Dixit Ramakant, Jalutharia Jitendra, Gupta Avinash, Mathur Reena, Goyal Mukesh, Gupta Neeraj, Chaudhary Pradeep, Tiwari Tarun
Department of Respiratory Medicine, J. L. N. Medical College, Ajmer, Rajasthan, India.
Department of Radiodiagnosis, J. L. N. Medical College, Ajmer, Rajasthan, India.
Lung India. 2022 Jul-Aug;39(4):352-356. doi: 10.4103/lungindia.lungindia_280_21.
This study was conducted to evaluate diffusion capacity of lung for carbon monoxide (DLCO) in patients with simple and complicated silicosis and to correlate abnormal findings detected, if any, with the computed tomography abnormalities in these patients.
This study included 56 patients with simple and complicated silicosis and without tuberculosis, in whom we performed DLCO as per standard technique. Various computed tomography findings, that is, presence, size and distribution of nodules associated with relative parenchymal and vascular markings, were recorded in the study subjects and classified into standard grading to be finally compared with DLCO. Visual grading score system was used to describe the extent of emphysematous changes based on the area of abnormally low attenuation, vascular disruption, bullae and so on and data were recorded.
Results showed that 85.7% patients had small opacities of varying grades and 28.5% showed large opacities, with 16% of them having type 'C' large opacities. The mean DLCO (% predicted) of patients with category '0' high-resolution computed tomography (HRCT) abnormality was 92.3 ± 6.8 (within normal limits), and this gradually decreased with increasing HRCT category to 44.2 ± 11.2 in grade '4' of progressive massive fibrosis (PMF) patients in this study (P < 0.01). This reflects a significant inverse correlation between visual HRCT category and the DLCO % predicted (r > -0.89, P < 0.001). The mean DLCO (% predicted) was 51 ± 12.6 in patients with grade '1' emphysema in HRCT, 53 ± 13.5 in grade '2', 43 ± 6.4 in grade '3' and 37.7 ± 6.3 in grade '4'; however, there was no correlation between emphysema grading and pulmonary functional index (r = -0.33, P = 0.15).
This study observed significant abnormality in DLCO among silicosis patients and its strong correlation with the extent of radiological abnormality. HRCT finding of large opacities could be an important indicator of the severity of silicosis, as reflected by significantly reduced DLCO in such patients.
本研究旨在评估单纯矽肺和复杂矽肺患者的肺一氧化碳弥散量（DLCO），并将检测到的异常结果（如有）与这些患者的计算机断层扫描异常情况相关联。
本研究纳入了56例无结核病的单纯矽肺和复杂矽肺患者，按照标准技术对其进行DLCO检测。记录研究对象的各种计算机断层扫描结果，即结节的存在、大小和分布以及相关的实质和血管标记，并将其分类为标准分级，最终与DLCO进行比较。采用视觉分级评分系统，根据异常低衰减区域、血管破坏、肺大疱等情况描述肺气肿变化程度并记录数据。
结果显示，85.7%的患者有不同程度的小阴影，28.5%的患者有大阴影，其中16%为“C”型大阴影。本研究中，“0”级高分辨率计算机断层扫描（HRCT）异常的患者平均DLCO（预测值%）为92.3±6.8（在正常范围内），随着HRCT分级增加，该值逐渐降低，在进行性大块纤维化（PMF）患者的“4”级中降至44.2±11.2（P<0.01）。这反映出视觉HRCT分级与预测的DLCO%之间存在显著的负相关（r>-0.89，P<0.001）。HRCT“1”级肺气肿患者的平均DLCO（预测值%）为51±12.6，“2”级为53±13.5，“3”级为43±6.4，“4”级为37.7±6.3；然而，肺气肿分级与肺功能指标之间无相关性（r=-0.33，P=0.15）。
本研究观察到矽肺患者的DLCO存在显著异常，且与放射学异常程度密切相关。HRCT发现大阴影可能是矽肺严重程度的重要指标，此类患者的DLCO显著降低即反映了这一点。
