1965 Volume 14 Issue 3 Pages 233-239
Recently some photoscans are considered to have more clinical values than other monotone-dot scans. But it needs a special tube whose brightness must vary related with the density of pulses (these linearly related with distribution of radioactivity) and some complicated circuits to represent the results.
In this paper, a very simple way to get photoscintigrams is reported. This apparatus is superior also in the point of economy. For this purpose, the brightness of the lamp (argon lamp) is decreased by an absorption filter made of a plastic plate until the film density developed can not be observed by one pulse or by an accumulation of a few pulses. By this way the density of the film can be observed when the accumulation of pulses becomes more times, and then the density of the film increases by the number of the pulses accumulated, according to the density characteristic curve of the film. Consequently the density in scintigrams is varied consecutively according to the exposed number of pulses accumulated, that is related with an activity of radioisotope distributed in a patient. To make more suitable scintigrams the shape of the light dot is widened, and the brightness of the light is controlled by a variable resistance inserted in the circuit of argone lamp directly.
And the results by this scanner about the phantom o f thyroid and liver are compared with results by other scanners, and the scintigrams by this apparatus is considered to be rather superior than by others instead of the smaller crystal of this apparatus. Some considerations in future are added.