Nontuberculous mycobacterial pulmonary disease presenting as bronchiolitis pattern on CT without cavity or bronchiectasis.

BACKGROUND: This study aimed to investigate the radiological changes in patients with nontuberculous mycobacterial pulmonary disease (NTM-PD) having bronchiolitis patterns on computed tomography (CT). METHODS: We retrospectively reviewed the final diagnosis and radiologic changes of patients suspected of having NTM-PD without cavity or bronchiectasis on CT image, between January 1, 2005 and March 31, 2021. NTM-PD was diagnosed based on the American Thoracic Society and Infectious Diseases Society of America criteria. The initial and final CT findings (bronchiectasis, cellular bronchiolitis, cavity formation, nodules, and consolidation) were compared between patients diagnosed with and without NTM-PD. RESULTS: This study included 96 patients and 515 CT images. The median CT follow-up duration was 1510.5 (interquartile range: 862.2-3005) days. NTM-PD was recognized in 43 patients. The clinical variables were not significantly different between patients with and without NTM-PD, except for underlying chronic airway disease (P < 0.001). Nodule and consolidation were more frequently observed on the initial CT scans of patients with NTM-PD compared with those without (P < 0.05). On the final follow-up CT scan, bronchiectasis (P < 0.001), cavity (P < 0.05), nodule (P < 0.05), and consolidation (P < 0.05) were more frequently observed in patients with NTM-PD. Among the 43 patients with NTM-PD, 30 showed a radiological progression on CT, with bronchiectasis (n = 22) being the most common finding. The incidence of bronchiectasis increased over time. CONCLUSION: The bronchiolitis pattern on CT images of patients with NTM-PD showed frequent radiological progression during the follow-up period.

Reducing unwarranted chest x-rays in bronchiolitis: Importance of a robust analysis.

AIM: Bronchiolitis is the commonest reason for hospitalisation amongst infants and is often a target for low-value care (LVC) reduction. We aimed to assess the impact of a multifaceted intervention (clinician education, parent engagement, audit-feedback) on rates of chest x-rays (CXR) in bronchiolitis. METHODS: Longitudinal study of CXRs ordered in infants (1-12 months) diagnosed with bronchiolitis in the Emergency Department (ED) of an Australian paediatric hospital between May 2016 and February 2023. We used logistic regression to measure the impact of the intervention on unwarranted CXR orders, controlling for other potential impacting variables such as time, patient characteristics (age/sex), clinical variables (fever, hypoxia, tachypnoea), seasonal factors (month, day of the week, business hours) and time passed since intervention. RESULTS: Ten thousand one hundred and nine infants were diagnosed with bronchiolitis in the ED over the study period, with 939 (9.3%) receiving a CXR, of which 69% (n = 651) were considered unwarranted. Rates of unwarranted CXRs reduced from 7.9% to 5.4% post-intervention (P < 0.0001). Logistic regression showed the intervention had no significant effect (OR 0.89, 95% CI 0.65-1.23) once other variables and underlying time-based trends were accounted for. CONCLUSIONS: Although pre-post rates appeared significantly improved, a robust analysis demonstrated that our multi-faceted intervention was not effective in reducing CXRs in bronchiolitis. The decision to order CXR was associated with clinical features that overlap with pneumonia suggesting ongoing misconceptions regarding the role of CXR for this indication. Our study highlights the value of large electronic medical record datasets and robust methodology to avoid falsely attributing underlying trends to the LVC intervention.

Evaluation of respiratory bronchiolitis nodules with maximum intensity projection images.

OBJECTIVE: Respiratory bronchiolitis is a disease associated with heavy smoking. Computed tomography in this disease often shows symmetrical and bilaterally ill-defined circumscribed centriacinar micronodular involvement in the upper-middle lobes. The maximum intensity projection method is a kind of image processing method and provides a better evaluation of nodules and vascular structures. Our study aimed to show whether maximum intensity projection images increase the diagnostic accuracy in the detection of micronodules in respiratory bronchiolitis. METHODS: Two radiologists with different experiences (first reader: 10-year radiologist with cardiothoracic radiology experience and second reader: nonspecific radiologist with 2 years of experience) reviewed images of patients whose respiratory bronchiolitis diagnosis was supported by clinical findings. The evaluation was done independently of each other. Both conventional computed tomography images and maximum intensity projection images of the same patients were examined. The detection rates on conventional computed tomography and maximum intensity projection images were then compared. RESULTS: A total of 53 patients were evaluated, of whom 48 were men and 5 were women. The first reader detected centriacinar nodules in 42 (79.2%) patients on conventional computed tomography and centriacinar nodules in all 53 (100%) patients on maximum intensity projection images. The second reader detected centriacinar nodules in 12 (22.6%) patients on conventional computed tomography images and in 48 (90.6%) patients on maximum intensity projection images. For the less experienced reader, the detection rate of micronodules in respiratory bronchiolitis in maximum intensity projection images increased statistically significantly (p<0.001). CONCLUSION: Maximum intensity projection images in respiratory bronchiolitis increase the detectability of micronodules independently of the experience of the radiologist.

Eosinophilic bronchiolitis successfully treated with benralizumab.

A 53-year-old non-smoking Japanese woman was admitted to our hospital with a 20-year history of wet cough and dyspnoea on exertion. Bronchial asthma (BA) had been diagnosed 20 years earlier. Although she has been treated with high-dose inhaled corticosteroid, she had experienced frequent exacerbation of BA, and short-term oral corticosteroid bursts were occasionally administered. High-resolution CT of the chest revealed diffuse centrilobular nodules with bronchial wall thickening and patchy ground-glass opacities in both lungs. Lung biopsy specimens showed widespread cellular bronchiolitis with follicle formations in the membranous and respiratory bronchioles, accompanied by marked infiltration of plasma cells and eosinophils. In addition, immunohistochemical immunoglobulin G4 (IgG4) staining revealed many IgG4-positive plasma cells, and the ratio of IgG4-positive cells to IgG-positive cells exceeded 40%. The final diagnosis was eosinophilic bronchiolitis with marked IgG4-positive plasma cell infiltration in association with BA. With benralizumab therapy, her clinical condition dramatically improved.

Rheumatoid Arthritis Accompanying Diffuse Panbronchiolitis.

A 58-year-old woman with rheumatoid arthritis (RA) visited our hospital complaining of a persistent cough and sputum for the past year. She had a high cold hemagglutinin titer and chronic sinusitis. Chest computed tomography revealed bilateral diffuse centrilobular nodules, bronchiectasis, and bronchial wall thickening. A surgical lung biopsy was performed that confirmed diffuse panbronchiolitis (DPB) because of the lymphocytic and plasmacytic infiltrates in the respiratory bronchioles. Her condition improved after the administration of clarithromycin. Several cases of RA complicating DPB have previously been reported, but only in Japan. We need to consider DPB as a bronchiolitis types accompanying RA among Japanese patients.

High-resolution CT in smoking-related interstitial lung diseases.

In addition to chronic obstructive pulmonary disease (COPD) and bronchogenic carcinoma, smoking can also cause interstitial lung diseases (ILDs) such as respiratory bronchiolitis (RB), RB with ILD (RB-ILD), desquamative interstitial pneumonia (DIP), Langerhans cell granulomatosis (LCG) and idiopathic pulmonary fibrosis-usual interstitial pneumonia (IPF-UIP). However, smoking seems to have a protective effect against hypersensitivity pneumonitis (HP), sarcoidosis and organising pneumonia (OP). High-resolution computed tomography (HRCT) has a pivotal role in the differential diagnosis. RB is extremely frequent in smokers, and is considered a marker for smoking exposure. It has no clinical relevance in itself since most patients with RB are asymptomatic. It is frequent to observe the association of RB with other smoking-related diseases, such as LCG or pulmonary neoplasms. In RB-ILD, HRCT features are more conspicuous and diffuse than in RB, but there is no definite cut-off between the two entities and any distinction can only be made by integrating imaging and clinical data. RB, RB-ILD and DIP may represent different degrees of the same pathological process, consisting in a bronchiolar and alveolar inflammatory reaction to smoking. Smoking is also a well-known risk factor for pulmonary fibrosis. Multidisciplinary discussion and follow-up can generally solve even the most difficult cases.

New-onset nontuberculous mycobacterial pulmonary disease in bronchiectasis: tracking the clinical and radiographic changes.

BACKGROUND: The close association between bronchiectasis and nontuberculous mycobacterial pulmonary disease (NTM-PD) is well-known. However, the clinical impact of subsequent new-onset NTM-PD in bronchiectasis patients has not been elucidated. The aim of this study is to investigate the clinical courses and radiographic changes of patients with bronchiectasis in whom NTM-PD subsequently developed. METHODS: A total of 221 patients with bronchiectasis who had participated in a non-NTM bronchiectasis cohort between July 1st 2011 and August 31st 2019 at Seoul National University Hospital were included in this study. The data of patients in whom NTM-PD developed during this observation period were analyzed; specifically, changes in the Bronchiectasis Severity Index (BSI) and lesions on computerized tomography (CT) scan of the chest arising during the observation period. RESULTS: During the observation period, NTM was isolated from 35 patients. A total of 31 patients (14.0%) satisfied the diagnostic criteria of NTM-PD. The median time from enrollment in the cohort to the development of subsequent NTM-PD was 37 months (Interquartile range [IQR], 18-78 months). Mycobacterium avium complex was the most common pathogen (80.6%). Twelve patients underwent antibiotic treatment for NTM-PD with a median interval of 20 months (IQR, 13-30) from the time of NTM-PD diagnosis. When NTM-PD developed, the severity and extent of bronchiectasis, cellular bronchiolitis, and the extent of nodules worsened on CT scans, while BSI did not change. CONCLUSIONS: NTM-PD can develop in previously negative bronchiectasis patients. It is associated with worsening radiographic lesions. Active screening of non-NTM bronchiectasis patients for new-onset NTM infection should be considered, especially if radiographic findings worsen. The BSI is not a reliable predictor of new-onset NTM-PD. TRIAL REGISTRATION: This study was performed at Seoul National University Hospital ( NCT01616745 ).

Bronchiolitis and Bronchiolar Disorders.

Bronchioles are noncartilaginous small airways with internal diameter of 2 mm or less, located from approximately the eighth generation of purely air conducting airways (membranous bronchioles) down to the terminal bronchioles (the smallest airways without alveoli) and respiratory bronchioles (which communicate directly with alveolar ducts and are in the range of 0.5 mm or less in diameter). Bronchiolar injury, inflammation, and fibrosis may occur in myriad disorders including connective tissue diseases, inflammatory bowel diseases, lung transplant allograft rejection, graft versus host disease in allogeneic stem cell recipients, neuroendocrine cell hyperplasia, infections, drug toxicity (e.g., penicillamine, busulfan), inhalation injury (e.g., cigarette smoke, nylon flock, mineral dusts, hard metals, Sauropus androgynous); idiopathic, common variable immunodeficiency disorder, and a host of other disorders or insults. The spectrum of bronchiolar disorders is wide, ranging from asymptomatic to fatal obliterative bronchiolitis. In this review, we discuss the salient clinical, radiographic, and histological features of these diverse bronchiolar disorders, and discuss a management approach.

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.

Immune Checkpoint Inhibitor Therapy-related Pneumonitis: Patterns and Management.

In recent years, the use of immune checkpoint inhibitor (ICI) therapy has rapidly grown, with increasing U.S. Food and Drug Administration approvals of a variety of agents used as first- and second-line treatments of various malignancies. ICIs act through a unique mechanism of action when compared with those of conventional chemotherapeutic agents. ICIs target the cell surface receptors cytotoxic T-lymphocyte antigen-4, programmed cell death protein 1, or programmed cell death ligand 1, which result in immune system-mediated destruction of tumor cells. Immune-related adverse events are an increasingly recognized set of complications of ICI therapy that may affect any organ system. ICI therapy-related pneumonitis is an uncommon but important complication of ICI therapy, with potential for significant morbidity and mortality. As the clinical manifestation is often nonspecific, CT plays an important role in diagnosis and triage. Several distinct radiographic patterns of pneumonitis have been observed: (a) organizing pneumonia, (b) nonspecific interstitial pneumonia, (c) hypersensitivity pneumonitis, (d) acute interstitial pneumonia-acute respiratory distress syndrome, (e) bronchiolitis, and (f) radiation recall pneumonitis. Published guidelines outline the treatment of ICI therapy-related pneumonitis based on the severity of symptoms. Treatment is often effective, although recurrence is possible. This article reviews the mechanism of ICIs and ICI therapy complications, with subsequent management techniques and illustrations of the various radiologic patterns of ICI-therapy related pneumonitis.©RSNA, 2019.

Chest Radiography in Children Hospitalized with Bronchiolitis.

In uncomplicated bronchiolitis, chest radiography (CR) is not routinely recommended, yet it is still frequently made. This study seeks to evaluate the use of CR in children with bronchiolitis due to a lower respiratory tract infection (RSV-RTI) with respiratory syncytial virus (RSV) and the influence of CR on patient treatment during the 2010-2017 seasons. There were 581 children included into the study: 459 with bronchiolitis (390 RSV-RTI and 69 non-RSV), 65 with RSV pneumonia and 57 with RSV bronchitis. We found that CR was performed in 28.6% (166/581) patients. CR was much more frequent in patients with RSV than non-RSV infections (61% vs. 31%). CR prognostic sensitivity and specificity in guiding antibiotic treatment was low, 78% and 58%, respectively. Positive and negative predicted values of CR were 78% and 58%, respectively and the number needed to diagnose was 2.777. Children in whom CR was performed (irrespective of the result) were at 22.9-fold higher risk of antibiotic therapy (95%CI: 14.1-37.1; p < 0.01), while those with a positive CR were only at 4.4-fold higher risk of antibiotic therapy (95%CI: 2.2-8.9; p < 0.01). Children with CR required a longer hospital stay than those without it (10 vs. 8 days, respectively; p < 0.01). The percentage of CR decreased from 78% in 2010 to 33% in 2017, with the lowest value of 11% in 2015. The additional cost of CR, which had no influence on treatment, would have been €381 had it been performed in each patient, which amounts to 1% of the total hospitalization cost. We conclude that CR is overused and in most cases it has no influence on the patient management. The recognition of practical meaning of CR is essential to avoid unnecessary radiation of children.

Perplexing case of lung mass perfectly mimicking a malignancy.

A 35-year-old man, a known asthmatic and with a history of smoking presented with a history of recurrent episodes of mild haemoptysis. On examination, there was decreased intensity of breath sounds on the right infraclavicular area. The chest X-ray and CT chest showed a mass in right upper lobe with nodules in the other lobe. The VAT showed large heavily vascularised mass with surface laden with multiple nodules. The wedge resection of the mass was taken and sent for histopathology examination. The biopsy result showed picture suggestive of connective tissue disease associated follicular bronchiolitis. The patient did not have any signs or symptoms of connective tissue disease. However he was positive for Rheumatoid factor, ANA, anti-RO, anti-CCP antibodies. He was started on steroids and azathioprine. After 6 months of treatment, the size of the mass and nodules reduced by 50% and ESR was reduced to 5 from 75.

Case of steroid-resistant Crohn's-associated bronchiolitis in the setting of quiescent gastrointestinal disease treated with infliximab.

A fit, 36-year-old man with a history of Crohn's disease previously treated with azathioprine, presented acutely with progressive shortness of breath on exertion and pleuritic chest pain. At the time of presentation, his Crohn's disease was quiescent, supported by a normal faecal calprotectin. The initial chest CT suggested the presence of a diffuse inflammatory disorder and he was subsequently started on high dose oral steroids. Despite 4 months of steroid therapy, there was minimal improvement. Following discussion at the inflammatory bowel disease multidisciplinary team meeting, a decision was made to commence infliximab. Subsequently, he made a dramatic clinical and physiological recovery. His forced expiratory volume in 1 s improved from 2.22 L/min (50% predicted) to 3.65 L/min (93% predicted) and he returned to baseline levels of exercise.

A quality improvement intervention to reduce emergency department radiography for bronchiolitis.

INTRODUCTION: Bronchiolitis is one of the most common infectious diseases in children and the most frequent cause of hospitalization in infants. Clinical practice guidelines recommend that a chest X-ray (CXR) should not be routinely obtained in the diagnosis of bronchiolitis, as studies have shown that they do not affect clinical outcomes, but rather lead to overuse of pharmacological agents and a longer length of hospital stay. OBJECTIVE: To determine whether active institution of bronchiolitis practice guidelines as part of a quality improvement project decreased the use of CXRs in the Pediatric Emergency Department (ED). Secondary outcomes included a decrease in the use of unnecessary medical interventions and a shorter mean hospital length of stay. METHODS: The study was conducted at two Hadassah Medical Center Pediatric EDs. Guidelines were reviewed with the ED staff during departmental seminars by a senior pediatric pulmonologist, and posted at the physician computer stations in the ED. Prospective, post-intervention, data obtained during the study period was compared to retrospective, pre-intervention, data from the year prior to implementation of the intervention. RESULTS: Post-intervention, 37% of patients vs. 58% in the retrospective cohort had a CXR via ED referral (p < 0.001). The use of hypertonic saline and bronchodilators decreased, while there was no significant change in antibiotic or corticosteroid use. There was a decrease in hospitalizations post-intervention (70% vs. 77%, p = 0.05). CONCLUSION: This key intervention was successful in reinforcing the AAP guidelines, promoting greater cost-effectiveness, reducing radiation exposure, and saving valuable time and resources for the ED staff and the hospital.

Reducing unnecessary chest X-rays, antibiotics and bronchodilators through implementation of the NICE bronchiolitis guideline.

Chest X-rays (CXR), antibiotics and inhaled/nebulized therapy are overused in bronchiolitis, despite evidence-based guidelines suggesting supportive management only. This study investigates the effect of the implementation of the NICE bronchiolitis guideline in a secondary paediatric unit in England. We present a quality improvement project with a completed audit cycle (winter 2014-2015 and 2015-2016) pre- and post-implementation of the NICE bronchiolitis guideline. The educational intervention included sessions for raising awareness of appropriate and inappropriate management of bronchiolitis for both clinicians and nursing staff. As a result, the number of chest radiographs reduced fivefold (from 20 to 4% of patients, absolute reduction 16%), antibiotics reduced more than threefold (from 22 to 6% of patients, absolute reduction 16%) and inhaled/nebulised treatment up to twofold (from 30 to 16%, absolute reduction 14%). Overall NICE guideline compliance rose from 28 to 63%. CONCLUSION: Implementation of the NICE bronchiolitis guideline supported by a simple educational intervention can effectively reduce the number of inappropriate chest radiographs and antibiotic prescribing in bronchiolitis, and enhance compliance with the NICE guideline. What is Known: • Bronchiolitis management in paediatric units in the UK is variable, with poor evidence for existing guidance. Best available evidence was compiled into the NICE guideline, aiming to standardize care. • Some evidence exists for the effectiveness of quality improvement approaches to improve the management of bronchiolitis. What is New: • NICE guidance can be effectively applied to a department using simple educational tools. • Effective NICE implementation reduces the rates of unnecessary chest radiograph and antibiotic administration for patients admitted with bronchiolitis in District General Hospitals.

Follicular bronchiolitis in an HIV-infected individual on combination antiretroviral therapy with low CD4+ cell count but sustained viral suppression.

A 36-year-old Danish man, living in Asia, was diagnosed with Pneumocystis pneumonia (PCP) and HIV in 2013 (CD4+ count: 6 cells/µL; viral load: 518 000 copies/mL). He initiated combination antiretroviral therapy. Later that year, he was also diagnosed with granulomatosis with polyangiitis and was treated with prednisolone. Despite complete viral suppression and increasing CD4+ count (162 cells/µL), he was readmitted with PCP in April 2015. Subsequently, he returned to Denmark (CD4+ count: 80 cells/µL, viral suppression). Over the following months, he developed progressive dyspnoea. Lung function tests demonstrated severely reduced lung capacity with an obstructive pattern and a moderately reduced diffusion capacity. High resolution computer tomography revealed minor areas with tree-in-bud pattern and no signs of air trapping on expiratory views. Lung biopsy showed lymphocytic infiltration surrounding the bronchioles with sparing of the alveolar septa. He was diagnosed with follicular bronchiolitis. The patient spontaneously recovered along with an improvement of the immune system.

Smoking-Related Interstitial Fibrosis: Evidence of Radiologic Regression with Advancing Age and Smoking Cessation.

More data are needed regarding the radiology, co-morbidities and natural history of smoking-related interstitial fibrosis (SRIF), a common pathological finding, mainly described heretofore in association with lung cancer, where respiratory bronchiolitis (RB) usually co-exists. We prospectively acquired high resolution CT scan data (edge-enhancing lung reconstructions) to detect any radiologic interstitial lung abnormality (ILA) in individuals who ultimately underwent surgical lobectomy for lung cancer (n = 20), for radiologic/pathologic correlation. We also re-examined other smoking-related benign histologic cases: chronic obstructive pulmonary disease (COPD lung explants, n = 20), alpha 1-antitrypsin deficiency (A1AT, explanted lungs n = 20), combined pulmonary fibrosis and emphysema (CPFE, n = 8) and idiopathic pulmonary fibrosis (IPF, n = 10). Finally, we pooled our data with all peer-reviewed published data describing histologic SRIF of known ILA status. SRIF was observed in 40% of cancer lobectomies, mean (±SD) age 65.8 ± 8.7 years, none of whom had ILA. SRIF was observed in other smoking-related benign diseases (COPD 35%, A1AT 20%, CPFE 25%, and IPF 10%). 71.4% of benign SRIF cases had no RB (nearly all ex-smokers) versus 0% of cancer-associated SRIF cases (P = 1.7 × 10-3). Pooled data showed that those SRIF subjects without ILA were 15.05 years older than those with ILA (95% confidence interval 8.99 to 21.11, P = 2.5 × 10-5) and more likely to be former smokers (P = 7.2 × 10-3). SRIF is frequently found without lung cancer, and mostly without RB in former smokers. SRIF is less likely to have ILA in older subjects and with smoking cessation, which could represent RB+/-SRIF regression.

HRCT findings of childhood follicular bronchiolitis.

BACKGROUND: Follicular bronchiolitis is a lymphoproliferative form of interstitial lung disease (ILD) defined by the presence of peribronchial lymphoid follicles. Follicular bronchiolitis has been associated with viral infection, autoimmune disease and immunodeficiency. The most common clinical manifestation is respiratory distress in infancy followed by a prolonged course with gradual improvement. We found no reports of systematic review of high-resolution computed tomography (HRCT) findings in pediatric follicular bronchiolitis. OBJECTIVE: The purpose of this study was to describe the HRCT findings of follicular bronchiolitis in children and correlate these imaging findings with histopathology. MATERIALS AND METHODS: A 5-year retrospective review of all pathology-proven cases of follicular bronchiolitis was performed. Inclusion criteria were age <18 years and an HRCT within 6 months of lung biopsy. HRCTs were reviewed by three observers and scored using the system previously described by Brody et al. RESULTS: Six patients met the inclusion criteria with age range at HRCT of 7-82 months (median: 39.5 months). Pulmonary nodules (n=6) were the most common HRCT finding followed by focal consolidation (n=5), bronchiectasis (n=4) and lymphadenopathy (n=3). Tree and bud opacities and nodules on CT correlated with interstitial lymphocytic infiltrates and discrete lymphoid follicles on pathology. CONCLUSION: The salient HRCT findings of childhood follicular bronchiolitis are bilateral, lower lung zone predominant pulmonary nodules and bronchiectasis with infantile onset of symptoms. These characteristic HRCT findings help differentiate follicular bronchiolitis from other forms of infantile onset ILD.