Hatt Charles R, Oh Andrea S, Obuchowski Nancy A, Charbonnier Jean-Paul, Lynch David A, Humphries Stephen M
Imbio LLC, 1015 Glenwood Ave, Minneapolis, MN 55405 (C.R.H.); School of Medicine and Public Health, Division of Radiology, University of Michigan, Ann Arbor, Mich (C.R.H.); Department of Radiology, National Jewish Health, Denver, Colo (A.S.O., D.A.L., S.M.H.); Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio (N.A.O.); and Thirona, Nijmegen, the Netherlands (J.P.C.).
Radiol Cardiothorac Imaging. 2021 Apr 22;3(2):e200503. doi: 10.1148/ryct.2021200503. eCollection 2021 Apr.
To evaluate the reproducibility and predicted clinical outcomes of CT-based quantitative lung density measurements using standard fixed-dose (FD) and reduced-dose (RD) scans.
In this retrospective analysis of prospectively acquired data, 1205 participants (mean age, 65 years ± 9 [standard deviation]; 618 men) enrolled in the COPDGene study who underwent FD and RD CT image acquisition protocols between November 2014 and July 2017 were included. Of these, the RD scans of 640 participants were also reconstructed using iterative reconstruction (IR). Median filtering was applied to the RD scans (RD-MF) to investigate an alternative noise reduction strategy. CT attenuation at the 15th percentile of the lung CT histogram (Perc15) was computed for all image types (FD, RD, RD-MF, and RD-IR). Reproducibility coefficients were calculated to quantify the measurement differences between FD and RD scans. The ability of Perc15 to predict chronic obstructive pulmonary disease (COPD) diagnosis and exacerbation frequency was investigated using receiver operating characteristic analysis.
The Perc15 reproducibility coefficients with and without volume adjustment were as follows: RD, 29.43 HU ± 0.62 versus 32.81 HU ± 1.70; RD-MF, 7.42 HU ± 0.42 versus 19.40 HU ± 2.65; and RD-IR, 7.10 HU ± 0.52 versus 22.46 HU ± 3.91. Receiver operating characteristic curve analysis indicated that Perc15 on volume-adjusted FD and RD scans were both predictive for COPD diagnosis (area under the receiver operating characteristic curve [AUC]: FD, 0.724 ± 0.045; RD, 0.739 ± 0.045) and for having one or more exacerbation per year (AUCs: FD, 0.593 ± 0.068; RD, 0.589 ± 0.066). Similar trends were observed when volume adjustment was not applied.
A combination of volume adjustment and noise reduction filtering improved the reproducibility of lung density measurements computed using serial FD and RD CT scans.© RSNA, 2021.
使用标准固定剂量（FD）和低剂量（RD）扫描评估基于CT的定量肺密度测量的可重复性和预测的临床结果。
在这项对前瞻性采集数据的回顾性分析中，纳入了1205名参与者（平均年龄65岁±9[标准差]；618名男性），他们参加了COPDGene研究，在2014年11月至2017年7月期间接受了FD和RD CT图像采集方案。其中，640名参与者的RD扫描还使用迭代重建（IR）进行了重建。对RD扫描（RD-MF）应用中值滤波，以研究另一种降噪策略。计算所有图像类型（FD、RD、RD-MF和RD-IR）的肺CT直方图第15百分位数（Perc15）处的CT衰减。计算可重复性系数，以量化FD和RD扫描之间的测量差异。使用受试者操作特征分析研究Perc15预测慢性阻塞性肺疾病（COPD）诊断和加重频率的能力。
有和没有体积调整时Perc15的可重复性系数如下：RD，29.43 HU±0.62对32.81 HU±1.70；RD-MF，7.42 HU±0.42对19.40 HU±2.65；以及RD-IR，7.10 HU±0.52对22.46 HU±3.91。受试者操作特征曲线分析表明，体积调整后的FD和RD扫描上的Perc15均对COPD诊断具有预测性（受试者操作特征曲线下面积[AUC]：FD，0.724±0.045；RD，0.739±0.045），并且对每年有一次或多次加重具有预测性（AUC：FD，0.593±0.068；RD，0.589±0.066）。未应用体积调整时观察到类似趋势。
体积调整和降噪滤波相结合提高了使用连续FD和RD CT扫描计算的肺密度测量的可重复性。©RSNA，2021。
