Hepatobiliary Scintigraphy in Acute Cholecystitis
Mark Tulchinsky, MD,* Patrick M. Colletti, MD,
†
and Thomas W. Allen, MD*
Hepatobiliary scintigraphy is a mature imaging technique for evaluation of patients with
acute cholecystitis (AC). It is effective in calculous and acalculous forms of AC. The test is
used in contemporary medical practice as the arbiter when the findings from screening
abdominal ultrasound do not fit a clinical picture. It is also performed in severely ill patients
who have AC suspected on other testing, but whose frail condition and high operative risk
demand the highest level of certainty. This review, therefore, examines all technique
variations of hepatobiliary scintigraphy, offering an approach that may best fit a variety of
clinical situations and philosophies on AC.
Semin Nucl Med 42:84-100 © 2012 Elsevier Inc. All rights reserved.
T
he first clinical trials of hepatobiliary scintigraphy
(HBS) in the diagnosis of acute cholecystitis (AC) were
conducted by Eikman et al at Johns Hopkins
1
and, inde-
pendently, by Ronai et al at the Institute of Medical and
Veterinary Sciences in South Australia.
2
These landmark
contributions ignited a rapid evolution of radiopharma-
ceuticals used for HBS and their subsequent prompt
incorporation into clinical practice. Ultimately, 2 radiophar-
maceuticals with superior characteristics emerged—
99m
Tc-
disofenin (TDF) and
99m
Tc-mebrofenin (TMF). The latter is
the most liver-specific agent, which was developed at Squibb
Institute for Medical Research by Adrian D. Nunn who re-
ported initial results at the Society of Nuclear Medicine an-
nual meeting in 1981 with a subsequent comprehensive re-
port published in 1983.
3
TMF’s key advantage is its high liver
clearance, as 98% is eliminated by normal liver in 24 hours
and only 2% eliminated by the kidneys.
4
TDF is less liver
specific (88% hepatic elimination), but this difference is not
clinically significant for patients with normal hepatic func-
tion who are being evaluated for AC. However, this difference
becomes important in patients with elevated bilirubin levels
secondary to hepatocellular dysfunction, which affects TMF
significantly less than TDF and that variance expands with
increasing bilirubin level. Given the higher hepatic specificity
of TMF and the small cost difference between the 2 agents,
TMF is the radiotracer of choice for HBS.
Opinion on which test should be done first, second, or at
all in AC must not be based entirely on the test’s diagnostic
accuracy, but instead should be grounded in comprehensive
appreciation of the clinical background and management
challenges in AC. For those who believe that best outcome in
AC is afforded by a prompt laparoscopic cholecystectomy
(LC),
5-7
the most sensitive and expeditious test would be the
most desirable one. In contrast, for those who believe in
effectiveness of conservative treatment in AC,
8
the most spe-
cific test may be more helpful, even if it takes longer to con-
duct than a less specific alternative. Radiation exposure and
test cost are also important considerations that should be
balanced against the possible benefits. This framework along
with the constraints and philosophy of one’s individual prac-
tice setting must be critically considered to perform optimal
diagnostic evaluation of patients with suspected AC.
Definition of Terms and
Pathophysiology of Cholecystitis
AC is an acute inflammation of the gallbladder (GB). Acute
calculous cholecystitis (ACC) is a complication of cholelithi-
asis and represents more than 90% of all AC cases.
9
Hence,
the terms ACC and AC are often used interchangeably. In
fact, most clinical and imaging studies of AC do not report the
breakdown of ACC versus acute acalculous cholecystitis
(AAC). The only pathological difference between the 2 is the
absence of cholelithiasis in the latter. The triggering event
(condicio sine qua non) in ACC is a stone impaction occurring
in the Hartmann’s pouch, the GB neck, or the cystic duct
causing obstruction to the bile outflow and/or the inflow—
biliary stasis. It is important to keep in mind that it is often
unknown whether obstruction is complete versus partial—
functioning as an absolute bidirectional block versus a one-
*Division of Nuclear Medicine, Department of Radiology, Milton S. Hershey
Medical Center, Pennsylvania State University, Hershey, PA.
†Division of Nuclear Medicine, Department of Radiology, Keck School of
Medicine, University of Southern California, Los Angeles, CA.
Address reprint requests to Mark Tulchinsky, MD, Division of Nuclear Med-
icine, Department of Radiology, Milton S. Hershey Medical Center,
Pennsylvania State University, M.C. H066, 500 University Drive, Her-
shey, PA 17033. E-mail: mtulchin@psu.edu
84
0001-2998/12/$-see front matter © 2012 Elsevier Inc. All rights reserved.
doi:10.1053/j.semnuclmed.2011.10.005