A new in vivo thyroid I-131 monitoring method was devised by using an imagi
ng plate (IP). A thyroid image obtained with a realistic neck-thyroid phant
om showed a unique shape characteristic of the thyroid gland. A I-131 thyro
id imaging allows visual confirmation of thyroid accumulation of I-131. The
detection limit of the IP system of 290 Bq was about 1/100 of the screenin
g level of 30 kBq in cases of public emergencies. The IP system is applicab
le for thyroid I-131 monitoring. (C) 2001 Elsevier Science Ltd. All rights
reserved.