Pathology

Pathology

• Liver pathology (steatosis, liver lesions)
• Gallbladder/bile ducts (bile stones, cholecystitis, dilated bile ducts)
• Renal pathology (hydronephrosis, kidney stones, kidney lesions)
• Bladder pathology (clot, bladder tumor)
• Spleen (splenomegaly)
• Pancreas (pancreatic tumor)
• Aorta (aneurysm)
• Intestines (appendicitis, diverticulitis, intestinal wall thickening)
• Trauma

Liver pathology

Steatosis

Fatty liver degeneration will make the liver parenchyma echogenic as compared to the kidney parenchyma (fig.  24). This is termed liver steatosis. Causes of steatosis include alcohol abuse, diabetes and obesity.

In liver cirrhosis patients, the liver surface will have an uneven/nodular aspect. In advanced stages, liver volume will decrease and the liver parenchyma will have a coarse-grain echo reflection pattern (fig

Liver lesions

Multiple focal abnormalities may be found in the liver.
In patients with a steatotic liver, anechogenic areas are frequently seen in the gallbladder bed or around the falciform ligament; in most cases, there will be areas without fatty degeneration or “focal non-steatosis” (fig. 26

 Another frequent finding in the liver is a liver cyst. A cyst is a benign, thin-walled fluid vesicle. Cysts have anechogenic (black) content. In order to distinguish cysts from anechogenic solid lesions, two artifacts are used: posterior wall enhancement and increased sound transmission (fig. 27). For additional information on ultrasound artifacts, see the Ultrasound Technique course.
Small liver cysts are usually asymptomatic and aspecific. Large cysts can in some cases exert a mass effect on the surrounding structures and thereby induce symptoms.

Another frequent benign abnormality in the liver is the hemangioma.  
Most hemangiomas are asymptomatic, sharply delineated echogenic small lesions (fig. 28). Perfusion in hemangiomas is slow, frequently preventing the use of color Doppler to demonstrate flow.  
In some cases, hemangiomas have an aspecific echo reflection pattern, making them indistinguishable from other liver abnormalities (e.g. metastases); additional diagnostics are then indicated.

Other benign liver lesions include granuloma, focal nodular hyperplasia (FNH) and adenoma; they will be discussed in more detail in a subsequent course. 
Metastases are the most common malignant liver abnormalities. In most cases, these patients have an oncologic history. Depending on the primary tumor, metastases may have either an anechogenic or echogenic reflection pattern (fig. 29). Usually they are mostly anechogenic. Metastases are frequently solid and vaguely delineated; flow cannot be demonstrated using color Doppler.

In patients with liver cirrhosis, hepatocellular carcinoma (HCC) is a common malignant abnormality.   The echo reflection pattern varies from anechogenic to echogenic or a mix. Flow may be imaged using color Doppler in HCC, making it distinguishable from a metastasis or hemangioma.