放射性核素肾动态显像中的辐射剂量计算

目的 研究在放射性核素肾动态显像中肾脏和膀胱所受到的内照射剂量。方法 建立一个双隔室链肾脏-膀胱排泄模型并推导出相关的数学表达式,模拟放射性核素肾动态显像剂被人体摄入后的转移、排泄过程,计算核素在肾脏、膀胱和人体其余组织内的总衰变数,再采用蒙特卡罗模拟的方法,计算核素衰变释放的射线在肾脏以及膀胱内产生的能量沉积,最后根据辐射的品质因数计算它们的有效剂量。结果 以 ¹³¹I-OIH和 ⁹⁹Tc^m-DTPA显像剂为例,肾脏受到的内照射剂量分别为0.058mGy/MBq(¹³¹I-OIH)和0.0054 mGy/MBq(⁹⁹Tc^m-DTPA);膀胱受到的内照射剂量分别为0.40mGy/MBq(¹³¹I-OIH)和0.033mGy/MBq(⁹⁹Tc^m-DTPA)。结论 常规剂量水平下的放射性核素肾动态显像对肾脏和膀胱造成的辐射剂量很小。

Radiation dose computation for renal dynamic radionuclide-imaging

Objective To study the internal radiation dose in kidney and bladder for the renal dynamic radionuclide-imaging. Methods A double compartment chain related to kidney-bladder excretion model was set out. The correlative mathematical expressions were educed to simulate the absorbed radionuclide medicament for renal dynamic imaging's transfer and excretion.The total disintegration amount in kidney, bladder and other organs was counted. Monte Calor methods were used to calculate the radionuclide disintegration radial energy deposited in kidney and bladder,and their effective doses were calculated according to the radiation quality factor. Results To take ¹³¹I-OIH and ⁹⁹Tc^m-DTPA imaging agents for example, the internal radiation dose in kidney was 0.058 mGy/MBq(for ¹³¹I-OIH)and 0.0054 mGy/MBq(for ⁹⁹Tc^m-DTPA), respectively,while the internal radiation dose in bladder is 0.40 mGy/MBq(for ¹³¹I-OIH)and 0.033 mGy/MBq(for⁹⁹Tc^m-DTPA), respectively. Conclusions The internal radiation doses in kidney and bladder are very low for renal dynamic radionuclide-imaging at the conventional dose.