A machine-learning based approach to quantify fine crackles in the diagnosis of interstitial pneumonia: A proof-of-concept study

Fine crackles are frequently heard in patients with interstitial lung diseases (ILDs) and are known as the sensitive indicator for ILDs, although the objective method for analyzing respiratory sounds including fine crackles is not clinically available. We have previously developed a machine-learning-based algorithm which can promptly analyze and quantify the respiratory sounds including fine crackles. In the present proof-of-concept study, we assessed the usefulness of fine crackles quantified by this algorithm in the diagnosis of ILDs.We evaluated the fine crackles quantitative values (FCQVs) in 60 participants who underwent high-resolution computed tomography (HRCT) and chest X-ray in our hospital. Right and left lung fields were evaluated separately.In sixty-seven lung fields with ILDs in HRCT, the mean FCQVs (0.121 ± 0.090) were significantly higher than those in the lung fields without ILDs (0.032 ± 0.023, P < .001). Among those with ILDs in HRCT, the mean FCQVs were significantly higher in those with idiopathic pulmonary fibrosis than in those with other types of ILDs (P = .002). In addition, the increased mean FCQV was associated with the presence of traction bronchiectasis (P = .003) and honeycombing (P = .004) in HRCT. Furthermore, in discriminating ILDs in HRCT, an FCQV-based determination of the presence or absence of fine crackles indicated a higher sensitivity compared to a chest X-ray-based determination of the presence or absence of ILDs.We herein report that the machine-learning-based quantification of fine crackles can predict the HRCT findings of lung fibrosis and can support the prompt and sensitive diagnosis of ILDs.     

65例老年间质性肺疾病临床特征分析

目的探讨我院和市东医院老年患者间质性肺疾病（ILDs）的临床特点,以提高对ILDs的认识,加强对ILDs病因和基础疾病的分析,更好地治疗ILDs患者。方法对我院和市东医院自2008年9月~2010年12月临床诊断为ILDs的病例进行回顾性分析,对比分析其病程、症状、体征及影像学（胸片、胸部高分辨CT或HRCT）、肺功能及血气分析结果,从中发现共性及各自的特点。结果 （1）65例老年ILDs患者中,特发性肺间质纤维化（IPF）发病率最高（43.08%）,其余发病率较多的依次为：结缔组织病、慢性阻塞性肺气肿（COPD）、肺癌合并ILDs和充血性心力衰竭,分别占21.54%、12.31%、9.23%和7.69%。（2）不同病因的ILDs老年患者有ILDs的共同表现,但其临床症状、体征、影像学表现和肺功能等方面又有各自的特点。结论认识ILDs的共性和个性对ILDs的病因诊断、针对性治疗及判断疾病进展和预后具有重要意义。     

65例间质性肺疾病临床特征分析

目的分析总结我院呼吸科间质性肺疾病（ILDs）的临床特点。方法对我院呼吸科间质性肺疾病患者的临床资料进行分析总结。结果 1年间共收治ILDs患者65例,临床表现主要为活动后气短（89.23%）,17例肺功能检查DLco均下降,胸部CT可有不同的表现,磨玻璃影（74.55%）,网格影（38.18%）,蜂窝肺（29.09%）,结节影（14.55%）,实变影（14.55%）,支气管扩张影（27.27%）,多以双下肺和胸膜下为著,血气分析以低氧血症（41.27%）为主,P（A-α）O2均有不同程度的升高,支气管肺泡灌洗液细胞计数以中性粒细胞比例增高为主,肺动脉压力亦有不同程度升高。结论间质性肺疾病的临床表现、实验室检查、影像学与肺功能特征等可做出初步诊断。     

Clinicoradiological profile of interstitial lung diseases at a tertiary care center in Northern India: An eight-year study

Background and objectivesInterstitial lung diseases (ILDs) are a varied group of disorders that have been clubbed together due to some common attributes. The data is abundant from the developed world. However, the developing countries have gradually amassed the knowledge of these disorders and epidemiological data is still missing. We aimed to profile the ILD patients at our center.MethodsAll ILD patients above the age of 14 years were included in the study. A detailed history, examination, exercise capacity assessment, pulmonary function test and relevant serological investigations were done. Tissue was obtained wherever possible. Diagnosis was made after discussion from concerned specialists.ResultsAmong the total 884 subjects recruited, 54% were females with a mean age of 53 years. Most were residents of rural areas. Reticulations and traction bronchiectasis was seen in most subjects. Hypersensitivity pneumonitis was present in 35.9% and connective-tissue disease related ILD (CTD-ILD) in 30.9%.ConclusionMost common ILDs at our center are hypersensitivity pneumonitis and CTD-ILD. Reticulations and traction bronchiectasis are the most common findings on HRCT thorax.     

Pulmonary complications of connective tissue diseases

Lung involvement is common in patients who have complications of connective tissue disease (CTDs) and causes considerable morbidity and mortality. High resolution CT (HRCT) has a pivotal role in the detection of lung fibrosis. In patients who have coexistent pathologic processes, HRCT often allows the predominant process to be identified. HRCT has an important role in detecting possible complications such as opportunistic infection or the development of malignancy. However, the limitations of HRCT should not be overlooked. In many cases, HRCT appearances are nonspecific and may or may not be related to an underlying CTD. Thus, radiologic findings should never be interpreted without knowledge of the clinical picture.     

Thoracic lymph node enlargement in usual interstitial pneumonitis and nonspecific-interstitial pneumonitis: prevalence, correlation with disease activity and temporal evolution

PURPOSE: To evaluate the prevalence of thoracic lymph node enlargement (LNE) in usual (UIP) and nonspecific (NSIP) interstitial pneumonitis, change in LNE over time, and if LNE is related to disease activity. METHODS AND MATERIALS: High-resolution CT scans (HRCT) in 20 patients each with UIP and NSIP were retrospectively reviewed. Two HRCT scans were reviewed for each patient, at diagnosis and a mean of 1 +/- 0.7 years later. Two thoracic radiologists independently recorded the location and size of thoracic lymph nodes (LNs) > 10-mm in short-axis diameter, using the American Thoracic Society lymph node mapping scheme. HRCT disease severity was scored for ground glass opacity and fibrosis. The number and size of enlarged LN stations were compared with HRCT scores. RESULTS: LNE was found on 44 HRCT examinations (21 baseline prevalence 52.5%, 23 follow-up, prevalence 57.5%), most common in the low right paratracheal (38%) and subcarinal (36%) regions. There was no significant difference in LN size or number of enlarged LN stations between baseline and follow-up CT. LNE prevalence was not different on baseline CT (P = 0.34) follow-up CT (P = 0.11) between UIP and NSIP patients. The mean size of the largest enlarged LN was 1.36 cm (1 to 2.1 cm) at baseline and 1.43 cm (1 to 1.9 cm) on follow-up CT. Mean CT ground glass and fibrosis scores were 1.98 and 1.6 when LNE was present, and 1.34 and 1.03 when absent (P = 0.008 and 0.003, respectively). The number and maximum size of enlarged LNs did not correlate with CT ground glass or fibrosis scores. Five patients who developed LNE between baseline and follow-up CT examinations had a greater increase in CT fibrosis scores than patients whose LNE status did not change (P = 0.004); CT ground glass scores were not significantly different. There was a trend for UIP patients to progress from absence of LNE to presence of LNE (4/20 patients or 20%). CONCLUSIONS: Intrathoracic LNE is common in both UIP and NSIP, and becomes increasingly prevalent in UIP patients over time. LNE is more prevalent with more severe lung disease. An increase in LNE over time is associated with the progression of fibrosis, and should not raise concern for co-existing infection or malignancy, in the absence of other clinical findings that would suggest this.     

High-Resolution-Computertomographie (HRCT)

High-resolution CT (HRCT) is the most important radiological tool for diagnosis and differential diagnosis of diffuse lung disease. In-depth knowledge of lung anatomy and concepts of image patterns is necessary to understand CT morphology of pulmonary diseases. These concepts are based on the components of the lung interstitium as well as the anatomy of the secondary pulmonary lobule. Some lung diseases have such a typical HRCT appearance that further??especially invasive??diagnostic procedures are not necessary for an accurate diagnosis. Other HRCT features, such as ground-glass opacities, have a very broad differential diagnosis so that a specific diagnosis cannot be established with HRCT. In these cases, HRCT is of value for definition of target zones for lung biopsy as well as for follow-up.     

Correlation among the indices of high-resolution computed tomography, pulmonary function tests, pulmonary perfusion scans and exercise tolerance in cases of chronic pulmonary emphysema

BACKGROUND: Mismatched distribution of pulmonary blood flow is a common characteristic in emphysematous patients. But few reports have mentioned the relationships between the morphological changes in the lungs as assessed by high-resolution computed tomography (HRCT), pulmonary blood flow (PBF) scan and the indices of exercise tolerance. We investigated these relationships. OBJECTIVE: Pulmonary function tests (PFT), HRCT, single photon emission computed tomography ((99m)SPECT) and treadmill exercise tests were performed on emphysematous patients, and the correlations between these examinations were studied. METHODS: We evaluated 20 patients (M 18, F 2, age 66 +/- 8.0 years). CT evaluation was performed according to the grade of emphysematous change. (99m)SPECT was performed to evaluate mismatched PBF by the score method. The better flow of the middle lobe was selected to be the standard lobe for the basic PBF. That score was set to 1 when the blood flow was below 60 or above 140%. PBF between 60 and 140% was scored as 0. RESULTS: FEV(1 )(r = 0.648, p = 0.002) and VC (r = 0.767, p = 0.001) correlated significantly with Vdot;O(2) peak. FEV(1) (r = 0.667, p = 0.0018) correlated significantly with anaerobic threshold (AT). CT grade did not correlate with PBF mismatch score (r = 0.266, p = 0.3376). %Vdot;O(2 )peak did not correlate with CT grade (r = -0.467, p = 0.0689) or with mismatch PBF score (r = -0.327, p = 0.2377). CONCLUSIONS: HRCT and (99m)SPECT were advantageous for detecting the progression of disease and emphysematous changes. However, the severity of anatomical emphysematous changes did not necessarily correlate with the indices of exercise tolerance and pulmonary function tests.     

A comparative study of computed tomographic techniques for the detection of emphysema in middle-aged and older patient populations]

Helical-scan computed tomography (CT) is now widely utilized as a mass screening procedure for lung cancer. By adding 3 slices of high-resolution CT (HRCT) to the standard screening procedure, we were able to compare the efficacy of helical-scan CT and HRCT in detecting pulmonary emphysema. Additionally, the prevalence of emphysema detected by HRCT was examined as a function of patient age and smoking history. The subjects (106 men and 28 women) were all community-based middle-aged and older volunteers who participated in a mass lung cancer screening program. Based on visual assessments of the CT films, emphysema was detected in 29 subjects (22%) by HRCT, but in only 4 (3%) by helical-scan CT. Although the prevalence of emphysema was higher among subjects with a higher smoking index, no correlations with age were observed. We concluded that the efficacy of helical scan CT in detecting pulmonary emphysema can be significantly improved with the inclusion of 3 slices of HRCT, and confirmed that cigarette smoking is linked to the development of pulmonary emphysema.     

High-resolution computed tomography in cases with environmental exposure to asbestos in Turkey

BACKGROUND AND OBJECTIVES: Although all parts of the lung can be affected as a consequence of asbestos exposure, most CT protocols tend to scan only the middle and lower parts of the thorax. The aim of this study was to investigate parenchymal and pleural lesions of persons exposed to environmental asbestos, using a high-resolution computed tomography (HRCT) protocol scanning the whole thorax. Methods: We analyzed the chest radiographs and HRCT scans of 26 patients who presented bilaterally with multiple pleural plaques related to environmental asbestos exposure. RESULTS: Twenty-four cases (92%) had an abnormal HRCT suggestive of asbestosis. Apart from common HRCT changes related to asbestosis, we detected apical pleural thickening (APT) in 9 cases as well as a coarse honeycomb pattern adjacent to APT in 7 of these cases. Cavitary lesions due to pulmonary tuberculosis were observed on HRCT scans from 4 patients in total. Neither apical pulmonary fibrosis nor cavitary lesions were visible on chest radiographs. CONCLUSIONS: We suggest that the HRCT protocol for examining asbestos-exposed individuals with pleural plaques on chest X-rays should include the whole thorax, since the asbestos-related pathologies may involve all parts of the lung.     

特发性肺纤维化20例临床分析

报告２０例特发性肺纤维化（ＩＰＦ），临床以进行性呼吸困难、干咳、杵状指及Ｖｅｌｃｒｏｓ罗音为突出表现。８例病人行高分辨薄层ＣＴ（ＨＲＣＴ）检查，并与普通ＣＴ及胸片对比，前者影像更加清晰，能显示病变分布特征、细微结构及胸片上看不到的影像。经纤维支气管镜肺活检或开胸肺活检是确诊的主要手段。     

High-resolution CT scan findings in patients with symptomatic scleroderma-related interstitial lung disease

BACKGROUND: Lung disease has become the leading cause of mortality and morbidity in scleroderma (SSc) patients. The frequency, nature, and progression of interstitial lung disease seen on high-resolution CT (HRCT) scans in patients with diffuse SSc (dcSSc) compared with those with limited SSc (lcSSc) has not been well characterized. METHODS: Baseline HRCT scan images of 162 participants randomized into a National Institutes of Health-funded clinical trial were compared to clinical features, pulmonary function test measures, and BAL fluid cellularity. The extent and distribution of interstitial lung disease HRCT findings, including pure ground-glass opacity (pGGO), pulmonary fibrosis (PF), and honeycomb cysts (HCs), were recorded in the upper, middle, and lower lung zones on baseline and follow-up CT scan studies. RESULTS: HRCT scan findings included 92.9% PF, 49.4% pGGO, and 37.2% HCs. There was a significantly higher incidence of HCs in the three zones in lcSSc patients compared to dcSSc patients (p = 0.034, p = 0.048, and p = 0.0007, respectively). The extent of PF seen on HRCT scans was significantly negatively correlated with FVC (r = - 0.22), diffusing capacity of the lung for carbon monoxide (r = - 0.44), and total lung capacity (r = - 0.36). A positive correlation was found between pGGO and the increased number of acute inflammatory cells found in BAL fluid (r = 0.28). In the placebo group, disease progression was assessed as 30% in the upper and middle lung zones, and 45% in the lower lung zones. No difference in the progression rate was seen between lcSSc and dcSSc patients. CONCLUSIONS: PF and GGO were the most common HRCT scan findings in symptomatic SSc patients. HCs were seen in more than one third of cases, being more common in lcSSc vs dcSSc. There was no relationship between progression and baseline PF extent or lcSSc vs dcSSc. Trial registration: Clinicaltrials.gov Identifier: NCT00004563.     

Recent advances in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) remains the most common of the idiopathic interstitial pneumonias and portends a poor prognosis. Significant strides have been made in the approach to diagnosis and in the ability to predict outcome in the last few years. Advances in high-resolution CT (HRCT) scanning have allowed an accurate diagnosis obviating the need for surgical biopsy in many patients. Furthermore, HRCT scanning may aid in determining prognosis and identifying disease progression. The appropriate use of the HRCT scan requires a multidisciplinary iterative approach incorporating all available data to reach a final diagnosis. However, there remains great heterogeneity in disease progression. Pulmonary hypertension and acute exacerbations of IPF negatively influence prognosis and are increasingly a target of therapy. There has been an increase in the number of well-designed clinical trials of IPF that have focused on more specific targets. While no cure has yet been found, each trial expands our understanding regarding the natural course of the disease and the impact of targeted therapy. In the interim, lung transplantation, which appears to improve survival in a subset of IPF patients, remains the only intervention. The objective of this article is to review advances in the understanding of IPF and the evidence for the findings outlined above.     

Diagnostic imaging of diffuse infiltrative disease of the lung

Plain chest radiography remains the first diagnostic approach to diffuse infiltrative lung disease but has limited diagnostic sensitivity and specificity. Many diseases remain occult or are not correctly assessed using chest X-ray, appearing as a nonspecific 'reticulonodular pattern'. High-resolution CT (HRCT) is actually the recommended imaging technique in the diagnosis, assessment, and follow-up of these diseases, allowing also the evaluation of the effectiveness of the medical therapy and the selection of the type and the location of the biopsy when required. Appropriate techniques must be used to acquire high-quality HRCT scans, with the thin collimation and high spatial reconstruction algorithm being the most important factors. A nodular pattern, linear and reticular opacities, cystic lesions, ground-glass opacities and consolidations are the most common HRCT patterns of diffuse infiltrative lung disease. This article reviews the role of chest radiography and HRCT in the diagnosis and assessment of these diseases, the technical aspects of HRCT, its clinical indications and the radiological pattern of the most common types of chronic diffuse infiltrative lung disease.     

Bronchoalveolar lavage in idiopathic interstitial lung diseases

Bronchoalveolar lavage (BAL) is useful for diagnosing various interstitial lung diseases (ILDs) and monitoring ILD during treatment. The ability to detect specific agents or substances by using BAL is especially helpful in determining whether idiopathic ILD has a background causality. BAL in combination with other intensive examinations may enable the definitive diagnosis of an idiopathic ILD. Among the idiopathic ILDs of concern, this article focuses on idiopathic interstitial pneumonia (IIP) and cryptogenic organizing pneumonia (COP). IIP and COP are classified together as idiopathic interstitial pneumonia (IIP), an integrated clinicoradiographic pathological disease entity. BAL has identified two points important for differentiating the disease entity: a paucity of lymphocytes appears in the BAL fluid of patients with idiopathic pulmonary fibrosis (IPF), and lymphocytosis with a decreased CD4:CD8 ratio appears in patients with COP. These findings can be useful, in combination with high-resolution computed tomographic (HRCT) data, for selecting a favorable treatment option. On the other hand, these rules cannot be applied to IP associated with collagen vascular disease (CVD). Furthermore, some IIP patients may manifest features of CVD during the clinical course after the detection of IP (interstitial pneumonia). Thus the definite role of BAL cell profiles remains to be determined.     

Computed tomography scanning techniques for the evaluation of cystic fibrosis lung disease

Multidetector computed tomography (MDCT) scanners allow diagnosis and monitoring of cystic fibrosis (CF) lung disease at substantially lower radiation doses than with prior scanners. Complete spiral chest CT scans are accomplished in less than 10 seconds and scanner advances now allow the acquisition of comprehensive volumetric datasets for three-dimensional reconstruction of the lungs and airways. There are two types of CT scanning protocols currently used to assess CF lung disease: (1) high-resolution CT (HRCT) imaging, in which thin 0.5-1.5-mm slices are obtained every 0.5, 1, or 2 cm from apex to base for inspiratory scans, and limited, spaced HRCT slices obtained for expiratory scans; and (2) complete spiral CT imaging covering the entire lung for inspiratory and expiratory scanning. These scanning protocols allow scoring of CF lung disease and provide CT datasets to quantify airway and air-trapping measurements. CF CT scoring systems typically assess bronchiectasis, bronchial wall thickening, mucus plugging, and atelectasis/consolidation from inspiratory scans, whereas air trapping is scored from expiratory imaging. Recently, CT algorithms have been developed for both HRCT and complete spiral CT imaging to quantify several airway indices, to determine the volume and density of the lung, and to assess regional and global air trapping. CT scans are currently acquired by either controlled-volume scanning techniques (controlled-ventilation infant CT scanning or spirometer-controlled CT scanning in children and adults) or by voluntary breath holds at full inflation and deflation.     

Radiological diagnosis of small pulmonary nodules detected on low-dose screening computed tomography

Background and objective: Early detection and treatment of small malignant pulmonary lesions can improve survival; however, screening by CT detects many false positives. This study retrospectively evaluated a protocol for the diagnostic work‐up of nodules detected by low‐dose CT (LDCT) that are ≤ 10 mm in diameter. Methods: A health screening programme included LDCT. Lesions detected were allocated to one of four categories: negative, semi‐negative, positive and semi‐positive. Positive and semi‐positive categories included non‐calcified nodules without a polygonal shape, and these patients had an initial diagnostic HRCT and were then followed up using high‐resolution CT (HRCT) at intervals determined by the characteristics of the lesion on screening LDCT and the initial diagnostic HRCT. Results: There were 275 nodules detected on screening LDCT; 84 patients had lesions classified as positive and 99 as semi‐positive. Thirteen nodules detected on screening LDCT were only determined to be polygonal and benign following the diagnostic HRCT. The sensitivity and specificity of the screening CT, when compared with diagnostic HRCT, for determining if nodules should be classified as positive were 100% and 97%. The sensitivity and specificity of the initial diagnostic HRCT for being able to predict lung cancer were 87.5% and 91.7% respectively. Conclusions: Following the detection of a pulmonary lesion on screening LDCT, a diagnostic HRCT is necessary to determine the timing of follow‐up HRCT. Diagnostic HRCT is needed to rationalize the screening for lung cancer to reduce the frequency of unnecessary follow‐up scans.     

高分辨率CT定量在慢性阻塞性肺疾病评估中的应用价值

慢性阻塞性肺疾病（COPD）是常见的呼吸系统疾病之一,其表现为持续的、进行性的气流阻塞,是全球发病率和死亡率的主要原因,经济和社会负担巨大。随着科学技术的不断进步和发展,胸部高分辨率计算机断层扫描（HRCT）检查在COPD患者诊断和评估中具有重要应用价值。本文就HRCT定量参数在COPD患者的诊断、急性加重及并发症评估的相关研究进展进行综述。     

Pulmonary function testing in interstitial lung diseases

Interstitial lung diseases (ILDs) are functionally characterized by a restrictive ventilatory defect due to a reduced distensibility of the lung parenchyma. ILD patients also show a reduced exercise tolerance, the main factors limiting exercise capacity being ventilatory and gas exchange abnormalities. Functional abnormalities in ILDs are typical, but not specific. Despite the fact that different lung function patterns have been described among ILDs, they overlap and their practical application to differentiate ILDs is poor. Resting pulmonary function and exercise-induced hypoxemia can aid in defining the prognosis of ILDs and in referring patients for lung transplantation. Additionally, spirometry and diffusing capacity are useful to monitor the response of patients to therapy.