Tc-99m-tetrofosmin thyroid scan in patients with low I-131 thyroid uptake.
Low 24-hour thyroid uptake of I-131 (I-131 uptake) is a common finding that influences evaluation of the thyroid gland.


METHODS
We studied 20 female patients aged 16-82 years with low I-131 uptake. The following causes of reduced I-131 uptake were defined as (A) six cases with subacute thyroiditis, (B) seven cases with T4 suppression therapy, and (C) seven cases with iodinated pharmaceuticals use. Thirty-minute Tc-99m tetrofosmin thyroid scan was performed within 24 hours of the I-131 thyroid study.


RESULTS
The results were correlated with neck ultrasound, serum TSH and biopsy histopathological findings. Tc-99m tetrofosmin thyroid scans revealed 10 normal thyroids, five diffuse goiters, four multinodular goitres, and one solitary thyroid nodule.


CONCLUSIONS
Our results suggest that Tc-99m tetrofosmin thyroid scans may provide additional information to diagnose thyroid pathology in patients with low 24-hour I-131 uptake.
Wang
Tzu-Yuan
TY
Division of Endocrinology and Metabolism, China Medical College Hospital, Taichung, Taiwan.
Wu
Hurng-Sheng
HS
Lin
Cheng Chieh
CC
Lee
Cheng Chun
CC
Kao
Chia-Hung
CH
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007455:Iodine / Q000493:pharmacokinetics*; D007457:Iodine Radioisotopes; D008875:Middle Aged; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D013959:Thyroid Diseases / Q000000981:diagnostic imaging* / Q000378:metabolism*; D013961:Thyroid Gland / Q000000981:diagnostic imaging* / Q000378:metabolism*
D007457:Iodine Radioisotopes; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C078700:technetium tc-99m tetrofosmin; D007455:Iodine