction to patients
who immediately have hepatic artery
thrombosis as in this case.
This is the first ultrasound
after transplant, eight hours after transplantation.
We were unable to find any hepatic arterial flow.
This is the portal vein. There was no flow by this point.
The liver was already quite heterogeneous islands
that are hypoechoic alternating with hypoechoic.
This is the same pattern that you're seeing here.
The patient immediately went back to the operating room
where an arterial thrombectomy was performed, which was able
to reestablish the patient's flow and that was fine.
These are a series of CT scans at day 11, 16 and two months.
Fortunately, the right lobe was preserved
but you can see that the left lobe infarcted
and over time collapsed down.
Patient had enough right lobe to survive
so this is not fulminant liver failure,
from primary graft dysfunction non-function.
This is what happens when there is an immediate thrombosis

Trauma

Acute liver failure can in occasional
circumstances occur from trauma.
This patient had a gunshot wound to the inferior aspect
of the right lobe of the liver,
which also involved the right kidney
and the head of the pancreas.
The patient had no imaging
and went immediately to the operating room where part
of the right lobe of the liver was resected.
Subsequently, the patient was not doing well and had CT
and ultrasound on CT.
You can see the remainder of the right lobe had large areas
that were poorly enhancing thought to be ischemic.
Similarly, on ultrasound, a large hypo coic area
of the liver with alternating echogenicity more normal just
as similar to the other patients.
Hepatic artery was a little bit odd.
It was kind of parvis tortoise in this patient.
What happened was that there was progressive infarction
of the right lobe due to a blast effect.
So the bullet didn't go through this piece of liver
but the effect that the, the trauma
to the liver from shaking it up from that bullet going
through essentially infarcted that portion of the liver
and the patient went on
to have a complete right hepatectomy.
At this point the only thing
that the patient had was the left lobe
and not surprisingly that started to show signs of ischemia,
alternating areas of increased echogenicity
and decreased echogenicity and you can see that here.
The contour was still smooth at this point.
The patient was in acute liver failure
and was listed for a transplant.
Fortunately this was an otherwise healthy young person
and the left lobe went on to hypertrophy.
The patient did not need a liver transplant
and survived

Malignancy

Acute liver failure can occasionally be
due to malignancy.
This was an unusual case transferred to our diag,
to our hospital with the diagnosis of acute liver failure,
which the patient was in clinically
and we received the patient having
the other institution told us
that the patient had chronic bud Kiri syndrome.
This was our ultrasound
and we didn't find any findings of bud Kiri syndrome.
There was hepato ugal flow in the portal vein
and the hepatic veins and the IVC were open.
What we did see was a very,
very abnormal appearance of the liver.
The right lobe was shrunken
and had these large areas of calcification and shadowing.
The left lobe looked large and much more normal.
There was ascites.
This was a CT that came with the patient
and you can see that the right lobe was essentially
completely contracted.
The part that wasn't calcified was odd in its enhancement
and the left lobe had hypertrophy.
So we didn't at this point know anything about
what was going on in the right lobe.
The patient was in acute liver failure
and received a transplant.
The explan showed
that this patient had something called an epithelial
epitheloid angiosarcoma
that had diffusely involved the liver, even the left lobe
and that the right lobe was shrunken down.
As you can see here,
with some residual non neoplastic left lobe.

As I mentioned, this is a very unusual cause
of acute liver failure.
As far as what kinds of malignancies cause it,
they can be the hematologic malignancies that cause it
by diffuse infiltration such as lymphoma or leukemia
and they go on to cause massive hepatocyte necrosis.
The one other tumor that causes it is an angiosarcoma,
as in our case, which is a, a very rare primary liver tumor,
which is highly vascular
and just causes necrosis everywhere.
So those calcifications were due
to necrotic regions of the liver.
It's probably a multifactorial cause
of liver failure due both to the tumor
and to the vascular necrosis.

Budd-Chiari Syndrome

Another cause of liver failure.
It can present with acute liver failure
and one in which imaging can make a big difference as far
as making the diagnosis is bud Chiari syndrome,
which is hepatic vein
and often IVC thrombosis and narrowing.
This patient came with in postpartum state
with acute liver failure.
This is the spleen the liver was not,
was moderately normal to large in size,
somewhat heterogeneous hypo and hyper coic
and once again the small gallbladder with the emus wall.
However, in this situation the
doppler was very, very helpful.
The IVC in this patient was obliterated.
We could not even find it
and a little piece here
that showed up in the lower liver was fed
by collaterals from portal vein,
but there was no IBC going through to the heart.
This same patient went on to have CT
and these are the arterial
and portal venous phases which show very classic findings
of Bud Chiari syndrome.
The liver was large emus,
poorly enhancing in the arterial phase,
poorly enhancing in the portal phase other than some areas
such as the quad eight lobe which had some blood supply.
The image that you see on the right is an injection
of the IVC through the heart.
This is the catheter and you should normally see the IVC
and flow going back into the hepatic veins.
All you see is this tangle of tiny funny vessels here,
which is the classic finding in Bud Chiari syndrome.
These are all that's left
of the little hepatic veins which open up and,
and essentially makes the diagnosis of Bud Chiari.

This is a 39-year-old patient who had Bette syndrome
and presented with acute liver failure.
The liver was somewhat large here
and nobody had suspected the possibility of bud Kiri.
This is the left hepatic vein filled with thrombus.
This is the IVC partially thromboses small gallbladder.
Again, this patient had CT
with similar findings.
When the hep venogram was performed,
there were some normal hepatic veins in the right lobe
of the liver, none in the left
and this is the marked narrowing
of the inferior vena cava which wasn't completely thrombo.
Fortunately, this patient recovered from the acute incident
and did not need a liver transplant.
Came back two years later
and you can see that the inferior vena cava did completely
thrombose in the liver.
There were numerous collaterals.
We saw some of them in the anterior abdominal wall
and you can see them here but the liver survived

but Chiari syndrome can be a cause of a hyperacute
and acute liver failure.
There are a variety of causes.
As you can see here, imaging is different
and you can make this diagnosis
with ultrasound and other imaging.
As I've shown you here, catheter venography shows
that spiderweb appearance
of hepatic vessels in the parenchyma.

Other Considerations

Just a few other issues to consider before we finish.
There are some patients who present
with acute viral hepatitis.
They have very abnormal liver, functions
and they are jaundiced
but typically do not develop encephalopathy.
As far as imaging goes, they overlap with the patients
with the hyperacute fulminant liver failure,
so they may have a slightly hypoechoic liver.
As you can see here, these are some lymph nodes
and often the gallbladder is small and emis.
It's the clinical findings that allow us
to separate these patients from those
with true acute fulminant liver failure.

Sometimes, as I mentioned, there are patients with a liver
that looks cirrhotic and it's not cirrhosis
and in addition it may not be acute liver failure.
So just to reiterate that this patient
who had rather abnormal liver function studies
but not acutely so had no known history of liver disease
and came looking like this,
the liver contour was slightly nodular,
very heterogeneous liver.
As you can see here, vessels were open.
As you can see in the CT scan, this is a rather nodule liver
and heterogeneous.
There are some mass like areas,
but it wouldn't be an unusual thing to call this cirrhosis
and that was certainly contemplated in this patient.
This is an octreotide scan
and the entire liver lit up in this patient
and what we're dealing with here is metastatic carcinoid
and this causes, it's one of the metastatic lesions
that is known to cause something called pseudo cirrhosis.
There's, the, the tumor is all over in here
and it causes the contour of the liver
to be somewhat nodular
and often in the routine imaging
of the liver in the portal venous phase, it's very hard
to actually see the discreet masses.
They're better seen in the arterial phase,
which isn't always done
and you can mistake this
for a cirrhotic heterogeneous liver.

Lastly, there are patients
who present in acute fulminant liver failure who happen
to have some chronic underlying liver disease
and we're learning more and more about these patients.
So these are people who have cirrhosis
and then acutely decompensate and have multi-organ failure.
This is a clinical diagnosis rather than
an imaging diagnosis.
We will see chronic liver failure in these patients
and you can begin to understand that it might be difficult
to differentiate these patients from those
with subacute fulminant liver failure.
They often have a high mortality if they do not receive a
liver transplant and
they are put fairly high on the transplant list,
though not quite as high as the patients who present
with fulminant liver failure without underlying cirrhosis.
Generally speaking, there's some precipitating events such
as sepsis or surgery
that puts these patients into fulminant liver failure.

Conclusion

So in conclusion, what have we learned?
The entity of acute fulminant liver failure is relatively
rare and you may not, depending on where you practice
and the center in which you are, see that many cases of it,
the clinical history is exceedingly important.
We need to know the length
of the patient's symptoms of course.
Unfortunately that may be somewhat unreliable.
Biopsy can be performed in these patients
and would be very helpful,
but is often very hazardous if they have a great,
coagulopathy imaging when performed is usually done
with ultrasound if the patient is very ill
and in the intensive care unit.
The key thing for ultrasound is does this look
acute or chronic?
And remember, patients with the hyperacute liver,
failure will have a smooth surface and whether
or not we can make the diagnosis of a,
of the actual clinical syndrome doesn't matter.
Our job is to tell the clinicians
that the liver surface is smooth
and this does not look like cirrhosis.
The problem for imaging is those patients in the acute
and subacute phases, the liver can become very nodular
and very abnormal and simulate cirrhosis
and you may not be able to tell the difference.
Just be honest with the clinicians and they will understand.
There are other findings, as you know, that you can see,
and those are the findings of liver failure
and portal hypertension.
The other thing to think about when imaging these patients
is can we find an identifiable cause of acute liver failure
that would be a minority of patients
and would be something like a Bud Chiari syndrome,
metastasis, or a primary tumor.
Thank you.