108
duct strictures that simulate primary sclerosing cholan- sectional information similar to CT and ultrasound [6, 7,
8]. After the intravenous administration of mangafodi-
gitis.
Most nonanastomotic strictures are due to ischemia pir, manganese from a DPDP ligand is excreted pri-
unrelated to iatrogenic bile duct injury, and 50% are marily via bile and produces increased signal on
due to hepatic artery thrombosis, the most common gradient-echo sequences [9]. Recent work has shown
vascular complication following liver transplantation. that by using a gradient-echo (GRE) technique, con-
Causes ofhepatic artery thrombosis include long cold
trast-enhanced MR cholangiography produces better
ischemic time, hypercoagulability, and rejection [5]. contrast and spatial resolution than standard MR
After transplantation, the bile ducts are entirely de- cholangiography [7]. In addition, Vitellas et al. showed
pendent on the hepatic artery for perfusion. Therefore, that this technique can be used for detecting bile duct
any deficiency ofhepatic arterial supply places the
leaks [6]. Furthermore, a recent prospective study at our
transplanted liver at risk ofischemia, which can result in institution involving 12 patients with suspected bile duct
fulminant hepatic necrosis, bile duct strictures, bile duct leaks following cholecystectomy demonstrated that
leak, abscess, and sepsis. Other, less common causes of contrast-enhanced MR cholangiography was more ac-
nonanastomotic bile duct strictures in the liver trans- curate than both contrast cholangiography and hepa-
plant, including prolonged preservation time, bacterial tobiliary scintigraphy for detecting bile duct leaks
or viral cholangitis, rejection, recurrent primary sclero- (Vitellas et al., unpublished data). In that study, all bile
sing cholangitis, and cholangiocarcinoma, should also duct leaks were detected between 1 and 2 h following the
be excluded.
The work-up in these patients usually begins with CT
intravenous administration ofmangaof dipir trisodium.
Recently, we have been asked by our transplant
and/or ultrasonography. Both modalities can determine surgeons to perform contrast-enhanced MR cholangi-
the presence offluid collections which would suggest a ography in two liver transplant patients presenting to
bile duct leak or abscess, and biliary dilatation. Doppler the emergency department with suspected leaks follow-
ultrasonography can also detect vascular patency. ing removal ofa T-tube. In both patients, we accurately
However, these cross-sectional studies cannot accurately demonstrated the presence and location ofthe leaks
determine the cause ofobstruction (e.g., stricture, stone) shortly after the admission to the emergency room
or whether a fluid collection represents an active bile duct (Fig. 3). In addition, we have been successful in dem-
leak. Therefore, patients with suspected bile duct ab-
normalities usually undergo hepatobiliary scintigraphy
and/or standard contrast cholangiography (endoscopic
retrograde cholangiography, percutaneous transhepatic
cholangiography). Hepatobiliary scintigraphy is very
sensitive and specific for detecting bile duct leaks, but
usually cannot indicate the location ofthe leak, stric-
tures, or stones. Standard contrast cholangiography is
the gold standard imaging modality for detecting biliary
disease and can accurately detect the presence and loca-
tion ofleaks, strictures, and stones. Although these tests
are accurate, they add cost and risk to the patient, since
they are invasive studies. In addition, many surgeons are
reluctant to perform endoscopic cholangiography in the
first month after transplantation because of friability of
the anastomosis. Ifnonanastomotic bile duct strictures
and/or a bile duct leak are detected by these tests,
Doppler ultrasonography is usually performed to assess
for hepatic artery thrombosis, and conventional arteri-
ography is usually reserved for equivocal cases. There-
fore, it is common for patients with biliary disease after
liver transplantation to undergo a multitude ofdiag-
nostic imaging tests. This can delay diagnosis and treat-
ment in these immunocompromised patients who are
already at an increased risk ofdeveloping inefctious
complications and ofdeath.
Contrast-enhanced MR cholangiography with intra-
Fig. 3. A 48-year-old male 5 months status post liver transplan-
tation presented to the emergency department with abdominal pain
2 days after removal of a T-tube. Axial fat-saturated GRE image
obtained 1 h after intravenous administration of mangafodipir
trisodium demonstrates contrast extravasation from the common
bile duct at the site where the T-tube had been (arrows)
venous mangafodipir trisodium (Amersham Health;
Princeton, New Jersey) is a new technique under inves-
tigation, which can provide functional information in a
similar way to hepatic scintigraphy, anatomic informa-
tion similar to contrast cholangiography, and cross-
Alder
