Ultrasound of liver for Acute hepatitis and Fatty liver

Ultrasound of liver for Acute hepatitis and Fatty liver

Acute hepatitis

In acute hepatitis, there is diffuse swelling of the hepatocytes proliferation of cup for cells and infiltration of the portal areas by lymphocytes and monocytes the sonographic features parallel the histologic findings in most patients the liver appears normal hepatomegaly is seen in many cases thickening of the gallbladder wall occurs in up to 80 percent of acute hepatitis particularly in viral hepatitis as you can see in this case it occurs due to hypoalbuminemia that generates gallbladder wall edema periportal lymphadenopathy can be seen in patients with acute hepatitis particularly in viral hepatitis as you can see in this case the liver parenchyma may show diffuse hypoechogenicity with accentuated brightness of the portal triads or periportal cuffing this appearance is called starry sky appearance starry sky appearance is non-specific but most commonly associated with hepatitis it has poor sensitivity and specificity.

Fatty liver

Sonographic features of fatty infiltration depends on the amount of fatty deposition and whether it is diffuse or focal the key sonographic feature of diffuse fatty infiltration is diffuse increased echogenicity of the liver parenchyma and decreased acoustic penetration hepatomegaly may be present as you can see on the image on your right hand this is a normal liver you can see the liver is isoechoic to the renal cortex on the image on your left hand the liver shows diffuse fatty changes manifested by diffuse increased parenchymal echogenicity as compared to the renal cortex there is decreased acoustic penetration with slightly impaired visualization of diaphragm as the red arrow pointing visualization of the normal bright intrahepatic vessel walls diminishes in fatty liver because the surrounding liver tissue becomes more hyperechoic looking at these two images in the normal liver, we can see the echogenic vessel walls in fatty liver the echogenic vessel walls are not visualized due to increased echogenicity of the surrounding liver parenchyma depending on the severity of fatty deposition a subjective and semi-quantitative grading of the fatty liver can be made ranging from mild to severe in mild fatty infiltration there is mild diffuse increased hepatic echogenicity with normal visualization of diaphragm and intrahepatic vessel borders as you'll see during this case in moderate fatty infiltration there's moderate diffuse increased hepatic echogenicity with slightly impaired visualization of intrahepatic vessels and diaphragm in severe fatty infiltration there is marked increased echogenicity with poor penetration of posterior segments of right lobe of liver and poor or no visualization of hepatic vessels and diaphragm as you can see in this case the posterior segment of the right lobe and the diaphragm are not visualized special attention should be given to patients with severe fatty liver in these cases focal hepatic lesions are difficult to visualize due to posterior attenuation and ct is recommended for solving unclear cases although the process of fatty infiltration is usually diffuse fatty deposition or fatty sparing may be focal resembling a mass focal fatty infiltration is hyperechoic area in a liver with normal echogenicity while focal fatty sparing is hypoechoic area in a hyperechoic liver focal fatty changes is usually seen in characteristic locations a typical common site of focal hepatic changes

is the gallbladder fossa as you can see in this case the liver shows diffuse increased echogenicity of fatty infiltration with hypoechoic area at the gallbladder fossa representing focal fatty sparing another typical site of focal fatty changes is anterior to the porta hepatis as seen in this case it can also be seen near the fossee form ligament or in the subcapsular parenchyma as you can see in this case or it can be seen in the caudate lobe as in this case focal fatty changes may mimic a focal neoplastic lesion however ultrasound characteristics of focal fatty pattern may differentiate the two entities focal fatty changes have characteristic locations as previously described there is lack of mass effect and hepatic vessels are not displaced focal fatty changes also have geographic margins however it may appear round or inter-digitating with normal tissue as you can see in this case there is an area of focal fatty infiltration in the right hepatic lobe it is seen in the subcapsular parenchyma and showing geographic margins a hepatic vein is seen passing through it with no mass effect most cases of fatty liver changes are of the diffuse type however segmental and lober distribution has been reported as you can see in these two cases.