Frayre A S, Torres P, Gaona E, Rivera T, Franco J, Molina N
Hospital General Dr Manuel Gea González, Calz. de Tlalpan 4800, 14800 México DF, Mexico.
Appl Radiat Isot. 2012 Dec;71 Suppl:57-60. doi: 10.1016/j.apradiso.2012.04.015. Epub 2012 Apr 30.
The purpose of this study was to evaluate the dose received by chest x-rays in neonatal care with thermoluminescent dosimetry and to determine the level of exposure where the quantum noise level does not affect the diagnostic image quality in order to reduce the dose to neonates. In pediatric radiology, especially the prematurely born children are highly sensitive to the radiation because of the highly mitotic state of their cells; in general, the sensitivity of a tissue to radiation is directly proportional to its rate of proliferation. The sample consisted of 208 neonatal chest x-rays of 12 neonates admitted and treated in a Neonatal Intensive Care Unit (NICU). All the neonates were preterm in the range of 28-34 weeks, with a mean of 30.8 weeks. Entrance Surface Doses (ESD) values for chest x-rays are higher than the DRL of 50 μGy proposed by the National Radiological Protection Board (NRPB). In order to reduce the dose to neonates, the optimum image quality was achieved by determining the level of ESD where level noise does not affect the diagnostic image quality. The optimum ESD was estimated for additional 20 chest x-rays increasing kVp and reducing mAs until quantum noise affects image quality.
本研究的目的是采用热释光剂量测定法评估新生儿护理中胸部X光检查的受照剂量，并确定量子噪声水平不影响诊断图像质量时的照射水平，以降低新生儿的受照剂量。在儿科放射学中，尤其是早产儿，由于其细胞处于高度有丝分裂状态，对辐射高度敏感；一般来说，组织对辐射的敏感性与其增殖速率成正比。样本包括在新生儿重症监护病房（NICU）收治并接受治疗的12名新生儿的208张胸部X光片。所有新生儿均为28至34周的早产儿，平均孕周为30.8周。胸部X光检查的体表入射剂量（ESD）值高于国家放射防护委员会（NRPB）建议的50μGy的剂量参考水平（DRL）。为了降低新生儿的受照剂量，通过确定噪声水平不影响诊断图像质量时的ESD水平，实现了最佳图像质量。对另外20张胸部X光片估计了最佳ESD，增加千伏峰值（kVp）并降低毫安秒（mAs），直到量子噪声影响图像质量。
