低管电压结合双源 CT 新技术在幼儿胸部检查中的应用研究

目的：探讨应用双源C T新技术后，在幼儿胸部检查中较为合理的电压参数。方法选择150例行双源C T胸部扫描年龄在1～3岁的患儿，将其按不同管电压分组（80、100、120 Kv ），采用Flash模式行胸部平扫，使用实时在线毫安秒调节技术（CARE Dose 4D），均采用SAFIRE技术进行图像重建。由2名医师采用5分制双盲法分别对图像质量进行评价，并用Kappa检验评价观察者间的一致性。记录并比较不同电压组主观图像质量、客观噪声及辐射剂量之间差异。结果随着管电压值的升高，纵隔及肺窗图像质量均有所提高；肺窗图像均可满足临床诊断需要；纵隔窗图像评分较肺窗低，其中，80 kV纵隔图像质量低于3分，无法满足诊断需要；100及120 kV纵膈图像可满足临床需要。CT容积剂量指数、剂量长度乘积值及有效剂量随电压值升高明显增加。80及100 kV组有效剂量为120 kV组的26.9、58.1％。结论双源CT在幼儿胸部检查中，应根据患儿临床需要选择合理的管电压值。对于肺及支气管病变，80 kV可满足临床诊断需要并明显减少辐射剂量；而对于纵隔内病变，则需要选择更高的管电压值。

The applications of low tube voltage combined with dual-source CT new technology in early childhood chest examination

Objective To explore a more reasonable voltage parameters in early childhood chest examination with dual‐source CT new technology .Methods Selected 150 children product dual‐source CT chest scans which ages 1 to 3 years old ,the tube voltage of 80Kv group （ 50 cases ） ,100Kv group （ 50 cases ） ,120Kv group （ 50 cases ） ,with flash chest scan mode ,using real‐time online mA second adjustment techniques （CARE Dose 4D） and SAFIRE technology for image reconstruction .Two physi‐cians using 5‐point double‐blind method ,evaluated interobserver consistency with Kappa test ,recorded objective noise of ima‐ges ,CT dose index volume （CTDIvol） and dose length product （DLP） .Compared different voltage group subjective image quali‐ty ,objective noise and radiation dose .Results As the tube voltage value increased ,mediastinal and lung windows were improved image quality ,lung window image quality are more than four points ,able to meet the clinical diagnosis requires .Mediastinal win‐dow image score lower than the lung window ,which 80kV mediastinal image quality were less than 3 minutes ,unable to meet the diagnostic needs ,100kV and 120kV mediastinal image able to meet clinical needs .With tube voltage increases The objective noise significantly reduced .CT dose index volume ,dose length product value and the effective dose increases with the voltage in‐creased significantly .The group 80kV and 100kV CT dose index for the group 120kV of 24.2% ,55% .The group 80kV and 100kV effective dose for the group 120kV of 26.9% ,58.1% .Conclusion Chest examination with dual‐source CT in early childhood should be based on clinical needs to choose the right tube voltage .For lung and bronchial lesions ,80kV is able to meet clinical diagnostic needs and significantly reduce radiation measurement ,while for mediastinal lesions ,you need to select a high‐er tube voltage value .