So in this lecture we'll be talking about hepatic cirrhosis
and the imaging findings associated with it.
What is hepatic cirrhosis?
It is chronic liver disease that's characterized by diffuse fibrosis.
You can see a pathologic picture of hepatic fibrosis
and you can see that the entire liver looks slightly abnormal,
you have little nodules
and the entire liver looks just a little bit shrunken and nodular.
Some of the common causes of hepatic cirrhosis include chronic hepatitis C
which is one of the most common causes worldwide,
alcoholic liver disease which is also one of the most common causes
of hepatic cirrhosis, hepatic steatosis also called non-alcoholic liver disease,
chronic hepatitis B, and occasionally, autoimmune or metabolic conditions
which are a lot more rare.
Some of the complications associated
with hepatic cirrhosis include portal hypertension,
ascites or free fluid within the abdomen, pleural effusion or fluid within the lung,
hepatic failure, renal failure, hepatocellular carcinoma, and possibly, death.
So, what exactly is portal hypertension?
It's elevated pressure within the portal venous system.
So this diagram here shows you what the portal venous system looks like.
Here's the portal vein right here
and here is the superior mesenteric vein coming down.
So this entire venous system becomes engorged in portal hypertension.
Some of the imaging features of portal hypertension
include esophageal or splenic varices, reversal of flow or thrombosis
of the portal vein, you can have a patent paraumbilical vein,
you can have an enlarged spleen or splenomegaly, gallbladder wall thickening,
and you can also have stomach wall and small bowel or colon thickening.
So let's look at some of the contour changes associated with hepatic cirrhosis.
As we saw on the pathologic picture, even on the radiological picture,
you can see a lot of nodularity to the contour of the liver,
and this is really one of the earliest signs of hepatic cirrhosis.
The liver also looks somewhat shrunken;
regenerative nodules or nodular proliferation of the liver parenchyma
can also be seen but it's hard to appreciate on a CT.
This is usually better appreciated on an MRI.
Ascites is also a very common finding
and you can see here surrounding the liver
a low density fluid collection representing free fluid in the abdomen or ascites.
So let's discuss other findings of hepatic cirrhosis.
What do you see on this image?
Do you see the abnormality pointed out by the arrows?
What do you think that represents?
So this is actually an example of a small pleural effusion
which is the low density that's back here
and adjacent to compressive atelectasis or atelectasis of the lung
caused by compression by the pleural effusion,
and this is a very common finding of hepatic cirrhosis.
What kind of ultrasound of the liver is this?
This right here is all liver parenchyma, and then what do these colors represent?
So this is actually a Doppler ultrasound.
It's a color Doppler ultrasound of the portal vein
and Doppler demonstrates flow within the vessels.
So this actually shows that there is flow within all of these vessels
but there is no flow within the main portal vein right here.
This indicates portal vein thrombosis
which is also a complication of hepatic cirrhosis.
This is an example of splenomegaly.
The spleen should be less than 12 cm in longitudinal dimension.
This is usually best measured on ultrasound
but it can also be extrapolated on a CT.
You can see here that the spleen looks very big.
By measurement, it measured over 12 cm
and you can see this liver has a very nodular contour,
again associated with hepatic cirrhosis with a small amount of fluid surrounding it.
And what do these circles represent?
So you have multiple serpiginous densities in the region of the porta hepatis.
This actually represents splenic and gastric varices
and this is all due to portal hypertension and back flow within the venous system.
So the vessels become engorged and appear enlarged.
Varices are abnormally dilated tortuous veins
and they are due to elevated vascular pressures
within the liver that cause blood flow to be directed
into the smaller collateral vessels and then they become dilated.
Let's take a look at this image.
What do you see here?
So again we see an example of hepatic cirrhosis
with a very nodular liver contour and free fluid surrounding the liver
as well as surrounding the spleen.
It's important to take a look at a lot of these images
because it's sometimes very subtle, the nodularity of the liver,
and it's important to be able to differentiate from a normal smooth liver contour.
So on this, we again have high density surrounding the esophagus.
These represent esophageal varices
which is also a very common finding in hepatic cirrhosis.
As these varices become larger and larger,
they can often bleed and may have to be embolized.
This is an example of a patent paraumbilical vein.
So the umbilical vein is patent during fetal development
and it supplies oxygenated blood from the placenta to the fetus.
After birth, it closes but then can become re-opened or re-canalized
when the portal venous pressures become very high.
So if you see an example of a patent paraumbilical vein,
this is often seen in hepatic cirrhosis and that should be a strong consideration.
This patient also has a shrunken nodular liver
and a large amount of free fluid within the abdomen.
So bowel wall thickening is also seen with hepatic cirrhosis.
Often it's artifactual and it's due to the adjacent ascites
looking like bowel wall thickening.
The fluid from the ascites actually gets within the folds of the small bowel
and it can appear that the small bowel wall is thickened.
Gallbladder and bowel thickening may be related to small vessel engorgement
as well from portal hypertension.
So imaging findings of hepatic cirrhosis as we discussed include a nodular,
shrunken liver; regenerative nodules within the liver
which are really best seen on MRI; splenomegaly
which we can see in this example here, we have a very enlarged spleen.
It's actually larger than the liver which is abnormal.
The liver is usually the largest organ.
Here you can that the liver is actually shrunken
and nodular with a large amount of fluid around it.
And splenic, gastric, and esophageal varices which can often bleed.
We also can see reversal of portal vein flow or portal vein thrombosis
and the patient can develop hepatocellular carcinoma in a liver that has cirrhosis.
We can see gallbladder or bowel wall thickening
and often we can see a pleural effusion associated with the ascites.
The pleural effusion is most often located in the right lung.
So we've discussed the multiple findings associated with hepatic cirrhosis.
It's important to be able to recognize some of the subtle earlier findings
such as hepatic nodularity because it can be very subtle
and difficult to differentiate from a normal smooth liver contour.