Densitometric and local histogram based analysis of computed tomography images in patients with idiopathic pulmonary fibrosis
Densitometric and local histogram based analysis of computed tomography images in patients with idiopathic pulmonary fibrosis
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DOI：
10.1186/s12931-017-0527-8
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发表时间：
2017-03-07
影响因子：
5.8
通讯作者：
Washko, George R.
中科院分区：
文献类型：
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作者：
Ash, Samuel Y.;Harmouche, Rola;Washko, George R.
背景：先前使用计算机断层扫描（CT）对特发性肺纤维化（IPF）临床预后的研究通常采用主观分析或单独评估定量措施。本研究探讨了密度测量和基于局部直方图的定量CT测量与肺功能测试（PFT）参数和死亡率之间的关系。此外，本研究试图将定量CT测量的风险预测评分与先前描述的系统进行比较。方法：从马萨诸塞州波士顿布里格姆妇女医院的间质性肺病患者登记处确定了46例活检证实的IPF患者。使用先前发表的方法对每个受试者的CT扫描进行视觉评分。在使用半自动方法将肺与周围组织分割后，对每个患者的整个肺进行密度测量，包括高衰减面积百分比、平均肺密度、偏度和峰度。使用一个单独的自动化工具来检测和量化肺间质性特征所占肺的百分比。这些分析被用于创建临床和定量的基于CT的风险预测评分，并将这些评分的表现与基于临床和视觉分析的方法的表现进行比较。结果：所有密度测量值均与强迫肺活量和弥散量相关，间隙变化总量和局部直方图法测量的间隙变化百分比与局部直方图法测量的间隙变化百分比相关。较高的高衰减面积百分比、较高的平均肺密度、较低的偏度、较低的峰度和较高的蜂窝状比例与较差的无移植生存相关。基于定量CT的风险预测评分与基于临床和视觉分析的方法相似。结论：密度测量和基于特征的定量CT测量与肺功能测试测量相关，并与无移植生存相关。这些客观措施可能有助于识别高风险患者和监测疾病进展。需要进一步的工作来验证这些措施和其他队列中基于定量成像的风险预测评分。
Background: Prior studies of clinical prognostication in idiopathic pulmonary fibrosis (IPF) using computed tomography (CT) have often used subjective analyses or have evaluated quantitative measures in isolation. This study examined associations between both densitometric and local histogram based quantitative CT measurements with pulmonary function test (PFT) parameters and mortality. In addition, this study sought to compare risk prediction scores that incorporate quantitative CT measures with previously described systems.Methods: Forty six patients with biopsy proven IPF were identified from a registry of patients with interstitial lung disease at Brigham and Women's Hospital in Boston, MA. CT scans for each subject were visually scored using a previously published method. After a semi-automated method was used to segment the lungs from the surrounding tissue, densitometric measurements including the percent high attenuating area, mean lung density, skewness and kurtosis were made for the entirety of each patient's lungs. A separate, automated tool was used to detect and quantify the percent of lung occupied by interstitial lung features. These analyses were used to create clinical and quantitative CT based risk prediction scores, and the performance of these was compared to the performance of clinical and visual analysis based methods.Results: All of the densitometric measures were correlated with forced vital capacity and diffusing capacity, as were the total amount of interstitial change and the percentage of interstitial change that was honeycombing measured using the local histogram method. Higher percent high attenuating area, higher mean lung density, lower skewness, lower kurtosis and a higher percentage of honeycombing were associated with worse transplant free survival. The quantitative CT based risk prediction scores performed similarly to the clinical and visual analysis based methods.Conclusions: Both densitometric and feature based quantitative CT measures correlate with pulmonary function test measures and are associated with transplant free survival. These objective measures may be useful for identifying high risk patients and monitoring disease progression. Further work will be needed to validate these measures and the quantitative imaging based risk prediction scores in other cohorts.