title: Effective visualization of suppressed thyroid tissue by means of baseline 99mTc-methoxy isobutyl isonitrile in comparison with 99mTc-pertechnetate scintigraphy after TSH stimulation.
abstract: Baseline 99mTc-MIBI thyroid scintigraphy was compared with 99mTc-pertechnetate scintigraphy after TSH stimulation in seven patients with suppressed thyroid tissue due to an autonomously functioning thyroid nodule (AFTN). In all patients the suppressed thyroid tissue was visualized by means of both baseline 99mTc-MIBI and post-TSH 99mTc-pertechnetate scintigraphy, and in some cases the former technique provided better visualization. In one patient presenting a "warm" nodule T3-suppression did not affect the nodular/extranodular uptake ratio of 99mTc-MIBI, whereas the 99mTc-pertechnetate uptake ratio increased significantly. This leads us to hypothesize that the thyroid uptake of 99mTc-MIBI is not related to TSH control, but rather to other mechanisms such as the blood flow. Since exogenous TSH is no longer available, 99mTc-MIBI scintigraphy can be successfully used in the place of repeated 99mTc-pertechnetate scintigraphy after TSH stimulation in the assessment of AFTN.
authors.affiliation: Nuclear Medicine Unit, University of Siena, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Vattimo
authors.forename: P
authors.initials: P
authors.lastname: Bertelli
authors.forename: L
authors.initials: L
authors.lastname: Burroni
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009570:Nitriles; D015609:Organotechnetium Compounds; D011877:Radionuclide Imaging; D013670:Sodium Pertechnetate Tc 99m; D017256:Technetium Tc 99m Sestamibi; D016606:Thyroid Nodule / Q000000981:diagnostic imaging*; D013972:Thyrotropin / Q000008:administration & dosage*
chemical_list: D009570:Nitriles; D015609:Organotechnetium Compounds; D013972:Thyrotropin; D017256:Technetium Tc 99m Sestamibi; D013670:Sodium Pertechnetate Tc 99m