title: An Unusual False-Positive Uptake of Radioiodine in Pericardial Effusion on Posttherapy Scan.
abstract: Posttherapy scan in a 21-year-old woman with papillary carcinoma of thyroid with lymph node metastasis, who received 5.55 GBq of radioiodine (I), revealed halo-like diffuse tracer uptake in the pericardial region. Echocardiography showed no abnormality except pericardial effusion, which subsided after reinstitution of levothyroxine therapy. Although rare, false-positive radioiodine uptake can occur in pericardial effusion secondary to thyroxine withdrawal-related hypothyroidism and needs close monitoring of the patient.
authors.affiliation: From the Radiation Medicine Centre, Bhabha Atomic Research Centre, Mumbai, India.
authors.forename: Gaurav
authors.initials: G
authors.lastname: Malhotra
authors.forename: Surendra H
authors.initials: SH
authors.lastname: Moghe
authors.forename: Rohit
authors.initials: R
authors.lastname: Ranade
authors.forename: R Ramesh V
authors.initials: RR
authors.lastname: Asopa
mesh_terms: D002291:Carcinoma, Papillary / Q000000981:diagnostic imaging / Q000378:metabolism; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000150:complications; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics*; D010490:Pericardial Effusion / Q000000981:diagnostic imaging* / Q000378:metabolism; D011877:Radionuclide Imaging / Q000379:methods; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging; D055815:Young Adult
chemical_list: D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals