Physiological Uptake of 131I in Gallbladder
Female patient, 44 year old. With diagnosis of thyroid papillary cancer treated with total thyroidectomy and referred to Nuclear Medicine for 100 mCi of radioiodine. TSH previous to dose of I131 was 79.5 uUI/L.
Whole body scan at the left hand side (131 I): shows evidence of a focal zone of uptake in neck midline. Also intense, ovoid mass with well defined borders on right upper abdominal quadrant (large arrows). In the rest of the body there was expected activity of the radiotracer in oronasal region, gastrointestinal tract.
131 I-Na Spect-CT with markers was performed and seen at the right hand side. The fusion images show perfect definition of the gallbladder in both modalities. CT also demonstrated several stones in the gallbladder.
The table above shows tracers including radioiodine that have been reported to physiologically concentrate in the gallbladder (3).
References:
1
Charles W. Sutter. False-positive results of I-131 whole-body scans in patients
with thyroid cancer. Original Research Article Seminars in Nuclear
Medicine, Volume 25, Issue 3, July 1995, Pages 279-282.
2 Shapiro B. Artifacts, anatomical and physiological variants, and
unrelated diseases that might cause false-positive whole-body 131-I scans in
patients with thyroid cancer. Semin Nucl Med. 2000 Apr;30(2):115-32.
3 Ryan
D. Niederkohr and I. Ross McDougall. Incidental Gallbladder Visualization on
Nonhepatobiliary Nuclear Medicine Studies Case Series and Review of the
Literature. Clin Nucl Med 2007;32: 915–919.