Pertechnetate thyroid uptake is not always suppressed in patients with subacute thyroiditis

Clin Nucl Med. 1997 Feb;22(2):109-14. doi: 10.1097/00003072-199702000-00008.


The authors studied the clinical courses and immunologic aspects in 15 patients (age range, 32-69 years old; 14 women) with clinical features that were similar to subacute thyroiditis (SAT). In 2 patients (group A) whose thyrotropin-binding inhibitory immunoglobulins (TBII) and thyroid stimulating antibody (TSAb) showed strongly positive activity at the initial visit, Tc-99m pertechnetate thyroid uptake (Tc-99m uptake) was elevated (5.6% and 3.8%, respectively, normal; 0.7-3.0%). In 6 (group B) of 13 other patients, Tc-99m uptake was not completely suppressed (2 normal, 4 near normal) and imaging showed uptake in one lobe. In 7 (group C), however, there was no evidence of uptake in either lobe. Inflammatory process was localized in one lobe in all group B patients, and was in both lobes in all group C patients but one. Serum TSH levels were detectable in at least 4 patients (2 group B, 2 group C) low in all. There were no patients in both groups B and C in whom TBII and/or TSAb were detected at the initial visit. In SAT, marked suppression of Tc-99m uptake may be ascribed mainly to inflammatory follicular cell damage, but it is not always suppressed, owing to an association similar to Graves' disease and other unknown mechanism(s).

MeSH terms

  • Adult
  • Aged
  • Autoantibodies / blood
  • Female
  • Graves Disease / diagnostic imaging
  • Humans
  • Immunoglobulins, Thyroid-Stimulating / blood
  • Male
  • Middle Aged
  • Radionuclide Imaging
  • Radiopharmaceuticals* / pharmacokinetics
  • Receptors, Thyrotropin / blood
  • Sodium Pertechnetate Tc 99m* / pharmacokinetics
  • Thyroid Gland / diagnostic imaging*
  • Thyroid Gland / immunology
  • Thyroid Gland / metabolism
  • Thyroiditis, Subacute / diagnostic imaging*
  • Thyroiditis, Subacute / immunology
  • Thyroiditis, Subacute / metabolism
  • Thyrotoxicosis / diagnostic imaging
  • Thyrotoxicosis / immunology
  • Thyrotoxicosis / metabolism
  • Thyrotropin / blood


  • Autoantibodies
  • Immunoglobulins, Thyroid-Stimulating
  • Radiopharmaceuticals
  • Receptors, Thyrotropin
  • thyrotropin-binding inhibitory immunoglobulin
  • Thyrotropin
  • Sodium Pertechnetate Tc 99m