Acute cholecystitis and abscess: Fig. 1
Acute cholecystitis is a very common entity in radiology emergencies.
Most cholecystitis is due to a stone impacted in the infundibulum,
causing an accumulation of bile and secretions that can not drain into the bile duct,
favoring infection.
One of the most frequent acute complications of cholecystitis is perforation and the formation of an abscess.
If the perforation is surrounded by hepatic parenchyma,
the complications are minor,
because the pus is contained,
although a hepatic abscess may form.
If the perforation opens to peritoneum,
a chemical / infectious peritonitis occurs,
with serious consequences for the patient.
The development of an abscess secondary to cholecystitis can also affect other organs such as the pancreas,
spleen,
kidneys and abdominal wall.
Emphysematous cholecystitis: Fig. 2
It represents less than 1% of the total acute cholecystitis.
It is characterized by being rapidly progressive,
with an increased risk of perforation,
causing death to 15% of patients.
It differs from the usual acute cholecystitis in the following aspects:
- It is more common in males.
- The majority of patients have diabetes.
- About half of the cases are not associated with lithiasis.
Ultrasound findings can be subtle and may go unnoticed.
The gas will often be present inside the gallbladder light as in the wall.
It manifests as echogenic lines with a dirty back shadow or a reverberant artifact.
If the gas is abundant,
a bright echogenic line can be seen with a dirty back shadow in all the gallbladder light.
There may also be pneumobilia.
CT is more sensitive than ultrasound in visualizing gas in the wall and in the light.
Xanthogranulomatous cholecystitis: Fig. 3
It is a rare form of chronic cholecystitis.
It is characterized by the presence of cholelithiasis and thickening of the wall,
with multiple nodules or hypoechoic bands (xanthogranulomatous nodules full of lipids) in the wall thickness.
Porcelain gallbladder: Fig. 4
It corresponds to partial or total calcification of the gallbladder wall,
secondary to chronic lithiasic cholecystitis.
The greatest importance is that it is associated with an increased risk of developing gallbladder cancer,
which is why a prophylactic excision is recommended.
When the entire wall is calcified,
a dense acoustic shadow will be observed and the luminal content may not be visible.
This acoustic shadow can be confused with the shadow left by the gas from the adjacent colon (hepatic angle of the colon) to the gallbladder or to a vesicle full of lithiasis.
Adenomyomatosis: Fig. 5
It is a benign pathology caused by an exaggerated development of the normal invaginations of the luminal endothelium (Rokitansky-Aschoff sinus) associated with a smooth muscle proliferation.
In the ultrasound image a thickening is observed that can be confused with a perivesicular mass.
If the involvement is extensive,
the gallbladder may collapse.
MRI helps confirm the findings on ultrasound,
by visualizing cystic spaces inside a thickened wall.
Gallbladder cancer: Fig. 6
It is an infrequent neoplasm that occurs mainly in the elderly population,
more frequent in women.
It is usually related to the chronic presence of cholelithiasis and the vesicle in porcelain.
Forms of presentation:
- Mass from the fossa of the gallbladder that obliterates the light and invades the adjacent liver.
- It can affect diffusely,
manifesting itself as an irregular thickening of the wall.
- It can also present itself as a polypoid mass of the wall.
One way to differentiate it from bile content is the existence of vascularization in the US-color doppler,
absence of movement,
and in some cases a lithiasis trapped by the mass can be observed.