Epidemic adenoviral lower respiratory tract infection in pediatric patients: radiographic and clinical characteristics

Radiographic findings of adenoviral pneumonia in children

OBJECTIVE

Adenovirus pneumonia is a common cause of community-acquired pneumonia in children and can mimic bacterial pneumonia, but there are few publications on its radiographic features. This study has evaluated the chest radiography findings of community-acquired adenovirus pneumonia in children. The frequency of radiological findings mimicking bacterial pneumonia was investigated. The clinical features of patients with adenovirus pneumonia possessing radiological findings mimicking bacterial pneumonia were also evaluated.

MATERIALS AND METHODS

The chest radiographs of patients diagnosed with adenovirus pneumonia were retrospectively reviewed. The chest radiographs were interpreted independently by a pediatric infectious disease specialist and a pediatric radiologist. Chest radiography findings mimicking bacterial pneumonia (bacterial-like) were specified as consolidation +/- pleural effusion. Other findings on chest radiography or a completely normal chest X-ray were specified as findings that were compatible with "typical viral pneumonia".

RESULTS

A total of 1407 patients were positive for adenovirus with respiratory multiplex PCR. The 219 patients who met the study criteria were included in the study. Chest radiographs were normal in 58 (26.5 %) patients. The chest radiograph findings mimicked bacterial pneumonia in 41 (18.7 %) patients.

CONCLUSION

Adenovirus pneumonia occurs predominantly in children aged five years and younger, as with other viral pneumonias. The radiographic findings in adenovirus pneumonia are predominantly those seen in viral pneumonia. Increasing age and positivity for only adenovirus without other viruses on respiratory multiplex PCR were associated with the chest radiograph being more likely to be "bacterial-like". Adenovirus may lead to lobar/segmental consolidation at a rate that is not very rare.

The Global Burden of Pleural Diseases

Pleural diseases include a spectrum of disorders broadly categorized into pneumothorax and pleural effusion. They often cause pain, breathlessness, cough, and reduced quality of life. The global burden of diseases reflects regional differences in conditions and exposures associated with pleural disease, such as smoking, pneumonia, tuberculosis, asbestos, cancer, and organ failure. Disease burden in high-income countries is overrepresented given the availability of data and disease burden in lower-income countries is likely underestimated. In the United States, in 2016, there were 42,215 treat-and-discharge visits to the emergency room for pleural diseases and an additional 361,270 hospitalizations, resulting in a national cost of $10.1 billion.

Liver Involvement in Acute Respiratory Infections in Children and Adolescents - Results of a Non-interventional Study

BACKGROUND

In children and adults with acute respiratory tract infections (ARTI), elevations of serum liver enzyme activities are frequently observed in clinical practice. However, epidemiological data particularly in the pediatric population are very limited. The aim of this study was to assess the incidence of hepatic involvement, to identify the viruses and to analyze risk factors in children and adolescents with ARTI in a real-world setting.

METHODS

We report on a prospective, multicenter, non-interventional study with 1,010 consecutive patients aged 1-17 years with ARTI who consulted a physician within 5 days after onset of symptoms. Laboratory blood tests and PCR virus detection in nasopharyngeal lavage were performed at first presentation and after 3-7 days. Patients with elevated activities of serum liver enzymes (ASAT, ALAT, and γ-GT) were determined in local laboratories and values were normalized by dividing by the individual upper limit of the normal range (ULN). The resulting index (<1 means below ULN, >1 means above ULN) allowed to compare results from laboratories with different reference ranges.

RESULTS

Laboratory test results of 987 patients were available at first visit. 11.1% (95% CI: 9.2-13.3%) exhibited an elevation of ASAT, ALAT, and/or γ-GT activities. Virus DNA or RNA was identified in nasopharyngeal lavages of 63% of the patients. 12.2% of patients with positive PCR and 9.7% of those with negative PCR (p = 0.25) had elevated serum liver enzyme activities. The highest rates were observed in patients with a positive result for influenza B virus (24.4%) followed by human metapneumovirus (14.6%), and human coronavirus (others than SARS-CoV-2) (13.6%). The rate of children and adolescents with ARTI and elevation of serum liver enzyme activities correlated with the virus species and with overweight of the patients but did not differ in patients with or without previous medication intake.

CONCLUSION

Elevated enzyme activities are present in about 10% of children and adolescents with ARTI. In our cohort, these elevations were mild to moderate; probably resulting from an inflammation process with hepatic involvement.

Analysis of Clinical Characteristics and Risk Factors of Severe Adenovirus Pneumonia in Children

Objective: To analyze the clinical characteristics of adenovirus pneumonia (ADVP) in children and explore risk factors for severe ADVP. Methods: Clinical data from 7,008 hospitalized children with community-acquired pneumonia and 211 with ADVP were retrospectively analyzed between July 2014 and June 2019. Eighty-six patients were diagnosed with severe pneumonia, and related risk factors were analyzed. Results: ADVP accounts for 3.01% (211/7008) of CAP in hospitalized children. Among 211 patients, 167 (64.9%) children aged 1-5 years old, and the onset was in winter and spring for 126 (59.7%) children. All patients had cough, and 116 (92.8%) patients with mild cases and 82 (95.4%) patients with severe cases had varying degrees of fever. The duration of fever in the severe ADVP group and mild ADVP group was 7.3 and 5.4 days, respectively. The average hospital stays were 9.8 and 5.8 days, respectively. There was no significant difference in the levels of WBC and ESR between the two groups, but the levels of N%, CRP, PCT and LDH in children with severe ADVP were significantly higher than those in the mild ADVP group. The univariate analysis showed that there were significant differences between the severe ADVP group and the mild ADVP group in ≥7 days of fever and high IgE (P < 0.05). There was no significant difference in sex, age, onset season, mycoplasma infection, bacterial infection between the two groups (P > 0.05). The multivariate logistic analysis showed that ≥7 days of fever and high IgE were independent risk factors for severe ADVP (P < 0.05). Conclusions: Children with severe ADVP have long fever duration, a strong inflammatory response and immune function disturbance. Fever duration (≥7 days) and high IgE were independent risk factors for severe ADVP.

Immune status affects the clinical features and outcomes of adult patients with respiratory adenovirus infection

The differences in the clinical features and outcomes of respiratory adenovirus infection (RAI) between immunocompetent and immunocompromised adult patients remain unclear. Thirty-nine adult RAI patients, including 28 (71.8%) immunocompetent patients and 11 (28.2%) immunocompromised patients were enrolled in this retrospective study. Demographic characteristics, symptoms, laboratory tests, radiographic findings, therapies and clinical outcomes were compared between the two groups. We found fever (94.9%), cough (66.7%) and sputum production (56.4%) were the most frequent symptoms. Compared with immunocompetent RAI patients, the immunocompromised RAI patients were more likely to experience anaemia (g/l; 90.8 ± 24.0 vs 134.3 ± 14.6, P < 0.001), thrombocytopaenia ( × 10⁹/l; 116.9 ± 92.7 vs 178.4 ± 74.6, P = 0.037), hypoalbuminaemia (g/l; 29.6 ± 5.5 vs 36.9 ± 5.2, P < 0.001), hyponatraemia (mmol/l; 134.8 ± 5.6 vs 138.5 ± 3.9, P = 0.026) and low levels of cholinesterase (U/l; 2650.5 ± 1467.4 vs 5892.8 ± 1875.1, P < 0.001). Chest computed tomography (CT) scans indicated that lung infiltrate was the most common finding (64.1%). Immunocompromised patients had a higher likelihood of bilateral lung involvement (72.7%) and lower lobe involvement (81.8%) of both lungs. The hospitalized mortality rate was 27.3% in immunocompromised RAI patients, but no death occurred among immunocompetent RAI patients (P = 0.018). Our data suggested immunocompromised RAI patients had worse laboratory test results, more bilateral lung and lower lobe involvement and higher in-hospital mortality compared with immunocompetent RAI patients.

Severe Adenovirus Pneumonia Requiring Extracorporeal Membrane Oxygenation Support in Immunocompetent Children

Objective: To highlight severe adenovirus pneumonia in immunocompetent patients by analysis of severe adenovirus pneumonia associated with acute respiratory distress syndrome in whom extracorporeal membrane oxygenation (ECMO) support is required. Methods:Pediatric patients with adenovirus pneumonia and ECMO supports in our hospital from February 2018 to May 2019 were retrospectively analyzed, and having 100 common adenovirus pneumonia children as a control. Results:A total of 8 patients, including 4 boys (50.0%), were enrolled. They were previously immunocompetent with a median age of 31 months. They were admitted as persistent fever and cough for more than one week. Median time prior to development of respiratory failure requiring intubation and invasive mechanical ventilation was 5 days. Venoarterial ECMO support as rescue ventilation was instituted after a median time of 24.5 h of conventional mechanical ventilator support. The median duration on ECMO support was 9 days and mechanical ventilation was 14 days, respectively. Six patients (75%) were recovered and 2 (25%) died. Median length of stay in ICU and hospital were 27.5 days and 47.5 days, respectively. Conclusion:The promising outcomes of our cases suggested that ECMO support for rescue ventilation may be considered when symptoms deteriorated in adenovirus pneumonia patients, and may improve outcome. However, sequelae of adenovirus pneumonia and ECMO-related complications should also be taken into account.

Clinical Features and Radiological Findings of Adenovirus Pneumonia Associated with Progression to Acute Respiratory Distress Syndrome: A Single Center Study in 19 Adult Patients

Objective

To describe radiologic findings of adenovirus pneumonia and to understand clinico-radiological features associated with progression to acute respiratory distress syndrome (ARDS) in patients with adenovirus pneumonia.

Materials and Methods

This study included 19 patients diagnosed with adenovirus pneumonia at a tertiary referral center, in the period between March 2003 and April 2015. Clinical findings were reviewed, and two radiologists assessed imaging findings by consensus. Chi-square, Fisher's exact, and Student's t tests were used for comparing patients with and without subsequent development of ARDS.

Results

Of 19 patients, nine were immunocompromised, and 10 were immunocompetent. Twelve patients (63%) progressed to ARDS, six of whom (32%) eventually died from the disease. The average time for progression to ARDS from symptom onset was 9.6 days. Initial chest radiographic findings were normal (n = 2), focal opacity (n = 9), or multifocal or diffuse opacity (n = 8). Computed tomography (CT) findings included bilateral (n = 17) or unilateral (n = 2) ground-glass opacity with consolidation (n = 14) or pleural effusion (n = 11). Patients having subsequent ARDS had a higher probability of pleural effusion and a higher total CT extent compared with the non-ARDS group (p = 0.010 and 0.007, respectively). However, there were no significant differences in clinical variables such as patient age and premorbid condition.

Conclusion

Adenovirus pneumonia demonstrates high rates of ARDS and mortality, regardless of patient age and premorbid conditions, in the tertiary care setting. Large disease extent and presence of pleural effusion on CT are factors suggestive of progression to ARDS.

Viral diseases affecting the pleura

BACKGROUND

Viruses affect the human body in multiple ways producing various disease states. The infections of the pulmonary parenchyma have been well described. However, there has been no current review of the literature pertaining to the pleura.

AIM

To review the available literature pertaining to diseases of the pleura that are caused by viral infections.

METHODS

A Medline search was performed and available research and review articles relating to viral infections that resulted in pleural effusions, pleural masses, pleural thickening, and pleural nodularity were reviewed.

CONCLUSION

There are numerous viruses that cause diseases of the pleura. Pleural effusions and lesions within the pleura are the most common presentation of the disease state. Polymerase chain reaction has the potential to further diagnose viral infections and expand our knowledge base in this field.

Adenovirus respiratory tract infections in Peru

Background

Currently, there is a paucity of data regarding human adenovirus (HAdv) circulation in Andean regions of South America. To address this shortcoming, we report the clinical, phylogenetic, and epidemiologic characteristics of HAdv respiratory tract infection from a large sentinel surveillance study conducted among adults and children in Peru.

Methods/Principal Findings

Oropharyngeal swabs were collected from participants visiting any of 38 participating health centers, and viral pathogens were identified by immunofluorescence assay in cell culture. In addition, molecular characterization was performed on 226 randomly selected HAdv samples. Between 2000 and 2010, a total of 26,375 participants with influenza-like illness (ILI) or severe acute respiratory infection (SARI) were enrolled in the study. HAdv infection was identified in 2.5% of cases and represented 6.2% of all viral pathogens. Co-infection with a heterologous virus was found in 15.5% of HAdv cases. HAdv infection was largely confined to children under the age of 15, representing 88.6% of HAdv cases identified. No clinical characteristics were found to significantly distinguish HAdv infection from other respiratory viruses. Geographically, HAdv infections were more common in sites from the arid coastal regions than in the jungle or highland regions. Co-circulation of subgroups B and C was observed each year between 2006 and 2010, but no clear seasonal patterns of transmission were detected.

Conclusions/Significance

HAdv accounted for a significant fraction of those presenting with ILI and SARI in Peru and tended to affect the younger population disproportionately. Longitudinal studies will help better characterize the clinical course of patients with HAdv in Peru, as well as determine the role of co-infections in the evolution of illness.

Severe community-acquired pneumonia caused by adenovirus type 11 in immunocompetent adults in Beijing

BACKGROUND

Severe community-acquired pneumonia (CAP) due to human adenoviruses (HAdVs) in immunocompetent adults has raised concerns.

OBJECTIVE

To describe the clinical, laboratorial, and radiological characteristics of adenovirus pneumonia and detect the type and diversity of human adenoviruses that caused acute respiratory distress syndrome (ARDS) in Beijing.

STUDY DESIGN

An etiological study of adult community-acquired pneumonia was carried out prospectively at Beijing Chao-Yang Hospital. A total of 18 cases with laboratory-confirmed adenovirus infections in 487 cases with CAP were observed clinically. The viral type and phylogenetic analysis were tested by polymerase chain reaction (PCR).

RESULTS

Patients with adenovirus pneumonia typically reported flu-like symptoms. Some of them developed shortness of breath or severe dyspnea on 6 days after disease onset. The patients with ARDS usually present dyspnea, higher level of serum muscle enzymes and bilateral, mutilobal consolidation and patchy/ground-glass opacities. HAdVs type was detected in 17 samples and all of them belonged to species B (HAdV-11, 7, 3 and 14). Among them, HAdV-11 was most frequently (10/17), followed by HAdV-7 (5/17). Phylogenetic analysis of the partial penton nucleotide confirmed a close relationship with stains circulating in the Beijing region.

CONCLUSIONS

Our identification of severe respiratory illness due to adenovirus, especially type 11 may highlight the need for rapid diagnosis and improved surveillance, which may assist with targeted development of antiviral agents or type-specific vaccines.

Radiological findings in 210 paediatric patients with viral pneumonia: a retrospective case study

OBJECTIVE

The objective of this study was to assess the radiological presentations of different types of viral pneumonia in children.

METHODS

Nasopharyngeal swab specimens and bronchial aspirate samples from children with acute respiratory infections were obtained and tested for influenza B, adenovirus, respiratory syncytial virus and parainfluenza (Types 1, 2 and 3) by direct immunofluorescence assay, or for influenza A (Subtype H1N1) by quantitative real-time polymerase chain reaction. The chest radiographs of the 210 confirmed cases of viral pneumonia were analysed retrospectively by two independent radiologists for the identification, characterisation and description of the distribution of imaging abnormalities. The cases were divided into six groups on the basis of confirmed causative viral agent, and radiographic findings were compared, analysed and presented.

RESULTS

The abnormal chest radiograph findings consisted of bilateral patchy areas of consolidation (n=133), interstitial lung disease (n=33), diffuse areas of air space consolidation (n=29) and lobar consolidation (n=15). The abnormalities were distributed bilaterally in 195 cases and observed more frequently in the lower zones than in other regions. The radiological findings varied significantly among the six groups (p=0.0050). Pairwise comparison showed significant difference between influenza A (H1N1) and adenovirus (p=0.0031) only.

CONCLUSION

The predominant radiological finding in paediatric viral pneumonia was bilateral patchy areas of consolidation. The radiological findings differed significantly only between adenovirus and influenza A pneumonia. The diagnosis of the specific causative organism requires laboratory confirmation.

Prolonged mechanical support in children with severe adenoviral infections: a case series and review of the literature

Adenovirus infections occur primarily in infants and children less than 5 years of age, accounting for 2% to 5% of respiratory illnesses in the pediatric population and 4% to 10% of childhood pneumonias. Although the majority of children with adenovirus disease develop mild upper respiratory tract disease, more severe disease may occur with involvement of the lower respiratory tract characterized by pneumonitis and/or small airways disease. The authors present a case series of 3 high-risk children with severe lower respiratory tract adenoviral infections. These cases demonstrate the potential for the development of severe respiratory involvement from adenovirus in infants and children with comorbid conditions and illustrate that there may be a rapid progression of the disease as well as the need, in selected circumstances, for prolonged mechanical support. We review the role of adenovirus in lower respiratory tract infections in infants and children, its potential to result in life-threatening complications in pediatric patients with comorbid conditions, and the potential life-saving role of mechanical ventilation and extracorporeal life support (ECLS) in these children.

Various computed tomography findings of 2009 H1N1 influenza in 17 patients with relatively mild illness

Purpose

We retrospectively analyzed the computed tomography (CT) findings of H1N1 virus infection in 17 patients with relatively mild illness.

Materials and methods

From September 2009 to January 2010, a total of 17 patients with confirmed H1N1 infection were included in the study (mean age 30.7 years). All patients were managed as outpatients or required short hospitalization without ventilation assistance. The CT scans were assessed for the presence of nodules, ground glass opacity (GGO), consolidation, bronchial wall thickening, reticulation, effusion, and lymph node enlargement. Location and distribution were evaluated.

Results

The most frequent manifestation was a mixture of nodules, consolidation, and GGO (5/17, 29.4%). In one case there was a focal area of bronchiolitis (centrilobular nodules with tree-in-bud appearance), and 10 of 17 cases (58.8%) showed bronchial wall thickening (findings of bronchitis/peribronchitis) and/or other abnormalities. In 16 of the 17 cases (94.1%) there were CT abnormalities with bilateral and random distribution without zonal predominance. Pleural effusions were seen in eight cases (47.1%).

Conclusion

In contrast to several reports so far, CT findings of H1N1 virus infection in patients with mild illness are variable, including suggestive findings of inflammation involving large and/or small airways. This study showed various CT findings overlapping with other viral, atypical, or bacterial pneumonia and even cryptogenic organizing pneumonia.

Radiological findings of pneumonia in patients with swine-origin influenza A virus (H1N1)

Purpose

During spring 2009, a pandemic swine-origin influenza A (H1N1) virus (S-OIV) emerged and spread globally. We describe the chest X-ray and computed tomography (CT) findings of 40 patients with pneumonia due to S-OIV observed in our institution.

Material and methods

Among 534 patients with S-OIV, according to the US Centers for Disease Control and Prevention case definition, seen between June and November 2009, 121 underwent chest X-ray and 40 (median age 44 years, range 16–79) had pneumonia. The initial chest radiographs were evaluated for pattern, distribution and extent of lung abnormalities. Unenhanced chest CT scans were performed in two patients and were reviewed for the same findings. Underlying medical conditions were present in 42% of patients (17/40).

Results

Our patients had predominantly mild illness, and pneumonia was observed in 40 individuals (40/121 patients who had chest X-rays, 33%; and 40/534 patients with S-OIV, 7.5%). However, S-OIV can cause severe illness requiring admission to the intensive care unit for advanced mechanical ventilation and extracorporeal life support, including adult respiratory distress syndrome (ARDS) and death. The major radiological abnormalities observed were interstitial changes (60.0%), with (22.0%) or without patchy ground-glass appearance, mostly bilateral, and located in the lower lung zones (7.5%). Extensive disease was seen in 37.5% (15/40), and ARDS was observed in three individuals (0.30%)with underlying medical conditions. Subtle pleural effusion was noted in four patients.

Conclusions

In our series, the most frequent pneumonia patterns observed during S-OIV (H1N1) virus were interstitial changes and patchy ground-glass appearance, mostly bilateral, and located in the lower lung zones. CT, performed in severely ill patients, confirmed the ARDS identified with chest X-rays, better depicting the features and extent of lung abnormalities.

Survival after prolonged pediatric extracorporeal membrane oxygenation support for adenoviral pneumonia

Adenoviral pneumonia can cause significant pulmonary morbidity leading to extracorporeal membrane oxygenation (ECMO) rescue. Reported survival of adenoviral pneumonia requiring ECMO has been poor, and prolonged time on ECMO is associated with increased mortality. We present 2 pediatric cases of adenoviral pneumonia in patients who survived after greater than 30 days on ECMO and review the Extracorporeal Life Support Organization (ELSO) registry to describe the collective experience of children with viral pneumonia requiring prolonged ECMO. Although survival has improved over the past decade for pediatric adenoviral pneumonia, the ELSO database previously has had no surviving children reported with a primary diagnosis of adenovirus after more than 4 weeks on ECMO. Our experience suggests that there may be use for prolonged ECMO support in children despite severe adenoviral pneumonia.

Bronchiolitis obliterans in children: clinical presentation, therapy and long-term follow-up

AIM

To delineate the predisposing factors, clinical, radiological features and outcomes of bronchiolitis obliterans (BO) in children for minimising morbidity and mortality.

METHODS

Ten children who had BO from July 1995 to July 2005 were retrospectively reviewed at a tertiary paediatric facility in northern Taiwan.

RESULTS

Bronchiolitis obliterans complicated by infections, Stevens-Johnson syndrome was found in eight and two patients, respectively. In children with post-infectious BO, adenoviruses were the most common etiologic agents (7/8). Among them, six patients needed intensive management and five patients needed mechanical ventilation. All patients presented persistent dyspneic respirations and wheezing since the initial lung infection. Initial focal atelectasis (n = 3) on chest radiographs progressed to atelectasis/lobar collapse (n = 8) when the diagnosis of BO was made. After adequate supportive management, atelectatic bronchiectasis was the most common complication (n = 5).

CONCLUSION

Severe adenovirus bronchiolitis and/or pneumonia appear to have higher risk of development of BO in children. In order to minimise associated complications of BO, meticulous respiratory care for preventing pulmonary collapse may be considered in such instances.

Viral pneumonia after hematopoietic stem cell transplantation: high-resolution CT findings

Hematopoietic stem cell transplantation (HSCT) is the treatment of choice for many hematologic malignancies and nonmalignant disorders of bone marrow function. Pulmonary infections from bacterial, fungal, and viral organisms are a major cause of morbidity and mortality in patients after HSCT. The radiographic and high-resolution computed tomography (HRCT) findings of the different lower respiratory tract viral infections are quite similar. Findings of viral pneumonia on HRCT include small poorly defined centrilobular nodules and patchy, often bilateral, areas of peribronchial ground-glass opacity and consolidation. Air trapping may be present because of associated bronchiolitis. Interlobular septal thickening, bronchial wall thickening, and tree-in-bud opacities may also be present. Advanced viral pneumonia with diffuse alveolar damage is characterized by patchy or confluent consolidation and ground-glass opacities. Although nonspecific, in the correct clinical setting, these HRCT findings can help suggest the diagnosis of viral pneumonia in recipients of HSCT.

The other causes of 'atypical' pneumonia

Mycoplasma, Chlamydia and Legionella are the usual organisms considered to be the etiologic agents of 'atypical' pneumonia. Other microorganisms such as bacteria, viruses, parasites, fungi and mycobacteria can also present with atypical pneumonia manifestations. Outbreaks and isolated cases of respiratory viruses with atypical pneumonia presentations have been reported among immunocompetent and immunosuppressed patients. Severe infections due to these respiratory viruses alone or as a concomitant bacterial or viral infection have been observed. Additionally, in endemic areas, certain zoonotic infections may present as atypical pneumonia.

Adenovirus pneumonia in adults: radiographic and high-resolution CT findings in five patients

OBJECTIVE

The purpose of this study was to describe the radiographic and high-resolution CT (HRCT) findings of adenovirus pneumonia in five patients.

CONCLUSION

Adenovirus pneumonia in adults appears as bilateral patchy parenchymal opacities on chest radiographs and as bilateral ground-glass opacities with a random distribution with or without consolidation on HRCT images. These findings, however, are not specific for adenovirus pneumonia.

Imagerie moderne des pneumonies infectieuses aiguës

Les pneumonies infectieuses aiguës constituent un problème de santé publique important, car elles sont une cause majeure de morbidité et de mortalité chez l’adulte. Si les données cliniques et radiographiques permettent le plus souvent de faire le diagnostic de pneumonie infectieuse, le diagnostic étiologique est plus difficile. En effet, de nombreux agents pathogènes peuvent être responsables de pneumonie et la réaction du parenchyme pulmonaire est peu variée, d’où la faible spécificité des lésions radiologiques observées en dehors de quelques cas particuliers. C’est pourquoi la compréhension des mécanismes physiopathologiques permet d’expliquer certains aspects radiologiques. De même, la connaissance des bases anatomocliniques et radiologiques autorise la reconnaissance de trois aspects radiographiques principaux. Quant à l’appréciation des contextes épidémiologique et immunitaire, ils peuvent permettre également d’approcher le germe en cause.

[Radiomorphology of inflammatory lung diseases in childhood]

Imaging plays an important role in the diagnosis and therapy of children with suspected pulmonary infections. The role consists in confirmation or exclusion of pneumonia, differentiation between the entities, exclusion of other causes and evaluation of related complications.

Viral pneumonias in adults: radiologic and pathologic findings

Numerous viruses, including influenza virus, measles virus, Hantavirus, adenovirus, herpesviruses, varicella-zoster virus, cytomegalovirus, and Epstein-Barr virus, can cause lower respiratory tract infection in adults. Viral pneumonia in adults can be classified into two clinical groups: so-called atypical pneumonia in otherwise healthy hosts and viral pneumonia in immunocompromised hosts. Influenza virus types A and B cause most cases of viral pneumonia in immunocompetent adults. Immunocompromised hosts are susceptible to pneumonias caused by cytomegalovirus, herpesviruses, measles virus, and adenovirus. The radiographic findings, which consist mainly of patchy or diffuse ground-glass opacity with or without consolidation and reticular areas of increased opacity, are variable and overlapping. Computed tomographic findings, which are also overlapping, consist of poorly defined centrilobular nodules, ground-glass attenuation with a lobular distribution, segmental consolidation, or diffuse ground-glass attenuation with thickened interlobular septa. The radiologic findings reflect the variable extents of the histopathologic features: diffuse alveolar damage (intraalveolar edema, fibrin, and variable cellular infiltrates with a hyaline membrane), intraalveolar hemorrhage, and interstitial (intrapulmonary or airway) inflammatory cell infiltration. Clinical information such as patient age, immune status, community outbreaks, symptom onset and duration, and presence of a rash remain important aids in diagnosis of viral causes.

Application of computed tomography in childhood respiratory infections

The role of computed tomography (CT), including high-resolution computed tomography (HRCT), is still evolving in children. Radiation dose is an important consideration, but CT has advantages over chest radiography as it is more sensitive and specific for a variety of conditions affecting the pulmonary parenchyma. Careful attention to CT technique is vital for good quality diagnostic images in the paediatric population. The CT appearances of bacterial, viral, fungal, tuberculous and mycoplasma respiratory tract infections are discussed. The role of CT in specific circumstances such as the investigation of complicated bacterial pneumonia, the immunocompromised child and the sequelae of respiratory infections is addressed.

Trends in pediatric emergency imaging

Abdominal pain, respiratory infections, and skeletal trauma are among the most common reasons for imaging infants and children in the emergency department. The types of pathology and the imaging findings for the various causes of these conditions often differ significantly from those seen in adults with similar symptoms. Although radiographs remain the primary imaging tool, ultrasound, helical CT, and MR imaging play an increasingly important role in solving diagnostic problems in emergency pediatrics. This article highlights some of the common diagnostic dilemmas and discusses current trends in the use of advanced imaging in pediatric patients.