GI hepatobiliary Flashcards
1
Q
T/F normal calibre of the CHD is 5mm
A
True
2
Q
T/F bile duct variants are found in 10% of all autopsies?
A
F- 1-3%
3
Q
Name some anatomical variants that can result in bile leaks/obstruction post op?
A
- 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.
4
Q
T/F cystic duct variants account for 40% of bile duct variants?
A
F- 15-25%.
5
Q
T/F the most common cystic duct variant is the cystic duct insuring into the middle third of the extra-hepatic duct.
A
T- 75%
6
Q
T/F
A
True
7
Q
In what % of ppl does the hepatic artery arise from the common hepatic artery?
A
50-60%
8
Q
In what % of ppl does the common hepatic artery divide into the gastroduodenal artery and either right or left hepatic arteries?
A
10%
9
Q
T/F the hepatic artery waveform is pulsatile, High resistance and shows a rapid systolic upstroke with a continuous diastolic flow?
A
False- the hepatic artery waveform is pulsatile, LOW resistance and shows a rapid systolic upstroke with a continuous diastolic flow
10
Q
What is the normal velocity and resistive index of the hepatic artery?
A
30-60cm/second
Resistive index: 0.6 +/- 0.06
11
Q
T/F Portal vein flow is non-pulsatile?
A
True, mild resp variation
12
Q
What is the normal velocity of the portal vein?
A
20-30cm/s.
13
Q
T/F hepatic vein waveform is tri-phasic with reap and cardiac variation?
A
True
14
Q
Acute hepatitis- raised AST, ALT and unconjugated bili?
A
F- Raised AST, ALT and conjugated bili
15
Q
Acute hepatitis may show diffuse decreased echogenicity on US?
A
True
16
Q
Chronic hepatitis lasts at least 6 months- name some causes?
A
PBC, Hep B, C, D, PSC, Wilson’s, Alpha 1
17
Q
3 US features chronic hepatitis?
A
Increased echogenicity, coarse echo, loss of definition of portal vessels.
18
Q
What % of cases of cirrhosis are secondary to C2H5?
A
75%
19
Q
Causes of cirrhosis?
A
V I = hepatitis T A = PBC, PSC M = HH, Wilson's, Alpha 1 I Nutritional: severe steatosis, malnutrition C D = mtx, nitrofurantoin, isoniazid
20
Q
Cirrhosis- what are the 3 morphological types?
A
micronodular, macro nodular, mixed
21
Q
What are the 4 types of nodular lesions?
A
- 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
22
Q
T/F regenerative nodules can be seen on CT if they are siderotic?
A
True i.e. high atten nodules without arterial enhancement and similar to liver parenchyma on portal venous phase.
23
Q
What are T1/T2 signal characteristics of regenerative nodules?
A
T1 - high
T2 - low due to siderosis
24
Q
What are T1/T2 signal characteristics of dysplastic nodules?
A
T1- homogeneously high
T2- very low
ENhance post IV contrast
25
T/F neoplastic nodules in cirrhosis show variable appearance?
True
26
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
27
HH CT liver appearance?
Generalised increase in liver attenuation
28
What are T1/T2 liver features of HH
Low signal on both T1 and T2
29
T/F pancreas may be dark late in disease?
True
30
T/F spleen is normal in primary HH and dark in secondary HH?
True
31
What is the most common origin of a liver abscess?
- biliary spread
| other causes: contiguous spread, trauma, portal venous
32
Liver abscess- most common age?
60-70
33
T/F left lobe most common location for liver abscess?
F- right lobe, central lesions common
34
T/F a single liver abscess is more common than multiple liver abscesses?
False
35
What organism causes amoebic liver abscess?
Entamoeba histolytica
36
amoebic liver abscess- most common age?
30-40
37
T/F amoebic liver abscess most commonly located within periphery of left lobe?
F- periphery of right lobe
38
T/F amoebic liver abscess- usually multiple?
F- single
39
T/F amoebic liver abscess- usually small
F- can be greater than 5cm
40
amoebic liver abscess- name 3 Xray features?
- raised right hemi-diaphragm
- right basal atelectasis
- right pleural effusion
41
T/F US: amoebic liver abscess- early hyperechoic
F hypo echoic, ill-defined
42
T/F amoebic liver abscess later becomes better defined with posterior enhancement and a thick reflective wall?
True
43
T/F amoebic liver abscess may be simple or multi-loculated and single or multiple?
True
44
Amoebic or pyogenic abscesses are likely to be homogenous or heterogenous?
Homogenous
45
Pyogenic or fungal abscesses are likely to be homogenous or heterogenous?
Heterogenous
46
Describe CT findings of amoebic abscess?
- low attenuation lesions causing mass effect.
- peripheral wall enhancement
- Simple or multi-loculated with modularity of the wall
47
T/F Amoebic abscesses may contain gas?
F- pyogenic abscesses do!
48
Describe 2 CT signs specific to pyogenic abscesses?
1. Double target sign: wall enhances with surrounding low attenuation zone caused by oedematous liver tissue
2. Cluster sign: several abscesses cluster together looking as if they may coalesce
49
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
50
Nuc med findings of liver abscess?
- uptake of sulphur colloid on Tc99m and WBCs
51
T/F Gallium is taken up by both pyogenic and amoebic liver abscesses?
False just by pyogenic abscesses
52
What is the commonest benign liver lesion?
- haemangioma (70-80% of all liver lesions)
53
T/F Haemangiomas are usually peripheral and single in 50% of cases
F- single in 90%
54
T/F haemangiomas are associated with FNH and Osler Weber Rendu?
True
55
How may haemangiomas present?
- incidental
- spontaneous haemorrhage
- Kasabach Merritt syndrome: haemangioma plus thrombocytopaenia
56
T/F haemangiomas usually
True
57
What does haemangioma produce when greater than 4cm?
Giant cavernous haemangioma
58
Haemangiomas- where does their blood supply come from?
Hepatic artery
59
Hepatic haemangiomas- X-ray features?
Calcifications
60
Hepatic haemangiomas- US features?
Variable
- majority are hyperechoic but may be hypoechoic
- may show acoustic enhancement
- NO flow on colour Doppler?
61
T/F Hepatic haemangiomas- may show acoustic enhancement?
T
62
T/F Hepatic haemangiomas- arterial flow on Doppler?
False- NO flow
63
Hepatic haemangiomas- CT findings?
- well- circumscribed, low attenuation
- peripheral nodular enhancement that fills in over time on delayed images
- enhance immediately
64
Hepatic haemangiomas- MRI findings?
- well-defined
- T1- Low signal
- T2- high signal
- central fibrous scar
- peripheral nodular enhancement that progresses centripetally with central uniform enhancement taking approx 15mins
65
What is the 2nd most common benign liver lesion?
FNH
66
FNH- peak age?
30-50, F>M
67
T/F FNH is associated with hepatic haemangiomas?
True
68
T/F FNH more common in left lobe?
False- right lobe
69
T/F FNH usually
True
70
T/F FNH- Encapsulated and sometimes pedunculated?
False - non-encapsulated and sometimes pedunculated
71
T/F FNH is a central scar that contains an AVM?
True
72
T/F FNH relatively avascular?
F- very vascular
73
T/F FNH contains Kuppfer cells?
True
74
T/F FNH usually calcified?
False- no calcifications
75
FNH US features?
- hyperechoic lesion showing a homogenous mass.
| - displaces vessels around it
76
T/F - FNH US- Hyperechoic, a central hypo echoic scar seen in 90% of cases?
False- FNH US- Hyperechoic, a central hypo echoic scar seen in 15- 20% of cases
77
FNH Doppler features?
- enlarged vessels within the lesion with a central artery and large peripheral draining vein.
78
FNH- CT findings?
- ill-defined low attenuation mass
79
FNH- CT findings post contrast?
- transient high signal in the portal-venous phase that leaches away in equilibrium.
80
FNH- spoke wheel pattern with central scar seen in what % of cases?
20-30%
| Central scar seen on delayed images
81
FNH MRI findings?
T1- isointense with well-defined central hypo intense scar
T2- isointense with hyper intense central scar in 75% of cases
Post-gad- intense arterial enhancement that becomes less intense, central scar enhances early
Kuppfer cell-specific agents such as superoxides cause enhancement of the lesion.
82
FNH differential?
- fibrolamellar HCC
- adenoma
- well-differentiated HCC
- giant cavernous haemangioma
- hypervascular metastasis
- intra-hepatic cholangiocarcinoma
83
Hepatocellular adenoma- seen in which patients?
Females on OCP
Men on anabolic steroids
Peak age 20-40
84
T/F Hepatocellular adenoma- most commonly sub capsular, left lobe
most commonly sub capsular, right lobe
85
Hepatocellular adenoma- typically what size?
5-10cm
86
Hepatocellular adenoma- what do they consist of?
Hepatocytes and Kuppfer cells with fat but no portal tracts within it.
Areas of haemorrhage and necrosis within.
87
Hepatocellular adenoma- US features?
- heterogenous, solid
- variable echotexture
- hypoechoic rim due to compression of liver tissue around the tumour
88
Hepatocellular adenoma- CT features?
- well-defined rounded lesion
| - may have hyper dense areas if there has been haemorrhage within
89
T/F Hepatocellular adenoma can't be reliably distinguished from HCC on MRI?
True- areas of haemorrhage of differing ages result in heterogenous lesion with variable appearance on different sequences
90
Hepatocellular adenoma- MRI signal characteristics?
T1- bright
| T2 - isointense
91
Hepatocellular adenoma- nuc med findings?
- photopenic lesion on sulphur colloid scintigraphy surrounded by a rim of increased uptake
- no uptake on gallium scan
92
HCC- peak age?
60-70 years, most com visceral malignancy
93
HCC causes?
```
Wilsons
HH
Alpha 1 AT
Tyrosinosis
Hepatitis
Cirrhosis (from hep B/C 40-50% of cases) C2H5 (
```
94
T/F HCC solitary in 30% of cases?
True
95
T/F HCC multi-focal in 60-70% of cases?
True
96
HCC- diffuse in what % of cases?
5 %
97
HCC invades the portal vein in what % of cases?
50-60%
98
HCC invades the hepatic vein/IVC in what % of cases?
99
HCC- metastasis seen in what % of cases?
70%
100
HCC- what is the commonest lymphatic site for mets?
hepatoduodenal nodes
101
HCC- commonest sites for haematogenous spread?
lungs, adrenal glands, bones
102
HCC- what is the pathological progression?
regen nodule- adenomatous nodule- dysplastic nodule- small HCC
103
HCC US findings?
- variable echogenicity
- bg cirrhosis
- invasion to hepatic or portal veins seen on colour flow
104
HCC CT findings?
- heterogenous enhancing mass with focal necrosis
| - calcification seen in 10%
105
HCC invasion features?
- arterial- portal fistulae
- peri-portal streaks of high attenuation
- dilation of portal vein and branches
- no enhancement of segment of liver that is blocked
106
T/F intrinsic portal vein obstruction is specific to HCC?
True
107
How is portal vein thrombosis differentiated from HCC?
lack of enhancement of the thrombus
108
HCC- MRI features?
- T2- high
- T1- variable, low signal on T1 in 30-40% of cases, high T1 signal in 40-50% of cases, isointense T1 in 10-20%
- diffusion restriction
- avid enhancement post gad
109
T/F high grade dysplasia and small HCCs may show a "nodule in nodule" appearance?
True- esp within sideritic nodules
110
Large HCC- what is the mosaic pattern?
- confluent small nodules separated by thin septa
- best seen on T2Wi
- heterogenous appearance post contrast
111
T/F HCC- tumour capsule present in 20% of cases? Signal of tumour capsule?
F- tumour capsule present in 60-80% of cases. Dark on both T1 and T2 W images
112
HCC- extra capsular extension with satellite nodules seen in what % of cases?
50-70%
113
HCC- what are MRI findings of vascular invasion?
- high on T1
- high on GRE T1
enhancement of tumour thrombus within the vein in arterial phase and filling defect on later phases
114
HCC- nuc med findings?
- sulphur colloid scans- cold spot
| - avid uptake on gallium scan
115
T/F fibrolamellar HCC is a subtype of HCC?
True- no underlying cirrhosis or risk factors for HCC.
116
fibrolamellar HCC- peak age?
30-40
117
T/F fibrolamellar HCC- usually a solitary lobulated lesion with a central scar?
true
118
T/F fibrolamellar HCC- encapsulated with a pseudo capsule of compressed hepatic tissue?
true
119
T/F fibrolamellar HCC- central amorphous calcification seen in 30-40%?
True
120
Fibrolamellar HCC- regional lymphadenopathy is seen in what %? and what is the commonest site?
50-60%, porta hepatis
121
T/F fibrolamellar HCC- distant mets are uncommon and prognosis is good?
True
122
Fibrolamellar HCC- US findings?
- heterogenous, predominantly hyper echoic central scar.
123
Fibrolamellar HCC- CT findings?
- lobulated mass
- enhancing mass with central non-enhancing scar
- pseudocapsule
124
Fibrolamellar HCC- MRI findings?
```
T1- dark
T2- bright
Scar dark on T1 and T2Wi
Heterogenous enhancement but no enhancement of the scar
Not known to cause vasc invasion
```
125
Fatty liver CT findings?
- Areas of low attenuation with HU 10
- reversed liver-spleen density
- Hyperdense intra-hepatic vessels
- focal fatty infiltration has no mass effect
126
Fatty liver MRI findings?
- T1- high
- T2- dark
- in and out of phase: dark on out of phase images
127
T/F Liver mets- most common malignant liver lesion?
True usually from colon, pancreas, breast or lung
128
Liver mets- both lobes involved in what % of cases?
75%
129
Liver mets- lesions solitary in what percent?
10%
130
Liver mets- US features?
- distort anatomy
| - variable echogenicity
131
Echogenic liver mets are usually of what origin?
GiT or GuT
132
Liver mets do not dem Doppler flow except ...?
Carcinoid
133
Liver mets- CT features?
- Pre-dom low attenuation
| - May demo peripheral ring enhancement
134
How can cystic liver mets be differentiated from benign liver cysts?
- mural nodule
- fluid-fluid levels
- septations
135
Name 4 exclusion criteria for resection of liver mets?
1. Advanced stage of primary tumour
2. > 4 mets
3. Extra-hepatic mets
4.
136
5 causes of calcified liver mets?
```
Colon
Renal
Ovarian
Malignant melanoma
Gastric
```
137
5 causes of hyper vascular liver mets?
```
Carcinoid
Renal
Thyroid
Melanoma
Pancreatic islet cell tumours
```
138
5 causes of haemorrhagic liver mets?
```
Colon
choriocarcinoma
Breast
Thyroid
Melanoma
```
139
What causes Budd Chiari syndrome?
- occlusion of the venous outflow of the liver: occlusion of the hepatic vein or IVC.
- most often idiopathic
140
Thrombotic obstruction- What is Virchow's triad and what are the 5 Ps?
Virchow
- problem with blood FLOW
- problem with blood CONSTITUENTS
- problem with vessel WALL
Ps
- Pregnancy
- Pill
- Polycythemia rubra vera
- Platelets (excess or abnormal)
- PNH
141
4 causes of non-thrombotic obstruction?
Right heart failure
Constrictive pericarditis
Right atrial tumour
IVC membranes
142
Budd Chiari- US features?
- hepatomegaly
- caudate hypertrophy
- GB wall thickening
- Obliteration of the hepatic vein +/or IVC
- Portal vein enlargement and change in flow dynamics
- Portosystemic anastomoses
- Prominence of the azygos and hemi-azygos systems
143
Budd Chiari- Doppler features?
- absence/reversal of flow in the hepatic veins with dampening of the IVC waveform
- hepatic artery resistive index > 0.7
144
Budd Chiari- CT features?
- Hepatomegaly and ascites
- non-homogenous liver enhancement with central area of enhancement and delayed enhancement of the periphery which may demo low attenuation
- enlarged caudate lobe which enhances floridly
- poor identification of the hepatic veins
145
Budd Chiari- MRI features?
- peripheral liver: low signal on T1 and bright signal on T2
- non-homogenous liver parenchyma
- variable gad enhancement
- comma-shaped intra-hepatic varicose caused by intra-hepatic collateral vessels and characteristically seen on coronal images
- reduction in calibre or absence of the hepatic veins/IVC
146
Budd chiari- differential diagnosis?
- cirrhosis
- hepatic veno-occlusive disease
- right heart failure
147
What causes hepatic veno-occlusive disease?
- radiation or chemotherapy in transplant patients
148
MRi features of hepatic veno-occlusive disease?
- occlusion of the small centre-lobular venues without major hepatic vein thrombosis.
149
US features of hepatic veno-occlusive disease?
- bi-directional flow in the portal vein without evidence of hepatic vein or IVC obstruction
- GB wall thickening
150
Portal vein thrombosis- occurs in what % of cases of HCC?
30%
151
Portal vein thrombosis- occurs in what % of cases of cirrhosis?
5-10%
152
9 causes of portal vein thrombosis?
1. Idiopathic in neonates
2. Malignancy: HCC, cholangiocarcinoma, pancreatic carcinoma, liver mets.
3. Hypercoagulable states
4. Trauma eg iatrogenic following introduction of umbilical vein catheter
5. intra-peritoneal inflammation
6. Umbilical sepsis
7. Pancreatitis
8. Peritonitis
9. Ascending cholangitis
153
Portal vein thrombosis- US features?
- acute phase: echogenic material within the portal vein
- increased PV diameter
- thickened lesser omentum in acute phase
154
Portal vein thrombosis- CT features?
- low attenuation thrombus in the portal vein on PV phase
- decrease in attenuation of the liver
- chronic- multiple peripheral collaterals may be seen
155
Portal vein thrombosis- MRI features?
- GRE flow voids in the portal vein
- first 5 weeks, thrombus demonstrates high T1 and T2 signal
- then high T2 signal
156
What is peliosis hepatis?
- benign
- dilation of sinusoidal blood-filled spaces and within the blood-filled spaces of the organs of the reticule-endothelial system- liver, spleen, bone marrow, lymph nodes and lungs
157
What causes peliosis hepatic? x 5
1. AIDS
2. Chronic infection eg TB
3. Anabolic steroids
4. Chronic renal failure
5. Tamoxifen
158
Peliosis hepatis- US features?
Multiple echogenic or hypo echoic areas
159
peliosis hepatis- CT features?
- enhancing round lesions within the organs
- lesions are initially hypo-attenuating but become iso-attenuating with time
Cold on PETCT
