A survey and analysis of dose level for adults undergoing posteroanterior chest X-rays photography in Shanghai / 中华放射医学与防护杂志

ABSTRACT

Objective To survey the current dose level for adults undergoing posteroanterior (PA) chest X-ray photography in Shanghai,and to analyze the main factors affecting the dose level.Methods The thermoluminescence dosimeters (TLDs) were deployed to measure entrance surface dose (ESD) in the center of radiated fields.According to the numbers of three types of X-ray equipment and their distribution among different grade hospitals in Shanghai,the ESDs were surveyed for 1032 adults undergoing examination of PA chest X-ray photography from 2008 to 2010,and the relevant information was also recorded.The differences of the mean ESDs among different grade hospitals,equipment types and photographic parameters were statistically analyzed.Results The arithmetic mean of the ESDs for adults undergoing examination of PA chest X-ray photography in Shanghai was 0.23 mGy,and the 75th percentile value was 0.29 mGy,which were all below the current China diagnostic reference level (0.40 mGy).The averaged ESDs were significantly correlated with the grade of hospital,the equipment types and the photographic parameters.Conclusions Compared with the value in the last century,the ESD for adults undergoing PA chest X-ray photography in Shanghai obviously decreases,and there are the potentials for further reduction.