Buchmann Robert F, Bruce Greenberg S
From the Department of Radiology, Arkansas Children's Hospital, Little Rock, AR.
J Comput Assist Tomogr. 2014 Sep-Oct;38(5):786-9. doi: 10.1097/RCT.0000000000000122.
To compare radiation exposure and image quality in children undergoing torso helical acquisition computed tomography (CT) using filtered back projection (FBP) or adaptive iterative dose reduction (AIDR) 3D reconstruction algorithms. A secondary purpose is to compare radiation exposure and image quality in children undergoing torso CT acquired with helical or wide-detector techniques reconstructed with AIDR 3D.
The study was approved by the institutional review board. Phase 1 included 200 helical torso CT studies: 100 using FBP and 100 using AIDR 3D. The size-specific dose estimate (SSDE) was calculated for each study. Region of interest (ROI) noise measurements were recorded in the thorax, abdomen, and pelvis for each study. Unpaired t tests compared SSDE and image noise for each group. Phase 2 included 100 wide-detector CT torso studies using AIDR 3D. Size-specific dose estimate and ROI noise measurements were calculated. Unpaired t tests compared helical and wide-detector SSDE and ROI. Additional t tests looked for age- and weight-specific differences in the helical and wide-detector groups.
Phase 1: AIDR 3D showed significant reduction in SSDE (P = 0.0001) and significant improvement in image quality. Phase 2: no significant difference in SSDE was observed. Children younger than 6 years had a significant reduction in SSDE with wide-detector technique (P = 0.0445) with no loss in image quality.
Adaptive iterative dose reduction 3D produces significant reduction in radiation dose without degradation to image quality compared with FBP. Significant dose reduction without loss of image quality can also be obtained in younger, smaller children using wide-detector technique.
比较采用滤波反投影（FBP）或自适应迭代剂量降低（AIDR）3D重建算法进行躯干螺旋采集计算机断层扫描（CT）的儿童的辐射暴露和图像质量。次要目的是比较采用AIDR 3D重建的螺旋或宽探测器技术进行躯干CT检查的儿童的辐射暴露和图像质量。
本研究经机构审查委员会批准。第一阶段包括200例螺旋躯干CT研究：100例采用FBP，100例采用AIDR 3D。计算每项研究的体型特异性剂量估计值（SSDE）。记录每项研究在胸部、腹部和骨盆的感兴趣区（ROI）噪声测量值。采用非配对t检验比较每组的SSDE和图像噪声。第二阶段包括100例采用AIDR 3D的宽探测器CT躯干研究。计算体型特异性剂量估计值和ROI噪声测量值。采用非配对t检验比较螺旋和宽探测器的SSDE及ROI。另外的t检验寻找螺旋和宽探测器组中年龄和体重特异性差异。
第一阶段：AIDR 3D显示SSDE显著降低（P = 0.0001），图像质量显著改善。第二阶段：未观察到SSDE有显著差异。6岁以下儿童采用宽探测器技术时SSDE显著降低（P = 0.0445），且图像质量无损失。
与FBP相比，自适应迭代剂量降低3D可显著降低辐射剂量且不降低图像质量。采用宽探测器技术在年龄更小、体型更小的儿童中也可实现显著的剂量降低且不损失图像质量。
