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25 Cards in this Set
- Front
- Back
what is the hepatobiliary agents for MR
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gadobenate dimegulmine (MultiHance) 5% hepatocyte uptake
gadoxetate disodium (Eovist/Pimovist) 50% hepatocyte uptake |
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how are most primary liver tumors supplied
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hepatic arteries, are hypervascular
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why are primary hepatic tumors so hypervascular
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they have numerous unpaired arteries --> increased arterial supply
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behavior of HCC with DWI
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most have restricted diffusion
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appearance of HCC on hepatobiliary
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most are hypointense (although 10-20% are not)
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how to screen pts for HCC in high risk pts
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US q6m
if nodules <1cm, repeat US in 3 months if >1cm, contrast enhanced MDCT or MR |
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why do some liver tumors have progressive enhancement
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these tumors have more fibrous tissue centrally
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intrahepatic cholangioCA - pathologically, what is it
what are the risk factors |
adenoCA of intrahepatic bile ducts - a mass forming periductal infiltrating tumor with central fibrotic tissue
liver flukes, PSC, cirrhosis, HBV, HCV, fibrocystic disease (caroli's, etc) |
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enhancement pattern of intrahepatic cholangioCA
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arterial phase has a peripheral rim or hetero central enh
hyperenhancement of the central fibrous areas during the equilibrium phase |
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findings a/w intrahepatic cholangioCA
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capsular retraction
peripheral bil dil |
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epithelioid hemangioendothelioma - pathology
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multiple peripheral lesions that infarct themselves
they are highly cellulary peripherally, fibrous centrally may have myxoid areas within it, as well |
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enhancement pattern of epithelioid hemangioendothelioma
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arterial: mild peripheral enhancement
progressive delayed central enhancement with halo or target appearance |
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ancillary findings of epithelioid hemangioendothelioma
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multiple coalescent subscapsular masses
capsular retraction eventual central calcifications |
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hepatic tumors with a central scar
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FNH
fibrolamellar carcinoma giant cavernous hemangioma |
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pathology of FNH
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arterial malformation that results from a localized vascular abnormality
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enhancement pattern of FNH
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arterieal: uniform nodular hyperenhancement
PV/equilib: iso-slight hyperenhancement delayed - enhancement of central scar hepatobiliary phase - iso to hyperintense lesions drain slowly, often difficutl to see on PV phase, enhance similar to liver, do not washout |
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signal characteristic of central scar in FNH
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high on T2 low on T1 b/c of inflammatory changes and ductules within the lesion
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enhancement pattern of fibrolamellar CA
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art: hetero hyperattenuation wiht progressive homogeneity
variable delayed enhancement of central scar (doesn't usually enhance) |
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appearance of central scar in fibrolamellar CA
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low T2, calcifications
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how to differentiate FNH scar from fibrolamellar scar
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FNH scar will not have calcs and will be high on T2,
fibrolamellar will have calcs and will be low on all sequences |
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most common benign hepatic tumor
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cavernous hemangioma
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scar in cavernous hemangioma
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high on T2 (higher than remainder of hemangioma), no enhancement
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kasabach merritt syndrome
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sequestration of thrombocytes in hemangioma --> thrombocytopenia
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size criteria for giant cavernous hemangioma
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>5cm
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enhancement pattern of giant cavernous hemangioma
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arterial peripheral discontinuous nodular enhancement with progressive centripetal enhancement
can also have thin linear fibrous septa that are low on T2 and don't enhance |