Radiology Institute, University of Erlangen, Germany.
Acad Radiol. 2011 Jun;18(6):690-3. doi: 10.1016/j.acra.2011.01.004. Epub 2011 Mar 9.
Since the introduction of computed tomographic (CT) imaging in the 1970s, the number of examinations has increased steadily. CT imaging is an essential part of routine workup in diagnostic radiology. The great advantage of multidetector computed tomography is the acquisition of a large amount of data in a short time period, thus speeding up diagnostic procedures. To protect patients from unnecessary radiation exposure, different approaches have been developed. In this study, the efficacy of automated exposure control (AEC) software in multidetector CT imaging with a focus on dose reduction in pediatric examinations was assessed.
Between August 2004 and September 2005, a total of 71 children (40 male, 31 female; age range, 2-13 years; mean age, 7.2 years) were examined using a multisource CT scanner. Three different regions (chest, upper abdomen, and pelvis) were examined. Overall image quality was assessed with a subjective scale (1 = excellent, 2 = diagnostic, 3 = nondiagnostic). For all examinations, AEC was used. From the scanner's patient protocol, dose-length product, volume CT dose index, and tube current-time product were calculated for each examination.
With AEC, a mean dose reduction of 30.6% was calculated. Images were rated as excellent (n = 39) or diagnostic (n = 32). Nondiagnostic image quality was not seen. Dose-length product and volume CT dose index were reduced by 30.4% and 29.5%, respectively. Overall, a mean dose reduction of 30.1% of the effective dose (5.8 ± 3.1 vs 8.4 ± 4.6 mSv) was achieved (P < .001).
With AEC software, a mean dose reduction of 30% without any loss in diagnostic image quality is possible.
自 20 世纪 70 年代计算机断层扫描（CT）成像问世以来，检查数量稳步增加。CT 成像已成为诊断放射学常规检查的重要组成部分。多排 CT 的一大优势在于可以在短时间内采集大量数据，从而加快诊断过程。为了保护患者免受不必要的辐射暴露，已经开发出不同的方法。本研究旨在评估多排 CT 成像中自动曝光控制（AEC）软件的效果，重点关注儿科检查中的剂量降低。
2004 年 8 月至 2005 年 9 月，使用多源 CT 扫描仪对 71 名儿童（男 40 名，女 31 名；年龄 2-13 岁；平均年龄 7.2 岁）进行了检查。检查了三个不同的区域（胸部、上腹部和骨盆）。使用主观评分（1 = 优秀，2 = 诊断，3 = 非诊断）评估整体图像质量。所有检查均使用 AEC。从扫描仪的患者协议中，计算了每次检查的剂量长度乘积、容积 CT 剂量指数和管电流时间乘积。
使用 AEC 可计算出平均剂量降低 30.6%。图像评为优秀（n = 39）或诊断（n = 32）。未观察到非诊断性图像质量。剂量长度乘积和容积 CT 剂量指数分别降低了 30.4%和 29.5%。总体而言，有效剂量降低了 30.1%（5.8 ± 3.1 比 8.4 ± 4.6 mSv）（P <.001）。
使用 AEC 软件，可以在不降低诊断图像质量的情况下平均降低 30%的剂量。
