Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria.
Eur J Radiol. 2012 Dec;81(12):4156-60. doi: 10.1016/j.ejrad.2011.06.060. Epub 2011 Jul 27.
To compare image quality of standard-dose computed radiography and dose reduced needle-technology CR for supine CXR in a clinical setting.
We prospectively evaluated 128 radiographs of 32 immunocompromised patients. For each patient four clinical CXR were performed within one week, two with powder image plates (PIP; Fuji ST-V) and two with needle image plates (NIP; Agfa DXS) at standard and half dose, respectively. One experienced radiologist and two residents blinded to dose level and kind of imaging system rated different anatomical structures, image noise, tubes/lines and abnormalities on a image quality scale from 1 to 10 (1=poor, 10=excellent). The rating scores were tested for statistical differences using analysis of variance with repeated measures.
A statistical difference (p<0.05) was found for the two systems as well as for the two dose levels. Overall rating scores were 6.5 for PIP with full dose, 6.2 for PIP with half dose, 7.6 for NIP with full dose and 7.4 for NIP with half dose. There was a significant difference in favour of the NIP system at the same dose level. Also the NIP images obtained at half dose were ranked significantly better compared to the PIP images at standard dose. The differences in ranking of anatomical structures and abnormalities were more pronounced in low absorption areas (pulmonary vessels, parenchyma) than in high absorption areas (mediastinum, spine).
For supine chest radiograms the NIP technology allows for a dose reduction of 50% while providing higher image quality.
比较标准剂量计算机射线摄影和剂量降低的针技术 CR 在临床环境中对仰卧位胸部 X 线摄影的图像质量。
我们前瞻性地评估了 32 例免疫功能低下患者的 128 张射线照片。对于每个患者，在一周内进行了四次临床 CXR，其中两次使用粉末图像板（富士 ST-V），两次使用针式图像板（Agfa DXS），分别为标准剂量和半剂量。一位经验丰富的放射科医生和两位对剂量水平和成像系统类型均不知情的住院医师对不同的解剖结构、图像噪声、管/线和异常在图像质量量表上进行了 1 到 10 分（1=差，10=优）的评分。使用重复测量方差分析对评分进行了统计学差异检验。
两个系统以及两个剂量水平均存在统计学差异（p<0.05）。总体评分分别为全剂量时的 PIP 为 6.5，半剂量时的 PIP 为 6.2，全剂量时的 NIP 为 7.6，半剂量时的 NIP 为 7.4。在相同剂量水平下，NIP 系统具有显著优势。同样，与标准剂量的 PIP 图像相比，半剂量获得的 NIP 图像排名明显更好。在低吸收区域（肺血管、实质）与高吸收区域（纵隔、脊柱）相比，解剖结构和异常的排名差异更为明显。
对于仰卧位胸部射线照片，NIP 技术可将剂量降低 50%，同时提供更高的图像质量。
