Aroua A, Trueb Ph, Vader J-P, Valley J-F, Verdun F R
University Institute of Applied Radiation Physics, Grand-Pré 1, 1007 Lausanne, Switzerland.
Health Phys. 2007 May;92(5):442-8. doi: 10.1097/01.HP.0000254846.47107.9d.
A nationwide investigation was conducted in Switzerland to establish the exposure of the population by medical x rays and update the results of the 1998 survey. Both the frequency and the dose variations were studied in order to determine the change in the collective dose. The frequency study addressed 206 general practitioners (GPs), 30 hospitals, and 10 private radiology institutes. Except for the latter, the response rate was very satisfactory. The dose study relied on the assessment of the speed class of the screen-film combinations used by the GPs as well as the results of two separate studies dedicated to fluoroscopy and CT. The investigation showed that the total number of all medical x-ray examinations performed by GPs registered a 1% decrease between 1998 and 2003, and that the sensitivities of the film-screen combinations registered a shift towards higher values, leading to a reduction of the dose delivered by a GP of the order of 20%. The study indicated also that the total number of all x-ray examinations performed in hospitals increased by 4%, with a slight increase of radiographies by 1% but significant decrease of examinations involving fluoroscopy (39%), and a 70% increase for CT examinations. Concerning the doses, the investigation of a selection of examinations involving fluoroscopy showed a significant increase of the kerma-area product (KAP) per procedure. For CT the study showed an increase of the dose-length product (DLP) per procedure for skull and abdomen examinations, and a decrease for chest examination. Both changes in the frequency and the effective dose per examination led to a 20% increase in the total collective dose.
瑞士开展了一项全国性调查，以确定民众接受医用X射线照射的情况，并更新1998年调查的结果。对照射频率和剂量变化都进行了研究，以确定集体剂量的变化。频率研究涉及206名全科医生、30家医院和10家私立放射学研究所。除了后者，回复率非常令人满意。剂量研究依赖于对全科医生使用的增感屏-胶片组合的速度等级评估，以及两项分别针对荧光透视和CT的研究结果。调查显示，1998年至2003年间，全科医生进行的所有医用X射线检查总数下降了1%，并且增感屏-胶片组合的敏感度向更高值转变，导致全科医生的剂量减少了约20%。该研究还表明，医院进行的所有X射线检查总数增加了4%，其中X光摄影略有增加1%，但荧光透视检查显著减少（39%），CT检查增加了70%。关于剂量，对一系列荧光透视检查的调查显示，每次检查的比释动能面积乘积（KAP）显著增加。对于CT，研究表明，头颅和腹部检查每次检查的剂量长度乘积（DLP）增加，而胸部检查则减少。检查频率和每次检查的有效剂量的变化都导致总集体剂量增加了20%。
