Deriving Regionally Specific Biomarkers of Emphysema and Small Airways Disease Using Variable Threshold Parametric Response Mapping on Volumetric Lung CT Images.
Deriving Regionally Specific Biomarkers of Emphysema and Small Airways Disease Using Variable Threshold Parametric Response Mapping on Volumetric Lung CT Images.
复制标题
DOI：
10.1016/j.acra.2021.05.021
复制
发表时间：
2022-03
影响因子：
4.8
通讯作者：
Rizi R
中科院分区：
文献类型：
--
作者：
Baron R;Kadlecek S;Loza L;Xin Y;Amzajerdian F;Duncan I;Hamedani H;Rizi R
本研究旨在开发和验证一种参数响应映射（PRM）方法，通过使用可变阈值来解释仰卧位采集的CT图像中重力无关（前部）和重力依赖（后部）肺之间的局部肺功能变化，从而准确识别肺部病变区域。对34只雄性Sprague-Dawley大鼠（260-540 g）进行成像，其中4只接受弹性蛋白酶注射（100单位/kg）作为肺气肿（EMPH）模型。在吸气末（EI）和呼气末（EE）对自由呼吸（n = 20）和通气（n = 10）大鼠仰卧位进行门控容积CT。为了获得新PRM方法的可变阈值，首先基于沿着前后方向的分数距离将体素分组为100个箱。通过确定包含来自健康通气动物的98%体素的最小区域，设定每个箱中X射线衰减的正常下限（LLN）。当在传统PRM方法中使用固定阈值时，观察到明显的后-前梯度，其中几乎整个肺后部区域被识别为健康，而前部肺被标记为显著较低（t（29）= −3.27，p = 0.003）。在两个队列中，%SAD从后向前逐渐增加，而%HEALTHY肺以相同方向降低。在将我们的具有可变阈值的PRM方法应用于相同的大鼠图像后，从所有大鼠中去除了%SAD定量的后-前趋势，并且去除了前病变肺的显著增加。使用可变阈值的PRM方法通过校正与依赖性与非依赖性肺密度和顺应性的自然垂直梯度相关的局部肺功能改变，提供了%SAD和%EMPH的区域特异性标志物。
This study aims to develop and validate a parametric response mapping (PRM) methodology to accurately identify diseased regions of the lung by using variable thresholds to account for alterations in regional lung function between the gravitationally-independent (anterior) and gravitationally-dependent (posterior) lung in CT images acquired in the supine position. 34 male Sprague-Dawley rats (260–540 g) were imaged, 4 of which received elastase injection (100 units/kg) as a model for emphysema (EMPH). Gated volumetric CT was performed at end-inspiration (EI) and end-expiration (EE) on separate groups of free-breathing (n = 20) and ventilated (n = 10) rats in the supine position. To derive variable thresholds for the new PRM methodology, voxels were first grouped into 100 bins based on the fractional distance along the anterior-to-posterior direction. Lower limits of normal (LLN) for x-ray attenuation in each bin were set by determining the smallest region that enclosed 98% of voxels from healthy, ventilated animals. When utilizing fixed thresholds in the conventional PRM methodology, a distinct posterior-anterior gradient was seen, in which nearly the entire posterior region of the lung was identified as HEALTHY, while the anterior lung was labeled as significantly less so (t(29) = −3.27, p = 0.003). In both cohorts, %SAD progressively increased from posterior to anterior, while %HEALTHY lung decreased in the same direction. After applying our PRM methodology with variable thresholds to the same rat images, the posterior-anterior trend in %SAD quantification was removed from all rats and the significant increase of diseased lung in the anterior was removed. The PRM methodology using variable thresholds provides regionally specific markers of %SAD and %EMPH by correcting for alterations in regional lung function associated with the naturally occurring vertical gradient of dependent vs. non-dependent lung density and compliance.
登录
查看更多内容
俯卧的位置可以改善肺弹性，并独立于肺部募集而增加功能性残留能力。
影响因子：
3.5
作者：
Santini A;Protti A;Langer T;Comini B;Monti M;Sparacino CC;Dondossola D;Gattinoni L
通讯作者：
Gattinoni L
影响因子：
6.7
作者：
Zach JA;Newell JD Jr;Schroeder J;Murphy JR;Curran-Everett D;Hoffman EA;Westgate PM;Han MK;Silverman EK;Crapo JD;Lynch DA;COPDGene Investigators
通讯作者：
COPDGene Investigators
影响因子：
3.3
作者：
Subramaniam, K.;Clark, A. R.;Tawhai, M. H.
通讯作者：
Tawhai, M. H.
DOI：
10.1164/rccm.201807-1351so
发表时间：
2019-02-01
影响因子：
24.7
作者：
Bhatt, Surya P.;Washko, George R.;Lynch, David A.
通讯作者：
Lynch, David A.
影响因子：
5.7
作者：
Avants BB;Tustison NJ;Song G;Cook PA;Klein A;Gee JC
通讯作者：
Gee JC