Organizing pneumonia: chest HRCT findings

Relationship between idiopathic interstitial pneumonias (IIPs) and connective tissue disease-related interstitial lung disease (CTD-ILD): A narrative review

While idiopathic interstitial pneumonia (IIP) centering on idiopathic pulmonary fibrosis (IPF) is the most prevalent interstitial lung disease (ILD), especially in the older adult population, connective tissue disease (CTD)-related ILD is the second most prevalent ILD. The pathogenesis of IPF is primarily fibrosis, whereas that of other ILDs, particularly CTD-ILD, is mainly inflammation. Therefore, a precise diagnosis is crucial for selecting appropriate treatments, such as antifibrotic or immunosuppressive agents. In addition, some patients with IIP have CTD-related features, such as arthritis and skin eruption, but do not meet the criteria for any CTD, this is referred to as interstitial pneumonia with autoimmune features (IPAF). IPAF is closely associated with idiopathic nonspecific interstitial pneumonia (iNSIP) and cryptogenic organizing pneumonia (COP). Furthermore, patients with iNSIP or those with NSIP with OP overlap frequently develop polymyositis/dermatomyositis after the diagnosis of IIP. Acute exacerbation of ILD, the most common cause of death, occurs more frequently in patients with IPF than in those with other ILDs. Although acute exacerbation of CTD-ILD occurs at a low rate of incidence, patients with rheumatoid arthritis, microscopic polyangiitis, or systemic sclerosis experience more acute exacerbation of CTD-ILD than those with other CTD. In this review, the features of each IIP, focusing on CTD-related signatures, are summarized, and the pathogenesis and appropriate treatments to improve the prognoses of patients with various ILDs are discussed.

Uncommon Causes of Interlobular Septal Thickening on CT Images and Their Distinguishing Features

Interlobular septa thickening (ILST) is a common and easily recognized feature on computed tomography (CT) images in many lung disorders. ILST thickening can be smooth (most common), nodular, or irregular. Smooth ILST can be seen in pulmonary edema, pulmonary alveolar proteinosis, and lymphangitic spread of tumors. Nodular ILST can be seen in the lymphangitic spread of tumors, sarcoidosis, and silicosis. Irregular ILST is a finding suggestive of interstitial fibrosis, which is a common finding in fibrotic lung diseases, including sarcoidosis and usual interstitial pneumonia. Pulmonary edema and lymphangitic spread of tumors are the commonly encountered causes of ILST. It is important to narrow down the differential diagnosis as much as possible by assessing the appearance and distribution of ILST, as well as other pulmonary and extrapulmonary findings. This review will focus on the CT characterization of the secondary pulmonary lobule and ILST. Various uncommon causes of ILST will be discussed, including infections, interstitial pneumonia, depositional/infiltrative conditions, inhalational disorders, malignancies, congenital/inherited conditions, and iatrogenic causes. Awareness of the imaging appearance and various causes of ILST allows for a systematic approach, which is important for a timely diagnosis. This study highlights the importance of a structured approach to CT scan analysis that considers ILST characteristics, associated findings, and differential diagnostic considerations to facilitate accurate diagnoses.

Diffuse reversed halo sign in an immunocompetent patient

The reversed halo sign (RHS) is a specific radiological image observed mostly on computed tomography (CT) scans as a focal round area of ground-glass attenuation surrounded by a crescent or ring of consolidation. It is common to many entities of respiratory diseases and can be found in both infectious, noninfectious inflammatory pathologies and some malignant tumors, including invasive pulmonary fungal infection, tuberculosis (TB), community-acquired pneumonia, granulomatosis, sarcoidosis. It is also seen in pulmonary neoplasms and infarction, and following radiation and radiofrequency. We report the case of an immunocompetent 54-year-old North African male patient, initially hospitalized for chronic cough associated with dysphonia and general symptoms such as weight loss, fever, and night sweats. Radiological exploration surprisingly confirmed the presence of RHS, tuberculosis was confirmed by a postbronchoscopy positive sputum Xpert MTB/RIF essay tuberculosis after we started antibacillary treatment, and the evolution was spectacular with regression of the lesions. The objective of this report is to increase knowledge about RHS and its pathological correlation with TB. Since it is not specific to any disorder, it is important to explore its finding in a clinical and epidemiological manner, especially in endemic countries where the prevalence of tuberculosis is still high.

Cross-sectional imaging review of common to uncommon lung cancer mimickers in a tertiary care oncology center

Lung cancer is the most diagnosed cancer worldwide. Many non-malignant pulmonary lesions, such as tuberculosis, fungal infection, organizing pneumonia, inflammatory myofibroblastic tumor, and IgG4 disease, can mimic lung cancer due to their overlapping morphological appearance on imaging. These benign entities with minor differentiating imaging clues may go unnoticed in a high-volume cancer institution, leading to over-investigation that may result in repeated biopsies, pointless wedge resections, and related morbidities. However, with a thorough medical history, laboratory diagnostic work-up, and careful analysis of imaging findings, one can occasionally restrict the range of possible diagnoses or arrive at a definitive conclusion. When imaging features overlap, image-guided lung sampling is crucial since histopathological analysis is the gold standard.

Impact of computed tomographic patterns and extent on clinical management and outcomes of patients with organising pneumonia

Background

Organising pneumonia (OP) has variable clinical and radiographic presentations and unstandardised treatments. Most patients with OP have favourable outcomes, but some develop respiratory insufficiency, experience recurrence or die. In this study we investigated the impact of computed tomographic (CT) patterns and extent of OP on the diagnostic and therapeutic management that patients received, and that on the therapeutic response and prognosis (particularly the risk of respiratory insufficiency and death).

Methods

We retrospectively studied 156 patients with OP followed at our hospital between 2010 and 2021. The diagnosis was confirmed histologically and verified by multidisciplinary specialists. We performed Firth's logistic regression to determine the relationship between CT features and aetiologies, management and outcomes including the risk of severe disease (defined as the need for supplemental oxygen or mechanical ventilation). We conducted Kaplan-Meier analyses to assess survival differences.

Results

Patients exhibiting multilobe involvement or mixed patterns, or both, were more likely to have secondary OP and receive immunosuppressants. Higher proportions of these patients experienced recurrence. Compared to patients with single-lobe involvement and single-pattern, they also had an enhanced risk of severe disease (the adjusted odds ratio for patients who simultaneously had multilobe involvement and mixed patterns was 27.64; 95% confidence interval 8.25-127.44). Besides, these patients had decreased survival probabilities.

Conclusion

Different CT features of OP impact patients' management and prognosis. When treating patients with OP exhibiting multilobe involvement or mixed patterns, or both, it is important to identify the possible causative aetiology and follow closely for adverse outcomes.

Does cryptogenic organizing pneumonia change seasonal?

BACKGROUND AND AIM

Meteorological factors affect the respiratory system, and the most important factor is the change in ambient temperature and humidity. We aimed to investigate the seasonal characteristics of patients diagnosed with cryptogenic organizing pneumonia.

METHODS

The study included 84 cryptogenic organizing pneumonia, 55 chronic obstructive pulmonary disease, and 42 asthma patients. To determine the characteristics of the disease according to the seasons, the number of attacks and admissions was grouped according to the seasonal characteristics and analyzed for three groups.

RESULTS

Among cryptogenic organizing pneumonia and chronic obstructive pulmonary disease patients, males significantly predominated (p<0.001). The hospitalization rate was highest in chronic obstructive pulmonary disease patients but similar to cryptogenic organizing pneumonia and asthma patients (p<0.001). The highest admission rate in cryptogenic organizing pneumonia patients was observed in spring (39.3% in spring, 26.2% in fall, 22.6% in winter, and 11.9% in summer). In winter, cryptogenic organizing pneumonia patients were admitted less frequently than chronic obstructive pulmonary disease and asthma patients. The neutrophil-to-lymphocyte ratio was higher in cryptogenic organizing pneumonia patients than in asthma patients and similar to chronic obstructive pulmonary disease patients.

CONCLUSION

As a result of our study, the high rate of diagnosis and admission in the spring in cryptogenic organizing pneumonia suggested that the effect of allergens on the formation of cryptogenic organizing pneumonia should be investigated. In contrast, it should be kept in mind that cryptogenic organizing pneumonia may develop as a prolonged finding of involvement that may occur in the lung parenchyma due to lung infections and/or cold weather triggering during the winter months. In this regard, further studies can be conducted in which allergens and/or the history of infection in patients and meteorological variables are also evaluated.

The Hidden Pandemic of COVID-19-Induced Organizing Pneumonia

Since the beginning of the COVID-19 pandemic, clinical, radiological, and histopathological studies have provided evidence that organizing pneumonia is a possible consequence of the SARS-CoV2 infection. This post-COVID-19 organizing pneumonia (PCOP) causes persisting dyspnea, impaired pulmonary function, and produces radiological abnormalities for at least 5 weeks after onset of symptoms. While most patients with PCOP recover within a year after acute COVID-19, 5-25% of cases need specialized treatment. However, despite substantial resources allocated worldwide to finding a solution to this problem, there are no approved treatments for PCOP. Oral corticosteroids produce a therapeutic response in a majority of such PCOP patients, but their application is limited by the anticipated high-relapse frequency and the risk of severe adverse effects. Herein, we conduct a systematic comparison of the epidemiology, pathogenesis, and clinical presentation of the organizing pneumonias caused by COVID-19 as well as other viral infections. We also use the clinical efficacy of corticosteroids in other postinfection OPs (PIOPs) to predict the therapeutic response in the treatment of PCOP. Finally, we discuss the potential application of a candidate anti-inflammatory and antifibrotic therapy for the treatment of PCOP based on the analysis of the latest clinical trials data.

Clinical and Radiological Features of Interstitial Lung Diseases Associated with Polymyositis and Dermatomyositis

Polymyositis and dermatomyositis are autoimmune idiopathic systemic inflammatory diseases, characterized by various degrees of muscle inflammation and typical cutaneous lesions-the latter found in dermatomyositis. The underlying pathogenesis is characterized by a high level of uncertainty, and recent studies suggest diseases may have different immunopathological mechanisms. In polymyositis, components of the cellular immune system are involved, whereas in dermatomyositis, the pathogenesis is mainly mediated by the humoral immune response. The interstitial lung disease occurs in one-third of polymyositis and dermatomyositis patients associated with worse outcomes, showing an estimated excess mortality rate of around 40%. Lung involvement may also appear, such as a complication of muscle weakness, mainly represented by aspiration pneumonia or respiratory insufficiency. The clinical picture is characterized, in most cases, by progressive dyspnea and non-productive cough. In some cases, hemoptysis and chest pain are found. Onset can be acute, sub-acute, or chronic. Pulmonary involvement could be assessed by High Resolution Computed Tomography (HRCT), which may identify early manifestations of diseases. Moreover, Computed Tomography (CT) appearances can be highly variable depending on the positivity of myositis-specific autoantibodies. The most common pathological patterns include fibrotic and cellular nonspecific interstitial pneumonia or organizing pneumonia; major findings observed on HRCT images are represented by consolidations, ground-glass opacities, and reticulations. Other findings include honeycombing, subpleural bands, and traction bronchiectasis. In patients having Anti-ARS Abs, HRCT features may develop with consolidations, ground glass opacities (GGOs), and reticular opacities in the peripheral portions; nonspecific interstitial pneumonia or nonspecific interstitial pneumonia mixed with organizing pneumonia have been reported as the most frequently encountered patterns. In patients with anti-MDA5 Abs, mixed or unclassifiable patterns are frequently observed at imaging. HRCT is a sensitive method that allows one not only to identify disease, but also to monitor the effectiveness of treatment and detect disease progression and/or complications; however, radiological findings are not specific. Therefore, aim of this pictorial essay is to describe clinical and radiological features of interstitial lung diseases associated with polymyositis and dermatomyositis, emphasizing the concept that gold standard for diagnosis and classification-should be based on a multidisciplinary approach.

Late pulmonary complications related to cancer treatment in children

As the number of childhood cancer survivors increases, a heightened awareness and recognition of therapy-related late effects is becoming more important. Pulmonary complications are the third leading cause of late mortality in cancer survivors. Diagnosis of these complications on chest imaging helps facilitate prompt treatment to mitigate adverse outcomes. In this review, we summarize the imaging of late pulmonary complications of cancer therapy in children and highlight characteristic findings that should be recognized by radiologists.

Black Fungus and beyond: COVID-19 associated infections

Globally, many hospitalized COVID-19 patients can experience an unexpected acute change in status, prompting rapid and expert clinical assessment. Superimposed infections can be a significant cause of clinical and radiologic deviations in this patient population, further worsening clinical outcome and muddling the differential diagnosis. As thrombotic, inflammatory, and medication-induced complications can also trigger an acute change in COVID-19 patient status, imaging early and often plays a vital role in distinguishing the cause of patient decline and monitoring patient outcome. While the common radiologic findings of COVID-19 infection are now widely reported, little is known about the clinical manifestations and imaging findings of superimposed infection. By discussing case studies of patients who developed bacterial, fungal, parasitic, and viral co-infections and identifying the most frequently reported imaging findings of superimposed infections, physicians will be more familiar with common infectious presentations and initiate a directed workup sooner. Ultimately, any abrupt changes in the expected COVID-19 imaging presentation, such as the presence of new consolidations or cavitation, should prompt further workup to exclude superimposed opportunistic infection.

WFUMB Technological Review: How to Perform Contrast-Enhanced Ultrasound of the Lung

The use of ultrasound has revolutionized the evaluation of pulmonary complaints and pathology. Historically, most lung ultrasound uses described are limited to B-mode, M-mode and occasionally color Doppler. However, the use of contrast can significantly expand the diagnostic capabilities of lung ultrasound. Ultrasound contrast enables significant expansion of therapeutic and intervention capabilities. We provide a detailed description of contrast administration, phases and uses in lung ultrasound. Additionally provided are example contrast use cases and illustrative examples of contrast use in a wide range of lung ultrasound applications including pneumonia, atelectasis, pulmonary embolism and neoplasms. Clinical practice examples will help providers incorporate contrast use into their lung ultrasound practice.

ERRATUM

[This corrects the article doi: 10.36416/1806-3756/e20200595].

Post-CMV Organizing Pneumonia - An Unusual Presentation 10 years after Kidney Transplantation

A 45-year-old gentleman underwent kidney transplantation in March 2010. He remained apparently healthy for the next 10 years when he developed anorexia and weight loss. Diagnostic workup revealed cytomegalovirus (CMV) pneumonia. While viremia resolved within 3 weeks of initiation of valganciclovir, he developed progressive breathlessness and hypoxia on exertion. Imaging of thorax revealed central peri-bronchovascular consolidation and fine reticulations with peripheral sparing. Computed tomography (CT)-guided percutaneous lung biopsy revealed organizing intra-alveolar exudates, suggestive of organizing pneumonia, with no evidence of active infection on biopsy as well as bronchoalveolar lavage (BAL) cytology. This atypical pattern of central distribution of opacities is not typical of organizing pneumonia where peripheral subpleural distribution is more common. Patient responded dramatically following escalation of steroids, with complete resolution of infiltrates on follow-up imaging.

The role of imaging techniques in understanding and evaluating the long-term pulmonary effects of COVID-19

INTRODUCTION

Limited data exist regarding the long-term pulmonary sequelae of COVID-19. Identifying features utilizing multiple imaging modalities engenders a clearer picture of the illness's long-term consequences.

AREAS COVERED

This review encompasses the common pulmonary findings associated with different imaging modalities during acute and late remission stages of COVID-19 pneumonia.

EXPERT OPINION

Chest x-ray, a common preliminary diagnostic imaging technique, is not optimal for extended care due to limited tissue contrast resolution providing suboptimal assessment of pulmonary pathology and subtle interval changes. Ultrasound may be utilized on a case-by-case basis in certain patient populations, or in countries with limited resources. Chest CT's accessibility, high tissue contrast and spatial resolution make it the foremost modality for long-term COVID-19 follow-up. While MRI can viably monitor extrapulmonary disease due to its lack of radiation and high inherent soft-tissue contrast, it has limited pulmonary utility due to motion artifact and alveolar gas decreasing lung signal. Although 18F-FDG-PET/CT is costly and has limited specificity, it can provide molecular level data and inflammation quantification. Lung perfusion scintigraphy may also explain COVID-19 induced thromboembolic events and persistent dyspnea despite normal structural imaging and testing results. Correlating the long-term pulmonary findings of COVID-19 with each imaging modality is essential in elucidating the post-recovery course.

High-resolution computed tomography (HRCT) analysis in anti-synthase antibody syndrome with organizing pneumonia

OBJECTIVE

The organizing pneumonia (OP) pattern is the second most common finding in anti-synthase antibody syndrome (ASS), and nonspecific interstitial pneumonia (NSIP) is the most common finding. This study analysed the OP score changes by semiquantitative and quantitative analysis methods and the correlation between the high-resolution computed tomography (HRCT) indexes and the pulmonary function test parameters (PFTs) in ASS patients.

METHODS

Data from ASS-OP patients admitted to the respiratory department of Ping Jin Hospital from October 2014 to June 2020 were retrospectively reviewed and analysed.

RESULTS

Fourteen ASS-OP patients were recruited for this study. (1) In method-1, the consolidation (CO) score and the mean lung attenuation (MA) of poorly aerated and fibrosis lung fields (MA_fibrosis) (r=0.56, P=0.04), the ground-glass opacity (GGO) score and the MA of non-aerated lung fields (MA_nonaerated) (r=-0.64, P=0.01), and the CO plus the GGO (CG) score and the MA_nonaerated (r=-0.59, P=0.03) of the lung fields had liner correlations. In method-2, the GGO score to the MA_nonaerated (r=-0.58, P=0.03), and the CG (r=-0.68, P=0.01) score to the MA_nonaerated had liner correlations. The FVC% (r=0.68, P=0.01) and FEV₁% (r=0.64, P=0.01) to the MA_fibrosis had good linear correlations. (2) Compared to the values before treatment, the CO pattern score, volume and weight percentages of the extracted whole lung volume with attenuation values of the nonaerated area (V_nonated%, W_nonaerated%), the volume of poorly aerated and fibrosis lung tissue (V_fibrosis%, W_fibrosis%), the weight percentages of normal aerated lung (W_normal%), and the MA_fibrosis exhibited significant differences during the 3-6 month follow-up period.

CONCLUSION

The GGO and CO scored by the semiquantitative or quantitative analysis methods was similar. The HRCT quantitative analysis parameters showed a good correlation with the PFTs in ASS-OP patients, can provide an accurate OP pattern interpretation, and may be used as a monitoring and therapeutic indicator for ASS-OP patients.

Consensus statement on thoracic radiology terminology in Portuguese used in Brazil and in Portugal

Effective communication among members of medical teams is an important factor for early and appropriate diagnosis. The terminology used in radiology reports appears in this context as an important link between radiologists and other members of the medical team. Therefore, heterogeneity in the use of terms in reports is an important but little discussed issue. This article is the result of an extensive review of nomenclature in thoracic radiology, including for the first time terms used in X-rays, CT, and MRI, conducted by radiologists from Brazil and Portugal. The objective of this review of medical terminology was to create a standardized language for medical professionals and multidisciplinary teams.

Cryptogenic organising pneumonia: current understanding of an enigmatic lung disease

Organising pneumonia (OP) is currently recognised as a nonspecific lung injury response that is associated with a variety of imaging patterns obtained with high-resolution computed tomography (HRCT) of the chest and is characterised histopathologically by the presence of inflammatory cells and a connective tissue matrix within distal airspaces of the lungs. OP is associated with many conditions that include connective tissue disorders, various infections, drug reactions, hypersensitivity pneumonitis and aspiration. When OP cannot be linked to an associated condition and appears to be idiopathic, it is termed cryptogenic organising pneumonia.

Clinical features of acute fibrinous and organizing pneumonia: An early histologic pattern of various acute inflammatory lung diseases

Background

Acute fibrinous and organizing pneumonia (AFOP) is a rare histologic pattern of acute lung involvement with intra-alveolar fibrin deposition. However, the clinical significance of the pathological findings of AFOP remains unclear. This study aimed to explore the clinical significance of AFOP through a comprehensive clinical examination.

Methods

The medical records of patients with lung diseases accompanied by the pathological finding of intra-alveolar organization between January 2010 and December 2019 were retrospectively reviewed. The clinical and radiological findings were compared between the groups with and without the histologic pattern of AFOP.

Results

We identified 34 patients with AFOP (AFOP group) and 143 without AFOP (non-AFOP group). The underlying diseases of the AFOP group were as follows: 19 patients had cryptogenic organizing pneumonia (OP), 5 had connective tissue diseases, 3 had radiation pneumonitis, 3 had chronic eosinophilic pneumonia, 2 had myelodysplastic syndromes, and 2 had drug-induced pneumonia. Fever was more common, the time from symptom onset to biopsy was shorter, and the serum C-reactive protein level was higher in the AFOP group than in the non-AFOP group. On high-resolution computed tomography, 85% of patients had OP pattern, and halo sign was more common in the AFOP group. Corticosteroids were effective in 94% of the patients in the AFOP group; however, recurrences were more frequent, and a higher corticosteroid dose was needed during recurrence.

Conclusions

AFOP might be an early phase of a histologic pattern associated with known etiologies. In addition, it could be a marker indicating intense inflammatory diseases with a tendency of recurrence.

Differential diagnoses of acute ground-glass opacity in chest computed tomography: pictorial essay

Ground-glass opacity is a very frequent and unspecified finding in chest computed tomography. Therefore, it admits a wide range of differential diagnoses in the acute context, from viral pneumonias such as influenza virus, coronavirus disease 2019 and cytomegalovirus and even non-infectious lesions, such as vaping, pulmonary infarction, alveolar hemorrhage and pulmonary edema. For this diagnostic differentiation, ground glass must be correlated with other findings in imaging tests, with laboratory tests and with the patients' clinical condition. In the context of a pandemic, it is extremely important to remember the other pathologies with similar findings to coronavirus disease 2019 in the imaging exams.

Everolimus induced organizing pneumonia in a patient with tuberous sclerosis complex

Organizing pneumonia is characterized by a distinct histologic pattern in the lung interstitium and presents clinically as hypoxemia, fever, cough, and dyspnea that is not attributable to concurrent infection. Typical etiologies of this condition include inflammatory disease, malignancy, toxic inhalation, and an array of medications including the mTOR inhibitor everolimus. In this report, we describe the case of a female with tuberous sclerosis complex on everolimus therapy for renal angiomyolipomas who presented to the hospital with persistent cough, dyspnea, and fevers and bilateral lower lobe opacities on chest X-ray despite multiple courses of antibiotic therapy. Bronchoscopy was performed with transbronchial biopsies, and results demonstrated a lymphocytic predominance and pathologic findings of intraluminal plugs composed of fibroblasts and myofibroblasts consistent with organizing pneumonia. Everolimus therapy was discontinued and patient completed a steroid course with resolution of symptoms. To our knowledge, this is the first published case of organizing pneumonia secondary to everolimus in a patient with tuberous sclerosis complex.

Cryptogenic organising pneumonia: an unusual cause of pleuritic chest pain

A 76-year-old woman presented with a 2-hour history of pleuritic chest pain with no other associated symptoms. Blood investigations revealed raised inflammatory markers and an elevated white cell count. On chest radiograph, an airspace shadow indicative of a consolidation was prominent. This was followed by a CT scan of her thorax which showed a spiculated lesion in the right upper lobe, a lesion in the posterior segment of the left lower lobe and mildly enlarged right hilar lymph nodes. She was started on dual antibiotic therapy; however, the patient's clinical status and inflammatory markers did not improve. A bronchoscopy was performed which excluded malignancy and atypical pathogens. CT-guided biopsy confirmed the presence of cryptogenic organising pneumonia. Prednisolone 50 mg daily was prescribed with quick resolution of symptoms.

Childhood interstitial lung disease: A case-based review of the imaging findings

Childhood interstitial lung disease (chILD) consists of a large, heterogeneous group of individually rare disorders. chILD demonstrates major differences in disease etiology, natural history, and management when compared with the adult group. It occurs primarily secondary to an underlying developmental or genetic abnormality affecting the growth and maturity of the pediatric lung. They present with different clinical, radiologic, and pathologic features. In this pictorial review article, we will divide chILD into those more prevalent in infancy and those not specific to infancy. We will use a case based approach to discuss relevant imaging findings including modalities such as radiograph and computed tomography in a wide variety of pathologies.

The lingering manifestations of COVID-19 during and after convalescence: update on long-term pulmonary consequences of coronavirus disease 2019 (COVID-19)

The long-term sequelae of coronavirus disease 2019 (COVID-19) are still unknown. Lessons from past viral epidemics reveal that, after recovery, patients with viral pulmonary infections can suffer from irreversible pulmonary dysfunction and demonstrate residual imaging or functional abnormalities. Residual ground glass opacities, consolidations, reticular and linear opacities, residual crazy paving pattern, melted sugar sign, and parenchymal fibrotic bands are several features found in the late or remission stages of COVID-19. These radiologic findings have been observed weeks after symptom onset, even after hospital discharge, and they may or may not correlate with clinical manifestations. High-resolution CT may be indicated to establish new baselines and track changes in residual impairments. In our previous review, we observed significant pulmonary sequelae in some COVID-19 survivors at follow-up. In this update, we review the current literature on the clinical and radiologic manifestations of post-recovery COVID-19 toward the end of hospital admission and after discharge.

The Many Faces of Covid-19: Organizing Pneumonia (OP) Pattern HRCT Features

Covid-19 (coronavirus disease 2019) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). On 30 January 2020 the World Health Organization (WHO) declared that the outbreak of Covid-19 realizes a public health emergency of international concern. Because of the primary involvement of the respiratory system, chest CT is strongly recommended in suspected Covid-19 cases, for both initial and follow-up. We present the case of a Covid-19 patient, a 57-year-old man, with a typical HRCT course of OP reaction.

The Many Faces of Covid-19: Organizing Pneumonia (OP) Pattern HRCT Features

Covid-19 (coronavirus disease 2019) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). On 30 January 2020 the World Health Organization (WHO) declared that the outbreak of Covid-19 realizes a public health emergency of international concern. Because of the primary involvement of the respiratory system, chest CT is strongly recommended in suspected Covid-19 cases, for both initial and follow-up. We present the case of a Covid-19 patient, a 57-year-old man, with a typical HRCT course of OP reaction.

Cryptogenic Organizing Pneumonia: Evolution of Morphological Patterns Assessed by HRCT

To evaluate the radiological findings in patients with cryptogenic organizing pneumonia (COP) before steroid treatment and their behavior after therapy, we retrospectively evaluated a total of 22 patients with a diagnosis of COP made by bronchoalveolar lavage (BAL), biopsy or clinical/radiological features, and the patients were followed between 2014 and 2018 at the hospital; the demographic data, symptoms, radiologic findings, diagnostic methods and treatment plans of patients were collected from patients’ hospital records. At least two CT scans of 22 patients (16 female and six men) were evaluated, the first one before starting steroid therapy and the others after therapy. At baseline CT scans, the most common radiological finding was the presence of consolidations (18/22 patients, 81.8%); ground-glass opacities were also very common (15/25, 68.1%). The other findings were as follows: nodules and masses (5/22, 22.7%), atoll sign (4/22, 18.1%), perilobular pattern (3/22, 13.6%) and parenchymal bands (3/22, 13.6%). Two patients had a significant relapse after reducing/interrupting therapy, while three had a complete resolution and are not currently under therapy (maintenance of clinical remission with no oral corticosteroid (OCS)). In High-resolution computed tomography (HRCT) scans after therapy, consolidations were still observable in seven patients (five in new areas of the lung-migratory infiltrates), while most of them disappeared, leaving a residual area of ground glass opacity in two patients. One patient had a residual of the perilobular pattern, with the disappearing of the other findings (consolidations and ground-glass opacities). Two patients developed a fibrosing pattern despite the therapy (9.5%). Cryptogenic organizing pneumonia tends to respond to oral corticosteroid treatment, but some patients may have a null or partial response. We highlight the behavior of this disease after proper therapy.

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.

Organizing Pneumonia Induced by Tocilizumab in a Patient with Rheumatoid Arthritis

Interstitial lung disease is a significant extra-articular manifestation of rheumatoid arthritis, due to its prevalence, morbidity and mortality. Biological therapies are widely used for rheumatoid arthritis treatment. However, some biological agents have been related to the induction or exacerbation of interstitial lung disease. We report a 51-year-old woman with knee arthralgia, hand and foot joint deformities. Although there were no respiratory symptoms, rheumatoid arthritis and interstitial lung disease were diagnosed. High-resolution computed tomography (HRCT) detected a radiological pattern of nonspecific interstitial pneumonia. After tocilizumab therapy for nine months, a second HRCT detected a worsening of interstitial lung disease, presenting a pattern of organizing pneumonia. Tocilizumab was discontinued and prednisone (1 mg/kg/day) was introduced. After two months, a further HRCT detected a significant improvement in organizing pneumonia. There are few similar cases in the literature of tocilizumab-induced organizing pneumonia in patients with rheumatoid arthritis. Despite being a rare adverse effect, knowledge of this association is important for monitoring the use of tocilizumab.

Chest CT imaging features for prediction of treatment response in cryptogenic and connective tissue disease-related organizing pneumonia

OBJECTIVES

To investigate CT imaging features associated with poor clinical outcome after corticosteroid treatment in patients diagnosed with cryptogenic organizing pneumonia (COP) and connective tissue disease-related organizing pneumonia (CTD-OP) and to assess the difference in CT findings and treatment responses between COP and CTD-OP.

METHODS

Chest CT images from 166 patients (COP, 131; CTD-OP, 35) with pathologically proven organizing pneumonia were reviewed by two thoracic radiologists. The type, distribution pattern, and extent of parenchymal abnormalities, along with other associated imaging features, were assessed for each patient. Logistic regression analyses were used to identify features associated with poor clinical outcomes such as residual disease (RD) and disease relapse. The differences between COP and CTD-OP were also analyzed.

RESULTS

Consolidation involving more than 10% of parenchyma (hazard ratio [HR], 2.27), detectable bronchiectasis (HR, 3.59), and diagnosis of CTD-OP (HR, 4.31) were associated with a higher risk of RD after adjustments for patient age and sex. More than 10% consolidation involvement (HR, 2.54) and diagnosis of CTD-OP (HR, 6.42) were also associated with a higher risk of disease relapse. Compared with COP, CTD-OP demonstrated a greater extent of parenchymal abnormalities, especially consolidation, and was less likely to show a peribronchovascular distribution pattern.

CONCLUSION

Bronchiectasis and a greater extent of consolidation were associated with RD, with the latter also being associated with disease relapse. Compared with COP, CTD-OP was associated with worse treatment outcomes and demonstrated a greater extent of parenchymal abnormalities, which were also less likely to show a peribronchovascular pattern.

KEY POINTS

• The presence of bronchiectasis and a high parenchymal involvement of consolidation on initial chest CT were associated with a worse response to corticosteroids in patients with organizing pneumonia. • Connective tissue disease-related organizing pneumonia (CTD-OP) was associated with worse treatment outcomes than its idiopathic counterpart cryptogenic organizing pneumonia (COP). • Compared with COP, CTD-OP generally demonstrated a greater extent of parenchymal abnormalities, especially consolidation, and was less likely to show a peribronchovascular distribution pattern.

The Reversed Halo Sign: Not Such a Specific Sign of Organising Pneumonia

The reversed halo sign is defined as a focal rounded area of ground-glass opacity surrounded by a more or less complete ring of consolidation. It is a relatively rare sign and initially considered a specific sign of organising pneumonia. We report the case of a 55-year-old female who was being followed-up in a pulmonology consultation due to a 6 mm nodule which required vigilance. On a re-evaluation chest CT scan, besides a stable 6 mm nodule, a 36 mm mass with the reversed halo sign was diagnosed. The presence of the reversed halo sign misled the multidisciplinary team into the diagnosis of organising pneumonia and initiation of corticotherapy was suggested. However, after further investigation, a final diagnosis of pulmonary tuberculosis was made. Even though this sign is relatively rare, and still considered an important clue to the diagnosis of organising pneumonia in immunocompetent patients, other causes must be excluded before starting treatment.

Acute and Chronic Respiratory Failure in Cancer Patients

In 2016, there was an estimated 1.8 million new cases of cancer diagnosed in the United States. Remarkable advances have been made in cancer therapy and the 5-year survival has increased for most patients affected by malignancy. There are growing numbers of patients admitted to intensive care units (ICU) and up to 20% of all patients admitted to an ICU carry a diagnosis of malignancy. Respiratory failure remains the most common reason for ICU admission and remains the leading causes of death in oncology patients. There are many causes of respiratory failure in this population. Pneumonia is the most common cause of respiratory failure, yet there are many causes of respiratory insufficiency unique to the cancer patient. These causes are often a result of immunosuppression, chemotherapy, radiation treatment, or hematopoietic stem cell transplant (HCT). Treatment is focused on supportive care and specific therapy for the underlying cause of respiratory failure. Noninvasive modalities of respiratory support are available; however, careful patient selection is paramount as indiscriminate use of noninvasive positive pressure ventilation is associated with a higher mortality if mechanical ventilation is later required. Historically, respiratory failure in the cancer patient had a grim prognosis. Outcomes have improved over the past 20 years. Survivors are often left with significant disability.

Organising pneumonia in Rhupus syndrome

Interstitial lung disease (ILD) is seen in 17% of patients with Rhupus syndrome. Organising pneumonia (OP), a subtype of connective tissue disease-associated ILD, is rare but associated with good outcomes. Here, we present a patient with Rhupus who developed OP.

Interstitial Lung Disease with Anti-melanoma Differentiation-associated Protein 5 Antibody: Rapidly Progressive Perilobular Opacity

Objective Rapidly progressive interstitial lung disease (RP-ILD) with anti-melanoma differentiation-associated protein 5 (MDA5) antibody potentially presents with a fatal clinical course and requires early intensive treatment. Recently, perilobular opacity was reported to pathologically correspond to the acute phase of diffuse alveolar damage in RP-ILD with anti-MDA5 antibody. We aimed to investigate whether or not perilobular opacity was a common radiological finding in RP-ILD patients with anti-MDA5 antibody. Methods We conducted a retrospective review of the medical records of eight consecutive patients with RP-ILD with anti-MDA5 antibody. The clinical features and radiological findings of follow-up computed tomography (CT) during the course of their disease were evaluated. Results Among eight RP-ILD patients with anti-MDA-5 antibody, six showed perilobular opacity in the lower lobes, and the remaining two had only consolidation on high-resolution CT. Of note, the perilobular opacity in all six patients thickened and progressed to consolidation with a loss of lung volume in a short period. Despite intensive treatment, 6 patients (75%) died within 100 days after the first visit. Notably, the two patients with consolidation presented with a very rapid clinical course and died in 13 days each. In the two survivors, the perilobular opacity and consolidation recovered with improvement in the loss of lung volume. Conclusion Rapidly progressive perilobular opacity that thickens and progresses to consolidation is characteristic of RP-ILD with anti-MDA5 antibody. Chest physicians should immediately check the status of anti-MDA-5 antibody in order to initiate early aggressive therapy in RP-ILD patients with rapidly progressive perilobular opacity.

Cryptogenic and Secondary Organizing Pneumonia: Clinical Presentation, Radiological and Laboratory Findings, Treatment, and Prognosis in 56 Cases

OBJECTIVES

Organizing pneumonia is an important disease that is associated with non-specific clinical findings and radiographic appearance. Our aim was to examine the clinical and radiological features, laboratory findings, diagnostic approach, and response to therapy in subjects with cryptogenic (COP) and secondary organizing pneumonia (SOP).

MATERIALS AND METHODS

Patients' medical records were retrospectively reviewed between 2010 and 2016 in our hospital. We analyzed the symptoms, radiological features, pulmonary function tests, laboratory data, bronchoalveolar lavage findings, treatment, and prognosis.

RESULTS

Thirty-seven patients were diagnosed with COP and 19 patients with SOP. The most common causes of SOP were determined as rheumatologic diseases. The most common symptoms were cough (71.4%) and dyspnea (66.1%). Bilateral symmetrical consolidations were the most prominent radiological appearance in both COP and SOP. The general radiographic findings were not different in COP and SOP. However, pulmonary lesions were located rather in the central (p=0.023) and middle (p=0.001) zones in patients with SOP. Corticosteroid (CS) therapy was administered to 34 (60.7%) patients. Two patients showed deterioration despite CS therapy.

CONCLUSION

The clinical and radiographic findings, treatment response, prognosis were similar in patients with COP and SOP.

Pathology and radiology correlation of idiopathic interstitial pneumonias

By nature, idiopathic interstitial pneumonias have been diagnosed in a multidisciplinary manner. As classifications have been subject to significant refinement over the last decade, the importance of correlating clinical, radiologic, and pathologic information to arrive at a diagnosis, which will predict prognosis in any given patient, has become increasingly recognized. In 2013, the American Thoracic Society and European Respiratory Society updated the idiopathic interstitial pneumonias classification scheme, addressing the most recent updates in the field. The purpose of this review is to highlight the correlations between radiologic and pathologic findings in idiopathic interstitial pneumonias while using updated classification schemes and naming conventions.

'Crazy-paving' pattern: an exceptional presentation of cryptogenic organising pneumonia associated with chronic obstructive pulmonary disease

Organising pneumonia (OP) is a distinct but uncommon entity with characteristic clinicoradiological features and histological findings. When the aetiology of OP remains unknown, it is termed as cryptogenic OP (COP). COP is seen in the majority of patients with OP and usually observed in non/former smokers. A 54-year-old man, a smoker, presented with breathlessness, cough and mucoid sputum. Imaging demonstrated unilateral 'Crazy-paving' pattern in the left upper lobe and left-sided effusion. In addition, paraseptal emphysema and left lower lobe bullae along with very severe obstructive ventilatory defect and impaired diffusion suggested chronic obstructive pulmonary disease (COPD). Transbronchial biopsy was suggestive of OP. In the absence of a definite aetiology, a diagnosis of COP associated with COPD was established. COP presenting as a unilateral 'Crazy-paving' pattern is yet to be documented. To the best of our knowledge, this is the first detailed description of COP presenting as unilateral 'Crazy-paving' pattern associated with COPD.

Organizing Pneumonia in a Patient with Quiescent Crohn’s Disease

A 64-year-old man with Crohn's disease (CD) was admitted to our hospital due to moderate risk of pneumonia while receiving scheduled adalimumab maintenance therapy. Symptoms remained virtually unchanged following administration of antibiotics. A final diagnosis of organizing pneumonia (OP) was made based on findings of intra-alveolar buds of granulation tissue and fibrous thickening of the alveolar walls on pathological examination and patchy consolidations and ground glass opacities on computed tomography. Immediate administration of prednisolone provided rapid, sustained improvement. Although a rare complication, OP is a pulmonary manifestation that requires attention in CD patients.