Transcript PZ - Diffuse Liver Diseases

Diffuse Liver Disease
Diffuse Liver Disease
Differentiation of liver disease into diffuse or focal disease is an
artificial but convenient way to analyze liver disorders
radiographically.
Although historical, physical and laboratory testing are the first
means for identifying these diseases, imaging may be required as a
part of the overall assessment of the patient.
From: Basic Radiology M. Chen et al.
Diffuse Liver Disease
Except for hemochromatosis, diffuse liver diseases are not an
indication for CT scanning. However, CT performed for other
indications will commonly show findings that are referable to
diffuse hepatic disease.
Many of these diseases are associated with an increased
incidence of HCC, and multiphasic CT should be performed in
patients with elevated alpha-fetoprotein levels or equivocal
sonographic findings
From: Spiral and Multislice Computed Tomography of the Body M. Prokop, MGalanski; Thieme, 2003.
Cirrhosis
Cirrhosis
Cirrhosis and chronic liver disease comprise the 10th most
common cause of death in the United States since 1994
• In the US and Europe the
most common cause of
cirrhosis is alcoholism,
whereas in Asia, the most
common cause of
cirrhosis is viral hepatitis
Cirrhosis
There are a number of conditions that can lead to cirrhosis:
•
•
•
•
Primary biliary cirrhosis - an autoimmune liver disease
Primary sclerosing cholangitis - a disease of the bile ducts
Prolonged exposure to environmental toxins
Some forms of heart disease (cardiac cirrhosis)
• Schistosomiasis (parasitic infection)
Chronic Passive
Congestion
• Inherited of congenital disease:
- hemochromatosis - abnormal accumulation of iron in the liver and other
organs due to the decreased excretion of iron from the liver
- Wilson’s disease - abnormal accumulation of copper in the liver and other
organs due to the decreased excretion of copper from the liver
- alpha1-antitrypsin deficiency - inherited absence of a specific enzyme in
the liver
- glycogen storage diseases - inability to properly utilize sugars
- autoimmune hepatitis - progressive inflammation of the liver associated with
an abnormality of the body’s immune system
Cirrhosis
• Cirrhosis of the liver is the end stage of a complex
process resulting from hepatocyte injury and the
response of the liver that leads to partial
regeneration and fibrosis.
Normal Liver
Microcellular cirrhosis
Macrocellular cirrhosis
• Nodular regeneration of the liver results in nodular
edge of the liver and inhomogeneity of the
parenchyma
• Most authorities are increasingly convinced that MRI
is the most sensitive imaging modality for
examination of the liver in cirrhosis and other diffuse
diseases of the liver
Cirrhosis
Ultrasound
• Real-time US, in combination with color flow Doppler, is currently the most frequently used
diagnostic imaging modality worldwide in the screening and evaluation of patients with
cirrhosis.
• In patients with cirrhosis, the liver parenchyma is coarsened in its echogenic pattern.
Surface nodularity is well seen in the presence of ascites. The size of the right lobe of
the liver is found to shrink in comparison to the caudate lobe as the cirrhosis progresses.
Cirrhosis
Ultrasound
Печень, цирроз печени
Surface
nodularity is
well seen in
the presence
of ascites.
Cirrhosis
Ultrasound
Early stages of
cirrhosis
shows
hepatomegaly,
ascites and
decreased
vasulature.
From: http://www.gehealthcare.com/
Cirrhosis
Ultrasound
Late stage
cirrhosis with
ascites and a
shrunken liver.
From: http://www.gehealthcare.com/
Cirrhosis
Ultrasound
Gallstones are seen in 3346% of patients with
cirrhosis, and their
prevalence is known to
increase with the duration
and severity of liver
disease.
Cirrhosis
CT Findings
CT is useful in demonstrating the morphologic evidence of cirrhosis within the liver
and in showing mesenteric and GI tract abnormalities and development of collateral
vessels in portal hypertension.
Early cirrhosis shows a normal
liver or enlargement of the
hilar periportal space anterior
to the right portal vein.
Cirrhosis
CT Findings
Early cirrhosis
CT demonstrates irregularity of
external contour of left lobe.
Cirrhosis
CT Findings
With progression, morphologic
changes are common and
include atrophy of the right
hepatic lobe and left medial
segment and enlargement of
the caudate lobe and left lateral
segment
Cirrhosis
MRI Findings
• MRI offers an alternative noninvasive method to image the liver based on tissue-specific
characteristics.
• MRI has not been widely applied in screening except in specialized transplant centers.
Cirrhosis
Secondary extrahepatic changes of cirrhosis include splenomegaly,
portal hypertension, portosystemic collateral vessels, varices,
and ascites.
Advanced cirrhosis:
Portal venous phase CT
demonstrating thickened
gallbladder wall, splenomegaly,
numerous collaterals within
omentum (arrow), and marked
ascites (A). The liver is atrophic
and irregular in external contour.
Cirrhosis
Portosystemic
collateral vessels
Portal venous phase CT demonstrating
splenomegaly, numerous collaterals within
omentum, and superficial vessel
anastomosing with paraumbilical vessel.
Very large varix in the umbilical region
(clinically evident as a caput medusa)
Cirrhosis
Portosystemic
collateral vessels
Development of extensive collateral vessels at the lower
esophagus
Ascites and marked splenomegaly
Varices are adjacent to and within esophageal wall.
Cirrhosis
Liver disease is the second most
common cause of death in persons
with cystic fibrosis.
About 5% of individuals with CF have
potentially fatal liver disease that
requires liver transplantation,
Sonogram shows heterogeneous liver
architecture. Nodules are visible within the liver
and at its edge. The path of the portal veins is
deformed by the nodules. A hyperechoic area in
the liver probably represents steatosis.
Cirrhosis
Portosystemic
collateral vessels
Liver disease is the second most
common cause of death in persons
with cystic fibrosis.
About 5% of individuals with CF have
potentially fatal liver disease that
requires liver transplantation,
Sagittal Doppler sonogram
shows the aorta and the
nodular contour of the left
lobe of the liver. Between
these structures, blood flow
(blue Doppler signals)
within the left gastric vein is
hepatofugal and directed
toward the esophagus.
Cirrhosis
Ascites
More than 500 mL of fluid is usually
required for ascites to be
diagnosed based on findings from
abdominal films.
Many nonspecific signs indicate
ascites:
• diffuse abdominal haziness,
• bulging of the flanks,
• indistinct psoas margins,
• poor definition of the intraabdominal organs,
• erect position density increase,
• separation of small bowel loops,
and centralization of floating gas
containing small bowel.
Cirrhosis
Ascites
Real-time sonography is the easiest
and most sensitive technique for
the detection of ascitic fluid.
Volumes as small as 5-10 mL can
routinely be visualized.
Uncomplicated ascites appears as
a homogenous, freely mobile,
anechoic collection in the peritoneal
cavity that demonstrates deep
acoustic enhancement.
Cirrhosis
Ascites
Most patients (95%) with carcinomatous peritonitis have a gallbladder wall that is
less than 3 mm thick.
Mural thickening of the gallbladder is associated with benign ascites in 82% of
cases. The thickening of the gallbladder is primarily a reflection of cirrhosis and
portal hypertension.
carcinomatous peritonitis
ascites associated with cirrhosis
Hemochromatosis
Hemochromatosis is characterized by a progressive increase
in total body iron stores with abnormal iron deposition in
multiple organs.
Primary hemochromatosis is a genetic disorder (one of the
most common genetic diseases in humans), whereas
secondary hemochromatosis can be the result of a variety of
disorders, most commonly chronic hemolytic anemias.
Cirrhosis and Hemochromatosis
• The organ is shrunken.
• The parenchyma shows very coarse
nodularity, best seen along the edges
of the specimen.
• The parenchyma is rusty brown (due
to hemosiderin).
Hemochromatosis
The use of T2-weighted gradient echo sequence is necessary to detect a slight iron overload.
Using this type of sequences, the liver is usually hyperintense to the muscle. A liver
hypointense to the muscle indicates a liver iron overload.
Normal liver
T1
PD
T2
T1
PD
T2
In case of slight
overload, liver
signal intensity
decrease can
only be seen on
T2-weighted
gradient echo
sequences. The
liver is then
hypointense to
the muscle.
Hemochromatosis
MRI is the best imaging examination to evaluate abnormal iron deposition
in the liver.
Normal liver
T1
T1
PD
PD
T2
T2
In case of
major
overload the
decrease of
the liver signal
intensity is
depicted on all
sequence.
Hemochromatosis
CT is less sensitive than MRI but can demonstrate increased iron if it is
severe.
Patients with increased
hepatic iron demonstrate
diffuse increased attenuation
of the liver, usually greater
than 75 Hounsfield units on
noncontrast examination.
Other abnormalities that can cause increased attenuation of the liver on CT
include: amiodarone toxicity, glycogen storage disease, gold therapy, and
Wilson disease.
Hemochromatosis
Ultrasound
Iron deposits in the liver usually do not alter liver echogenicity. If sonographic
liver abnormalities are present, they are usually secondary to cirrhosis.
Fatty liver (Steatosis)
Fatty liver, or steatosis is common disorder.
It is found in up to 50% of patients who are diabetic or alcoholic.
The many causes of fatty liver, besides diabetes or alcoholism, include:
1. Obesity
2. Chronic illness
3. Corticosteroid excess
4. Parenteral nutrition
5. Hepatotoxins including chemotherapy
Fatty liver may be distributed
evenly or focally
Fatty liver (Steatosis)
When distributed uniformly, fatty liver is recognizable as a pattern of
homogeneous increased echogenicity on US, decreased attenuation
on CT, or increased signal intensity on T1-weighted MR images.
Ultrasound
A sonogram of a fatty
liver showing increased
echotexture compared
with the adjacent kidney
Fatty liver (Steatosis)
CT Findings
Homogenous decreased atenuation
Fatty liver (Steatosis)
When distributed nonuniformly, it resembles focal disease of the liver
in that normal islands of the liver tissue are seen against the
background of lower density fatty liver
Focal spared fatty liver.
Schistosomiasis
• Occurs in many tropical and subtropical regions around the world
(Africa, South America, the Caribbean, Middle East, southern China,
and southeast Asia). Not yet found in the U.S.
• Infects as many as 200 million people each year. Of these, 20 million
are severely infected.
• Second (to malaria) most common disease caused by a parasite.
Intestinal schistosomiasis is caused by the species schistosoma mansoni
Urinary schistosomiasis is caused by schistosoma haematobium
Schistosoma sp.
in liver and
bladder
Schistosomiasis
Schistosomiasis is
a major source of
morbidity and
mortality for
developing
countries in Africa,
South America, the
Caribbean, the
Middle East, and
Asia; tourism to,
and immigration
from, endemic
areas can result in
schistosomiasis
cases presenting
anywhere in the
developed world.
The main forms of human schistosomiasis are caused by five species
of flatworms, or blood flukes, known as schistosomes.
Schistosomiasis
People are
infected by
contact with
infested water
during their
normal daily
activities for
personal or
domestic
purposes, such
as hygiene and
recreation
(swimming), or
in professional
activities such
as fishing, rice
cultivation,
irrigation, etc.
Schistosomiasis Life Cycle
Schistosomiasis
• Schistosomiasis life cycle leads to a granulomatous inflammation,
periportal fibrosis, portal vein occlusion, varices and splenomegaly.
• Imaging studies demonstrate periportal fibrosis.
Granulomatous reactions to eggs of S. mansoni and S.
japonicum in the liver produce a diffuse nodular periportal
cirrhosis (pipestem fibrosis).
Schistosomiasis
• The characteristic periportal fibrosis of hepatic cirrhosis due to S.
mansoni infections can be demonstrated by both US and CT scanning.
• Both US and CT, may show the dense bands which follow the portal vein
branches into the periphery of the liver.
• On US the bands are hyperechogenic. Depending on the angle, the foci
can be round or linear and the branching pattern allows differentiation from
metastases.
US scans of
the left lobe
of the liver
showing
well-marked
periportal
fibrosis
Schistosomiasis
• On CT bands are of low density but enhance strongly with contrast, becoming
either homogenous or denser than the surrounding liver. Depending on the
angle, the foci can be round or linear and the branching pattern allows
differentation from metastases.
Nonenhanced CT scans show both round and linear patterns of low density throughout the liver.
Schistosomiasis
• On CT bands are of low density but enhance strongly with contrast, becoming
either homogenous or denser than the surrounding liver. Depending on the
angle, the foci can be round or linear and the branching pattern allows
differentation from metastases.
In the early phase of contrast scanning, the
inferior vena cava has just filled, and there is
compression of the left main portal vein.
One minute later there is contrast enhancement
of both the linear and circular zones: this
pattern persists for several minutes
Schistosomiasis
MRI Findings
Linear and parenchymal band enhancement is seen.
The liver surface can be nodular and fibrosis may show increased periportal fat.
MRI images show presence of peripheral hepatic vessels
Schistosomiasis
With S. haematobium, ulcerations in
the bladder wall may cause dysuria
and hematuria.
Over time, chronic cystitis develops;
strictures may lead to hydroureter
and hydronephrosis; papillomatous
masses in the bladder are common
and may become malignant.
1. Calcification of the distal two thirds of
both ureters.
2. Bladder calcifications.
3. Seminal vesicle calcifications
superimposed on bladder calcifications.
Polycystic Liver Diseases
Polycystic liver diseases occurs either in autosomal dominant
polycystic kidney disease (ADPKD) or isolated autosomal
dominant polycystic liver disease (ADPLD).
Both forms are part of the ductal plate malformation.
Cysts in both syndromes are more
prominent in females than in
males and they usually grow up to
the menopause.
Presentation is usually with:
1. a feeling of fullness,
2. pain
3. symptoms of gastric outlet
obstruction.
Polycystic Liver Diseases
ADPKD on CT scan of the abdomen.
There are multiple cysts in both kidneys and in the liver.
Polycystic Liver Diseases
Ultrasound
ADPKD on liver ultrasound scan of the abdomen.
There are multiple cysts in both kidneys and in the liver.
Polycystic Liver Diseases
Multiple cysts have almost completely replaced the liver
parechyma. Both kidneys appear normal - ADPLD.