Vol. VII, N° 3-4 RADIOIODINE UPTAKE MEASUREMENT consisted of the upper half of a body that was completely filled with a body-back- ground radiation. A simulated thyroid gland, filled with either a higher or lower amount of mock-iodine, was placed in the neck region. A small thigh section was included 133 perthyroid simulated activities. For each type a 10 microcurie and a 50 microcurie total dose was made. The figures shown in Table 1 are the nominal uptakes of the manikins. They are not the true figures. The true calibrations of the uptakes of these manikins Fic. 5. X rays of a manikin to show the shape and position of the babbit metal thyroid. with the manikin and also a set of nine 100 per cent dose standards. These 100 per cent dose standards ranged from thesize of a gelatin capsule to that of a 100 cc paper cup and very closely simulated most of the types of “100 per cent dose standards” that were used in clinical practice. Figure 5 shows an X ray of one of the completed manikins illustrating the positioning of the babbit metal thyroid in the manikin. In the survey manikins, a 25 ml volume thyroid was simulated with two lateral lobes and a median lobe. The simulated thy- roid was placed in a position forward in the neck closely simulating the anatomical position of the true thyroid gland. Six manikins were originally made for the survey. Nineteen manikins have now been made, plus one additional one for training purposes and two for more complex problems of scanning. The six survey manikins were divided into euthyroid, hypothyroid, and hy- have been destroyed since it was not the purpose of the survey to determine that some methods were correct and sowe were incorrect. This is a much more complex problem and will be taken up in the third phase of the calibration program. For the survey, all that was wanted was to determine whether there was or was not a variation in the way in which physicians measured thyroid uptake. Table 2 shows the results of the survey to date. More than 200 laboratories have participated in the test. The answers given from the laboratories ranged from an 8 per cent uptake to a 154 per cent uptake. Well over 90 per cent of the laboratories were more than 10 percentage points off the true answer. Any of the manikins could have been diagnosed in the laboratories in the United States and England as either hyperthyroid, hypothyroid or euthyroid. Since some of the best research laboratories in the United States and England wereincluded in this survey,