器官剂量调制技术在儿童鼻旁窦CT扫描中的应用

目的 探讨儿童鼻旁窦CT扫描中器官剂量调制（ODM）技术对眼眶区辐射剂量及图像质量的影响。方法 前瞻性收集65例疑诊鼻旁窦病变患儿行鼻旁窦CT平扫，按就诊时间顺序分为2组：对照组（n=27）采用常规CT扫描，观察组（n=38）采用常规CT扫描加眼眶区ODM技术。分析2组眼眶区前、后、左、右4个方向的管电流分布情况，比较图像对比噪声比及有效辐射剂量的组间差异。结果 观察组眼眶前方向管电流（127.39±17.98）mA]低于对照组（141.00±26.46）mA，t=2.47，P=0.02]，2组间眼眶后、左、右方向的管电流均差异无统计学意义（t=-0.38，-0.90，-0.90，P均>0.05）。2组间图像对比噪声比及有效辐射剂量差异无统计学意义（t=-1.44，1.21，P>0.05）。结论 儿童鼻旁窦CT扫描中，应用ODM技术，可在不影响图像质量的前提下有效降低眼眶前方向局部管电流，减少眼眶区域辐射剂量。

Application of organ dose modulation technique in CT scanning of children paranasal sinus

Objective To explore the effect of organ dose modulation (ODM) technique on radiation dose of orbit area and image quality in children paranasal sinus CT scanning. Methods A total of 65 children with suspected paranasal sinus lesions requiring CT scanning were prospectively collected. The children were divided into 2 groups according to the order of visit, i.e.control group (n=27) received conventional CT scanning, and observation group (n=38) received conventional CT scanning with orbital ODM technique. The distribution of tube current in different direction (anterior/left/posterior/right) of orbital region was analyzed, and the differences of contrast to noise ratio of images and effective radiation dose were compared between 2 groups. Results The tube currents of orbital anterior direction in observation group(127.39±17.98]mA) was lower than that in control group (141.00±26.46]mA, t=2.47, P=0.02), while no statistical difference of tube current of orbital posterior, left, right direction was found between groups(t=-0.38, -0.90, -0.90, all P>0.05). There was no statistical difference of contrast to noise ratio of images nor effective radiation dose between 2 groups (t=-1.44, 1.21, both P>0.05).Conclusion Application of ODM technique in children paranasal sinus CT scanning can effectively reduce the local tube current in the anterior direction of orbital region and reduce the radiation dose in the orbital region without affecting image quality.