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HISTORY:
The patient is a 31 year old white female who presented with right
upper quadrant and epigastric pain. She had several days of persistent
pain from right breast to her right side. She initially presented to
the emergency department experiencing nausea and nonbilious vomiting.
At that time the vomiting had ceased but the pain had increased. She
received an ultrasound which showed a normal gallbladder with no
stones, no wall thickening, normal anatomy and normal pancreas. She
also received a chest/abdomen CT which was negative. She returned
following another episode of vomiting and was referred to a
specialist. She has a history of asthma, gastric ulcer and is
borderline diabetic. Her past surgical history includes an
appendectomy and tubal ligation. She is allergic to demerol and sulfa
medications.
Physical Examination:
Vital signs – temperature 97, blood pressure 98/40, pulse 52,
respiration 20.
GI – unable to eat due to pain exacerbation in epigastric region.
Hospital Course:
The patient was admitted for IV fluids. All laboratory values were
within normal limits.
Technique:
A hepatobiliary study was performed with 6 mCi Tc99m Mebrofenin.
Dynamic images of upper abdomen for one hour, homogeneous distribution
of gallbladder was seen at 19 minutes, at 60 minutes a physiologic
dose of CCK, which showed an ejection fraction of 13 % (normal > 35%).
The study showed patent cystic and common bile ducts, chronic
cholecystitis could not be excluded. The study shows the uptake of
tracer in the liver, then the gallbladder begins to fill, and then the
small intestine is seen. If there was an obstruction, then this
sequence would have been altered.
| Gallbladder
Results Ejection Fraction (%) =
12.7
Ejection Period = 17.0 min
Latent Period = 11.0 min
Ejection Rate = 0.7 %/min |
Normal Values
(>35%)
(8-12 min)
(<3.0 min)
(>3.5 %/min) |
 |
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- CCK Infused 2.0 ng/kg/min
- Duration of Infusion = 10 minutes
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From the Literature:
Chronic acalculous (without stones) cholecystitis
(CAC) occurs in 10% of patients with symptomatic chronic
cholecystitis. Before CCK cholescintigraphy, physicians did not
have an objective test to preoperatively confirm their suspicion of
CAC. During the initial clinical trials of gallbladder ejection
fraction (GBEF) studies, there was a greater than 90% chance that if
the ejection fraction was low, then the patient had CAC. However, the
participants in the trials were carefully screend and many other
disease states were ruled out before they had an ejection fraction
study preformed. The ejection fraction studies were performed to
confirm the physician’s diagnosis.
As this tool became more popular, the patients
having ejection fraction studies were not as likely to have been as
extensively diagnosed as the patient pool used in the clinical trials.
Because of the differences in the two patient groups, the use of GBEF
has lost its role as a confirmation tool, and become a tool for
diagnosis. In the trial group, the patients had a high pretest
likelihood for CAC. The patients currently referred in practice today
do not have the same likelihood for CAC. The main reason is that there
are many other conditions that can cause a low GBEF such as diabetes,
irritable bowel syndrome and pregnancy. There are also many
medications that can cause the same problem, such as morphine or
nifedipine. In the clinical trials, the underlying problems were ruled
out as the cause of GBEF, whereas in the new group these conditions
may not always be addressed.
Another possible cause of false-positives is the
rate that the Cholecystokinin (CCK) is administered. A dose that is
given as a 0.2 ug/kg dose over 60 sec may elicit a low ejection
fraction, < 35%. However, if the same dose is given to the same
patient at a rate over 45 minutes the GBEF is greatly increased, up to
96%. This information suggests that more attention should be paid to
the patient’s medical history, before a GBEF study is ordered. Another
important fact to consider is the delivery rate of the CCK, when
performing this type of study (1).
Summary:
We have a 31 year old female presented with right upper quadrant pain,
nausea and vomiting. A Tc-99m Mebrofenin study was preformed to detect
acalculous cholecystitis or biliary dyskinesia. It was determined that
the patient did not have an obstruction, although she did have a low
gallbladder ejection fraction. The patient's low GBEF may be due to
CAC or her past history of peptic ulcer disease and diabetes. It was
determined that the patient had a recurrence of her peptic ulcer
disease. She was treated for Helicobacter pylori infection, and was
discharged.
1. HA Zeissman Cholecystokinin cholescintigraphy: victim of its own
success?
J. Nucl. Med. 1999 40: 2038-2042.
© 2004 Nuclear Education Online
- Case submitted by Britt Young,
PharmD candidate at the University of Arkansas College of Pharmacy.
Images courtesy of UAMS Dept of Nuclear Medicine.
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