eeeSounded by a low photon flux.
Most of these studies were performed
: presence of this equipment in combination with the use of iodine-123 makes
such a study possible with a high degree of accuracy.
Our method of 99m. uptake has been previously presented (20).
now been utilized for early iodine-123 uptakes as well.
It has
The pin-hole
collimator is positioned 19cm above the surface of the neck and sequential
images are obtained over the next half-hour following intravenous administration of the radiopharmaceutical.
technetium-99m.
A 4.75 om pinhole is used with
For the dynamic part of the study, a 10 mm pinhole is used
with iodine-123 because of the relatively low level of activity per patient
available to us with this radionuclide (~90,Ci).
study with fodine-123 the smaller pinhole is
For detailed anatomical
used.
The radioiodine studies
were performed on each patient the day following the technetium study.
Following field correction of the pinhole images, curves were generated
of counts per minute over the thyroid area and a background area just
The background curve was subtracted from the thyroid
beneath the thyroid.
area curve to obtain a net thyroid uptake curve.
The results were converted
to percent uptake in the thyroid by comparison of a standard in a neck
phantom counted with the Same geometry and corrected for radioactive decay.
The results were then submitted to a larger computer facility for processing
using the Berman and Weiss SAAM program (30).
This program smoothed the
curves by least squares fitting and gave the slopes and intercepts for a
\
two component: solution.
At the time of this writing 26 patients have been studied by this
Procedure.
was
Of these, three were hyperthyroid and 23 euthyroid.
\
thought to have Hashimotos thyroiditis.
50071354
One patient
A comparison of the