Smoking-related interstitial lung disease: radiologic-clinical-pathologic correlation

Smoking-Related Interstitial Lung Disease and Emphysema

Diagnosis and treatment of patients with smoking-related lung diseases often requires multidisciplinary contributions to optimize care. Imaging plays a key role in characterizing the underlying disease, quantifying its severity, identifying potential complications, and directing management. The primary goal of this article is to provide an overview of the imaging findings and distinguishing features of smoking-related lung diseases, specifically, emphysema/chronic obstructive pulmonary disease, respiratory bronchiolitis-interstitial lung disease, smoking-related interstitial fibrosis, desquamative interstitial pneumonitis, combined pulmonary fibrosis and emphysema, pulmonary Langerhans cell histiocytosis, and E-cigarette or vaping related lung injury.

Spectrum of Thoracic Imaging Findings in the Setting of Substance Abuse

ABSTRACT

Substance abuse continues to be prevalent nationwide and can lead to a myriad of chest pathologies. Imaging findings are vast and can include nodules, masses, ground-glass opacities, airspace disease, and cysts. Radiologists with awareness of these manifestations can assist in early identification of disease in situations where information is unable to be obtained from the patient. This review focuses on thoracic imaging findings associated with various forms of substance abuse, which are organized by portal of entry into the thorax: inhalation, ingestion, and injection.

Exploring the Relation Between Interstitial Lung Diseases and Chronic Periodontitis: A Systematic Review

The objective of this systematic review is to determine the association between interstitial lung diseases and chronic periodontitis from various aspects such as microbial, biomarker, genetic, and environmental levels. A systematic review was carried out from 2000 to 2021 following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations including studies searched in PubMed-Medline, Google Scholar, and Cochrane databases. A total of more than 100 articles were obtained in the initial screening process. Out of these 42 studies fulfilled the inclusion criteria and were included in the study. According to the extracted data, there is mounting evidence suggesting the association between these two diseases. Our systematic review raises the prospect of a connection between chronic periodontitis and interstitial lung diseases, within the limitations of the studies we included.

Comorbidity of Pulmonary Fibrosis and COPD/Emphysema: Research Status, Trends, and Future Directions --------- A Bibliometric Analysis from 2004 to 2023

Objective

The comorbidity of pulmonary fibrosis and COPD/emphysema has garnered increasing attention. However, no bibliometric analysis of this comorbidity has been conducted thus far. This study aims to perform a bibliometric analysis to explore the current status and cutting-edge trends in the field, and to establish new directions for future research.

Methods

Statistical computing, graphics, and data visualization tools such as VOSviewer, CiteSpace, Biblimatrix, and WPS Office were employed.

Results

We identified a total of 1827 original articles and reviews on the comorbidity of pulmonary fibrosis and COPD/emphysema published between 2004 and 2023. There was an observed increasing trend in publications related to this comorbidity. The United States, Japan, and the United Kingdom were the countries with the highest contributions. Professor Athol Wells and the University of Groningen had the highest h-index and the most articles, respectively. Through cluster analysis of co-cited documents, we identified the top 17 major clusters. Keyword analysis predicted that NF-κB, oxidative stress, physical activity, and air pollution might be hot spots in this field in the future.

Conclusion

This bibliometric analysis demonstrates a continuous increasing trend in literature related to the comorbidity of pulmonary fibrosis and COPD/emphysema. The research hotspots and trends identified in this study provide a reference for in-depth research in this field, aiming to promote the development of the comorbidity of pulmonary fibrosis and COPD/emphysema.

Air trapping in small airway diseases: A review of imaging technique and findings with an overview of small airway diseases

Air trapping is a common finding radiologists encounter on CT imaging of the thorax. This term is used when there are geographic areas of differing attenuation within the lung parenchyma. Most commonly, this is the result of abnormal retention of air due to complete or partial airway obstruction from small airway pathologies. Perfusional differences due to underlying vascular diseases could also result in these appearances, and hence, inspiratory and full expiratory phase CT studies are required to accurately diagnose air trapping. It is important to note that this can occasionally be present in healthy patients. Multiple diseases are associated with air trapping. Determining the aetiology relies on accurate patient history and concomitant findings on CT. There is currently no consensus on accurate assessment of the severity of air trapping. The ratio of mean lung density between expiration and inspiration on CT and the change in lung volume have demonstrated a positive correlation with the presence of small airway disease. Treatment and resultant patient outcome depend on the underlying aetiology, and hence, radiologists need to be familiar with the common causes of air trapping. This paper outlines the most common disease processes leading to air trapping, including Constrictive bronchiolitis, Hypersensitivity pneumonitis, DIPNECH, and Post-infectious (Swyer-James/Macleod). Various diseases result in the air trapping pattern seen on the expiratory phase CT scan of the thorax. Combining patient history with other concomitant imaging findings is essential for accurate diagnosis and to further guide management.

Tips and Tricks in Thoracic Radiology for Beginners: A Findings-Based Approach

This review has the purpose of illustrating schematically and comprehensively the key concepts for the beginner who approaches chest radiology for the first time. The approach to thoracic imaging may be challenging for the beginner due to the wide spectrum of diseases, their overlap, and the complexity of radiological findings. The first step consists of the proper assessment of the basic imaging findings. This review is divided into three main districts (mediastinum, pleura, focal and diffuse diseases of the lung parenchyma): the main findings will be discussed in a clinical scenario. Radiological tips and tricks, and relative clinical background, will be provided to orient the beginner toward the differential diagnoses of the main thoracic diseases.

HRCT findings in secondhand smokers with respiratory symptoms

PURPOSE

The present study aims to investigate the occurrence and severity of HRCT abnormalities in symptomatic never-smokers, passively exposed to cigarette smoke.

MATERIALS AND METHODS

A total of 135 never-smokers with respiratory symptoms, without underlying lung disease, underwent paired inspiratory-expiratory HRCT and completed the secondhand smoking (SHS) exposure scale questionnaire. Individuals passively exposed to tobacco consisted the secondhand smoking group (SHS group) (n = 68); the remaining 67 controls were never exposed to SHS. Statistical analysis was performed using the Kolmogorov-Smirnov, x² and Pearson Point-Biserial correlation tests. P < 0.05 was statistically significant.

RESULTS

HRCT findings in SHS group included bronchial wall thickening (98.5%), mild cylindrical bronchiectasis (44%), ground-glass opacities (17.6%), and mosaic attenuation pattern (53%). Air trapping occurred in 65% of expiratory scans. Differences in occurrence of findings between SHS group participants and controls were statistically significant (p < 0.0001). There was significant correlation between exposure to tobacco smoke in hours/day and in number of cigarettes/day and the presence of mosaic attenuation pattern, ground-glass opacities, cylindrical bronchiectasis and air trapping, respectively (p < 0.05). Cumulative SHS exposure in years was also strongly correlated with the presence of ground-glass opacities, mosaic attenuation pattern, cylindrical bronchiectasis, and air trapping, as well as with the frequency of respiratory symptoms (p < 0.05).

CONCLUSION

HRCT findings attributed to SHS are mostly related to airway involvement and are correlated with the duration and grade of exposure to environmental tobacco smoke. SHS followed by lifestyle adjustments should be considered in symptomatic non-smokers with such HRCT findings.

Case report: Streptococcus pneumoniae pneumonia characterized by diffuse centrilobular nodules in both lungs

Background

Streptococcus pneumoniae (S. pneumoniae) is the most common pathogen in community-acquired pneumonia (CAP) and takes the form of lobar pneumonia as typical computed tomography (CT) findings. Various patterns of radiological manifestation have also been reported in patients with S. pneumoniae pneumonia; however, the appearance of diffuse centrilobular nodules in both lungs is rarely reported.

Case presentation

We report the case of a patient with a history of chronic lymphocytic leukemia (CLL) for 9 years who presented with new-onset fever, cough, excess sputum, and shortness of breath for 1 week. He was given intravenous antibacterial (cephalosporin) treatment for 4 days, but his condition did not improve and dyspnea became more serious. The chest CT indicated diffuse centrilobular nodules in both lungs at admission. Patient's bronchoalveolar (BAL) fluid was sent for metagenomic next-generation sequencing, which only supported a diagnosis of S. pneumoniae infection. His condition improved gradually after antimicrobial treatment (moxifloxacin) and a follow-up CT showed that the diffuse centrilobular nodules in both lungs were absorbed completely.

Conclusion

This case highlights a rare CT presentation of S. pneumoniae pneumonia that should alert clinicians, so as to avoid taking unnecessary treatment measures.

Diffuse cystic lung diseases: Imaging spectrum and diagnostic approach using high-resolution computed tomography

The lung cyst is an air-containing lucent area surrounded by thin imperceptible walls. Other lucent lung lesions like centrilobular emphysema, cavity, cystic bronchiectasis, honeycomb cyst, and pneumatoceles are close mimics of a lung cyst on high-resolution computed tomography (HRCT). Various diseases with multiple lung cysts throughout both the lungs are classified as diffuse cystic lung diseases (DCLDs). HRCT is considered the imaging of choice for diagnosis of such diffuse cystic lung diseases. Common DCLDs like lymphangioleiomyomatosis, Birt-Hogg-Dubé syndrome (BHS), Langerhans cell histiocytosis (LCH), lymphocytic interstitial pneumonia (LIP), and desquamative interstitial pneumonia (DIP) can be confidently diagnosed on HRCT without further requirement of histopathological confirmation. The imaging also helps in differentiation of uncommon DCLDs and exclusion of the mimics. This review describes a simple algorithmic approach for DCLDs on HRCT based on scrutinizing the cyst's distribution, size, and shape, background parenchymal changes, and its correlation with clinical features and extrapulmonary imaging findings.

Cigarette Smoke Particle-Induced Lung Injury and Iron Homeostasis

It is proposed that the mechanistic basis for non-neoplastic lung injury with cigarette smoking is a disruption of iron homeostasis in cells after exposure to cigarette smoke particle (CSP). Following the complexation and sequestration of intracellular iron by CSP, the host response (eg, inflammation, mucus production, and fibrosis) attempts to reverse a functional metal deficiency. Clinical manifestations of this response can present as respiratory bronchiolitis, desquamative interstitial pneumonitis, pulmonary Langerhans’ cell histiocytosis, asthma, pulmonary hypertension, chronic bronchitis, and pulmonary fibrosis. If the response is unsuccessful, the functional deficiency of iron progresses to irreversible cell death evident in emphysema and bronchiectasis. The subsequent clinical and pathological presentation is a continuum of lung injuries, which overlap and coexist with one another. Designating these non-neoplastic lung injuries after smoking as distinct disease processes fails to recognize shared relationships to each other and ultimately to CSP, as well as the common mechanistic pathway (ie, disruption of iron homeostasis).

CT Findings and Patterns of E-Cigarette or Vaping Product Use-Associated Lung Injury: A Multicenter Cohort of 160 Cases

BACKGROUND

E-cigarette and vaping-induced lung injury (EVALI) causes a spectrum of CT lung injury patterns. Relative frequencies and associations with vaping behavior are unknown.

RESEARCH QUESTION

What are the frequencies of imaging findings and CT patterns in EVALI and what is the relationship to vaping behavior?

STUDY DESIGN AND METHODS

CT scans of 160 subjects with EVALI from 15 institutions were retrospectively reviewed. CT findings and patterns were defined and agreed on via consensus. The parenchymal organizing pneumonia (OP) pattern was defined as regional or diffuse ground-glass opacity (GGO) ± consolidation without centrilobular nodules (CNs). An airway-centered OP pattern was defined as diffuse CNs with little or no GGO, whereas a mixed OP pattern was a combination of the two. Other patterns included diffuse alveolar damage (DAD), acute eosinophilic-like pneumonia, and pulmonary hemorrhage. Cases were classified as atypical if they did not fit into a pattern. Imaging findings, pattern frequencies, and injury severity were correlated with substance vaped (marijuana derives [tetrahydrocannabinol] [THC] only, nicotine derivates only, and both), vaping frequency, regional geography, and state recreational THC legality. One-way analysis of variance, χ² test, and multivariable analyses were used for statistical analysis.

RESULTS

A total of 160 patients (79.4% men) with a mean age of 28.2 years (range, 15-68 years) with EVALI underwent CT scan. Seventy-seven (48.1%), 15 (9.4%), and 68 (42.5%) patients admitted to vaping THC, nicotine, or both, respectively. Common findings included diffuse or lower lobe GGO with subpleural (78.1%), lobular (59.4%), or peribronchovascular (PBV) sparing (40%). Septal thickening (50.6%), lymphadenopathy (63.1%), and CNs (36.3%) were common. PBV sparing was associated with younger age (P = .02). Of 160 subjects, 156 (97.5%) had one of six defined patterns. Parenchymal, airway-centered, and mixed OP patterns were seen in 89 (55.6%), 14 (8.8%), and 32 (20%) patients, respectively. Acute eosinophilic-like pneumonia (six of 160, 3.8%), DAD (nine of 160, 5.6%), pulmonary hemorrhage (six of 160, 3.8%), and atypical (four of 160, 2.5%) patterns were less common. Increased vaping frequency was associated with more severe injury (P = .008). Multivariable analysis showed a negative association between vaping for > 6 months and DAD pattern (P = .03). Two subjects (1.25%) with DAD pattern died. There was no relation between pattern and injury severity, geographic location, and state legality of recreational use of THC.

INTERPRETATION

EVALI typically causes an OP pattern but exists on a spectrum of acute lung injury. Vaping habits do not correlate with CT patterns except for negative correlation between vaping > 6 months and DAD pattern. PBV sparing, not previously described in acute lung injury, is a common finding.

Evaluations of Muscular Strength, Ability to Balance and Health Status in Prisoners during COVID-19

Recent events in prisons during the COVID-19 pandemic showed how the health situation and overcrowding in prisons are a source of high risk to the health and physical and mental well-being of the prison population and how this has become an important medical problem. The original purpose of this study, which was initially planned to last 6 months, was to examine the effects of a training program on cardio-respiratory capacity, resistance to dynamic strength of the upper and lower body and muscle mass. Following the COVID-19 pandemic, the purpose was subsequently modified by highlighting whether and which deficiencies occurred as a result of the absence of physical activity. Forty adult men between 35 and 55 years of age with more than 1 year of detention were selected and randomly divided into two groups: the experimental group and control group. The fitness training protocol of the experimental group consisted of three weekly sessions lasting 90 min, while control group subjects followed a walk of 30-60 min three days a week without running or resistance training. The unpaired and paired t-tests revealed significant effects of both health status and fitness level (p < 0.05; p < 0.01) on group training. The results of this research show that prisoners can improve their fitness and health through participation in physical education programs. This conclusion is especially important for prisoners who have to serve very long prison sentences and who are at great risk of showing poor physical condition levels.

CT findings of pulmonary cysts

Pulmonary cysts are thin-walled radiolucent lesions that may appear in a variety of uncommon disorders known as diffuse cystic lung diseases (DCLD) that essentially includes lymphangioleiomyomatosis (LAM), Langerhans cell histiocytosis (LCH), lymphocytic interstitial pneumonia (LIP), Pneumocystis jiroveci pneumonia (PJP), and Birt-Hogg-Dubé syndrome (BHDS). Moreover, they have been reported in several cases of coronavirus disease 2019 (COVID-19). The purpose of this review is to provide a practical approach for evaluating lung cysts when encountered on CT. We describe the imaging findings of DLCD emphasising their differences in terms of shape and distribution of the cysts, as well as their association with other findings such as nodules or ground-glass opacities, which may help in making a confident diagnosis. We also discuss the link between pulmonary cysts and COVID-19.

A comprehensive assessment of environmental exposures and the medical history guides multidisciplinary discussion in interstitial lung disease

BACKGROUND

Multidisciplinary discussion (MDD) is widely recommended for patients with interstitial lung disease (ILD), but published primary data from MDD has been scarce, and factors influencing MDD other than chest computed tomography (CT) and lung histopathology interpretations have not been well-described.

METHODS

Single institution MDD of 179 patients with ILD.

RESULTS

MDD consensus clinical diagnoses included autoimmune-related ILD, chronic hypersensitivity pneumonitis, smoking-related ILD, idiopathic pulmonary fibrosis, medication-induced ILD, occupation-related ILD, unclassifiable ILD, and a few less common pulmonary disorders. In 168 of 179 patients, one or more environmental exposures or pertinent features of the medical history were identified, including recreational/avocational, residential, and occupational exposures, systemic autoimmune disease, malignancy, medication use, and family history. The MDD process demonstrated the importance of comprehensively assessing these exposures and features, beyond merely noting their presence, for rendering consensus clinical diagnoses. Precise, well-defined chest CT and lung histopathology interpretations were rendered at MDD, including usual interstitial pneumonia, nonspecific interstitial pneumonia, and organizing pneumonia, but these interpretations were associated with a variety of MDD consensus clinical diagnoses, demonstrating their nonspecific nature in many instances. In 77 patients in which MDD consensus diagnosis differed from referring diagnosis, assessment of environmental exposures and medical history was found retrospectively to be the most impactful factor.

CONCLUSIONS

A comprehensive assessment of environmental exposures and pertinent features of the medical history guided MDD. In addition to rendering consensus clinical diagnoses, MDD presented clinicians with opportunities to initiate environmental remediation, behavior modification, or medication alteration likely to benefit individual patients with ILD.

COVID-19 mimics on chest CT: a pictorial review and radiologic guide

Chest imaging is often used as a complementary tool in the evaluation of coronavirus disease 2019 (COVID-19) patients, helping physicians to augment their clinical suspicion. Despite not being diagnostic for COVID-19, chest CT may help clinicians to isolate high suspicion patients with suggestive imaging findings. However, COVID-19 findings on CT are also common to other pulmonary infections and non-infectious diseases, and radiologists and point-of-care physicians should be aware of possible mimickers. This state-of-the-art review goal is to summarize and illustrate possible etiologies that may have a similar pattern on chest CT as COVID-19. The review encompasses both infectious etiologies, such as non-COVID viral pneumonia, Mycoplasma pneumoniae, Pneumocystis jiroveci, and pulmonary granulomatous infectious, and non-infectious disorders, such as pulmonary embolism, fat embolism, cryptogenic organizing pneumonia, non-specific interstitial pneumonia, desquamative interstitial pneumonia, and acute and chronic eosinophilic pneumonia.

Review of the Chest CT Differential Diagnosis of Ground-Glass Opacities in the COVID Era

Coronavirus disease 2019 (COVID-19), a recently emerged lower respiratory tract illness, has quickly become a pandemic. The purpose of this review is to discuss and differentiate typical imaging findings of COVID-19 from those of other diseases, which can appear similar in the first instance. The typical CT findings of COVID-19 are bilateral and peripheral predominant ground-glass opacities. As per the Fleischner Society consensus statement, CT is appropriate in certain scenarios, including for patients who are at risk for and/or develop clinical worsening. The probability that CT findings represent COVID-19, however, depends largely on the pretest probability of infection, which is in turn defined by community prevalence of infection. When the community prevalence of COVID-19 is low, a large gap exists between positive predictive values of chest CT versus those of reverse transcriptase polymerase chain reaction. This implies that with use of chest CT there are a large number of false-positive results. Imaging differentiation is important for management and isolation purposes and for appropriate disposition of patients with false-positive CT findings. Herein the authors discuss differential pathology with close imaging resemblance to typical CT imaging features of COVID-19 and highlight CT features that may help differentiate COVID-19 from other conditions.

A Stepwise Diagnostic Approach to Cystic Lung Diseases for Radiologists

Lung cysts are commonly seen on computed tomography (CT), and cystic lung diseases show a wide disease spectrum. Thus, correct diagnosis of cystic lung diseases is a challenge for radiologists. As the first diagnostic step, cysts should be distinguished from cavities, bullae, pneumatocele, emphysema, honeycombing, and cystic bronchiectasis. Second, cysts can be categorized as single/localized versus multiple/diffuse. Solitary/localized cysts include incidental cysts and congenital cystic diseases. Multiple/diffuse cysts can be further categorized according to the presence or absence of associated radiologic findings. Multiple/diffuse cysts without associated findings include lymphangioleiomyomatosis and Birt-Hogg-Dubé syndrome. Multiple/diffuse cysts may be associated with ground-glass opacity or small nodules. Multiple/diffuse cysts with nodules include Langerhans cell histiocytosis, cystic metastasis, and amyloidosis. Multiple/diffuse cysts with ground-glass opacity include pneumocystis pneumonia, desquamative interstitial pneumonia, and lymphocytic interstitial pneumonia. This stepwise radiologic diagnostic approach can be helpful in reaching a correct diagnosis for various cystic lung diseases.

Cystic Interstitial Lung Diseases: A Pictorial Review and a Practical Guide for the Radiologist

A cyst is a round circumscribed area of low attenuation, surrounded by epithelial or fibrous wall. Cysts can frequently occur on chest computed tomography (CT) and high-resolution computed tomography (HRCT); multiple parenchymal cysts of the lungs are the most typical feature of cystic lung interstitial diseases, characterizing a wide spectrum of diseases—ranging from isolated lung disorders up to diffuse pulmonary diseases. The aim of this review is to analyze scientific literature about cystic lung interstitial diseases and to provide a practical guide for radiologists, focusing on the main morphological features of pulmonary cysts: size, shape, borders, wall, location, and distribution. These features are shown on free-hand drawings and related to HRCT images, in order to help radiologists pursue the correct differential diagnosis between similar conditions.

E-cigarette, or vaping, product use-associated lung injury in adolescents: a review of imaging features

BACKGROUND

There has been a recent increase in recognition of lung disease related to the use of electronic cigarettes (called "vaping"). These patients present with acute respiratory illness following exposure to vaporized cannabis or nicotine products and sometimes require hospitalization and intensive care. We describe the imaging findings of this disease entity in the pediatric population.

OBJECTIVE

To describe the radiologic findings of lung injury associated with electronic cigarette use (vaping) in the adolescent pediatric population.

MATERIALS AND METHODS

We identified all adolescents with acute respiratory illness and a history of electronic cigarette use who presented at our institution within a 3-month period (June 2019 through August 2019). We excluded adolescents with potential intercurrent pulmonary disease. We reviewed the charts for symptomatology and laboratory and pathology data. In addition, we reviewed the chest radiographs and chest CTs of these adolescents.

RESULTS

The review group consisted of 12 teenage pediatric patients (10 boys and 2 girls; mean age 16.9 years, range 16.0-17.7 years) with acute respiratory illness found to have a temporal association with electronic cigarette use for cannabis products, nicotine, or both. Other etiologies for illness in these adolescents had been excluded by clinical and laboratory evaluation. All of the adolescents were admitted to the hospital for treatment. The clinical presentations included dyspnea, abdominal pain and constitutional symptoms. Pulmonary function testing that was performed in all patients during admission or follow-up demonstrated reduced diffusion capacity in 4/12 (33%), an obstructive ventilatory pattern in 4/12 (33%), a restrictive pattern in 1/12 (8%), and a mixed obstructive and restrictive pattern in 2/12 (17%) adolescents. Bronchoalveolar lavage studies, performed in 9 of the 12 adolescents, revealed inflammatory cells and lipid-laden macrophages. All of the patients underwent CT of the chest; the findings were notable for centrilobular ground-glass nodules (11/12; 92%) and confluent ground-glass opacities (12/12; 100%), with frequent subpleural sparing (9/12; 75%). Additionally, 6/12 (50%) adolescents demonstrated small pleural effusions; 6/12 (50%) had mild bronchial wall thickening; 9/12 (75%) had enlarged hilar or mediastinal lymph nodes; and 2/12 (17%) had a small pericardial effusion.

CONCLUSION

As seen in our teenage population, e-cigarette, or vaping, product use-associated lung injury (EVALI) is characterized by centrilobular ground-glass nodules and ground-glass opacities with subpleural sparing. The imaging findings are most consistent with acute lung injury resulting from toxic inhalation. Because adolescent pediatric patients might not be forthcoming with their history of electronic cigarette use, it is important for the pediatric radiologist to be aware of the imaging patterns of this disease.

Diffuse smoking-related lung diseases: insights from a radiologic-pathologic correlation

Cigarettes are well-recognized risk factors responsible for the emergence of a variety of pathologic conditions affecting both the airways and the lungs. Smoking-related lung diseases can be classified as chronic obstructive pulmonary disease (COPD) and several types of interstitial diseases, such as pulmonary Langerhans cell histiocytosis, bronchiolitis, desquamative interstitial pneumonitis, acute eosinophilic pneumonia, and interstitial fibrosing lung diseases. The evidence of combined lower lung fibrosis and predominant upper lung emphysema is renowned as a distinct clinical entity, named combined pulmonary fibrosis and emphysema. Although computerized tomography permits an adequate classification and distinction of these diseases, the clinical, imaging, and histological features often overlap and coexist in a single patient. Therefore, a combined radiologic and pathologic approach, in the appropriate clinical setting, is useful for best comprehension and distinction of these entities. Our goals are to describe the imaging features in smoking-related lung diseases and how the pathological manifestations translate on high-resolution computerized tomography.

Desquamative interstitial pneumonia with clinical, radiological and histologic correlation

Respiratory bronchiolitis-associated interstitial lung disease (ILD), desquamative interstitial pneumonia (DIP), and pulmonary Langerhans cell histiocytosis are entities of smoking-related ILD. While clinically regarded as 2 separate forms of idiopathic interstitial pneumonia, DIP, and respiratory bronchiolitis-associated ILD are thought to be representing ends of a continuous spectrum of disease that primarily affects tobacco smokers. This case report presents a 53-year-old female patient who has 58 pack-year smoking history who has been experiencing a dry cough and epigastric pains for 2 years. Open-lung biopsy is performed and histopathology indicated smoking-related interstitial fibrosis. The patient did not stop smoking, which after a year leads to significant clinical deterioration with a notable decrease in diffusion for carbon monoxide capacity. Upon smoking cessation and treatment with corticosteroids, a significant clinical improvement is achieved. In smokers complaining of cough and reduced exercise tolerance and in whom evidence of interstitial fibrosis is demonstrated radiologically, DIP should be considered as a differential diagnosis. Smoking is the exclusive etiologic factor of pathogenesis of DIP.

Relationship between current smoking, visual CT findings and emphysema index in cigarette smokers

PURPOSE

To evaluate whether visual CT findings could account for the effect of current smoking.

METHODS

500 CT scans were visually evaluated within each lobe. A multivariate model for emphysema index was constructed containing previously described confounders in addition to the visual components associated with smoking status.

RESULTS

Current smokers displayed 23% less visual emphysema, 19% more airway wall thickening, and 188% more centrilogular nodule than former smokers (all p < 0.001). The effect of current smoking on the emphysema index decreased after adjustment with confounders and visual parameters.

CONCLUSIONS

Visual CT findings could partially account for the effect of current smoking.

Interstitial Lung Disease and Pulmonary Fibrosis: A Practical Approach for General Medicine Physicians with Focus on the Medical History

Interstitial lung disease (ILD) and pulmonary fibrosis comprise a wide array of inflammatory and fibrotic lung diseases which are often confusing to general medicine and pulmonary physicians alike. In addition to the myriad of clinical and radiologic nomenclature used in ILD, histopathologic descriptors may be particularly confusing, and are often extrapolated to radiologic imaging patterns which may further add to the confusion. We propose that rather than focusing on precise histologic findings, focus should be on identifying an accurate etiology of ILD through a comprehensive and detailed medical history. Histopathologic patterns from lung biopsy should not be dismissed, but are often nonspecific, and overall treatment strategy and prognosis are likely to be determined more by the specific etiology of ILD rather than any particular histologic pattern. In this review, we outline a practical approach to common ILDs, highlight important aspects in obtaining an exposure history, clarify terminology and nomenclature, and discuss six common subgroups of ILD likely to be encountered by general medicine physicians in the inpatient or outpatient setting: Smoking-related, hypersensitivity pneumonitis, connective tissue disease-related, occupation-related, medication-induced, and idiopathic pulmonary fibrosis. Accurate diagnosis of these forms of ILD does require supplementing the medical history with results of the physical examination, autoimmune serologic testing, and chest radiographic imaging, but the importance of a comprehensive environmental, avocational, occupational, and medication-use history cannot be overstated and is likely the single most important factor responsible for achieving the best possible outcomes for patients.

Interstitial lung diseases: Imaging contribution to diagnosis and elementary radiological lesions

Interstitial pneumonias comprise a heterogeneous group of disorders in which a multidisciplinary approach is important for accuracy in diagnosis; indeed, one might say, even mandatory. The team of collaborators should include radiologists, because high resolution computed tomography (HRCT) of the thorax is the first, and most of times, the only imaging examination to be prescribed after chest X-ray. Elementary lesions of the interstitium can be accurately described with HRCT, inasmuch as lung windowing with sharp filtering in this technique reproduces the microscopic features of the lung. Guidance of bronchoalveolar lavage and biopsy procedures is also possible with HRCT.

Overlaps and uncertainties of smoking-related idiopathic interstitial pneumonias

Smoking-related interstitial lung disease (ILD) consists of a heterogeneous group of disorders that are considered a distinct entity. The 2013 American Thoracic Society and European Respiratory Society recommendations classified respiratory bronchiolitis (RB)/RB-ILD and desquamative interstitial pneumonia (DIP) as smoking-related idiopathic interstitial pneumonias (IIPs). The overlapping histopathological and radiological patterns of smoking-related IIPs must be considered. Overlap patterns of smoking-related IIPs are not easily classified as a single disorder. The initial radiological manifestation and follow-up changes are heterogeneous, even when diagnosed pathologically as RB or DIP. Therefore, a clinical–radiological–pathological consensus is important in the diagnosis of smoking-related IIPs, and long-term evaluation is essential to monitor the morphological changes in these patients. In this article, we reviewed the clinical, radiological, and pathological findings, and also the changes in radiological manifestations of smoking-related IIPs over time.

Thorax Computed Tomography Findings in Patients with Erectile Dysfunction

Objective:

Diabetes mellitus, smoking, dyslipidemia, and obesity play an important role in the etiology of erectile dysfunction, particularly in cases with vascular insufficiency. These risk factors also target the lungs due to their systemic effects.

Materials and Methods:

Patients with penile vascular insufficiency determined at Doppler ultrasonography and undergoing thoracic computerized tomography for various reasons were included in this study. A history of acute thoracic trauma, pneumonic consolidation, or pelvic surgery and trauma were regarded as exclusion criteria.

Results:

Thirty-seven male patients with identified vascular insufficiency (age 54.48 ± 13.62 years) were enrolled. Mass lesions with a malignant morphology were present in two patients. The most common mediastinal/vascular pathology was atherosclerosis, while the most common parenchymal lesion was emphysematous aeration. Other findings included parenchymal fibrotic bands, atelectasis, interstitial thickening, bronchiectasis, air trapping, aortic aneurysm, a dilated pulmonary artery, hiatal hernia, and pericardial effusion.

Conclusion:

Erectile dysfunction may be an early sign of cardiovascular diseases. Care must be taken in terms of existing or potential pulmonary pathologies in these patients due to their sharing common risk factors with systemic effects.

Pathologic and Radiologic Correlation of Adult Cystic Lung Disease: A Comprehensive Review

The presence of pulmonary parenchymal cysts on computed tomography (CT) imaging presents a significant diagnostic challenge. The diverse range of possible etiologies can usually be differentiated based on the clinical setting and radiologic features. In fact, the advent of high-resolution CT has facilitated making a diagnosis solely on analysis of CT image patterns, thus averting the need for a biopsy. While it is possible to make a fairly specific diagnosis during early stages of disease evolution by its characteristic radiological presentation, distinct features may progress to temporally converge into relatively nonspecific radiologic presentations sometimes necessitating histological examination to make a diagnosis. The aim of this review study is to provide both the pathologist and the radiologist with an overview of the diseases most commonly associated with cystic lung lesions primarily in adults by illustration and description of pathologic and radiologic features of each entity. Brief descriptions and characteristic radiologic features of the various disease entities are included and illustrative examples are provided for the common majority of them. In this article, we also classify pulmonary cystic disease with an emphasis on the pathophysiology behind cyst formation in an attempt to elucidate the characteristics of similar cystic appearances seen in various disease entities.

Clinical-Radiologic-Pathologic Correlation of Smoking-Related Diffuse Parenchymal Lung Disease

The direct toxicity of cigarette smoke and the body's subsequent response to this lung injury leads to a wide array of pathologic manifestations and disease states that lead to both reversible and irreversible injury to the large airways, small airways, alveolar walls, and alveolar spaces. These include emphysema, bronchitis, bronchiolitis, acute eosinophilic pneumonia, pulmonary Langerhans cell histiocytosis, respiratory bronchiolitis, desquamative interstitial pneumonia, and pulmonary fibrosis. Although these various forms of injury have different pathologic and imaging manifestations, they are all part of the spectrum of smoking-related diffuse parenchymal lung disease.

Smoking-related interstitial fibrosis combined with pulmonary emphysema: computed tomography-pathologic correlative study using lobectomy specimens

PURPOSE

To evaluate the incidence and pathologic correlation of thin-section computed tomography (TSCT) findings in smoking-related interstitial fibrosis (SRIF) with pulmonary emphysema.

PATIENTS AND METHODS

Our study included 172 consecutive patients who underwent TSCT and subsequent lobectomy. TSCT findings including clustered cysts with visible walls (CCVW) and ground-glass attenuation with/without reticulation (GGAR) were evaluated and compared in nonsmokers and smokers and among lung locations. TSCT findings, especially CCVW, were also compared with histological findings using lobectomy specimens.

RESULTS

The incidence of CCVW and GGAR was significantly higher in smokers than in nonsmokers (34.1% and 40.7%, respectively, vs 2.0% and 12.2%). CCVW and GGAR were frequently found in the lower and peripheral zones. Histologically, CCVW corresponded more often with SRIF with emphysema than usual interstitial pneumonia (UIP, 63.3% vs 30%). CCVW of irregular size and shape were seen in 19 of 20 SRIF with emphysema and in seven of nine UIP-manifested areas with similar round cysts. A less-involved subpleural parenchyma was observed more frequently in SRIF with emphysema.

CONCLUSION

SRIF with emphysema is a more frequent pathological finding than UIP in patients with CCVW on TSCT. The irregular size and shape of CCVW and a less-involved subpleural parenchyma may be a clue suggesting the presence of SRIF with emphysema.

A retrospective study of two populations to test a simple rule for spirometry

Background

Chronic lung disease is common and often under-diagnosed.

Methods

To test a simple rule for conducting spirometry we reviewed spirograms from two populations, occupational medicine evaluations (OME) conducted by Saint Louis and Wake Forest Universities at 3 sites (n = 3260, mean age 64.14 years, 95 % CI 58.94–69.34, 97 % men) and conducted by Wake Forest University preop clinic (POC) at one site (n = 845, mean age 62.10 years, 95 % CI 50.46–73.74, 57 % men). This retrospective review of database information that the first author collected prospectively identified rates, types, sensitivity, specificity and positive and negative predictive value for lung function abnormalities and associated mortality rate found when conducting spirometry based on the 20/40 rule (≥20 years of smoking in those aged ≥ 40 years) in the OME population. To determine the reproducibility of the 20/40 rule for conducting spirometry, the rule was applied to the POC population.

Results

A lung function abnormality was found in 74 % of the OME population and 67 % of the POC population. Sensitivity of the rule was 85 % for an obstructive pattern and 77 % for any abnormality on spirometry. Positive and negative predictive values of the rule for a spirometric abnormality were 74 and 55 %, respectively. Patients with an obstructive pattern were at greater risk of coronary heart disease (odds ratio (OR) 1.39 [confidence interval (CI) 1.00–1.93] vs. normal) and death (hazard ratio (HR) 1.53, 95 % CI 1.20–1.84) than subjects with normal spirometry. Restricted spirometry patterns were also associated with greater risk of coronary disease (odds ratio (OR) 1.7 [CI 1.23–2.35]) and death (Hazard ratio 1.40, 95 % CI 1.08–1.72).

Conclusions

Smokers (≥ 20 pack years) age ≥ 40 years are at an increased risk for lung function abnormalities and those abnormalities are associated with greater presence of coronary heart disease and increased all-cause mortality. Use of the 20/40 rule could provide a simple method to enhance selection of candidates for spirometry evaluation in the primary care setting.

Pitfalls in Radiographic Interpretation of Emphysema Patients

Emphysema commonly accompanies various complications such as pneumonia. Sometimes, these comorbidities look so strange on images, because destroyed airspaces could change the usual disease progression. So, we demonstrated various cases of common comorbidities with unusual radiographic findings in emphysema patients. Awareness of various findings of emphysema with commonly coexistent diseases may aid in the proper diagnosis and management of emphysema patients.

Combined pulmonary fibrosis and emphysema (CPFE): what radiologist should know

Combined pulmonary fibrosis and emphysema is a relatively newly defined entity, which has been deeply studied in the recent years. Despite the wide numbers of papers on this topic, there are still several open questions about pathogenesis, epidemiology, natural history and prognosis. The diagnosis could be assessed only after HRCT scan as functional tests often result in an underestimation of this syndrome. What radiologists need to know about this syndrome consists in the heterogeneity of appearances: emphysema is mainly paraseptal and fibrotic pattern could be variable, including the variant of airspace enlargement with fibrosis which needs to be differentiated from honeycombing. A special attention must be paid on complications which could worsen the prognosis, such as pulmonary hypertension and lung cancer. Further studies are needed to address if the type of fibrotic pattern as well as fibrosis CT index could be considered as prognostic factors. Thus, the role of radiologists in the management of these patients is crucial as it involves diagnosis, detection of complications and could possible concerns the identification of patients at higher risk.

[Pulmonary Langerhans cell histiocytosis]

Pulmonary Langerhans cell histiocytosis is regarded as a reactive proliferation of the dendritic Langerhans cell population stimulated by chronic tobacco-derived plant proteins due to incomplete combustion but can also occur in childhood as a tumor-like systemic disease. Currently, both these forms cannot be morphologically distinguished. In the lungs a nodular proliferation of Langerhans cells occurs in the bronchial mucosa and also peripherally in the alveolar septa with an accompanying infiltration by eosinophilic granulocytes and destruction of the bronchial wall. Langerhans cells can be selectively detected with antibodies against CD1a and langerin. In the reactive isolated pulmonary form, abstinence from tobacco smoking in most patients leads to regression of infiltration and improvement of symptoms. In high-resolution computed tomography (HRCT) the small star-like scars can still be detected even after complete cessation of tobacco smoking.

Mosaic Attenuation: Etiology, Methods of Differentiation, and Pitfalls

Mosaic attenuation is a commonly encountered pattern on computed tomography that is defined as heterogeneous areas of differing lung attenuation. This heterogeneous pattern of attenuation is the result of diverse causes that include diseases of the small airways, pulmonary vasculature, alveoli, and interstitium, alone or in combination. Small airways disease can be a primary disorder, such as respiratory bronchiolitis or constrictive bronchiolitis, or be part of parenchymal lung disease, such as hypersensitivity pneumonitis, or large airways disease, such as bronchiectasis and asthma. Vascular causes resulting in mosaic attenuation are typically chronic thromboembolic pulmonary hypertension, which is characterized by organizing thrombi in the elastic pulmonary arteries, or pulmonary arterial hypertension, a heterogeneous group of diseases affecting the distal pulmonary arterioles. Diffuse ground-glass opacity can result in a mosaic pattern related to a number of processes in acute (eg, infection, pulmonary edema), subacute (eg, organizing pneumonia), or chronic (eg, fibrotic diseases) settings. Imaging clues that can assist the radiologist in pinpointing a diagnosis include evidence of large airway involvement, cardiovascular abnormalities, septal thickening, signs of fibrosis, and demonstration of airtrapping at expiratory imaging.

Smoking-related idiopathic interstitial pneumonia: A review

For many years, cigarette smoking has been considered as the leading cause of chronic obstructive pulmonary disease and lung cancer. Recently, however, it has also been associated with the development of diffuse interstitial lung diseases. In the latest classification of the major idiopathic interstitial pneumonias (IIP), the term smoking-related IIP has been introduced, including two entities, namely desquamative interstitial pneumonia (DIP) and respiratory bronchiolitis-interstitial lung disease (RB-ILD). Other entities in which smoking has a definite or suggested role include pulmonary Langerhan's cell histiocytosis, smoking-related interstitial fibrosis, combined pulmonary fibrosis and emphysema syndrome and idiopathic pulmonary fibrosis. In this review, we will focus on the mechanisms of smoking-related lung damage and on the clinical aspects of these disorders with the exception of idiopathic pulmonary fibrosis, which will be reviewed elsewhere in this review series.

Improvement in idiopathic nonspecific interstitial pneumonia after smoking cessation

Although cigarette smoking has been recognized as a risk factor for the development of several interstitial lung diseases, the relationship between smoking and nonspecific interstitial pneumonia (NSIP) has not yet been fully elucidated. We here present a case of fibrotic NSIP with mild emphysema in an elderly male with normal pulmonary function, whose symptoms, serum KL-6 level, and high-resolution computed tomography findings of interstitial changes markedly improved without medication following the cessation of smoking. Our case suggests that smoking may be an etiological factor in some patients with NSIP and that early smoking cessation before a clinically detectable decline in pulmonary function may be critical for smokers with idiopathic NSIP.

Paraseptal emphysema: Prevalence and distribution on CT and association with interstitial lung abnormalities

OBJECTIVE

To investigate the prevalence and distribution of paraseptal emphysema on chest CT images in the Framingham Heart Study (FHS) population, and assess its impact on pulmonary function. Also pursued was the association with interstitial lung abnormalities.

MATERIALS AND METHODS

We assessed 2633 participants in the FHS for paraseptal emphysema on chest CT. Characteristics of the participants, including age, sex, smoking status, clinical symptoms, and results of pulmonary function tests, were compared between those with and without paraseptal emphysema. The association between paraseptal emphysema and interstitial lung abnormalities was investigated.

RESULTS

Of the 2633 participants, 86 (3%) had pure paraseptal emphysema (defined as paraseptal emphysema with no other subtypes of emphysema other than paraseptal emphysema or a very few centrilobular emphysema involved) in at least one lung zone. The upper zone of the lungs was almost always involved. Compared to the participants without paraseptal emphysema, those with pure paraseptal emphysema were significantly older, and were more frequently male and smokers (mean 64 years, 71% male, mean 36 pack-years, P<0.001) and had significantly decreased FEV1/FVC% (P=0.002), and diffusion capacity of carbon monoxide (DLCO) (P=0.002). There was a significant association between pure paraseptal emphysema and interstitial lung abnormalities (P<0.001).

CONCLUSIONS

The prevalence of pure paraseptal emphysema was 3% in the FHS population, predominantly affects the upper lung zone, and contributes to decreased pulmonary function. Cigarette smoking, aging, and male gender were the factors associated with the presence of paraseptal emphysema. Significant association between paraseptal emphysema and interstitial lung abnormalities was observed.

Pulmonary langerhans cell histiocytosis: case series and literature review

Pulmonary Langerhans cell histiocytosis (PLCH) is a rare disease with insidious onset and nonspecific manifestations. The objective of this article was to characterize the clinical manifestations and features of PLCH by retrospectively analyzing clinical data of patients with PLCH in addition to simultaneous review of literature.A retrospective analysis was conducted on clinical data of patients with PLCH (n = 7), whose conditions were diagnosed by biopsy from pulmonary tissue (n = 6) or enlarged lymph nodes in the neck (n = 1) and confirmed by PLCH typical radiological features on computed tomography (CT) scan, between January 2001 and September 2012 at the Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China. The review of published reports was made to further emphasize the clinical manifestation and radiological features of PLCH.Long history of cigarette smoking was found in 6 patients. Two patients had recurrent pneumothorax and the other 2 had pulmonary arterial hypertension (World Health Organization group 5 pulmonary hypertension), diagnosed through ultrasonic cardiogram. The nodular shadows were revealed by chest CT scan in 5 patients, cystic shadows in 5 patients, and reticular shadows in 2 patients, as major manifestations, respectively; most of the lesions were located in the middle or upper segments of the lung. The obvious shrank of lesion was found in 1 patient after completely quitting smoking.The pathogenesis of PLCH might be closely associated with smoking. The cystic or nodular lesion was the typical radiological features. Further prospective studies with large sample size are required to further validate the study results and understand the clinical characteristics of PLCH to avoid misdiagnosis.

Smoking-related idiopathic interstitial pneumonia

Cigarette smoking is a key factor in the development of numerous pulmonary diseases. An international group of clinicians, radiologists and pathologists evaluated patients with previously identified idiopathic interstitial pneumonia (IIP) to determine unique features of cigarette smoking. Phase 1 (derivation group) identified smoking-related features in patients with a history of smoking (n=41). Phase 2 (validation group) determined if these features correctly predicted the smoking status of IIP patients (n=100) to participants blinded to smoking history. Finally, the investigators sought to determine if a new smoking-related interstitial lung disease phenotype could be defined. Phase 1 suggested that preserved forced vital capacity with disproportionately reduced diffusing capacity of the lung for carbon monoxide, and various radiographic and histopathological findings were smoking-related features. In phase 2, the kappa coefficient among clinicians was 0.16 (95% CI 0.11-0.21), among the pathologists 0.36 (95% CI 0.32-0.40) and among the radiologists 0.43 (95% CI 0.35-0.52) for smoking-related features. Eight of the 100 cases were felt to represent a potential smoking-related interstitial lung disease. Smoking-related features of interstitial lung disease were identified in a minority of smokers and were not specific for smoking. This study is limited by its retrospective design, the potential for recall bias in smoking history and lack of information on second-hand smoke exposure. Further research is needed to understand the relationship between smoking and interstitial lung disease.