Hypersensitivity Pneumonitis: Spectrum of High-Resolution CT and Pathologic Findings

Imaging of Small Airways Disease

Bronchiolitis refers to a small airways disease and may be classified by etiology and histologic features. In cellular bronchiolitis inflammatory cells involve the small airway wall and peribronchiolar alveoli and manifest on CT as centrilobular nodules of solid or ground glass attenuation. Constrictive bronchiolitis refers to luminal narrowing by concentric fibrosis. Direct CT signs of small airway disease include centrilobular nodules and branching tree-in-bud opacities. An indirect sign is mosaic attenuation that may be exaggerated on expiratory CT and represent air trapping. Imaging findings can be combined with clinical and pathologic data to facilitate a more accurate diagnosis.

Unusual pediatric lung infections: imaging findings

Pediatric lung infections continue to be a leading cause of pediatric morbidity and mortality. Although both pediatric and general radiologists are familiar with typical lung infections and their imaging findings in children, relatively rare lung infections continue to present a diagnostic challenge. In addition, the advances in radiological imaging and emergence of several new lung infections in recent years facilitated the need for up-to-date knowledge on this topic. In this review article, we discuss the imaging findings of pediatric lung infections caused by unusual/uncommon and new pathogens. We review the epidemiological, clinical, and radiological imaging findings of viral (coronavirus disease 2019, Middle East respiratory syndrome, bird flu), bacterial (Streptococcus anginosus, Francisella tularensis, Chlamydia psittaci), and parasitic lung infections (echinococcosis, paragonimiasis, amoebiasis). Additional disorders whose clinical course and imaging findings may mimic lung infections in children (hypersensitivity pneumonitis, pulmonary hemorrhage, eosinophilic pneumonia) are also presented, to aid in differential diagnosis. As the clinical presentation of children with new and unusual lung infections is often non-specific, imaging evaluation plays an important role in initial detection, follow-up for disease progression, and assessment of potential complications.

Recurrent episodes of febrile dyspnoea: hypersensitivity pneumonitis caused by a household ultrasonic humidifier

Hypersensitivity pneumonitis is an immune-mediated interstitial lung disease that presents with respiratory symptoms, with or without systemic symptoms, following exposure to an identified or unidentified external factor. It can be caused by extrinsic factors including household items such as ultrasonic humidifiers.We present an intriguing case of a previously healthy 50-year-old man who displayed recurrent episodes of progressive dyspnoea and fever after repeated exposure to his household ultrasonic humidifier. He was treated with corticosteroids, followed by the removal of the humidifier, resulting in total recovery and absence of recurrence of further episodes.The clinical presentation of hypersensitivity pneumonitis can be dramatic, and the differential diagnosis is broad. The correct diagnosis is achieved by combining clinical, radiological and histopathological patterns. The key to finding the aetiology lies in a thorough history, with an important role for household investigations to identify the external factor.

The role of CT-scan in the diagnosis and prognosis of COVID-19 in a sample of Iraqi patients referred to Al-Diwaniyah Teaching Hospital, Iraq

The respiratory system is the primary target of the SARS-CoV-2 virus, leading to clinical manifestations such as dry cough, fever, and shortness of breath. Other reported manifestations include generalized weakness, dizziness, headache, vomiting, and diarrhea. A chest CT scan is one of the best imaging tools to screen and diagnose COVID-19. This prospective observational study was conducted at Al-Diwaniyah Teaching Hospital in the mid-Euphrates region of Iraq to assess the prognostic role of chest CT examinations in COVID-19 patients between February 2020 and July the 15th, 2020. The study included 100 patients suspected of COVID-19 based on clinical features and microbiological investigations, comprising 72 males and 28 females aged between 30 and 55. All patients were SARS-CoV-2 PCR positive and had no history of chronic lung disease. We categorized patients into two groups based on changes in density and lesion area: patients with changes (n=55) and patients without changes (n=45). Furthermore, we divided all patients into three groups according to treatment requirements and symptom severity: group 1 included patients with severe symptoms who required CPAP and admission to the Respiratory Care Unit, group 2 consisted of patients with moderate symptoms who needed oxygen therapy and hospital admission, and group 3 comprised patients with mild symptoms who were treated as outpatients with medication. Upon correlating the change in density and lesion area with these groups, we observed that most patients with no changes were in group 1, while patients with changes were predominantly seen in group 2. Additionally, the ratio of lesion area in the mediastinal CT window to lung CT was identified as a potential prognostic factor for COVID-19 patients.

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.

Diagnosis and Pharmacologic Management of Fibrotic Interstitial Lung Disease

Interstitial lung disease is an umbrella term that encompasses a spectrum of parenchymal lung pathologies affecting the gas exchanging part of the lung. While many of these disease entities are not fibrotic in nature, a number can lead to pulmonary fibrosis which may or may not progress over time. Idiopathic pulmonary fibrosis is the prototypical, progressive fibrotic interstitial lung disease, which can lead to worsening hypoxemic respiratory failure and mortality within a number of years from the time of diagnosis. The importance of an accurate and timely diagnosis of interstitial lung diseases, which is needed to inform prognosis and guide clinical management, cannot be overemphasized. Developing a consensus diagnosis requires the incorporation of a variety of factors by a multidisciplinary team, which then may or may not determine a need for tissue sampling. Clinical management can be challenging given the heterogeneity of disease behavior and the paucity of controlled trials to guide decision making. This review addresses current paradigms and recent updates in the diagnosis and pharmacologic management of these fibrotic interstitial lung diseases.

Is the combination of bilateral pulmonary nodules and mosaic attenuation on chest CT specific for DIPNECH?

Background

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is characterized by multifocal proliferation of pulmonary neuroendocrine cells. On chest CT, DIPNECH exhibits bilateral pulmonary nodules and mosaic attenuation in most patients. We sought to: (1) assess the specificity of this pattern (i.e., bilateral pulmonary nodules together with mosaic attenuation) for DIPNECH; (2) describe its differential diagnosis; and (3) identify the clinico-radiologic features that may help prioritize DIPNECH over other diagnostic considerations.

Methods

We searched the Mayo Clinic records from 2015 to 2019 for patients with bilateral pulmonary nodules and mosaic attenuation on CT who had a diagnostic lung biopsy. A thoracic radiologist reviewed all CT scans. Chi-square test was used for categorical variables, and odds ratios were utilized to measure the association between certain variables and DIPNECH.

Results

Fifty-one patients met our inclusion criteria; 40 (78%) were females and 34 (67%) were never-smokers. Median age was 65 (interquartile range 55–73) years. Lung biopsy was surgical in 21 patients (41%), transbronchial in 17 (33%), and transthoracic in 12 (24%); explanted lungs were examined in 1 (2%). Metastatic/multifocal cancer was the most common diagnosis, and was found in 17 (33%) cases. Bronchiolitis was diagnosed in 12 patients (24%), interstitial lung disease in 10 (20%), and DIPNECH in 5 (10%). Previous diagnosis of an obstructive lung disease (odds ratio 15.8; P = 0.002), and peribronchial nodular distribution on CT (odds ratio 14.4; P = 0.006) were significantly correlated with DIPNECH. Although statistical significance was not reached, DIPNECH nodules were more likely to display solid attenuations (80% vs. 67%, P = 0.45), and were more numerous; > 10 nodules were seen in 80% of DIPNECH cases vs. 52% in others (P = 0.23). Because DIPNECH primarily affects women, we analyzed the women-only cohort and found similar results.

Conclusions

Various disorders can manifest the CT pattern of bilateral pulmonary nodules together with mosaic attenuation, and this combination is nonspecific for DIPNECH, which was found in only 10% of our cohort. Previous diagnosis of an obstructive lung disease, and peribronchial distribution of the nodules on CT increased the likelihood of DIPNECH vs. other diagnoses.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-02103-w.

Interstitial Lung Abnormalities: State of the Art

The clinical importance of interstitial lung abnormality (ILA) is increasingly recognized. In July 2020, the Fleischner Society published a position paper about ILA. The purposes of this article are to summarize the definition, existing evidence, clinical management, and unresolved issues for ILA from a radiologic standpoint and to provide a practical guide for radiologists. ILA is a common incidental finding at CT and is often progressive and associated with worsened clinical outcomes. The hazard ratios for mortality range from 1.3 to 2.7 in large cohorts. Risk factors for ILA include age, smoking status, other inhalational exposures, and genetic factors (eg, gene encoding mucin 5B variant). Radiologists should systematically record the presence, morphologic characteristics, distribution, and subcategories of ILA (ie, nonsubpleural, subpleural nonfibrotic, and subpleural fibrotic), as these are informative for predicting progression and mortality. Clinically significant interstitial lung disease should not be considered ILA. Individuals with ILA are triaged into higher- and lower-risk groups depending on their risk factors for progression, and systematic follow-up, including CT, should be considered for the higher-risk group. Artificial intelligence-based automated analysis for ILA may be helpful, but further validation and improvement are needed. Radiologists have a central role in clinical management and research on ILA.

Occupational lung disease: A narrative review of lung conditions from the workplace

Occupational lung diseases are lung conditions caused or made worse by materials when a person is exposed to a workplace. The diagnosis of an occupational disease is important for workers' decision to continue work and for their eligibility under compensation programmes. We revisit the existing lung diseases that are closely associated with the occupation at the workplace namely occupational asthma, silicosis, black lung disease, farmers' lung disease, asbestos-linked disease, and hypersensitivity pneumonitis. Occupational lung diseases contribute toward global health and economic impacts. Prevention and control of occupational lung diseases require a collaborative effort among employers, workers, occupational physicians, pulmonary physicians, industrial hygienists, and members from other disciplines.

Differential diagnoses of COVID-19 pneumonia: the current challenge for the radiologist-a pictorial essay

BACKGROUND

COVID-19 pneumonia represents the most severe pandemic of the twenty-first century and has crucial clinical, social and economical implications. The scientific community has focused attention and resources on clinical and radiological features of COVID-19 pneumonia. Few papers analysing the vast spectrum of differential diagnoses have been published.

MAIN BODY

Complexity of differential diagnosis lays in the evidence of similar radiological findings as ground-glass opacities, crazy paving pattern and consolidations in COVID-19 pneumonia and a multitude of other lung diseases. Differential diagnosis is and will be extremely important during and after the pandemic peak, when there are fewer COVID-19 pneumonia cases. The aim of our pictorial essay is to schematically present COVID-19 pneumonia most frequent differential diagnoses to help the radiologist face the current COVID-19 pneumonia challenge.

CONCLUSIONS

Clinical data, laboratory tests and imaging are pillars of a trident, which allows to reach a correct diagnosis in order to grant an excellent allocation of human and economical resources. The radiologist has a pivotal role in the early diagnosis of COVID-19 pneumonia because he may raise suspicion of the pathology and help to avoid COVID-19 virus spread.

Chest Imaging in the Diagnosis of Occupational Lung Diseases

Imaging plays a crucial role in the diagnosis and monitoring of occupational lung diseases (OLDs); however, the sensitivity and specificity of detection and diagnosis vary greatly depending on the imaging modality used. There is substantial overlap in appearance with non-occupation-related entities. OLDs should be considered in the differential even in the absence of a provided exposure history. Because many findings are not specific, a multidisciplinary approach is important in arriving at the diagnosis and will continue to be important as workplace-related pulmonary diseases evolve with changing industrial practices and workplace regulations.

Micronodular lung disease on high-resolution CT: patterns and differential diagnosis

With the advent of high-resolution computed tomography (HRCT), micronodular lung disease is a routinely encountered pathology in thoracic imaging. This article will review how to differentiate the three main micronodular patterns and review the differential diagnosis for each. Differential diagnosis of micronodular lung disease may be extensive, but by identifying the pattern and using additional clues, such as distribution, additional imaging findings, and clinical history, a radiologist can make an accurate diagnosis. First, three micronodular patterns - centrilobular, peri-lymphatic, and random - can be identified by using a simple algorithm based on the location of nodules. This algorithm requires understanding of the anatomy and function of the secondary pulmonary lobule. Each micronodular pattern offers a unique differential diagnosis. Centrilobular nodules can be seen with inflammatory, infectious, or vascular aetiologies; peri-lymphatic nodules with sarcoidosis and lymphangitic carcinomatosis; and random nodules with haematogenous metastases or infections.

Clinico-etiological characteristics of organizing pneumonia: A retrospective study

Introduction:

Organizing pneumonia (OP) is an idiopathic interstitial pneumonia characterized radiologically by the patchy peripheral areas of ground-glass opacities and consolidation. It is commonly associated with a variety of conditions such as connective tissue diseases (CTD), drugs, infections, malignancy, radiation exposure, post-transplant, and other interstitial pneumonia. There are no specific clinical manifestations unless there is an underlying etiology. We present a series of such cases.

Aims and Objectives:

The aim of the study was to identify the clinical characteristics and etiological spectrum of patients manifesting radiologically with OP pattern.

Materials and Methods:

This was a retrospective analysis of clinico-radiological profile and etiological diagnosis of 23 patients, who had a radiological diagnosis of OP during the period of January 2017–September 2019.

Results:

Our patients presented with nonspecific symptoms of cough, fever, breathlessness, and occasionally with hemoptysis. The various etiologies identified were CTD (n = 4), infection (n = 2), drugs (n = 4), radiation (n = 1), chronic aspiration syndrome (n = 1), malignancy (n = 2), hypersensitivity pneumonitis (n = 1), and chronic heart failure (n = 2), and in majority (n = 7), no underlying etiology was evident and were labeled as cryptogenic organizing pneumonia.

Conclusion:

OP is an underdiagnosed entity and is associated with numerous diseases varying from pulmonary tuberculosis to malignancy. Identification of the underlying disease process is of paramount importance as it enables the treating physician to implement necessary therapeutic interventions.

Hypersensitivity Pneumonitis High-resolution Computed Tomography Findings, and Their Correlation with the Etiology and the Disease Duration

Hypersensitivity pneumonitis (HP) is an immune-mediated diffuse parenchymal lung disease induced by inhaled antigens. High-resolution computed tomography (HRCT) is widely used in the diagnosis and follow-up of patients and determining the progression and prognosis of the disease. In this retrospective study, 45 consecutive patients with the final diagnosis of HP, seen at a large tertiary care center during a period of 4 years, were included and their HRCT findings were evaluated. The most common HRCT findings were ground glass opacity and reticulation. Some HRCT patterns were detected more severely in bird fanciers in comparison with other etiologies. There is no "gold standard" for the diagnosis of HP. HRCT findings play an important role in hypersensitivity pneumonitis diagnosis and CT scan also help to define the severity of hypersensitivity pneumonitis injuries. In our study, reticulation and ground glass opacity were the most common findings in HRCT of patients with HP. We also find that patients with avian contacts had a significantly higher rate of fibrosis.

Chest computed tomography findings of coronavirus disease 2019 (COVID-19) pneumonia

OBJECTIVE

To retrospectively analyze the chest computed tomography (CT) features in patients with coronavirus disease 2019 (COVID-19) pneumonia.

METHODS

From January 9, 2020, to February 26, 2020, totally 56 laboratory-confirmed patients with COVID-19 underwent chest CT. For 40 patients, follow-up CT scans were obtained. The CT images were evaluated for the number, type and distribution of the opacity, and the affected lung lobes. Furthermore, the initial CT scan and the follow-up CT scans were compared.

RESULTS

Forty patients (83.6%) had two or more opacities in the lung. Eighteen (32.7%) patients had only ground-glass opacities; twenty-nine patients (52.7%) had ground-glass and consolidative opacities; and eight patients (14.5%) had only consolidation. A total of 43 patients (78.2%) showed two or more lobes involved. The opacities tended to be both in peripheral and central (30/55, 54.5%) or purely peripheral distribution (25/55, 45.5%). Fifty patients (90.9%) had the lower lobe involved. The first follow-up CT scans showed that twelve patients (30%) had improvement, 26 (65%) patients had mild-moderate progression, and two patients (5%) had severe progression with "white lungs." The second follow-up CT showed that 22 patients (71%) showed improvement compared with the first follow-up CT, four patients (12.9%) had aggravated progression, and five patients (16.1%) showed unchanged radiographic appearance.

CONCLUSIONS

The common CT features of COVID-19 pneumonia are multiple lung opacities, multiple types of the opacity (ground-glass, ground-glass and consolidation, and consolidation alone), and multiple lobes especially the lower lobe involved. Follow-up CT could demonstrate the rapid progression of COVID-19 pneumonia (either in aggravation or absorption).

KEY POINTS

• The predominant CT features of COVID-19 pneumonia are multiple ground-glass opacities with or without consolidation and, with both lungs, multiple lobes and especially the lower lobe affected. • CT plays a crucial role in early diagnosis and assessment of COVID-19 pneumonia progression. • CT findings of COVID-19 pneumonia may not be consistent with the clinical symptoms or the initial RT-PCR test results.

Clinical and radiological characteristics of e-cigarette or vaping product use associated lung injury

PURPOSE

E-cigarette or vaping product use associated lung injury (EVALI) has received national attention as an epidemic resulting in cases of significant morbidity and mortality. We aim to present the clinical and imaging findings in adolescents with pulmonary symptoms from suspected EVALI.

METHODS

Chest radiographs and CTs of adolescents (< 19 years) with acute pulmonary symptoms and history of vaping were reviewed by two radiologists in consensus. Clinical presentation and laboratory data were derived from the electronic medical records including pulmonary function tests (PFTs).

RESULTS

Eleven patients were identified (9 male, mean 16.6 years). The most common presentation was progressive, subacute respiratory distress with abdominal pain. All but one of the patients tested positive for tetrahydrocannabinol. Chest radiograph features were notable for interstitial pattern of opacities (91%) and basilar abnormalities (82%). CT features were notable for ground-glass opacities (89%), interstitial opacities (78%), and subpleural sparing (67%). Eight patients underwent PFTs. Six had diffusing capacity measurement, which demonstrated impaired diffusion in 3 (50%). All patients received supportive treatment with supplemental oxygen and corticosteroids.

CONCLUSION

Adolescents with suspected EVALI commonly present with subacute respiratory distress with abdominal pain. Imaging findings include ground-glass opacities, subpleural sparing, and basilar opacities, most consistent with organizing pneumonia or hypersensitivity pneumonitis. Recognition of the common imaging findings may have significant patient management implications, especially if the diagnosis is not suspected clinically. The lung function effects of vaping are consistent with mildly reduced airflow, which improves on follow-up testing, and reduced diffusion capacity, which, concerningly, does not improve.

A Pathophysiological Perspective on COVID-19's Lethal Complication: From Viremia to Hypersensitivity Pneumonitis-like Immune Dysregulation

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the coronavirus responsible for our recent coronavirus disease 2019 pandemic, is driving a lung immunopathology that strongly resembles a severe form of hypersensitivity pneumonitis (HP). A review of recent Severe acute respiratory syndrome-related coronavirus (SARS-CoV) and SARS-CoV-2 medical reports, as well as described characteristics of HP, lead us to postulate a theory for SARS-CoV-2 severe disease. We propose that the novel SARS-CoV-2 can act as a trigger and substrate of an HP-like severe immune reaction especially in genetically vulnerable individuals in addition to those with immune senescence and dysregulation. Accordingly, the purpose of our letter is to shift the emphasis of concern surrounding immune activity from viral infection to an HP-like severe immune reaction. We review similarities in disease presentation between infection and allergy, relevant immunopathology, and outline phases of SARS-CoV-2 disease with perspectives on therapy and critical care. Altogether, the favored course is to begin treatments that address the disease at the earliest phase before immune dysregulation leading to uncontrolled pulmonary inflammation.

Hamman-Rich Syndrome: A Diagnosis of Exclusion in the COVID-19 Pandemic

Hamman-Rich syndrome is a rapidly progressive interstitial lung disease with acute respiratory distress syndrome physiology. It carries a grave prognosis and a high early mortality rate. It is often distinguished from other similar pulmonary pathologies based on the clinical course, laboratory findings, bronchoalveolar lavage testing, and pathology report. We detail a 77-year-old lady with no prior pulmonary disease, smoking history, or occupational and environmental exposures present to the emergency department found to be in acute hypoxic respiratory failure with impressive progressive radiographic findings. The presumptive diagnosis of Hamman-Rich syndrome was made based on a combination of factors after ruling out other similar clinical entities, especially in the setting of an ongoing COVID-19 pandemic.

Clinical and imaging features of COVID-19

Since December 2019, multiple cases of 2019 coronavirus disease (COVID-19) have been reported in Wuhan in China's Hubei Province, a disease which has subsequently spread rapidly across the entire country. Highly infectious, COVID-19 has numerous transmission channels and humans are highly susceptible to infection. The main clinical symptoms of COVID-19 are fever, fatigue, and a dry cough. Laboratory examination in the early stage of the disease shows a normal or decreased white blood cell count, and a decreased lymphocyte count. While CT examination serves as the screening and diagnostic basis for COVID-19, its accuracy is limited. The nucleic acid testing is the gold standard for the diagnosis of COVID-19, but has a low sensitivity is low. There is clearly a divide between the two means of examination. This paper reviews the published literature, guidelines and consensus, and summarizes the clinical and imaging characteristics of COVID-19, in order to provide a reliable basis for early diagnosis and treatment.

Fibrotic Hypersensitivity Pneumonitis: Diagnosis and Management

Fibrotic hypersensitivity pneumonitis is a complex interstitial lung disease that is not entirely understood. In its chronic and fibrotic form, hypersensitivity pneumonitis is one of the main mimickers of idiopathic pulmonary fibrosis (IPF). Distinguishing between these two conditions is challenging but is of particular clinical relevance. Two approved therapies are available for IPF, and a considerable number of clinical trials are now exploring newer pharmacological options. This impressive research effort is a consequence of new pathogenetic understanding, updated diagnostic criteria and a long history of pharmacological trials. Conversely, current knowledge gaps on pathogenesis of chronic hypersensitivity pneumonitis, coupled with lack of validated diagnostic criteria, make the management of this disease an unsolved clinical challenge. This also reflects the paucity of therapeutic clinical trials in this field. In this review, we describe the current evidence and the possible future options to approach this complex disease.

Diagnostic value and key features of computed tomography in Coronavirus Disease 2019

On 31 December 2019, a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, Hubei province, China, and caused the outbreak of the Coronavirus Disease 2019 (COVID-19). To date, computed tomography (CT) findings have been recommended as major evidence for the clinical diagnosis of COVID-19 in Hubei, China. This review focuses on the imaging characteristics and changes throughout the disease course in patients with COVID-19 in order to provide some help for clinicians. Typical CT findings included bilateral ground-glass opacity, pulmonary consolidation, and prominent distribution in the posterior and peripheral parts of the lungs. This review also provides a comparison between COVID-19 and other diseases that have similar CT findings. Since most patients with COVID-19 infection share typical imaging features, radiological examinations have an irreplaceable role in screening, diagnosis and monitoring treatment effects in clinical practice.

ChILD: A Pictorial Review of Pulmonary Imaging Findings in Childhood Interstitial Lung Diseases

Childhood interstitial lung disease (chILD) is a group of lung disorders characterized by lung remodeling leading to abnormal gas exchange. ChILD is classified differently from adult interstitial lung disease and encompasses 2 broad categories: "disorders more prevalent in infancy" (<2 years) and "disorders not specific to infancy" (>2 years). High-resolution computed tomography can play an important role in the evaluation of chILD by narrowing the differential diagnosis and preventing unnecessary invasive procedures if typical imaging patterns are recognized. Thus, the pediatric radiologist should consider chILD in children with respiratory distress and identify the imaging patterns to suggest the diagnosis.

Chronic hypersensitivity pneumonitis in the southeastern United States: an assessment of how clinicians reached the diagnosis

Background

Chronic hypersensitivity pneumonitis (cHP) is a disease caused by exposure to inhaled environmental antigens. Diagnosis of cHP is influenced by the awareness of the disease prevalence, which varies significantly in different regions, and how clinicians utilize relevant clinical information. We conducted a retrospective study to evaluate how clinicians in the Southeast United States, where the climate is humid favoring mold growth, diagnosed cHP using items identified in the international modified Delphi survey of experts, i.e., environmental exposure, CT imaging and lung pathology,

Methods

We searched Duke University Medical Center database for patients over the age of 18 with a diagnosis of cHP (ICD-9 code: 495) between Jan. 1, 2008 to Dec. 31, 2013 using a query tool, Duke Enterprise Data Unified Content Explorer (DEDUCE).

Results

Five hundred patients were identified and 261 patients had cHP confirmed in clinic notes by a pulmonologist or an allergist. About half of the patients lived in the Research Triangle area where our medical center is located, giving an estimated prevalence rate of 6.5 per 100,000 persons. An exposure source was mentioned in 69.3% of the patient. The most common exposure sources were environmental molds (43.1%) and birds (26.0%). We used Venn diagram to evaluate how the patients met the three most common cHP diagnostic criteria: evidence of environmental exposures (history or precipitin) (E), chest CT imaging (C) and pathology from lung biopsies (P). Eighteen patients (6.9%) met none of three criteria. Of the remaining 243 patients, 135 patients (55.6%) had one (E 35.0%, C 3.3%, P 17.3%), 81 patients (33.3%) had two (E + C 12.3%, E + P 17.3%, C + P 4.9%), and 27 patients (11.1%) had all three criteria (E + C + P). Overall, 49.4% of patients had pathology from lung biopsy compared to 31.6% with CT scan.

Conclusions

Environmental mold was the most common exposure for cHP in the Southeast United States. Lung pathology was available in more than half of cHP cases in our tertiary care center, perhaps reflecting the complexity of referrals. Differences in exposure sources and referral patterns should be considered in devising future diagnostic pathways or guidelines for cHP.

An Algorithmic Approach to the Interpretation of Diffuse Lung Disease on Chest CT Imaging: A Theory of Almost Everything

We propose an algorithmic approach to the interpretation of diffuse lung disease on high-resolution CT. Following an initial review of pertinent lung anatomy, the following steps are included. Step 1: a preliminary review of available chest radiographs, including the "scanogram" obtained at the time of the CT examination. Step 2: a review of optimal methods of data acquisition and reconstruction, emphasizing the need for contiguous high-resolution images throughout the entire thorax. Step 3: initial uninterrupted scrolling of contiguous high-resolution images throughout the chest to establish the quality of examination as well as an overview of the presence and extent of disease. Step 4: determination of one of three predominant categories - primarily reticular disease, nodular disease, or diseases associated with diffuse alteration in lung density. Based on this determination, one of the three following Steps are followed: Step 5: evaluation of cases primarily involving diffuse lung reticulation; Step 6: evaluation of cases primarily resulting in diffuse lung nodules; and Step 7: evaluation of cases with diffuse alterations in lung density including those with diffusely diminished lung density vs those with heterogenous or diffusely increased lung density, respectively. It is anticipated that this algorithmic approach will substantially enhance initial interpretations of a wide range of pulmonary disease.

Hypersensitivity pneumonitis: Main features characterization in a Portuguese cohort

Hypersensitivity pneumonitis (HP) is an interstitial lung disease (ILD) which varies in prevalence across the world, depending on disease definition, diagnostic methods, exposure type and intensity, geographical environments, agricultural and industrial practices, and host risk factors. This study aimed to deepen knowledge about HP's clinical characteristics, diagnosis and functional and imaging features in a cohort of HP patients from the North of Portugal. To achieve this goal, a retrospective assessment of the clinical and diagnostic data was carried out, and patients were classified and compared according to disease presentation (acute, sub-acute and chronic HP forms). Of the 209 HP patients included (mean age 58.3 ± 16.0 years), 52.6% were female and 73.7% presented a chronic form. Most patients had prior exposure to birds (76.6%). Dyspnoea and cough were the most frequently experienced symptoms, but no statistically significant differences were found between groups (p = 0.089, p = 0.418, respectively). Fever was most common in acute HP form (p < 0.001). The most common patterns found in Chest CT were ground glass (p = 0.002) in acute/subacute presentation, and reticulation (p < 0.001) in chronic form, while mosaic attenuation, although was also frequently observed, no statistically significant differences were found between groups (p = 0.512). The most common functional pattern was restrictive (38% of patients, 73.7% with chronic HP form). Bronchoalveolar lavage lymphocytes were higher in acute and subacute forms although not reaching statistical significance (p = 0.072), with lowest CD4/CD8 ratio (p = 0.001) in acute forms. Thus, given the significant disease heterogeneity, further studies with different populations and ambient exposures are needed to achieve a better stratification of the exposure risk, to provide proper implementation of avoidance methods and a precise diagnostic and therapeutic approach.

Idiopathic pulmonary fibrosis: the radiologist's role in making the diagnosis

Radiologists have a critical role in the evaluation and diagnosis of suspected idiopathic pulmonary fibrosis (IPF). Accurate pattern identification on imaging is key in the multidisciplinary diagnostic process and frequently obviates the need for a surgical lung biopsy. In this review, we describe the clinical and imaging features of IPF in the context of recently revised international guidelines; contrast findings in other diseases that may inform differential diagnosis of fibrotic lung disease; and highlight common complications associated with pulmonary fibrosis.

Imaging of Pulmonary Hypertension: Pictorial Essay

Pulmonary hypertension (PH) is an end result of a diverse array of complex clinical conditions that invoke hemodynamic and pathophysiological changes in the pulmonary vasculature. Many patients' symptoms begin with dyspnea on exertion for which screening tests such as chest roentgenograms and more definitive noninvasive tests such as CT scans are ordered initially. It is imperative that clinicians are cognizant of subtle clues on these imaging modalities that alert them to the possibility of PH. These clues may serve as a stepping stone towards more advanced noninvasive (echocardiogram) and invasive (right heart catheterization) testing. On the CT scan, the signs are classified into mediastinal and lung parenchymal abnormalities. In addition to suspecting the diagnosis of PH, this paper provides a pictorial essay to guide health care professionals in identifying the etiology of PH. This paper also provides concrete definitions, wherever possible, of what constitutes abnormalities in PH, such as dilated pulmonary arteries, pruning of vessels, and increased thickness of free wall of the right ventricle. The sensitivities and specificities of each sign are enumerated. The common radiographic and clinical features of many different etiologies of PH are tabulated for the convenience of the readers. Some newer imaging modalities such as dual-energy CT of the chest that hold promise for the future are also described.

Desquamative interstitial pneumonia: Risk factors, laboratory and bronchoalveolar lavage findings, radiological and histopathological examination, clinical features, treatment and prognosis

Desquamative interstitial pneumonia is a type of smoking-associated major idiopathic interstitial pneumonia, which is characterized by accumulation of alveolar macrophages in alveolar lumens and septa and develops secondary to mainly active or passive exposure to cigarette smoke. Desquamative interstitial pneumonia mostly occurs in male smokers in association with non-specific symptoms responsive to steroid therapy and has a better prognosis than usual interstitial pneumonia. To date, no large-scale clinical studies have been performed on desquamative interstitial pneumonia patients. Factors responsible for the scarcity of data on the clinical course of this condition include the retrospective nature of the available information as well as its rare occurrence. Despite this, a general consensus exists as to the nature of its symptoms, association with smoking, age and gender distribution, findings of respiratory function tests, steroid responsivity and mortality. The objective of the present review article was to report on desquamative interstitial pneumonia and to describe its etiology, risk factors and clinical features, as well as the laboratory, bronchoalveolar lavage, radiological and histopathological findings, and the treatment and prognosis of affected patients.

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.

Mechanisms of exercise limitation in patients with chronic hypersensitivity pneumonitis

Small airway and interstitial pulmonary involvements are prominent in chronic hypersensitivity pneumonitis (cHP). However, their roles on exercise limitation and the relationship with functional lung tests have not been studied in detail.

Our aim was to evaluate exercise performance and its determinants in cHP. We evaluated maximal cardiopulmonary exercise testing performance in 28 cHP patients (forced vital capacity 57±17% pred) and 18 healthy controls during cycling.

Patients had reduced exercise performance with lower peak oxygen production (16.6 (12.3–19.98) mL·kg⁻¹·min⁻¹versus 25.1 (16.9–32.0), p=0.003), diminished breathing reserve (% maximal voluntary ventilation) (12 (6.4–34.8)% versus 41 (32.7–50.8)%, p<0.001) and hyperventilation (minute ventilation/carbon dioxide production slope 37±5 versus 31±4, p<0.001). All patients presented oxygen desaturation and augmented Borg dyspnoea scores (8 (5–10) versus 4 (1–7), p=0.004). The prevalence of dynamic hyperinflation was found in only 18% of patients. When comparing cHP patients with normal and low peak oxygen production (<84% pred, lower limit of normal), the latter exhibited a higher minute ventilation/carbon dioxide production slope (39±5.0 versus 34±3.6, p=0.004), lower tidal volume (0.84 (0.78–0.90) L versus 1.15 (0.97–1.67) L, p=0.002), and poorer physical functioning score on the Short form-36 health survey. Receiver operating characteristic curve analysis showed that reduced lung volumes (forced vital capacity %, total lung capacity % and diffusing capacity of the lung for carbon dioxide %) were high predictors of poor exercise capacity.

Reduced exercise capacity was prevalent in patients because of ventilatory limitation and not due to dynamic hyperinflation. Reduced lung volumes were reliable predictors of lower performance during exercise.

Besides significant small airway involvement, reduced exercise capacity is due to ventilatory limitation and not due to dynamic hyperinflation in chronic hypersensitivity pneumonitishttp://ow.ly/Ou9230kSBQz

Pulmonary measles disease: old and new imaging tools

BACKGROUND

Measles virus can cause lower respiratory tract infection, so that chest radiography is necessary to investigate lung involvement in patients with respiratory distress.

PURPOSE

To assess measles pneumonia imaging during the measles outbreak occurred in 2016-2017 in Italy.

MATERIAL AND METHODS

We retrospectively observed adult patients with a serological diagnosis of measles, who underwent chest-X rays for suspected pneumonia. If a normal radiography resulted, the patient underwent unenhanced CT. A CT post processing software package was used for an additional quantitative lung and airway involvement analysis .

RESULTS

Among 290 patients affected by measles, 150 underwent chest-X ray. Traditional imaging allowed the pneumonia diagnosis in 114 patients (76%). The most frequent abnormality at chest X-rays was bronchial wall thickening, observed in 88.5% of the cases; radiological findings are faint in the 25% of the cases (29/114 patients). In nine subjects with a normal chest X-ray, unenhanced CT with a quantitative analysis was performed, and depicted features consistent with constrictive bronchiolitis.

CONCLUSION

Measles may produce bronchiolitis and pneumonia. In the cases in which involvement of pulmonary parenchyma is not sufficient to result in radiological abnormalities, CT used with a dedicated postprocessing software package, provides an accurate lungs and airways analysis, also determining the percentage of lung involvement.

Utility of Bronchoalveolar Lavage and Transbronchial Biopsy in Patients with Hypersensitivity Pneumonitis

INTRODUCTION

Making the diagnosis of HP is challenging due to a lack of consensus criteria and variability of both pathologic and radiographic findings. The purpose of this retrospective study was to determine the diagnostic utility of the combination of BAL lymphocyte count and TBBX in patients with HP.

METHODS

We conducted a retrospective cohort study of all patients with a MDD diagnosis of HP at a single center.

RESULTS

155 patients were included in the study. 49% of patients who underwent BAL had a lymphocyte count > 20, 42% had a lymphocyte count > 30, and 34% had lymphocyte count > 40%. The median BAL lymphocyte count was higher in inflammatory HP compared to fibrotic HP. The addition of TBBX to BAL significantly increased the diagnostic yield regardless of the BAL lymphocyte cutoff used. The yield of bronchoscopy with TBBX and BAL when a lymphocyte count > 40% was used as a cutoff was 52%.

CONCLUSIONS

Our study suggests that the combination of TBBX with BAL significantly increases the likelihood that the procedure will provide adequate additional information to allow a confident MDD diagnosis of HP and may reduce the need for SLB in the diagnostic workup of HP.

Mold and Human Health: a Reality Check

There are possibly millions of mold species on earth. The vast majority of these mold spores live in harmony with humans, rarely causing disease. The rare species that does cause disease does so by triggering allergies or asthma, or may be involved in hypersensitivity diseases such as allergic bronchopulmonary aspergillosis or allergic fungal sinusitis. Other hypersensitivity diseases include those related to occupational or domiciliary exposures to certain mold species, as in the case of Pigeon Breeder's disease, Farmer's lung, or humidifier fever. The final proven category of fungal diseases is through infection, as in the case of onchomycosis or coccidiomycosis. These diseases can be treated using anti-fungal agents. Molds and fungi can also be particularly important in infections that occur in immunocompromised patients. Systemic candidiasis does not occur unless the individual is immunodeficient. Previous reports of "toxic mold syndrome" or "toxic black mold" have been shown to be no more than media hype and mass hysteria, partly stemming from the misinterpreted concept of the "sick building syndrome." There is no scientific evidence that exposure to visible black mold in apartments and buildings can lead to the vague and subjective symptoms of memory loss, inability to focus, fatigue, and headaches that were reported by people who erroneously believed that they were suffering from "mycotoxicosis." Similarly, a causal relationship between cases of infant pulmonary hemorrhage and exposure to "black mold" has never been proven. Finally, there is no evidence of a link between autoimmune disease and mold exposure.

Imaging of Asthma

Asthma is one of the most common diseases of the lung. Asthma manifests with common, although often subjective and nonspecific, imaging features at radiography and high-resolution computed tomography. The primary role of imaging is not to make a diagnosis of asthma but to identify complications, such as allergic bronchopulmonary aspergillosis, or mimics of asthma, such as hypersensitivity pneumonitis. This article reviews the imaging features of asthma as well as common complications and mimics.

Unabated occupational risk in a patient with rheumatoid pulmonary fibrosis

Background

This case highlights the importance of considering hypersensitivity pneumonitis (HP) in the differential diagnosis of interstitial lung disease (ILD) and of obtaining an occupational history so that remediable risk factors may be identified and managed.

Aims

To report a case of a chicken sexer with severe rheumatoid arthritis (RA) who developed progressively worsening dyspnoea and restrictive lung disease associated with pulmonary fibrosis.

Methods

Clinical investigation included physical examination, occupational history, pulmonary function tests (PFTs), chest imaging and bronchoalveolar lavage (BAL), as well as serological tests including standard IgE bird feather mixture and local IgG precipitin preparation to chicken excrement. Lung histopathology was examined post-mortem.

Results

The patient had worked as a chicken sexer for 29 years with limited control of exposure to chicken bioaerosols. PFTs initially showed mild restriction with a moderate gas transfer defect and computerized tomography of the chest exhibited extensive interstitial infiltrates throughout with severe honeycombing at the bases. Cytology from a BAL revealed multinucleated giant cells (MNGs). Specific serologic tests for bird antigens were negative. Histopathology demonstrated diffuse interstitial fibrosis with honeycombing, poorly formed granulomas and MNGs.

Conclusions

Findings were consistent with a diagnosis of HP with RA-associated ILD. The patient's history of severe RA biased the diagnosis to one of RA-associated ILD and her occupational risk had been less emphatically addressed. Obtaining a thorough occupational history can uncover exposures to workplace respiratory hazards and may create opportunities for intervention to limit morbidity from chronic lung disease.