Effect of Reduced Radiation Exposure and Iterative Reconstruction on Detection of LowContrast Low-A ttenuation Lesions in an Anthropomorphic Liver Phantom: An 18-Reader Study
Effect of Reduced Radiation Exposure and Iterative Reconstruction on Detection of LowContrast Low-A ttenuation Lesions in an Anthropomorphic Liver Phantom: An 18-Reader Study
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DOI：
10.1148/radiol.14131928
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发表时间：
2014-07-01
期刊：
影响因子：
19.7
通讯作者：
Baker, Mark E.
中科院分区：
文献类型：
--
作者：
Goenka, Ajit H.;Herts, Brian R.;Baker, Mark E.
目的：通过滤波反投影(FBP)和正弦图确认的迭代重建，测量减少的辐射暴露对拟人腹部模型中低对比度低密度肝脏病变检测的影响。材料和方法：18名放射科医生对模型盲目，研究设计解释随机图像数据集，包含36个三种大小和三个密度差的球形模拟肝脏病变(5 mm直径：比模拟肝插片的90HU背景衰减小12、18和24HU；10 mm和15 mm直径：6、12和18HU小于90-HU背景衰减)，使用四种离散曝光设置扫描，并通过FBP和正弦图确认的迭代重建进行重建。反应评估包括五分诊断置信度表上区域水平病变的存在或不存在。统计学评价包括多读数多相接收器工作特性曲线分析、非参数方法和非劣势分析。结果：FBP和正弦波图确认的迭代重建在75%曝光时的合并准确率均不低于100%曝光(分别为P=0.002和P<；.001)。随后的曝光量减少导致准确度显著下降。剔除最小(5 Mm)病灶时，100%曝光时，正弦图确认的迭代重建优于FBP(P=0.011)，减影25%和50%的迭代重建不逊于100%曝光的FBP(P
Purpose: To measure the effect of reduced radiation exposure on low-contrast low-attenuation liver lesion detection in an anthropomorphic abdominal phantom by using filtered back projection (FBP) and sinogram-affirmed iterative reconstruction.Materials and Methods: Eighteen radiologists blinded to phantom and study design interpreted randomized image data sets that contained 36 spherical simulated liver lesions of three sizes and three attenuation differences (5-mm diameter: 12, 18, and 24 HU less than the 90-HU background attenuation of the simulated liver insert; 10-and 15-mm diameter: 6, 12, and 18 HU less than the 90-HU background attenuation) scanned with four discrete exposure settings and reconstructed by using FBP and sinogram-affirmed iterative reconstruction. Response assessment included region-level lesion presence or absence on a five-point diagnostic confidence scale. Statistical evaluation included multireader multicase receiver operating characteristic curve analysis, with nonparametric methods and noninferiority analysis at a margin of 0.10.Results: Pooled accuracy at 75% exposure for both FBP and sinogram-affirmed iterative reconstruction was noninferior to 100% exposure (P = .002 and P < .001, respectively). Subsequent exposure reductions resulted in a significant decrease in accuracy. When the smallest (5-mm-diameter) lesions were excluded from analysis, sinogram-affirmed iterative reconstruction was superior to FBP at 100% exposure (P = .011), and sinogram-affirmed iterative reconstruction at 25% and 50% exposure reduction was noninferior to FBP at 100% exposure (P