Simultaneous measurement of thyroidal trapping (/sup 99m/TcO$sup 4-$) and binding ($sup 131$$I$$sup -$): clinical and experimental studies in man
Thyroidal uptake was measured repeatedly after simultaneous intravenous administration of /sup 99m/TcO/sub 4/ and /sup 131/I to assess the thyroidal trapping mechanism (/sup 99m/TcO/sub 4/) as well as combined trapping and binding (/sup 131/I). Studies in controls (n = 43) showed a mean thyroidal (neck minus thigh) /sup 99m/TcO/sub 4/ uptake of 3.5% reached within 10 to 20 min, followed by a gradual decrease. Iodine-131 uptake curves were normal. In hyperthyroidism (n = 9), uptake of both radionuclides was increased. ln untreated hypothyroidism and in goiter with low /sup 131/I uptake (n = 7), /sup 99m/TcO/su b 4/ uptake appears by this technique to be greater than the /sup 131/I uptake. In a series of normal volunteers, thyroid space (from T/S ratio) as well as thyroidal uptake were determined. TSH administration (n = 7) stimulated the thyroidal uptake and the thyroid space of both radionuclides. Triiodothyronine (n = 7), while markedly reducing /sup 131/I thyroidal uptake and space, had no effect on measurements of thyroidal /sup 99m/TcO/sub 4/ concentration by this technique although suppression could be demonstrated by a more specific technique. Propylthiouracil (n = 5) also reduced/sup 131/I thyroidal uptake and the/sup 131/ I space. It did not affect /sup 99m/Tc0/sub 4/ uptake but increased the /sup 99m/ Tc space. Lugol's solution (n = 6) virtually obliterated both thyroidal uptake and space for both radionuclides. This method uses generally available equipment and is useful in detecting the stimulation of trapping seen in hyperthyroidism and after TSH stimulation. Caution is advised when uptake levels are low because of the large, variable concentration of pertechnetate in nonthyroidal neck tissues. To study low /sup 99m/TcO/sub 4/ uptakes, techniques which specifically identify thyroidal radioactivity must be used. (auth)
- Research Organization:
- Univ. of California, Los Angeles
- NSA Number:
- NSA-29-000878
- OSTI ID:
- 4435592
- Journal Information:
- J. Nucl. Med., v. 14, no. 11, pp. 785-792, Other Information: Orig. Receipt Date: 30-JUN-74
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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Related Subjects
N40120 -Chemistry-Analytical & Separations Chemistry-Chemical & Spectral Procedures
N48710 -Life Sciences-Nuclide Kinetics & Toxicology-Man
*GOITER- DIAGNOSTIC TECHNIQUES
*HYPERTHYROIDISM- DIAGNOSTIC TECHNIQUES
*HYPOTHYROIDISM- DIAGNOSTIC TECHNIQUES
*IODINE 131- RETENTION
*TECHNETIUM 99- RETENTION
*THYROID- RADIONUCLIDE KINETICS
BLOOD SERUM
COMPARATIVE EVALUATIONS
ISOMERIC NUCLEI
LUGOL
PATIENTS
QUANTITATIVE CHEMICAL ANALYSIS
RESPONSE MODIFYING FACTORS
SAMPLING
SCINTISCANNING
THIOURACIL
TRACER TECHNIQUES
TRIIODOTHYRONINE
TSH
UPTAKE