Chaudakashetrin, PPleehachinda, RPusuwan, PawanaNa Songkla, SChanachai, RIntrasupht, S2012-05-112012-05-111988-07Chaudakashetrin P, Pleehachinda R, Pusuwan Pawana, Na Songkla S, Chanachai R, Intrasupht S. 123iodine. Siriraj Medical Journal, 1988 Jul; 40(7): 533-539.http://imsear.searo.who.int/handle/123456789/138312study was carried out to determine the suitability of utilizing 123Iodine for uptake measurement and imaging study as a replacement of 131Inodine. 131Inodine uptake had been done in 25 normal subjects and in 29 patients with 123Iodine was used in 28 patients. There was no discrepancy of both nuclide in euthyroid, hyperthyroid and patients who were treated with eltroxin. The early uptake proved equal discriminants of euthyroid from hyperthyrod patients. The advantage of 131Iodine over 123Iodine is its ready availability from abroad or its production locally in Thailand at lower cost. Besides it has no problems and pitfalls with technique and radionuclide impurities. The higher radiation dose to the body for function study, is not significant. The imaging studies were done by SPECT and retilinear scanner. Normal glands image of both nuclides were not significantly different. Late image of rectilinear scanner indicated equal quality early 123Iodine image has more attenuation effect. SPECT image of 123Iodine better than 131Iodine. The dose use for imaging study was about 10 times of function study. 123Iodine has shorter half life, lower photon energy, less radiation dose to the patients, so it is more suitable than 131Iodine. Proponent of 99mTc-pertechnetate image was well illustrated by SPECT and rectilinear acanner. It has advantages over 123Iodine in respect to the easy availability and lower cost. It is more convenient to use 99mTc-pertechnetate in stead of 123Iodine, while recognizing that discrepancy can sometime occur between images produced by pertechnetate and iodine.enIodineArticle