Singh Anubhuti, Kumar Santosh, Mishra Ashwini Kumar, Kumar Manoj, Kant Surya, Verma S K, Kushwaha R A S, Garg Rajiv
Department of Pulmonary Medicine, King George Medical University, Lucknow, Uttar Pradesh, India.
Department of Radio diagnosis, King George Medical University, Lucknow, Uttar Pradesh, India.
Lung India. 2016 Jan-Feb;33(1):42-8. doi: 10.4103/0970-2113.173064.
Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease affecting the airways, leading to significant morbidity and mortality throughout the world. There is a need to have a holistic evaluation of COPD patients, other than just measuring the level of obstruction as performed by spirometry. High resolution computed tomography (HRCT) scan of thorax partly fulfills this requirement.
Fifty patients of COPD (confirmed on spirometry as per the GOLD guidelines 2014 guidelines) were enrolled, out of which 35 patients got a HRCT done. Complete clinical evaluation was done. The Philips computer program for lung densitometry was used with these limits (-800/-1, 024 Hounsfield unit [HU]) to calculate densities, after validating densitometry values with phantoms. We established the area with a free hand drawing of the region of interest, then we established limits (in HUs) and the computer program calculated the attenuation as mean lung density (MLD) of the lower and upper lobes.
There was a significant correlation between smoking index and anteroposterior tracheal diameter (P = 0.036). Tracheal index was found to be decreasing with increasing disease severity which was statistically significant (P = 0.037). Mean upper lobe MLD was -839.27 HU, mean lower lobe MLD was -834.91 HU and the mean MLD was -837.08 HU. The lower lobes MLD were found to be decreasing with increasing disease severity. A mild linear correlation of pre forced expiratory volume in the first second (FEV1) was observed with lower lobe and total average MLD while a mild linear correlation of Post-FEV1 was observed with both coronal (P = 0.042) and sagittal (P = 0.001) lower lobes MLD. In addition, there was a linear correlation between both pre (P = 0.050) and post (P = 0.024) FEV1/forced vital capacity with sagittal lower lobe MLD. A predictive model can be derived to quantify obstruction severity (FEV1).
HRCT may be an important additional tool in the holistic evaluation of COPD. HRCT can well be correlated with the spirometric and clinical features and the level of obstruction can be indirectly derived from it by measuring the MLD.
慢性阻塞性肺疾病（COPD）是一种影响气道的慢性炎症性疾病，在全球范围内导致了显著的发病率和死亡率。除了像通过肺量计测量阻塞程度那样，还需要对COPD患者进行全面评估。胸部高分辨率计算机断层扫描（HRCT）部分满足了这一要求。
纳入50例COPD患者（根据2014年全球慢性阻塞性肺疾病倡议（GOLD）指南通过肺量计确诊），其中35例患者进行了HRCT检查。进行了全面的临床评估。在使用体模验证密度测定值后，使用飞利浦肺部密度测定计算机程序，设定这些限值（-800 / -1,024亨氏单位[HU]）来计算密度。我们通过徒手绘制感兴趣区域来确定面积，然后设定限值（以HU为单位），计算机程序计算下叶和上叶的平均肺密度（MLD）作为衰减值。
吸烟指数与气管前后径之间存在显著相关性（P = 0.036）。发现气管指数随着疾病严重程度的增加而降低，这具有统计学意义（P = 0.037）。上叶平均MLD为-839.27 HU，下叶平均MLD为-834.91 HU，平均MLD为-837.08 HU。发现下叶MLD随着疾病严重程度的增加而降低。观察到第一秒用力呼气量（FEV1）与下叶和总平均MLD之间存在轻度线性相关性；而在冠状面（P = 0.042）和矢状面（P = 0.001）下叶MLD与FEV1后均观察到轻度线性相关性。此外，FEV1/用力肺活量在矢状面下叶MLD的前后值（P = 0.050和P = 0.024）之间均存在线性相关性。可以推导出一个预测模型来量化阻塞严重程度（FEV1）。
HRCT可能是COPD全面评估中的一项重要辅助工具。HRCT与肺量计及临床特征具有良好的相关性，并且通过测量MLD可以间接从中得出阻塞程度。
