Yoon Haesung, Kim Myung-Joon, Yoon Choon-Sik, Choi Jiin, Shin Hyun Joo, Kim Hyun Gi, Lee Mi-Jung
Department of Radiology and Research Institute of Radiological Science, Severance Children's Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Republic of Korea.
Pediatr Radiol. 2015 Mar;45(3):337-44. doi: 10.1007/s00247-014-3176-9. Epub 2014 Sep 26.
New CT reconstruction techniques may help reduce the burden of ionizing radiation.
To quantify radiation dose reduction when performing pediatric chest CT using a low-dose protocol and 50% adaptive statistical iterative reconstruction (ASIR) compared with age/gender-matched chest CT using a conventional dose protocol and reconstructed with filtered back projection (control group) and to determine its effect on image quality in normal weight and overweight children.
We retrospectively reviewed 40 pediatric chest CT (M:F = 21:19; range: 0.1-17 years) in both groups. Radiation dose was compared between the two groups using paired Student's t-test. Image quality including noise, sharpness, artifacts and diagnostic acceptability was subjectively assessed by three pediatric radiologists using a four-point scale (superior, average, suboptimal, unacceptable).
Eight children in the ASIR group and seven in the control group were overweight. All radiation dose parameters were significantly lower in the ASIR group (P < 0.01) with a greater than 57% dose reduction in overweight children. Image noise was higher in the ASIR group in both normal weight and overweight children. Only one scan in the ASIR group (1/40, 2.5%) was rated as diagnostically suboptimal and there was no unacceptable study.
In both normal weight and overweight children, the ASIR technique is associated with a greater than 57% mean dose reduction, without significantly impacting diagnostic image quality in pediatric chest CT examinations. However, CT scans in overweight children may have a greater noise level, even when using the ASIR technique.
新的CT重建技术可能有助于减轻电离辐射负担。
与使用传统剂量方案并采用滤波反投影重建的年龄/性别匹配的儿童胸部CT（对照组）相比，量化使用低剂量方案和50%自适应统计迭代重建（ASIR）进行儿童胸部CT时的辐射剂量降低情况，并确定其对正常体重和超重儿童图像质量的影响。
我们回顾性分析了两组共40例儿童胸部CT（男：女 = 21:19；年龄范围：0.1 - 17岁）。使用配对t检验比较两组之间的辐射剂量。由三位儿科放射科医生使用四点量表（优、良、欠佳、不可接受）对包括噪声、清晰度、伪影和诊断可接受性在内的图像质量进行主观评估。
ASIR组有8名儿童超重，对照组有7名儿童超重。ASIR组的所有辐射剂量参数均显著更低（P < 0.01），超重儿童的剂量降低超过57%。正常体重和超重儿童的ASIR组图像噪声均更高。ASIR组中只有一次扫描（1/40，2.5%）被评为诊断欠佳，没有不可接受的研究。
在正常体重和超重儿童中，ASIR技术使平均剂量降低超过57%，在儿童胸部CT检查中对诊断图像质量没有显著影响。然而，即使使用ASIR技术，超重儿童的CT扫描噪声水平可能更高。
