title: Artifacts, anatomical and physiological variants, and unrelated diseases that might cause false-positive whole-body 131-I scans in patients with thyroid cancer.
abstract: 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.
authors.affiliation: University of Michigan, Department of Veterans' Affairs Health Systems, Department of Internal Medicine, Ann Arbor 48109-0028, USA.
authors.forename: B
authors.initials: B
authors.lastname: Shapiro
authors.forename: V
authors.initials: V
authors.lastname: Rufini
authors.forename: A
authors.initials: A
authors.lastname: Jarwan
authors.forename: O
authors.initials: O
authors.lastname: Geatti
authors.forename: K J
authors.initials: KJ
authors.lastname: Kearfott
authors.forename: L M
authors.initials: LM
authors.lastname: Fig
authors.forename: I D
authors.initials: ID
authors.lastname: Kirkwood
authors.forename: M D
authors.initials: MD
authors.lastname: Gross
mesh_terms: 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
chemical_list: D007457:Iodine Radioisotopes