Arch Michael E, Frush Donald P
Department of Radiology, Division of Pediatric Radiology, Duke University Medical Center, 1905 McGovern-Davison Children's Health Center, Box 3808 DUMC, Durham, NC 27710, USA.
AJR Am J Roentgenol. 2008 Aug;191(2):611-7. doi: 10.2214/AJR.07.2989.
The purpose of this study was to evaluate how pediatric body MDCT scanning parameters (i.e., the principal determinants of radiation dose) have changed since a prior survey conducted in 2001.
The survey used in this study consisted of 27 questions addressing practice setting; equipment; and scanning parameters including kilovoltage, tube current, and pitch. Members of the Society for Pediatric Radiology (SPR) received an email with a link to the Web-based survey. Respondents were asked to complete only one survey to represent their practice and indicate the number of pediatric radiologists their response represented.
Sixty-one responses representing 337 pediatric radiologists were received. Eighty-four percent of respondents practice in a university or children's hospital. No respondents reported using a peak kilovoltage setting of higher than 120 kVp for routine chest or abdomen scans. Those using 110 kVp or less increased from 4% to 48% for chest CT and from 1% to 32% for abdominal CT (p < 0.001). Weight-based adjustments in tube current are used by 98% of respondents. Tube current tends to increase with a patient's age or weight, with most pediatric body imaging examinations being performed with a tube current of less than 150 mA. The mean tube current used across all age groups decreased between 31 and 61 mA (p < 0.001), with the largest percentage decreases in patients in the 0-4 years age group.
Since 2001, the peak kilovoltage and tube current settings, two principal parameters determining radiation dose, used by SPR members have decreased significantly for pediatric body MDCT. It is a reasonable assumption that these changes are due to efforts to increase awareness about the risks of radiation.
本研究的目的是评估自2001年进行的一项前期调查以来,儿科体部MDCT扫描参数(即辐射剂量的主要决定因素)发生了怎样的变化。
本研究使用的调查问卷包含27个问题,涉及实践环境、设备以及扫描参数,包括千伏、管电流和螺距。儿科放射学会(SPR)的成员收到一封带有基于网络调查问卷链接的电子邮件。要求受访者仅完成一份调查问卷以代表其所在机构的情况,并指出其回答所代表的儿科放射科医生数量。
共收到代表337名儿科放射科医生的61份回复。84%的受访者在大学或儿童医院工作。没有受访者报告在常规胸部或腹部扫描中使用高于120 kVp的峰值千伏设置。对于胸部CT,使用110 kVp或更低千伏设置的比例从4%增加到48%,对于腹部CT,这一比例从1%增加到32%(p < 0.001)。98%的受访者使用基于体重的管电流调整。管电流往往随着患者年龄或体重的增加而增加,大多数儿科体部成像检查的管电流小于150 mA。所有年龄组使用的平均管电流在31至61 mA之间下降(p < 0.001),0至4岁年龄组患者的下降比例最大。
自2001年以来,SPR成员用于儿科体部MDCT的两个决定辐射剂量的主要参数——峰值千伏和管电流设置显著降低。合理推测这些变化是由于提高对辐射风险认识的努力所致。