Hepatobiliary Imaging Flashcards
purpose
trace formation and flow of bile from liver to small intestine
indications
- RUQ pain
- cholecystitis
- biliary obstruction
- gallbladder function (GBEF)
- biliary leakage
- biliary atresia vs. neonatal hepatitis
what causes gallbladder to contract?
fat as it stimulates the release of CCK
what does bilirubin indicate?
decrease in liver function
and/or
indication for CBD blockage
RPs
- Mebrofenin (BRIDA)
- Disofenion (DISIDA)
trade name for BRIDA
Choletec
trade name for DISIDA
Hepatolite
which RP is least affected by hyperbilirubinemia?
BRIDA/Mebrofenin
prep
- NPO min 4H but eaten within last 24H
- no opiates within 6H
if a patient is TPN, what needs to be done?
pre-treat with CCK
dose of RP
111-370 MBq (typically, 185 MBq)
why do we give a higher dose to those with higher levels of bili?
bili competes with the RP for uptake
dose of CCK
0.02 ug/kg administered over 60 mins
common names for CCK
sincalide (kinevac)
when do you inject the RP when using CCK?
30 mins post CCK infusion
FOV
liver in top FOV
normal results
liver, biliary ducts, GB and bowel seen by 60 min and GBEF >50%
normal variant
- reflux of bile
- delayed biliary to bowel transit (bowel not at >60 min)
false positives
- didn’t fast long enough
- fasted more than 24H
- TPN
what does morphine do?
contracts the sphincter of oddi = forces bile back into the GB
what can hepatic insufficiency cause?
it can lead to delayed GB filling due to poor uptake of RP
what does TPN do?
it can cause non-visualization of GB due to no stimulation of contraction
when can you calculate GBEF?
when you see GB, duct and small bowel
what does CCK do?
contracts the GB and relaxes the Sphincter of Oddi
what is an alternative to CCK?
fatty meal
ensure
what is done if small bowel is seen but no GB?
administer morphine
dose of morphine
0.04 mg/kg over 1-3 mins
delayed images when…
when no gb at 60 mins
when no bowel at 60 mins
morphine when…
when no gb at 60 mins
cck when…
when no bowel at 60 mins
normal GBEF
=>38%
formula for GBEF
[(decayed NET pre-CCK - NET post-CCK)/decayed NET pre-CCK] * 100
acute cholecystitis
- no GB after morphine
- delayed imaging up to 4H and still no GB
chronic cholecystitis
- GB after morphine
or… delayed GB visualization between 1H-4H
partial CBD (common bile duct)
- GB but no bowel after 60 mins
high grade CBD obstruction
no GB, biliary ducts or bowel but has prominent liver activity
view good for GB separation
LAO
GB sep from duodenum
rim sign
increased hepatic uptake or uptake beside GB fossa due to inflammation of liver
cystic duct sign
dilation proximal to obstruction that can be misinterpreted as GB
liver scan sign
no biliary tree but good visualization of liver
prep for biliary atresia
- pretreat with phenobarbital 5mg/kg/day for 5 days prior to scan
abnormal biliary atresia
no biliary clearance into bowel by 24H
positives for biliary leaks
progressive increasing pool of RP in area of GB fossa or hepatic hilum
liver parenchyma visualization by ______
5-10 mins
bile ducts and GB visualization by ______
10-20 mins
small intestines visualization by ______
30-60 mins
Which of the following would not be a cause of acute acalculous cholecystitis?
A. Inflammatory debris
B. Cholelithiasis
C. Local edema
D. Inspissated bile
b
key is no stones!
A dilated cystic duct proximal to a site of obstruction can be misinterpreted as the following:
A. False-positive for acute cholecystitis
B. Inflammation in the gallbladder fossa
C. Radiotracer activity in the bowel
D. Gallbladder filling
d
RP dose if bili 2-10 mg/dL
278 MBq
RP dose if bili 10 mg/dL
370 MBq
preferred RP for neonates
BRIDA
during blood flow imaging, what organ(s) are seen during the arterial flow phase?
spleen and kidneys
during blood flow imaging, what organ(s) are seen during the venous flow phase?
liver
what does increased blood flow to the gallbladder fossa indicate?
severe acute cholecystitis
by 60 mins, ductal activity should decreased by …
> 50% of peak activity
adverse reactions to CCK
nausea, vomiting, abdominal pain, urge to defecate
adverse reactions to morphine
resp depression, dizzy, sedation, nausea, vomiting, sweaty, constipation, tolerance, dependence
why do you not admin CCK if no bowels are seen?
because it can indicate obstruction
nm appearance of acute cholecystitis vs. acute acalculous cholecystitis
no visualization of GB
but with acute acalculous = no gallstones in anatomic imaging modalities and sometimes slight slight GB filling?
false positives for acute cholecystitis
- chronic cholecystitis
- partial cystic duct obstruction (rmr cystic duct to common bile duct to duodenum)
- viscous bile
- poor liver function
false negs for acute cholecystitis
- cystic duct sign/nubbin = dilation of cystic duct
- acute acalculous cholecystitis
how can you differentiate between chronic ACALCULOUS cholecystitis and calculous cholecystitis?
GBEF being normal = acalculous
symptoms of biliary duct obstruction
abdominal pain, jaundice, elevated ALP and bilirubin, fever IF infection is present
which pathology describes a congenital dilation of the bile ducts?
choledochal cyst
how does choledochal cysts present in kids?
biliary obstruction, pancreatitis or cholangitis
appearance of non obstructed choledochal cysts
GB filling slower with prolonged retention and then slow clearance
appearance of obstructed choledochal cysts
no filling due to high back pressure
