GI hepatobiliary Flashcards
T/F normal calibre of the CHD is 5mm
True
T/F bile duct variants are found in 10% of all autopsies?
F- 1-3%
Name some anatomical variants that can result in bile leaks/obstruction post op?
- Aberrant intra-hepatic ducts.
- Cystic duct entering hepatic duct.
- Duplication of cystic ducts.
- Ducts of Luschka (numerous ducts draining directly into the cystic duct).
- Congenital tracheobiliary fistula.
T/F cystic duct variants account for 40% of bile duct variants?
F- 15-25%.
T/F the most common cystic duct variant is the cystic duct insuring into the middle third of the extra-hepatic duct.
T- 75%
T/F
True
In what % of ppl does the hepatic artery arise from the common hepatic artery?
50-60%
In what % of ppl does the common hepatic artery divide into the gastroduodenal artery and either right or left hepatic arteries?
10%
T/F the hepatic artery waveform is pulsatile, High resistance and shows a rapid systolic upstroke with a continuous diastolic flow?
False- the hepatic artery waveform is pulsatile, LOW resistance and shows a rapid systolic upstroke with a continuous diastolic flow
What is the normal velocity and resistive index of the hepatic artery?
30-60cm/second
Resistive index: 0.6 +/- 0.06
T/F Portal vein flow is non-pulsatile?
True, mild resp variation
What is the normal velocity of the portal vein?
20-30cm/s.
T/F hepatic vein waveform is tri-phasic with reap and cardiac variation?
True
Acute hepatitis- raised AST, ALT and unconjugated bili?
F- Raised AST, ALT and conjugated bili
Acute hepatitis may show diffuse decreased echogenicity on US?
True
Chronic hepatitis lasts at least 6 months- name some causes?
PBC, Hep B, C, D, PSC, Wilson’s, Alpha 1
3 US features chronic hepatitis?
Increased echogenicity, coarse echo, loss of definition of portal vessels.
What % of cases of cirrhosis are secondary to C2H5?
75%
Causes of cirrhosis?
V I = hepatitis T A = PBC, PSC M = HH, Wilson's, Alpha 1 I Nutritional: severe steatosis, malnutrition C D = mtx, nitrofurantoin, isoniazid
Cirrhosis- what are the 3 morphological types?
micronodular, macro nodular, mixed
What are the 4 types of nodular lesions?
- Regenerative consisting of hepatocytes and stroma
- Cirrhotic which are regenerative nodules with surrounding fibrosis
- Dysplastic nodules which are hepatic adenomas with areas of dysplasia within them (not seen on imaging) seen in hep B/C cirrhosis.
- HCC
T/F regenerative nodules can be seen on CT if they are siderotic?
True i.e. high atten nodules without arterial enhancement and similar to liver parenchyma on portal venous phase.
What are T1/T2 signal characteristics of regenerative nodules?
T1 - high
T2 - low due to siderosis
What are T1/T2 signal characteristics of dysplastic nodules?
T1- homogeneously high
T2- very low
ENhance post IV contrast
T/F neoplastic nodules in cirrhosis show variable appearance?
True
What are charact MR findings of neoplastic nodules?
- arterial enhancement
- washout during portal-venous phase
- T2 “nodule in nodule” appearance with a high signal neoplastic nodule seen within a low signal dysplastic nodule
HH CT liver appearance?
Generalised increase in liver attenuation
What are T1/T2 liver features of HH
Low signal on both T1 and T2
T/F pancreas may be dark late in disease?
True
T/F spleen is normal in primary HH and dark in secondary HH?
True
What is the most common origin of a liver abscess?
- biliary spread
other causes: contiguous spread, trauma, portal venous
Liver abscess- most common age?
60-70
T/F left lobe most common location for liver abscess?
F- right lobe, central lesions common
T/F a single liver abscess is more common than multiple liver abscesses?
False
What organism causes amoebic liver abscess?
Entamoeba histolytica
amoebic liver abscess- most common age?
30-40
T/F amoebic liver abscess most commonly located within periphery of left lobe?
F- periphery of right lobe
T/F amoebic liver abscess- usually multiple?
F- single
T/F amoebic liver abscess- usually small
F- can be greater than 5cm
amoebic liver abscess- name 3 Xray features?
- raised right hemi-diaphragm
- right basal atelectasis
- right pleural effusion
T/F US: amoebic liver abscess- early hyperechoic
F hypo echoic, ill-defined
T/F amoebic liver abscess later becomes better defined with posterior enhancement and a thick reflective wall?
True
T/F amoebic liver abscess may be simple or multi-loculated and single or multiple?
True
Amoebic or pyogenic abscesses are likely to be homogenous or heterogenous?
Homogenous
Pyogenic or fungal abscesses are likely to be homogenous or heterogenous?
Heterogenous
Describe CT findings of amoebic abscess?
- low attenuation lesions causing mass effect.
- peripheral wall enhancement
- Simple or multi-loculated with modularity of the wall
T/F Amoebic abscesses may contain gas?
F- pyogenic abscesses do!
Describe 2 CT signs specific to pyogenic abscesses?
- Double target sign: wall enhances with surrounding low attenuation zone caused by oedematous liver tissue
- Cluster sign: several abscesses cluster together looking as if they may coalesce
Describe MRI features of liver abscess?
T1- low
T2- high
Wall enhancement post contrast
Target sign on T2WI- low T2 wall with surrounding high signal due to peri-lesional oedema
Nuc med findings of liver abscess?
- uptake of sulphur colloid on Tc99m and WBCs
T/F Gallium is taken up by both pyogenic and amoebic liver abscesses?
False just by pyogenic abscesses
What is the commonest benign liver lesion?
- haemangioma (70-80% of all liver lesions)
T/F Haemangiomas are usually peripheral and single in 50% of cases
F- single in 90%
T/F haemangiomas are associated with FNH and Osler Weber Rendu?
True
How may haemangiomas present?
- incidental
- spontaneous haemorrhage
- Kasabach Merritt syndrome: haemangioma plus thrombocytopaenia
T/F haemangiomas usually
True
What does haemangioma produce when greater than 4cm?
Giant cavernous haemangioma
Haemangiomas- where does their blood supply come from?
Hepatic artery
Hepatic haemangiomas- X-ray features?
Calcifications
Hepatic haemangiomas- US features?
Variable
- majority are hyperechoic but may be hypoechoic
- may show acoustic enhancement
- NO flow on colour Doppler?
T/F Hepatic haemangiomas- may show acoustic enhancement?
T
T/F Hepatic haemangiomas- arterial flow on Doppler?
False- NO flow
Hepatic haemangiomas- CT findings?
- well- circumscribed, low attenuation
- peripheral nodular enhancement that fills in over time on delayed images
- enhance immediately