摘要目的:研究天津市儿童CT扫描受检者剂量水平，为建立天津地区儿童CT检查诊断参考水平提供依据。方法:2022年在天津市2家儿童三级专科医院及根据地理位置、医疗经济水平的不同，综合考虑被调查医疗机构的依从性，采用分层配额抽样方法选取7家三级综合医院，开展儿童头颅、胸部、腹盆部CT扫描受检者剂量调查，调查对象按年龄～1、～5、～10、～15岁分为4个年龄组，采用方便抽样法，按扫描检查部位每家医院每个年龄组调查20例，收集受检者基本信息、CT扫描参数、容积CT剂量指数(CTDI vol)、剂量长度乘积(DLP)等剂量指标，分析同一部位不同年龄组间和同一部位不同医院间的CTDI vol、DLP差异。 结果:同一部位不同年龄组之间CTDI vol和DLP差异均有统计学意义(头部、胸部和腹盆部，CTDI vol： χ2＝296.51、193.82、291.72， P<0.001；DLP: χ2＝291.22、263.63、344.97， P<0.001)。同一部位不同类型医院之间CTDI vol和DLP差异均有统计学意义(头部、胸部和腹盆部，CTDI vol： Z＝－13.13、－7.57、－15.27, P<0.001；DLP: Z＝－9.07、－6.15、－11.57， P<0.001)。 结论:天津市三级医院儿童头颅、胸部和腹盆部CT扫描检查CTDI vol和DLP的75%分位数处于较好水平，部分年龄组扫描检查部位剂量较高，儿童CT扫描程序还有进一步优化的必要。

abstractsObjective:To study the level of CT dose to paediatric patients in Tianjin, and to provide basic data for establishing the diagnostic reference levels for paediatric patients from CT examinations in Tianjin.Methods:In 2022, a general survey was carried out of the CT doses to the head, chest, abdomen and pelvis of the scanned paediatric patients in two tertiary pediatric hospitals and seven tertiary general hospitals in Tianjin. The scanned pediatric patients were divided into four age groups in terms of the age of -1, -5, -10 and -15 years, and 20 patients were investigated in each age group in each hospital. The basic information were collected on the scanned patients, CT scanning parameters, volume CT dose index (CTDI vol), dose length product (DLP), and the differences in CTDI vol and DLP on the same site among different age groups and different types of hospitals were analyzed. Results:There were significant differences in CTDI vol and DLP between different age groups at the same site (head, chest, abdominal and pelvic, CTDI vol:χ2=296.51, 193.82, 291.72, P<0.001; DLP: χ2=291.22, 263.63, 344.97, P<0.001). There were significant differences in CTDI vol and DLP among different types of hospitals on the same site (head, chest, abdominal and pelvic, CTDI vol:Z=-13.13, -7.57, -15.27, P<0.001; DLP: Z=-9.07, -6.15, -11.57, P < 0.001). Conclusions:The 75 th percentile values of CTDI vol and DLP for pediatric head, chest, abdomen and pelvis CT scanning in tertiary hospitals in Tianjin are at a good level, and the dose on some examination sites are relatively high. Further optimization of pediatric CT scanning procedures is necessary.