al Jarad N, Strickland B, Bothamley G, Lock S, Logan-Sinclair R, Rudd R M
London Chest Hospital.
Thorax. 1993 Apr;48(4):347-53. doi: 10.1136/thx.48.4.347.
Crackles are a prominent clinical feature of asbestosis and may be an early sign of the condition. Auscultation, however, is subjective and interexaminer disagreement is a problem. Computerised lung sound analysis can visualise, store, and analyse lung sounds and disagreement on the presence of crackles is minimal. High resolution computed tomography (HRCT) is superior to chest radiography in detecting early signs of asbestosis. The aim of this study was to compare clinical auscultation, time expanded wave form analysis (TEW), chest radiography, and HRCT in detecting signs of asbestosis in asbestos workers.
Fifty three asbestos workers (51 men and two women) were investigated. Chest radiography and HRCT were assessed by two independent readers for detection of interstitial opacities. HRCT was performed in the supine position with additional sections at the bases in the prone position. Auscultation for persistent fine inspiratory crackles was performed by two independent examiners unacquainted with the diagnosis. TEW analysis was obtained from a 33 second recording of lung sounds over the lung bases. TEW and auscultation were performed in a control group of 13 subjects who had a normal chest radiograph. There were 10 current smokers and three previous smokers. In asbestos workers the extent of pulmonary opacities on the chest radiograph was scored according to the International Labour Office (ILO) scale. Patients were divided into two groups: 21 patients in whom the chest radiograph was > 1/0 (group 1) and 32 patients in whom the chest radiograph was scored < or = 1/0 (group 2) on the ILO scale.
In patients with an ILO score of < or = 1/0 repetitive mid to late inspiratory crackles were detected by auscultation in seven (22%) patients and by TEW in 14 (44%). HRCT detected definite interstitial opacities in 11 (34%) and gravity dependent subpleural lines in two (6%) patients. All but two patients with evidence of interstitial disease or gravity dependent subpleural lines on HRCT had crackles detected by TEW. In patients with an ILO score of > 1/0 auscultation and TEW revealed mid to late inspiratory crackles in all patients, whereas HRCT revealed gravity dependent subpleural lines in one patient and signs of definite interstitial fibrosis in the rest. In normal subjects crackles different from those detected in asbestosis were detected by TEW in three subjects but only in one subject by auscultation. These were early, fine inspiratory crackles.
Mid to late inspiratory crackles in asbestos workers are detected by TEW more frequently than by auscultation. Signs of early asbestosis not apparent on the plain radiograph are detected by TEW and HRCT with similar frequency. off
啰音是石棉沉着病的一个突出临床特征，可能是该病的早期体征。然而，听诊具有主观性，检查者之间的分歧是一个问题。计算机化肺音分析可以对肺音进行可视化、存储和分析，对啰音存在与否的分歧极小。高分辨率计算机断层扫描（HRCT）在检测石棉沉着病早期体征方面优于胸部X线摄影。本研究的目的是比较临床听诊、时间扩展波形分析（TEW）、胸部X线摄影和HRCT在检测石棉工人石棉沉着病体征方面的效果。
对53名石棉工人（51名男性和2名女性）进行了调查。两名独立阅片者对胸部X线摄影和HRCT进行评估以检测间质混浊。HRCT在仰卧位进行，俯卧位时在肺底部增加扫描层面。两名不了解诊断情况的独立检查者对持续性细吸气性啰音进行听诊。从肺底部33秒的肺音记录中获得TEW分析结果。在13名胸部X线摄影正常的受试者组成的对照组中进行TEW和听诊。有10名当前吸烟者和3名既往吸烟者。在石棉工人中，根据国际劳工组织（ILO）标准对胸部X线摄影上的肺部混浊程度进行评分。患者分为两组：2组中胸部X线摄影在ILO标准下>1/0的患者21例（第1组），胸部X线摄影评分为<或=1/0的患者32例（第2组）。
在ILO评分为<或=1/0的患者中，听诊发现7例（22%）患者有重复性中晚期吸气性啰音，TEW发现14例（44%）患者有此类啰音。HRCT在11例（34%）患者中检测到明确的间质混浊，2例（6%）患者中检测到重力依赖型胸膜下线。除2例HRCT显示有间质疾病或重力依赖型胸膜下线证据的患者外，所有患者TEW均检测到啰音。在ILO评分为>1/0的患者中，听诊和TEW显示所有患者均有中晚期吸气性啰音，而HRCT显示1例患者有重力依赖型胸膜下线，其余患者有明确的间质纤维化体征。在正常受试者中，TEW在3名受试者中检测到与石棉沉着病中检测到的不同的啰音，但听诊仅在1名受试者中检测到。这些是早期的细吸气性啰音。
石棉工人中，TEW比听诊更频繁地检测到中晚期吸气性啰音。TEW和HRCT以相似的频率检测到平片上不明显的早期石棉沉着病体征。
