Measurement of the interbronchial angle in acute viral bronchiolitis

BACKGROUND

Acute viral bronchiolitis (AVB) is the most common lower airway infection in children under 2 years. Attempts to determine disease severity based on clinical and radiological manifestations are a major challenge. Measurements of the anatomy of the trachea and main bronchi are not only limited to pure anthropometry, but are also useful for better care of critically ill patients. The purpose of the study is to verify the association between measurements of the interbronchial angle (ITB) and the severity of respiratory disease.

METHODS

A cross-sectional study, which included all patients admitted to the Santo Antônio Children's Hospital, over a period of 1 year, with diagnosis of AVB by respiratory syncytial virus (RSV) was designed. ITB angle was measured and clinical characteristics were analyzed. Quantitative variables were compared and correlation analysis was performed using Pearson's correlation coefficient. A receiving operator characteristic (ROC) curve was performed. P-value <0.05 was statistically significant.

RESULTS

A total of 425 patients with AVB due to RSV were included. Most of these patients were male and the median age was 130 days, 91.11% of them required oxygen therapy through a nasal catheter, 3.3% used noninvasive ventilation and 4% used mechanical ventilation. Those who required MV or NIV and intensive care unit support were considered severe. The mean ITB was lower for these patients than for those of lesser severity (p < 0.05).

CONCLUSION

The present study demonstrates that there is an association between ITB and AVB severity. The smaller the ITB, the greater the disease severity.

Association between clinical, serological, functional and radiological findings and ventilatory distribution heterogeneity in patients with rheumatoid arthritis

BACKGROUND

In rheumatoid arthritis (RA), the involvement of the pulmonary interstitium can lead to structural changes in the small airways and alveoli, leading to reduced airflow and maldistribution of ventilation. The single-breath nitrogen washout (SBN2W) test is a measure of the ventilatory distribution heterogeneity and evaluates the small airways. This study aimed to find out which clinical, serological, functional and radiological findings are useful to identify RA patients with pathological values of the phase III slope (SIII) measured by the SBN2W test.

METHODS

This was a cross-sectional study in which RA patients were assessed using the Health Assessment Questionnaire-Disability Index (HAQ-DI) and the Clinical Disease Activity Index (CDAI) and underwent serological analysis of autoantibodies and inflammatory markers. In addition, they underwent pulmonary function tests (including the SBN2W test) and chest computed tomography (CT).

RESULTS

Of the 60 RA patients evaluated, 39 (65%) had an SIII >120% of the predicted value. There were significant correlations between SIII and age (r = 0.56, p<0.0001), HAQ-DI (r = 0.34, p = 0.008), forced vital capacity (FVC, r = -0.67, p<0.0001), total lung capacity (r = -0.46, p = 0.0002), residual volume/total lung capacity (TLC) (r = 0.44, p = 0.0004), and diffusing capacity of the lungs for carbon monoxide (r = -0.45, p = 0.0003). On CT scans, the subgroup with moderate/severe disease had a significantly higher SIII than the normal/minimal/mild subgroup (662 (267-970) vs. 152 (88-283)% predicted, p = 0.0004). In the final multiple regression model, FVC, extent of moderate/severe involvement and age were associated with SIII, explaining 59% of its variability.

CONCLUSIONS

In patients with RA, FVC, extent of lung involvement and age, all of which are easily obtained variables in clinical practice, identify poorly distributed ventilation. In addition, the presence of respiratory symptoms and deteriorated physical function are closely related to the distribution of ventilation in these patients.

Expiratory CT scan: When to do it and how to interpret it

Expiratory CT scan is a complementary technique of inspiratory CT that provide valuable physiological information and may be more sensitive to detect air trapping than pul-monary function tests. It is useful in many obstructive airway diseases, including obliterative bronchiolitis, asthma, Swyer-James syndrome, tracheomalacia, hypersensitivity pneumonitis and sarcoidosis. In obliterative bronchiolitis, expiratory CT scan may be the only imaging technique that shows abnormalities in the early phase of disease. In order to obtain a good quality study, we should explain the procedure to the patient, use precise instructions and do some practice before image acquisition. Here we describe strategies to optimize the techni-que and propose an algorithm that help in interpretation of imaging findings in patients with obstructive airway disease.

Growth Rates of Pulmonary Carcinoid Tumors and Hamartomas

BACKGROUND

Pulmonary nodule growth is often measured by volume doubling time (VDT), which may guide management. Most malignant nodules have a VDT of 20 to 400 days, with longer VDTs typically observed in indolent nodules. We assessed the utility of VDT in differentiating pulmonary carcinoids and hamartomas.

METHODS

A review was performed from January 2012 to October 2021 to identify patients with pathologic diagnoses and at least 2 chest computed tomography scans obtained 6 or more months apart. Visualization software was used to segment nodules and calculate diameter and volume. Volume doubling time was calculated for scans with 1-mm slices. For the remainder, estimated nodule volume doubling time (eVDT) was calculated using nodule diameter. Volume doubling times/eVDTs were placed into growth categories: less than 400 days; 400-600 days; and more than 600 days.

RESULTS

Sixty nodules were identified, 35 carcinoids and 25 hamartomas. Carcinoids were larger than hamartomas (median diameter, 13.5 vs 11.5 mm; P = 0.05). For carcinoid tumors, median VDT (n = 15) was 1485 days, and median eVDT (n = 32) was 1309 days; for hamartomas, median VDT (n = 8) was 2040 days and median eVDT (n = 25) was 2253 days. Carcinoid tumor eVDT was significantly shorter than hamartomas ( P = 0.03). By growth category, 1 of 25 hamartomas and 5 of 35 carcinoids had eVDT less than 400 days and 24 of 25 hamartomas and 27 of 35 carcinoids had eVDT more than 600 days. Of 4 carcinoid tumors with metastases, 2 had eVDT less than 400 days and 2 had eVDT more than 600 days.

CONCLUSIONS

Growth rate was not a reliable differentiator of pulmonary hamartomas and carcinoids. Slow growing carcinoids can metastasize. Radiologists should be cautious when discontinuing computed tomography follow-up based on growth rates alone.

A breath of not so fresh air…

Despite being widely used as a recreational drug, "poppers" lack a legal framework for their delivery. Their composition may vary largely. This report describes a case of severe bronchiolitis following amyl nitrite mixture inhalation. https://bit.ly/3p3S7LM.

Do Not Miss Acute Diffuse Panbronchiolitis for Tree-in-Bud: Case Series of a Rare Lung Disease

Acute bronchiolitis is a common disease of infants affecting the small airways. Rarely, acute bronchiolitis may occur in adolescents and adults. Here, we present four unrelated adolescent patients with severe clinical presentation and unique CT imaging with extensive tree-in-bud pattern, representing a rare clinical phenotype of acute diffuse panbronchiolitis. This characteristic disease pattern caused by inhalation injury from waterpipes, smoked tobacco, and cannabinoids must be differentiated from e-cigarette or vaping product-use-associated lung injury (EVALI). Visual diagnosis of CT and an early diagnostic procedure for detection and differentiation of inhaled hazards, including sample storage for future identification of novel noxious agents, are warranted.

Prevalence and comorbidities of bronchiolitis in adults: A population-based study in South Korea

Bronchiolitis generally refers to inflammation and/or fibrosis of the non-cartilaginous small airways located approximately from the 8th airway generation down to the terminal and respiratory bronchioles. In contrast to young children, the frequency of small airway infection in adult bronchiolitis appears less frequent and a number of other pathophysiological conditions have been implicated in adult bronchiolitis. However, little information is available on the exact medical burden of bronchiolitis such as its prevalence and comorbidities in the adult population. The aim of this study is to elucidate the prevalence and comorbidities of bronchiolitis. We used the Korea National Health Insurance Service-National Sample Cohort, which provides data for 1,000,000 individuals out of the entire population by 2% stratified random sampling according to age, sex, residential area, and level of household income. We defined the cause of bronchiolitis other than acute infection as a patient with diagnostic code J448 or J684 and over 20 years of age who visited a clinic or hospital in South Korea. Then, 1:1 propensity score matching was performed to define a non-bronchiolitis (control) group to compare the comorbidities and mortality in the 2 groups. The overall prevalence of bronchiolitis was 688 cases/1,000,000 population during the study period (95% confidence interval, 625-751). The most common comorbid clinical condition in adults with bronchiolitis was rhinitis (52.3%), followed by bronchial asthma (52.23%), hypertension (43.69%), gastroesophageal reflux disease (30.56%), sinusitis (28.72%), diabetes (22.77%), and osteoporosis (17.85%). Other common bronchiolitis-associated comorbidities were cerebrovascular disease (16.86%), angina (14.37%), peripheral vascular disease (13.42%), congestive heart failure (11.9%), and malignancy in any organ (10.6%). Healthcare costs for bronchiolitis increased steeply during the same period. Malignancy in any organ was the leading cause of mortality in the patient group, followed by bronchiolitis itself. Further larger prospective multiethnic cohort studies should be carried out in the near future.

Nationwide survey of refractory asthma with bronchiectasis by inflammatory subtypes

RATIONALE

Bronchiectasis and bronchiolitis are differential diagnoses of asthma; moreover, they are factors associated with worse asthma control.

OBJECTIVE

We determined clinical courses of bronchiectasis/bronchiolitis-complicated asthma by inflammatory subtypes as well as factors affecting them.

METHODS

We conducted a survey of refractory asthma with non-cystic fibrosis bronchiectasis/bronchiolitis in Japan. Cases were classified into three groups, based on the latest fractional exhaled NO (FeNO) level (32 ppb for the threshold) and blood eosinophil counts (320/µL for the threshold): high (type 2-high) or low (type 2-low) FeNO and eosinophil and high FeNO or eosinophil (type 2-intermediate). Clinical courses in groups and factors affecting them were analysed.

RESULTS

In total, 216 cases from 81 facilities were reported, and 142 were stratified: 34, 40 and 68 into the type 2-high, -intermediate and -low groups, respectively. The frequency of bronchopneumonia and exacerbations requiring antibiotics and gram-negative bacteria detection rates were highest in the type 2-low group. Eighty-seven cases had paired latest and oldest available data of FeNO and eosinophil counts; they were analysed for inflammatory transition patterns. Among former type 2-high and -intermediate groups, 32% had recently transitioned to the -low group, to which relatively low FeNO in the past and oral corticosteroid use contributed. Lastly, in cases treated with moderate to high doses of inhaled corticosteroids, the frequencies of exacerbations requiring antibiotics were found to be higher in cases with more severe airway lesions and lower FeNO.

CONCLUSIONS

Bronchiectasis/bronchiolitis-complicated refractory asthma is heterogeneous. In patients with sputum symptoms and low FeNO, airway colonisation of pathogenic bacteria and infectious episodes are common; thus, corticosteroids should be carefully used.

Bronchiectasis in severe asthma and asthmatic components in bronchiectasis

Asthma and bronchiectasis are different diseases; however, differentiating them can be difficult because they share several symptomatic and physiological similarities. Approximately 20% of patients with bronchiectasis have eosinophilic inflammation, 34% show wheezing, and 7-46% have comorbid asthma, although comorbidity with severe asthma may be limited as shown in 3.3% of cases of bronchiectasis. Meanwhile, 25-68% of patients with severe asthma have comorbid bronchiectasis, and at least two phenotypes are present in the accompanying bronchiectasis: eosinophilic bronchiectasis and chronic infectious bronchiolitis/bronchiectasis. Recent studies show that type-2-targeted biologics are effective for eosinophilic bronchiectasis and theoretically effective for some of the remaining cases when used before oral corticosteroids. Further studies are needed to identify treatment strategies for severe asthma with comorbid bronchiectasis and vice versa.

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.

Complications of Lung Transplantation: Update on Imaging Manifestations and Management

As lung transplantation has become the most effective definitive treatment option for end-stage chronic respiratory diseases, yearly rates of this surgery have been steadily increasing. Despite improvement in surgical techniques and medical management of transplant recipients, complications from lung transplantation are a major cause of morbidity and mortality. Some of these complications can be classified on the basis of the time they typically occur after lung transplantation, while others may occur at any time. Imaging studies, in conjunction with clinical and laboratory evaluation, are key components in diagnosing and monitoring these conditions. Therefore, radiologists play a critical role in recognizing and communicating findings suggestive of lung transplantation complications. A description of imaging features of the most common lung transplantation complications, including surgical, medical, immunologic, and infectious complications, as well as an update on their management, will be reviewed here. Keywords: Pulmonary, Thorax, Surgery, Transplantation Supplemental material is available for this article. © RSNA, 2021.

Overview and Challenges of Bronchiolar Disorders

Bronchiolar abnormalities are common and can occur in conditions that affect either the large airways or the more distal parenchyma. In this review, we focus on the diagnosis and management of primary bronchiolar disorders, or conditions in which bronchiolitis is the predominant pathologic process, including constrictive bronchiolitis, follicular bronchiolitis, acute bronchiolitis, respiratory bronchiolitis, and diffuse panbronchiolitis. Due to the nature of abnormalities in the small airway, clinical and physiological changes in bronchiolitis can be subtle, making diagnosis challenging. Primary bronchiolar disorders frequently present with progressive dyspnea and cough that can be out of proportion to imaging and physiologic studies. Pulmonary function tests may be normal, impaired in an obstructive, restrictive, or mixed pattern, or have an isolated decrease in diffusion capacity. High-resolution computed tomography scan is an important diagnostic tool that may demonstrate one or more of the following three patterns: 1) solid centrilobular nodules, often with linear branching opacities (i.e., "tree-in-bud" pattern); 2) ill-defined ground glass centrilobular nodules; and 3) mosaic attenuation on inspiratory images that is accentuated on expiratory images, consistent with geographic air trapping. Bronchiolitis is often missed on standard transbronchial lung biopsies, as the areas of small airway involvement can be patchy. Fortunately, many patients can be diagnosed with a combination of clinical suspicion, inspiratory and expiratory high-resolution computed tomography scans, and pulmonary function testing. Joint consultation of clinicians with both radiologists and pathologists (in cases where histopathology is pursued) is critical to appropriately assess the clinical-radiographic-pathologic context in each individual patient.

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.

A Critical Review on Emerging Trends in Dry Powder Inhaler Formulation for the Treatment of Pulmonary Aspergillosis

Pulmonary aspergillosis (PA), a pulmonary fungal infection caused by Aspergillus spp., is a concern for immunocompromised populations. Despite substantial research efforts, conventional treatments of PA using antifungal agents are associated with limitations such as excessive systemic exposure, serious side effects and limited availability of the therapeutics in the lungs for an adequate duration. To overcome the limitations associated with the conventional regimens, pulmonary delivery of antifungal agents has become a focal point of research because of the superiority of local and targeted drug delivery. Dry powder inhalers and nebulized formulations of antifungal agents have been developed and evaluated for their capability to effectively deliver antifungal agents to the lungs. Moreover, progress in nanotechnology and the utilization of nanocarriers in the development of pulmonary delivery formulations has allowed further augmentation of treatment capability and efficiency. Thus, the following review provides an insight into the advantages and therapeutic potential of the utilization of nanocarriers in pulmonary delivery of antifungal agents for the treatment of PA. In addition, discussions on formulation aspects and safety concerns together with the clinical and regulatory aspects of the formulations are presented, which suggest the possibility and desirability of utilization of nanocarriers in the treatment of PA.

Recent advances in the understanding of bronchiolitis in adults

Bronchiolitis is injury to the bronchioles (small airways with a diameter of 2 mm or less) resulting in inflammation and/or fibrosis. Bronchioles can be involved in pathologic processes that involve predominantly the lung parenchyma or large airways, but, in some diseases, bronchioles are the main site of injury ("primary bronchiolitis"). Acute bronchiolitis caused by viruses is responsible for most cases of bronchiolitis in infants and children. In adults, however, there is a wide spectrum of bronchiolar disorders and most are chronic. Many forms of bronchiolitis have been described in the literature, and the terminology in this regard remains confusing. In clinical practice, a classification scheme based on the underlying histopathologic pattern (correlates with presenting radiologic abnormalities) facilitates the recognition of bronchiolitis and the search for the inciting cause of the lung injury. Respiratory bronchiolitis is the most common form of bronchiolitis in adults and is usually related to cigarette smoking. Currently, the diagnosis of respiratory bronchiolitis is generally achieved based on the clinical context (smoking history) and chest CT findings. Constrictive (obliterative) bronchiolitis is associated with airflow obstruction and is seen in various clinical contexts including environmental/occupational inhalation exposures, transplant recipients (bronchiolitis obliterans syndrome), and many others. Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is increasingly recognized and can be associated with progressive airflow obstruction related to constrictive bronchiolitis ("DIPNECH syndrome"). Diffuse aspiration bronchiolitis is a form of aspiration-related lung disease that is often unsuspected and confused for interstitial lung disease. Novel forms of bronchiolitis have been described, including lymphocytic bronchiolitis and alveolar ductitis with emphysema recently described in employees at a manufacturing facility for industrial machines. Bronchiolitis is also a component of vaping-related lung injury encountered in the recent outbreak.

Respiratory Diseases in Post-9/11 Military Personnel Following Southwest Asia Deployment

OBJECTIVE

Persistent respiratory symptoms following post-9/11 military deployment to Iraq and Afghanistan are well-recognized, but the spectrum of respiratory diseases remains poorly characterized. This study describes deployment-related respiratory diseases and the diagnostic utility of resting and exercise pulmonary function testing.

METHODS

Between 2009 and 2017, 127 consecutive military workers ("deployers") with new-onset respiratory symptoms underwent clinical evaluation. Deployment-related respiratory diseases were classified as proximal and/or distal. Using descriptive statistics and logistic regression, we analyzed lung function parameters associated with deployment-related distal lung disease (DDLD).

RESULTS

Common deployment-related respiratory diseases included asthma (31.5%), intermittent laryngeal obstruction (14.2%), rhinosinusitis (15%), and DDLD (68.5%). Decreased diffusion capacity (odds ratio [OR] = 4.6, 95% confidence interval [CI]: 1.4 to 15.1, P = 0.01) was significantly associated with DDLD.

CONCLUSIONS

A comprehensive diagnostic approach may identify a spectrum of proximal and distal respiratory diseases that can occur in symptomatic post-9/11 deployers, requiring a personalized approach to care.

Does the nitrogen single-breath washout test contribute to detecting pulmonary involvement in rheumatoid arthritis? A pilot study

Objective

There has been growing interest in studying small airway disease through measures of ventilation distribution, thanks to the resurgence of the nitrogen single-breath washout (N₂SBW) test. Therefore, this study evaluated the contribution of the N₂SBW test to the detection of pulmonary involvement in patients with rheumatoid arthritis (RA).

Results

Twenty-one patients with RA underwent clinical evaluation, pulmonary function tests (PFTs), including the N2_SBW test, and computed tomography (CT). The main tomographic findings were air trapping and bronchiectasis (57.1% and 23.8% of cases, respectively). According to the phase III slope of the N₂SBW (phase III slope), 11 and 10 patients had values < 120% predicted and > 120% predicted, respectively. Five patients with limited involvement on CT had a phase III slope > 120%. The residual volume/total lung capacity ratio was significantly different between patients with phase III slopes < 120% and > 120% (P = 0.024). Additionally, rheumatoid factor positivity was higher in patients with a phase III slope > 120% (P = 0.021). In patients with RA and airway disease on CT, the N₂SBW test detects inhomogeneity in the ventilation distribution in approximately half of the cases, even in those with normal conventional PFT results.

Lung Hyperlucency: A Clinical-Radiologic Algorithmic Approach to Diagnosis

Areas of diminished lung density are frequently identified both on routine chest radiographs and chest CT examinations. Colloquially referred to as hyperlucent foci of lung, a broad range of underlying pathophysiologic mechanisms and differential diagnoses account for these changes. Despite this, the spectrum of etiologies can be categorized into underlying parenchymal, airway, and vascular-related entities. The purpose of this review is to provide a practical diagnostic algorithmic approach to pulmonary hyperlucencies incorporating clinical history and characteristic imaging patterns to narrow the differential.