| We measured the radioactivity on patient's upper and lower garments, towels, broad sashes for the bust, and electrodes contaminated by sweat due to exercise 201Tl myocardial perfusion scintigraphy. In measuring activity, a scintillation survey meter adjusted to the energy of 201Tl was used. In measuring the radioactivity of clothing, more than 4 Bq/cm2 was considered to be a significant level of contamination. We detected contamination in 30% of upper garments and towels, 19% of broad sashes, 8% of lower garments and 4% of electrodes. Among these materials, several items of clothing and other items showed contamination exceeding 40 Bq/cm2. Towels were remarkably contaminated, with one towel showing a maximum contamination level of 420 Bq/cm2. Examinations done by exercise 201Tl myocardial perfusion scintigraphy often result in the contamination of clothing and other items through sweating. This contamination is especially common in summer, particularly in upper garments and towels. The contamination ratio for towels was over 50%. The contamination ratio increased as the level of exercise became more difficult. When the exercise load was more than 100W, the contamination ratio was 50%. In cases of extreme contamination, images of contaminated upper garments could be obtained by the scintigraphy camera. The areas of high activity on the images seemed to correspond to areas of the body where sweating was profuse. Based on these results, we should pay close attention to the handling of clothing and other items used in exercise testing by 201Tl myocardial perfusion scintigraphy and the points used in measuring contaminated clothing and other items after testing. |
