Flashcards in Liver Deck (94):
What are the characteristic findings of cirrhosis?
Nodular changes in surface contour
Atrophy of right lobe
Enlargement of left and caudate lobes
Caudate lobe enlargement is more prevalent in which type of cirrhosis
What are the two types of cirrhosis? What are the causes?
Micronodular - innumerable
Signal change between in and out of phase imaging in a nodular liver suggest what
Dysplasia - intracellular fat within nodules indicates dysplasia
How does blood flow in cirrhosis?
Through the fibrous septations as the acinar sinusoids are blocked
What is a recanalized umbilical vein?
Enlarged collateral vein that runs adjacent to the obliterated umbilical vein carrying hepatofugal (away) flow
Seen in portal hypertension
Make up caput medusae
What is hepatopetal vs hepatofugal
Hepatopetal is the normal flow in the portal system - blow flows through the portal vein TOWARDS the liver
Hepatofugal is abnormal flow caused by increased pressure AWAY from the liver through the protal vein
Wedge shaped ill defined band of abnormal signal (low T1 and high T2)
usually in anterior right lobe and medial segment left lobe
Confluent hepatic fibrosis
What is confluent hepatic fibrosis?
Wedged shaped region extending from porta hepatis to periphery
Usually anterior right hepatic lobe or medial left hepatic lobe
Spares veins and doesnt change in shape
What is nutmeg liver? How does it look? How does it look on doppler?
Hepatic congestion due to cardiac failure and constrictive pericarditis -> increased central venous pressure -> increased hepatic venous pressure -> sinusoidal engorgement -> diminished hepatic arterial flow -> hepatocellular hypoxia
Reflux of contrast into dilated hepatic veins and IVC, mottled enhancement, cardiomegaly, hepatomegaly, ascites, effusions
Will have pulsatility on doppler from direct transmission of fluid wave from heart through sinusoids
What is the cause of focal hepatic steatosis
REgional differences in hepatic blood flow
What/Where is the abnormality stored in primary hemachromatosis?
Ferritin and Hemosiderin
Liver - periportal hepatocytes then later biliary epithelium, kuppfer cells, fibrous septa
Pancreas and heart later as well
What are the complications of hemachromatosis? Most common cause of death
Cardiomyopathy, diabetes, arthropathy
Key feature differentiating hemachromatosis and hemosiderosis
Pancreas involvement and sparing of spleen in chromatosis
Splenic and marrow involvement with pancreatic sparing in siderosis
On MRI, what is a good comparison to determine liver signal abnormality?
What is von gierkes disease
Accumulation of glycogen within hepatocytes and proximal tubules of kidneys
Von gierkes has increased incidence of what?
Adenomas - and risk for HCC
What is the difference between solitary adenomas and adenomas in von gierkes disease
Von gierkes has an increased risk of HCC
What is budd chiari syndrome?
Hepatic venous outflow obstruction
Can be at the hepatic vein level or subdiaphragmatic IVC
What is primary budd chiari syndrome? What is the risk of HCC?
Membranous obstruction of hepatic veins
What is secondary budd chiari syndrome?
Occlusion at the central or sublobular vein or major hepatic vein
How does budd chiari show on angiogram
Wedge shaped hepatic venogram with spider web pattern of intrahepatic collaterals (pathognomonic for sublobular collaterals)
What is the enhancement pattern of acute budd chiari?
Heterogenous enhancement of liver with normal perfusion of central portion and caudate lobe)
DDx for diffusely hyperattenuating liver
Drugs (Gold, Amiodarone, Thorium Dioxide)
Glycogen storage disease
What are the doses for radiation injury to the liver in single and fractionated doses
Single - 12 Gy
Fractionated 40 Gy
What is hereditary hemorrhagic telangectasia?
Multiple AV malformations that lack capillaries
DDx for multiple enhancing liver nodules? Differentiate them
Multiple HCC - fast washout on venous, cirrhosis
HHT - will follow vessels
Budd chiari - peripheral changes are absent
Mets - rapid washout
What is pseudocirrhosis? What is it associated with?
Lobular hepatic contour with segmental volume loss and caudate enlargment seen in Breast Cancer
What is the association ARPKD?
Hepatic fibrois, differs from ADPKD
What are the non GI associations with ADPKD?
Bicuspid aortic valve
Aortic aneurysms and dissections
What are von meyenburg complexes?
Clusters of proliferated bile ducts embedded in fibrous stroma
US - can have ringdown artifact from cholesterol crystals in dilated tubules
High signal on T2 with faint rim enhancement or no enhancement
Who gets peribiliary cysts? What is the significance?
Liver disease, cirrhotics, Portal venous hypertension, thrombosis, cholangitis, transplant
Dilation of intrahepatic peribiliary glands
Intra/extrahepatic ducts are normal
Most common bug in pyogenic hepatic abscess? Children?
E Coli (adults)
Where does entamoeba histolytica invade?
Where is the abscess in E. histolytica? How does it look on CT? What is aspirated?
Right hepatic lobe
Water attenuation mass with low attenuation ring, solitary
Reddish anchovy paste
What is the host for echinococcus granulosus? multiloculare?
How does echinococcus look on imaging? how does multiloculare differ?
Peripherally calcified cystic lesion with visible daughter lesions
Granulosus - can be loculated. Daughter cysts are located in the periphery with lower attenuation
Multiloculare - geographic infiltrating regions of hypoattenuation with poorly defined invasive masses
What are the ultrasound findings in candidiasis? CT?
Bulls eye pattern - hyperechoic center with hypoechoic rim
Wheel within a wheel - central hypoechoic nidus with a hyperechoic rim and another hypoechoic rim
Uniformly hypoechoic liver due to progressive fibrosis
Echogenic liver caused by scar formation
Multiple hypoattenuating lesions in liver and spleen on CT
What is Kasabach-Merritt Syndrome?
Giant cavernous hemangioma (>4cm) that causes mass effect on adjacent structures, consumptive coagulopathy, and thrombosis
What is the blood supply to a hemangioma?
What is the imaging of hemangioma?
Peripheral globular enhancement that is iso/hyperattenuating to the aorta with progressive centripetal fill in
T2 hyper (slow moving fluid)
Delayed centripetal enhancement
Homogeneous hyperechoic with increased through transmission - usually doesnt have flow because they are slow moving
DDx for echogenic mass in liver?
Hyperechoic mets - will have hypoechoic halo
Focal fatty infiltration - geographic hyperechoic mass
What is the scintigraphy of hemangioma vs mets
Hemagioma will have delayed uptake (1-2 hours)
Mets will have early activity and rapid washout
What percentage of hemangiomas are atypical? How do they present on CT? US?
CT - diffuse early enhancement and washout (flash hemangioma)
US - thin hyperechoic rim, hypoechoic mass in diffusely hyperechoic liver
What is FNH? Pathophysiology?
Abnormally arranged hepatocytes, bile ducts, and kuppfer cells
Arises as a result of locally increased hepatic blood flow from a hepatic AV malformation
How does FNH appear on unenhanced CT? enhanced?
Unenhanced is ISOattenuating
Will have HOMOGENEOUS enhancement during arterial phase
Central scar is characteristic
Does FNH have a capsule?
No, but peripheral draining veins can give the appearance of a capsule
What makes up the central scar in FNH?
Supplying arteries and bile ductules
Key feature of FNH on imaging
HOMOGENEOUS enhancement on arterial phase
What is the US feature of FNH?
Central doppler activty with stellate pattern
What are the MRI findings of FNH?
Isointense on T1 and T2
Central scar is hypointense on T1 and hyperintense on T2
Homogeneous enhancement during arterial phase
What NM test is useful for FNH? How big must it be?
Sulfur colloid - will be taken up by kupffer cells
What percentage of FNH dont take up sulfur colloid?
What percentage of FNH is multifocal?
What makes gadoxetate special?
50% excretion from both biliary system and kidneys.
What are hepatic adenomas?
Cords of hepatocytes in an abnormal architecture
How do adenomas image?
Heterogeneous enhancement with a capsule
How are adenomas managed?
Surgical resection due to risk of hemorrhage
What is associated with multiple adenomas?
Von gierkes, anabolic steroids, familial diabetes
Low attenuation liver with multiple enhancing masses
Hyperechoic mass on US, Fat containing mass on CT
What is the association
Do liver AML have the same risk of rupture as renal?
How does a dysplastic nodule present on MRI?
Hyper on T1 and iso on T2
Capsule will be present occasionally
What is the nodule in a nodule appearance?
Progression of regenerative nodule to dysplastic nodule with a small focus of HCC
Match the following characteristics with type of nodule
Iso on T1/T2
Hyper T1 and iso on T2
Enhancement with rapid washout
Differentiate the enhancement of dysplastic nodule vs HCC
Dysplastic will enhance during arterial with isointensity on delayed
HCC will avidly enhance during arterial and be hypointense on delayed
What are the 3 types of HCC? Which is best prognosis?
Focal - best prognosis, expands rather than invades. Will have capsule
What percentage of HCC contain intratumoral fat?
Mosaic appearance of solid and cystic regions within a liver mass suggests what?
What is a THAD?
Transient Hepatic Attenuation Defect
THAD should prompt a search for what?
Underlying neoplasm causing compression or obstruction of supplying portal vein
What findings suggest multifocal HCC vs mets
What findings suggest a tumor thrombus over bland?
Contrast enhancement and arterial doppler waveform
What imaging findings are seen after a SUCCESSFUL ablation?
Water attenuation mass without evidence of enhancement
What suggest recurrence after ablation?
Large mass with central scar and calcification without underlying cirrhosis
Fibrolamellar or FNH (less likely to have calcs)
What are the risk factors for cholangiocarcinoma
Congenital hepatic fibrosis
How does lymphoma present in the liver on US and CT?
US - multiple small hypoechoic lesions
CT - multiple small low attenuation lesions
What are the two strongest risk factors for primary hepatic lymphoma
HIV and Hep C
What is post transplant lymphoproliferative disorder? How does it image?
Spectrum of abnormal lymphocyte proliferation ranging from abnormal proliferation of lymphoid cells to frankly malignant NHL
T cell suppressor chemo drugs activate overactive B cells
Solitary or multiple necrotic masses that encase vessels
What is a predisposing risk factor for PTLD
What is the rate of PTLD
Multiple solitary masses in the periphery of the liver that grow together over time and cause capsular retraction
Heterogeneous lacelike liver attenuation with a small atrophic spleen and hyperdense lymph nodes
Thorium dioxide induced angiosarcoma
What is the most common liver met? How does it present?
How do breast and lung mets appear?
Hypervascular mets arise from where
Colon - expansile hypoattenuating mass which may calcify (mucin)
PNET (carcinoma, islet cell, pheo), Melanoma, Thyroid, Renal, Choriocarcinoma, Breast
What are the imaging patterns on US for hepatic mets?
Multiple hypoechoic masses
Multiple isoechoic or hyperechoic masses with hyperechoic halos
What is the best phase for hypervascular mets?
Will usually be isoattenuating on portal venous phase
What does a hypoechoic ring surrounding a liver mass suggest on US? What does it represent
Mets or HCC
Normal hepatic tissue compressed by rapidly expanding tumor
Hyperechoic mass with posterior shadowing should prompt worry for what?
Shadowing is due to increased vascularity
What separates the liver into sup/inf? axially (r/m/l)?
What are the pathology in schistosomiasis?
Antigens released from eggs stimulate granulomatous reaction
Collagen deposition and fibrosis later on cause organ damage
What is the most common GI finding in schistosomiasis?
Periportal fibrosis leading to portal hypertension and GI bleed
What are the imaging findings in schistosomiasis?
Abnormal linear branching - Thickened portal tracts and hyperenhancement during portal venous/delayed phases