Liver Flashcards
Segment 1 liver
Caudate lobe
Segment 2 liver
lateral superior left lobe
Segment 3 liver
lateral inferior left lobe
Segment 4 liver
4a and 4b medial segment left lobe
Segment 5 liver
anterior segment inf right lobe
Segment 6
posterior segment inf right lobe
Segment 7
posterior segment sup right lobe
Segment 8
anterior segment sup right lobe
Liver cyst
Fluid filled space with epithelial lining. Thin, will defined wall and posterior acoustic enhancement.
Peribiliary cysts
- In patients with severe liver disease
- 0.2- 2.5 cm
- small obstructed periductal glands
- Discrete, clustered cysts or tubular appearing structures with thin septae
Bile duct hamartomas (VMCs)
- Small focal developmental lesions of liver
U/s appearance; simple or multiple innumerable well- defined solid nodules less than 1cm. Hypoechoic but can appear hyperechoic. Bright echogenic foci with comet tail artifact.
Hepatitis A-E transmission
A: faecal oral B: parentally (blood transfusions, needle punctures), sexual contact and birth C: needles or drug injectors D: uncommon, drug use E: fecal- oral route
Pyogenic bacteria (pyogenic abscess)
- Reaches liver by direct extension from the biliary tract in pts with cholangitis and cholecystitis
Symptoms: fever, malaise, anorexia, RUQ pain, jaundice
US appearance: hypoechoic, echogenic foci with posterior reverberation artefact
Candidiasis (fungal)
US appearance: wheel in wheel, bulls eye, uniform hypoechoic pattern.
Amebiasis (parasite)
- Entamoeba histolytica
- Fecal oral route.
Symptoms: pain, diarrhea.
US appearance: round or oval shaped lesion, absence of prominent abscess wall, hypoechogenic liver, fine low level internal echos
Hydatid disease
- Enhinococcus granulosus
- sheep and cat
- tapeworm, eggs in dog poo and swallowed by host
- Embryo free in duodenum pass thru mucosa and reach liver through portal vein system.
- Surviving embryos will form slow growing cysts
US appearance; simple cyst, cysts with detached endocyst, daughter cyst, densely calcified masses
Schistosomiasis
- Parasite infection caused by schistosoma mansoni, japonicum, mekongi, intercalatum
- Terminal portal vein branches become occluded, presinusoidal portal hypertension, splenomegaly, varices and ascites
US appearance: widened echogenic portal tracts, enlarged liver
Fatty liver (metabolic syndrome)
Causes: obesity, excessive alcohol, pregnancy
US appearance: bright, echogenic, poor sound penetration
Mild: minimal diffuse increase in echogenicity
Moderate: moderate diffuse increase in echogenicity, slightly impaired visualisation of vessels
Severe: marked increase in echogenicity, poor penetration
Cirrhosis
Diffuse process characterised by fibrosis
Process: cell death, fibrosis and regeneration
Causes: alcohol and cirrhosis
Appearance: hyper or hypoechoic nodules, volume redistribution, coarse echotexture, nodular surface, regenerating nodules, dysplastic nodules, portal hypertension
Portal hypertension
Defined as:
- Wedge hepatic vein pressure or direct portal vein pressure more than 5mm Hg greater than IVC pressure
- Splenic vein pressure greater than 15mmHg
- Portal vein pressure greater than 30cm H20
Presinusoidal portal hypertension (extrahepatic)
Extrahepatic causes: thrombosis of the portal or splenic veins. Causes; trauma, sepsis, HCC, pancreatic carcinoma, pancreatitis, portacaval shunts, splenectomy, and hypercoagulable states.
Presinusoidal portal hypertension (intrahepatic)
Causes: schistosomiasis, primary biliary cirrhosis, congenital hepatic fibrosis, and toxic substances, such as polyvinyl chloride and methotrexate.
Portal vein thrombosis
Causes include; HCC, metastatic liver disease, pancreatic carcinoma, hepatitis
US appearance: echogenic thrombus within the lumen of the vein, portal vein collaterals, expansion of the caliber of the vein, cavernous transformation (wormlike vessels).
Budd Chiari
Partial or complete obstruction of the hepatic veins
Clinical presentation: ascites, heptomegaly, abdo pain
Cause: thrombosis in hepatic veins
US appearance: heptomegaly, splenomegaly, heterogenous echotexture, hypertrophied caudate lobe, regenerative nodules, GB wall thickening, ascites
Portal vein aneurysm
Rare, proximally at the junction of superior mesenteric and splenic veins.
US appearance; vascular mass connected to the portal system w/ turbulent flow.
Haemangioma
Benign tumours that are made up of vascular channels
Small, asymptomatic
US appearance: <3cm in diameter, well defined, homogenous and hyperechoic
Focal Nodular Hyperplasia
Second most common benign liver mass due to preexisting arterial spider- like malformation.
US appearance: well circumscribed mass with a central scar, <5cm in diameter.
Hepatic Adenoma
Benign tumour that can cause complications such as bleeding and malignant transformation.
Presentation: pt palpable mass RUQ.
US appearance: echogenic solid mass
Hepatic Lipomas and AML
Presentation: asymptomatic
US appearance: well defined echogenic mass
HCC
- More common in men
Risk factors: cirrhosis, hep B and C
Clinical presentation: RUQ pain, weight loss, abdominal swelling, elevated alpha feto- protein levels
3 forms: solid, multiple nodules, diffuse infiltration
US appearance: hypoechoic, complex or echogenic, small, hyperechoic,
Fibrolamellar carcinoma
Found in younger patients.
Solid tumours, 6cm - 2cm, well differentiated, encapsulated by fibrous tissue.
Hemangiosarcoma
Rare malignant tumour.
60-70 years.
Large mass mixed echogenicity.
Hepatic metastases
GIT tract, breast carcinoma, lung cancer, GUS system cancer, melanoma. Usually asymptomatic.
US appearance: round, well defined, hypoechoic, hypoechoic halo, cystic, calcified, infiltrative, echogenic appearance.
Hepatic trauma
US appearance; fresh hemorrhage echogenic, hepatic laceration becomes more hypoechoic over time. Most common injury was perivascular laceration paralleling branches of the right and middle hepatic veins and the ant and post branches of the r. portal vein.
