Best Alan C, Lynch Anne M, Bozic Carmen M, Miller David, Grunwald Gary K, Lynch David A
Department of Radiology, University of Colorado Health Sciences Center, 3025 E 11th Ave, Denver, CO 80262, USA.
Radiology. 2003 Aug;228(2):407-14. doi: 10.1148/radiol.2282020274. Epub 2003 Jun 11.
To determine whether measurements of skewness, kurtosis, and mean lung attenuation on thin-section computed tomographic (CT) histograms in patients with idiopathic pulmonary fibrosis (IPF) correlate with pulmonary physiologic abnormality in a nonspirometrically controlled multicenter study.
The authors analyzed baseline digital thin-section CT data from 144 patients with IPF who enrolled in a double-blind placebo-controlled clinical effectiveness trial of interferon beta 1a in the treatment of IPF. All patients underwent thin-section CT in the supine position at full inspiration. The lungs were isolated by using a semiautomated thresholding technique, with an upper threshold of -200 HU. An attenuation correction algorithm was used. Pulmonary function tests (PFTs) included forced vital capacity, total lung capacity, forced expiratory volume in 1 second, and diffusing lung capacity. Univariate and multiple correlation and regression statistical analyses were used to determine relationships between histogram features and results of PFTs.
Moderate correlations existed between histogram features and PFT results. Kurtosis showed the greatest degree of correlation with physiologic abnormality (r = 0.53, P <.01). Strength of correlation increased with exclusion of suboptimal scans but did not change significantly after application of an attenuation correction algorithm. Attenuations for lungs, gas, and soft tissue varied considerably between scanner manufacturers. Kurtosis alone provided predictions of pulmonary function that were virtually as good as those from all histogram features combined.
Thin-section CT histograms of the lungs were found to correlate with results of PFTs in patients with IPF, which supports the claim that histogram features can be used as valid indexes of IPF in a multiinstitutional nonspirometrically controlled study.
在一项非肺活量测定控制的多中心研究中，确定特发性肺纤维化（IPF）患者薄层计算机断层扫描（CT）直方图上的偏度、峰度和平均肺衰减测量值是否与肺生理异常相关。
作者分析了144例IPF患者的基线数字薄层CT数据，这些患者参加了一项关于干扰素β-1a治疗IPF的双盲安慰剂对照临床疗效试验。所有患者在完全吸气时仰卧位接受薄层CT检查。使用半自动阈值技术分离肺组织，上限阈值为-200HU。采用衰减校正算法。肺功能测试（PFT）包括用力肺活量、肺总量、1秒用力呼气量和肺弥散量。使用单变量和多变量相关及回归统计分析来确定直方图特征与PFT结果之间的关系。
直方图特征与PFT结果之间存在中度相关性。峰度与生理异常的相关性最高（r = 0.53，P <.01）。排除欠佳扫描后相关性强度增加，但应用衰减校正算法后无显著变化。不同扫描仪制造商之间肺、气体和软组织的衰减差异很大。仅峰度就能提供与所有直方图特征综合起来几乎一样好的肺功能预测。
发现IPF患者的肺薄层CT直方图与PFT结果相关，这支持了在多机构非肺活量测定控制研究中，直方图特征可作为IPF有效指标的观点。
