Hepatobiliary Flashcards
Name of system that divides liver into multiple functional segments
Couinaud System
Cantile’s Line
Divides liver into functional left and right lobes. From IVC to middle of gallbladder fossa
MC vascular variant in the liver
Replaced right hepatic artery (from SMA)
MC biliary variant
Right posterior segmental into left hepatic duct
Bare areas of liver
1) bare area-superopst
2) gb fossa
3) porta hepatitis
What is result of injury to bare area
RP bleed
Light bulb sign
hemangioma
target sign
echogenic center surrounded by hypoechoic rim
reverse target sign
hypoechoic core with hyperechoic rim
double target sign
hypo center with surrounding vascular rim following by surrounding edema
- which is silly bc a “target’ sign is hyperecho center with hypo ring.
- aka abscess (pyogenic or amebic)
organism of amebiasis
entamoeba histolytica
ddx amebic abscess
- post treatment met
- pyogenic abscess
- infarct
- hydatid cyst
- biliary cystadenocarcindoma
organism of hydatid cysts
Echinococcus granulosus=MC. Echinogoccus multilocularis (alveolar)-less common but aggressive, tumor-like form.
-definitive host=dog/feox. Intermediate host=human, sheep or wild rodents.
MC causes pyogenic abscess
Klebsiella, E. Coli (multiple), SA
MC causes fungal abscess
Candida (MC), cyrptococcus, aspergillus
Amebiasis-mc locations
99% GI tract. Liver 2nd MC. Then peritoneum, pleural space, lung, pericardium, skin, brain.
When do you get maximum signal drop out on chemical shift?
50% fat, 50% water
Spared organs 1˚ vs 2˚ hemochromatosis
Primary-involves Pancreas, spleen spared (vice versa 2˚)
Von Meyenburg complex
numerous biliary hamartomas, uniform size (<15 mm)
flip flop pattern
classic acute BC imaging finding on PV phase: low attenuation centrally, high peripherally
Who gets nutmeg liver
- budd chiari
- hepatic veno-occlusive disease
- right hear failure
- constrictive pericarditis
Who gets massive caudate lobe hypertrophy?
- budd chiari
- primary sclerosis cholangitis
- primary biliary cirrhosis
cryptogenic cirrhosis
unknown cause of cirrhosis. MC nonEtOH fatty liver disease
MC reasons for liver tx
- hep C (MC)
- EtOH liver disease
- cryptogenic cirrhosis
Difference in liver transplant btw adults and kids
- adults-right lobe implanted
- kids-left lobe (little=left)
Liver transplant contraindications
- extrahepatic malignancy
- advanced cardiopulmonary disease
- active substance abuse
- PVT not a true CI but makes sx more difficult
MCC cirrhosis world-wide
Schistosomiasis
organism of schistosomiasis
Schisotoma (parasite)
“tortus shell/turtle back”
periportal fibrosis with septal and capsular calcification pathognomonic for schistosomiasis fibrosis
right posterior hepatic notch sign
focal indentation of the posteroinferior surface of the right lobe of the liver at the level of the right kidney secondary to enlargement of caudate lobe and atrophy of right lobe
caudate/right hepatic lobe ratio
> 0.75
Which lobe is more common in hepatic abscesses and why?
Right (75%) via longer right power vein (ascending hematogenous sources)
Definition of cirrhosis by pressure. When does variceal bleeding & ascites occur?
PV > HV by 6-8 mmHg. Varices + ascites at >12mmHg
What’s particular about collateral formation in pre-hepatic cirrhosis?
ABOVE diaphragm and in hepatogastric lig (to bypass obstruction)
What happens to hepatic artery in cirrhosis?
Increased velocity
Causes of THAD
-cirrhosis (pressure on vein first), clot, mass (dir ME or recruitment), abscess/infection (cholecystitis) (ME or “siphon effect”-hyperemia)
“central peripheral” phenomenon
-increased arterial response at periphery/subcapsular liver due to (portal?) venous fibrosis/decrease bf
why does PV reverse flow in cirrhosis (Rather than just clotting off?)
hepatic artery “parasitizing portosystemic decompression apparatus”
Portal hypertensive colopathy-why more common on right?
Colonic venous backup/stasis. More shunts on left. Resolves after tx
portal hypertensive gastropathy
-thickened wall AND UGI bleed IN ABSENCE OF VARICES
“nodule within nodule”
central bright T2 nodule has T2 dark border, concerning for transformation of regenerative nodule –> HCC
OATP-changes in HCC and exception?
Bile uptake transporter that decreases in HCC -HCC is hypoenhancing on delayed sequences.
*exception: well differentiated HCC retains OATP function
liver phase timing and window
- LATE arterial (20-30 s)
- PV (60-80s)
- hepatic venous-90 s if extra cell agent. 20 mins if biliary (45-3 hrs if Gd-BOPTA/multihance)
- window: C= 100, W=200
What is unique about hemangioma during US scanning?
Can change sonographic appearance during course of sing exam
Caveat of biopsying hemangioma?
must core (FNA doesn’t get enough tissue, only blood)
biopsy trivia for FNH
must hit scar (otherwise, results as normal hepatocytes)
multiple adenomas
- glycogen storage diseases (von Gierke)
- adenomatosis
FNH vs FL HCC CENTRAL SCARS
- FL HCC- T2 dark, central scar doesn’t enhance, gallium avid
- FNH- T2 iso-hyper, central scar enhances on delays, sulfur colloid avid
what chemotherapy agent can cause FNH
oxaliplatin (cry for bowel cancer)
Portal v involvement of HCC vs CholangioCA
- HCC invades
- Cholangio encases
RFs cholangioCA
- PSC-MC in West
- recurrent pyogenic oriental cholangitis-MC in East
- Caroli
- hepatitis, HIV, cholangitis, Clonorchis
- Thorotrast
THIS vs THAT- HCC vs cholangioCA
-cholangioCA-encases PV, delayed enhancement, no capsule, capsular retraction, biliary dil
surgical candidacy for cholangioCA
-worse if: proximal, vascular (atrophied lobe), bilateral
RFs hepatic angiosarcoma
-arsenic ~25 yrs latency
-thorotrast
-polyvinyl chloride
radiation
-hemochromatosis
-NF1
imaging of angiosarcoma
aggressive vascular malignancy, most often MF + splenic involvement
Hepatic lymphoma
hypoechoic masses
ultrasound of hepatic metastases
- hypervasc=hyperechoic (renal, melanoma, carcinoid, chorioCA
- hypovasc= hypoechoic (colo, lung, pancreas). MC.
- “target sign”-echogenic center with hypo echo rim
Hepatic kapose sarcoma
AIDS. periportal hypoechoic infiltration that looks similar to bd dil.
Hemangioma at US
- no doppler (slow flow)
- can change throughout course of exam
- hyperechoic. Atypically, “reverse target”
incidental liver lesions-size cut off for determine next step
1 cm
distance cut-off for portal venous gas
within 2 cm liver capsule
MCC jaundice
benign stricter
buzzword: central regenerative hypertrophy
cirrhotic pattern of PSC
buzzword: withered tree
PSC appearance on MRI with abrupt narrowing of branches
buzzword: beaded appearance
PSC strictures & focal dilations
aids cholangiopathy-what is it, classic orgm and classic association/finding?
- infection of biliary epithelium, ID app to PSC
- Cryptosporidium
- papillary stenosis
this vs that: aids cholangiopathy vs PSC
AIDs: long segment extra hepatic strictures >2cm, no saccular deformities, papillary stenosis
“straight rigid intrahepatic ducts”
recurrent pyogenic cholangitis, aka oriental cholangitis
Recurrent pyogenic cholangitis
- recurrent pyogenic choangitis MC in SE asia
- imaging-dilated ducts (central predominant) full of pigmented stones
- L > R (via longer flatter left biliary system.)
Which side is “recurrent pyogenic cholangitis” dominant and why?
Left, long/flatter biliary system
post transplant recurrence of PSC
20%
antimitochondiral ab’s (AMA)
primary biliary cirrhosis
Long common channel. Associated with which type of choledococyst?
- CBD and PD unite prematurely prior to sphincter of Oddi.
- Incr risk pancreatitis.
- associated with type I choledococysts
MC type of choledococyst?
Type 1
What is Caroli dx associated with?
PKD, medullary sponge kidney, cholangioCA, recurrent cholangitis (2/2 stones), cirrhosis
central dot sign
PV sure by dilated duct
duct of luschka
accessory cystic duct
mirizzi syndrome
duct in CD obstruction CHD
- co-incidence of GB CA 5x incr
- occ more commonly in people with low cystic duct insertion (normal variant)-more parallel course and pros to chd
> 50% stenosis of renal artery- acceleration time and index cutoffs
- > 0.07 s
- 3 m/s
direct and indirect signs stenosis
- direct: (+) PSV, spectral broadening
- indirect: tardes parvus, with time to peak (systolic acceleration) > 70ms. RI <0.5 (orgn starved for blood)
gallbladder polyp mx
< 6 mm: No follow-up
7-9 mm: Yearly US follow-up to monitor size
> 10 mm: Surgical consult
causes of hepatic retraction
- hepatic epithelioid hemangioendothelioma
- mets
- intrahepatic cholangioCA
ct evaluation of cirrhosis
- widened hepatic fissures
- segmental atrophy/HTr
- sg’s of portal HTN
- hepatic surface nodularity (least reliable)