[Prevalence of latent and manifest hyperthyroidism in an iodine-deficient area: non-selected patient population admitted for CT studies with iodine-containing contrast agents].
OBJECTIVE
To evaluate the prevalence of latent and manifest hyperthyroidism in a non-selected group of patients admitted for contrast enhanced CT studies blood samples were tested for the levels of thyroid-stimulating hormone (TSH).


METHODS
TSH blood levels were obtained in 548 consecutive patients who were scheduled for contrast-enhanced (Iopromide; 300 mg iodine/ml) CT scanning. In case of TSH levels < 0.4 mU/l, blood samples were also tested for triiodothyronine (T3) and tetraiodothyronine (T4) blood levels, and treatment with Irenat (sodium perchlorate) was commenced before scanning. In case of TSH levels < 0.1 mU/l, CT scanning was not performed but further evaluation of the thyroid function was initiated.


RESULTS
TSH blood levels ranged from 0.4 to 7.5 mU/l in 512 patients, and 36 patients (6.6%) had TSH blood levels < 0.4 mU/l and 9 patients blood levels < 0.1 mU/l, with 32 of those patients (5.8%) having regular T3 and T4 blood levels consistent with latent hyperthyroidism. In 4 patients (0.8%), T3 or T4 blood levels were increased consistent with manifest hyperthyroidism.


CONCLUSIONS
In South Germany, the prevalence of latent or manifest hyperthyroidism in a non-selected patient group is high. Therefore TSH blood levels should be obtained prior to contrast-enhanced CT studies.
Saam
T
T
Universitätsklinikum Heidelberg, Abteilung Radiodiagnostik, Heidelberg. saamt@u.washington.edu
Hess
T
T
Kasperk
C
C
Kauffmann
G W
GW
Düx
M
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005858:Germany / Q000453:epidemiology; D006801:Humans; D006980:Hyperthyroidism / Q000097:blood / Q000453:epidemiology*; D007472:Iohexol / Q000031:analogs & derivatives*; D008875:Middle Aged; D010472:Perchlorates / Q000008:administration & dosage; D015995:Prevalence; D017670:Sodium Compounds / Q000008:administration & dosage; D013972:Thyrotropin / Q000097:blood*; D013974:Thyroxine / Q000097:blood; D014057:Tomography, X-Ray Computed; D014284:Triiodothyronine / Q000097:blood
D003287:Contrast Media; D010472:Perchlorates; D017670:Sodium Compounds; D014284:Triiodothyronine; D007472:Iohexol; C038192:iopromide; D013972:Thyrotropin; C031068:sodium perchlorate; D013974:Thyroxine