Artifacts, anatomical and physiological variants, and unrelated diseases that might cause false-positive whole-body 131-I scans in patients with thyroid cancer.
The whole body 131-I scan remains an important component in the postoperative treatment of patients with well-differentiated thyroid cancer. Because normal thyroid tissue remnants and residual or metastatic foci of well-differentiated thyroid cancer have the unique ability to concentrate, organify, and store 131-I, the whole body scan provides a depiction of those tissues that can be ablated with therapeutic doses of 131-I. Over time, it has become obvious that the whole body scan may also reveal foci of 131-i uptake owing to a wide variety of other causes. We provide a detailed pathophysiological classification of the artifacts, anatomic and physiological variants, and nonthyroidal diseases that may give rise to false-positive whole body scans in postoperative patients with thyroid cancer. These include ectopic foci of normal thyroid tissue; nonthyroidal physiological sites (eg, choroid plexus, salivary glands, gastric mucosa, urinary tract); contamination by physiological sections; ectopic gastric mucosa; other gastrointestinal abnormalities; urinary tract abnormalities; mammary abnormalities; serous cavities and cysts; inflammation and infection; nonthyroidal neoplasms; and currently unexplained causes. This article also provides a detailed review of the widely scattered English language literature in which these phenomena were originally described.
Shapiro
B
B
University of Michigan, Department of Veterans' Affairs Health Systems, Department of Internal Medicine, Ann Arbor 48109-0028, USA.
Rufini
V
V
Jarwan
A
A
Geatti
O
O
Kearfott
K J
KJ
Fig
L M
LM
Kirkwood
I D
ID
Gross
M D
MD
D016477:Artifacts; D002828:Choristoma / Q000000981:diagnostic imaging; D005189:False Positive Reactions; D005753:Gastric Mucosa / Q000000981:diagnostic imaging; D006801:Humans; D007457:Iodine Radioisotopes; D011877:Radionuclide Imaging; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery
D007457:Iodine Radioisotopes