[The diagnostic value of lung ultrasound in children with community-acquired pneumonia].

Objective: To investigate the diagnostic value of lung ultrasound in hospitalized children with community-acquired pneumonia (CAP). Methods: In the cross-sectional study, a total of 422 children with CAP who were hospitalized in the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, from February 2021 to August 2022 and completed lung ultrasound examination within 48 hours after admission were enrolled. The clinical characteristics, lung ultrasound and chest CT were collected. The patients were divided into two groups according to the signs of pneumonia indicated by chest CT, and the signs of lung ultrasound with diagnostic value were screened according to the signs of pneumonia indicated by chest CT by least absolute shrinkage and selection operator (Lasso) regression. According to severity of the disease, the children were divided into the severe group and the mild group, and the differences of lung ultrasound signs between the two groups were compared. Kruskal-Wallis test, Fisher's exact test was selected for comparison between groups. Random forest classifier wes used to evaluate the value of lung ultrasound in the diagnosis of CAP and prediction of severe pneumonia in children. The receiver operating characteristic curve was used to evaluate the prediction effect. Use DeLong test to compare the area under the curve. Results: Among the 422 cases of CAP, there were 258 males and 164 females, and the age of onset was 2.8 (1.3, 4.3) years. The confluent B-line, consolidation and pleural effusion detected by lung ultrasound were 309 cases (73.2%), 232 cases (55.0%) and 16 cases (3.8%), respectively, and the size of consolidation was 3.0 (0, 11.0) mm. One hundred and ten children (26.1%) with CAP completed chest CT. There were 90 cases with signs of pneumonia in chest CT and 20 cases without signs of pneumonia. Lasso was used for feature selection.Lung consolidation (OR=2.46), bilateral lung consolidation (OR=1.16) and confluent B-line (OR=1.34) were the main index. With random forest classifier, the accuracy of models using full variables and Lasso-selected variables were 0.79 (95%CI 0.70-0.86) and 0.79 (95%CI 0.70-0.86), the sensitivity were 0.81 and 0.81, and the specificity were 0.75 and 0.70, and the area under curve were 0.87 (95%CI 0.81-0.94, P<0.001) and 0.84 (95%CI 0.76-0.91, P<0.001), respectively. There were 97 cases in severe group and 325 cases in mild group. Compared with the mild group, the detection rate of consolidation, multiple consolidation, the size of consolidation and the size of consolidation was adjusted by body surface area (consolidation size/body surface area) in severe group were higher (66 cases (68.0%) vs. 166 cases (51.1%), 42 cases (43.3%) vs. 93 cases (28.6%), 8.0 (0, 17.0) vs. 1.0 (0, 9.0) mm, 12.5 (0, 24.6) vs. 2.1 (0, 17.6), χ2=8.59, 9.98, Z=14.40, 12.79, all P<0.05). Using lung ultrasound lung consolidation size and consolidation size/body surface area to predict the severe CAP, the optimal cut-off value were 6.7 mm and 10.2, the accuracy was 0.80 (95%CI 0.75-0.83) and 0.89 (95%CI 0.86-0.92), the sensitivity was 0.99 and 0.99, the specificity was 0.14 and 0.56, respectively, and the area under the curve was 0.66 (95%CI 0.60-0.72, P<0.001) and 0.76 (95%CI 0.70-0.83, P<0.001), respectively. The area under the curve of consolidation size/body surface area was higher than that of consolidation size (Z=5.50, P<0.001). Conclusions: Consolidation and confluent B-line, are important index for lung ultrasound diagnosis of CAP in children. The actual consolidation size adjusted by body surface area is superior to the size of consolidation in predicting severe CAP.

Cost of Pediatric Pneumonia Episodes With or Without Chest Radiography.

BACKGROUND AND OBJECTIVES: Despite its routine use, it is unclear whether chest radiograph (CXR) is a cost-effective strategy in the workup of community-acquired pneumonia (CAP) in the pediatric emergency department (ED). We sought to assess the costs of CAP episodes with and without CXR among children discharged from the ED. METHODS: This was a retrospective cohort study within the Healthcare Cost and Utilization Project State ED and Inpatient Databases of children aged 3 months to 18 years with CAP discharged from any EDs in 8 states from 2014 to 2019. We evaluated total 28-day costs after ED discharge, including the index visit and subsequent care. Mixed-effects linear regression models adjusted for patient-level variables and illness severity were performed to evaluate the association between CXR and costs. RESULTS: We evaluated 225c781 children with CAP, and 86.2% had CXR at the index ED visit. Median costs of the 28-day episodes, index ED visits, and subsequent visits were $314 (interquartile range [IQR] 208-497), $288 (IQR 195-433), and $255 (IQR 133-637), respectively. There was a $33 (95% confidence interval [CI] 22-44) savings over 28-days per patient for those who received a CXR compared with no CXR after adjusting for patient-level variables and illness severity. Costs during subsequent visits ($26 savings, 95% CI 16-36) accounted for the majority of the savings as compared with the index ED visit ($6, 95% CI 3-10). CONCLUSIONS: Performance of CXR for CAP diagnosis is associated with lower costs when considering the downstream provision of care among patients who require subsequent health care after initial ED discharge.

Radiographic Imaging of Community-Acquired Pneumonia: A Case-Based Review.

The chest radiograph is the most common imaging examination performed in most radiology departments, and one of the more common indications for these studies is suspected infection. Radiologists must therefore be aware of less common radiographic patterns of pulmonary infection if they are to add value in the interpretation of chest radiographs for this indication. This review uses a case-based format to illustrate a range of imaging findings that can be associated with acute pulmonary infection and highlight findings that should prompt investigation for diseases other than community-acquired pneumonia to prevent misdiagnosis and delays in appropriate management.

Chest CT findings in community-acquired pneumonia due to Coxiella burnetii (Q fever) compared to Streptococcus pneumoniae, a cross sectional study in French Guiana, 2013-2017.

OBJECTIVES: Few and small studies previously examined chest CT-scan characteristics of Coxiella burnetii (Cb) community-acquired pneumonia (CAP). Larger studies are needed to guide physicians towards diagnosis of Q fever in case of pneumonia. METHODS: We conducted a single-center retrospective observational study between 2013 and 2017. All patients with Cb or Streptococcus pneumoniae (Sp) CAP who had a chest CT-scan on admission at Cayenne Hospital (French Guiana) were included. Chest CT-scan were all analyzed by the same expert radiologist. RESULTS: We included 75 patients with Cb CAP and 36 with Sp CAP. Fifty-nine percent of all patients were men (n = 66) and median age was 52 [IQR = 38-62]. Chest CT-scans of Cb CAP patients revealed 67 alveolar condensations (89 %), 52 ground-glass opacities (69 %), 30 cases of lymphadenopathy(ies) (40 %) and 25 pleural effusions (33 %). Parenchyma lesions caused by Cb were predominantly unilateral (67 %). We found high numbers of alveolar condensations in both Cb and Sp CAP (89 % and 75 %; respectively), but the presence of ground-glass opacities was significantly associated with Cb CAP (69 % versus 30 %; p < 0.01). Cb CAP were associated with more lymphadenopathies (40 % vs 17 %; p = 0.01) while Sp CAP showed more bronchial thickening (19 % versus 3 %; p < 0.01) and (micro)nodule(s) ≤1 cm (25 % vs 3 %, p < 0.01). CONCLUSIONS: This large study shows that the most typical aspect of chest CT-scan in case of Cb CAP in French Guiana is a unilateral alveolar consolidation associated with ground glass opacities and lymphadenopathies. C. burnetti and S. pneumoniae both most often cause alveolar consolidations, but present some significantly different CT-scan patterns. This could help physicians through therapeutic choices.

The potential clinical value of pairing procalcitonin and lung ultrasonography to guide antibiotic therapy in patients with community-acquired pneumonia: a narrative review.

INTRODUCTION: Lower respiratory tract infections (LRTIs) are among the most frequent infections and are prone to inappropriate antibiotic treatments. This results from a limited accuracy of diagnostic tools in identifying bacterial pneumonia. Lung ultrasound (LUS) has excellent sensitivity and specificity in diagnosing pneumonia. Additionally, elevated procalcitonin (PCT) levels correlate with an increased likelihood of bacterial infection. LUS and PCT appear to be complementary in identifying patients with bacterial pneumonia who are likely to benefit from antibiotics. AREAS COVERED: This narrative review aims to summarize the current evidence for LUS to diagnose pneumonia, for PCT to guide antibiotic therapy and the clinical value of pairing both tools. EXPERT OPINION: LUS has excellent diagnostic accuracy for pneumonia in different settings, regardless of the examiner's experience. PCT guidance safely reduces antibiotic prescription in LRTIs. The combination of both tools has demonstrated an enhanced accuracy in the diagnosis of pneumonia, including CAP in the ED and VAP in the ICU, but randomized controlled studies need to validate the clinical impact of a combined approach.

Association of Chest Radiography With Outcomes in Pediatric Pneumonia: A Population-Based Study.

OBJECTIVE: Chest radiograph (CXR) is often performed for the evaluation of community-acquired pneumonia (CAP) in the ED setting. We sought to evaluate the association of undergoing CXR with 7-day hospitalization after emergency department (ED) discharge among patients with CAP. METHODS: This was a retrospective cohort study including children 3 months to 17 years discharged from any ED within 8 states from 2014 to 2019. We evaluated the association of CXR performance with 7-day hospitalization at both the patient and ED levels using mixed-effects logistic regression models accounting for markers of illness severity. Secondary outcomes included 7-day ED revisits and 7-day hospitalization with severe CAP. RESULTS: Among 206 694 children with CAP, rates of 7-day ED revisit, hospitalization, and severe CAP were 8.9%, 1.6%, and 0.4%, respectively. After adjusting for illness severity, CXR was associated with fewer 7-day hospitalizations (1.6% vs. 1.7%, adjusted odds ratio: [aOR] 0.82, 95% confidence interval [CI]: 0.73-0.92). CXR performance varied somewhat between EDs (median 91.5%, IQR: 85.3%-95.0%). EDs in the highest quartile had fewer 7-day hospitalizations (1.4% vs 1.9%, aOR: 0.78, 95% CI: 0.65-0.94), ED revisits (8.5% vs 9.4%, aOR: 0.88, 95% CI: 0.80-0.96) and hospitalizations for severe CAP (0.3% vs. 0.5%, aOR: 0.70, 95% CI: 0.51-0.97) as compared to EDs with the lowest quartile of CXR utilization. CONCLUSIONS: Among children discharged from the ED with CAP, performance of CXR was associated with a small but significant reduction in hospitalization within 7 days. CXR may be helpful in the prognostic evaluation of children with CAP discharged from the ED.

Association of Radiology Findings with Etiology of Community Acquired Pneumonia among Children.

OBJECTIVE: To evaluate the association between consolidation on chest radiograph and typical bacterial etiology of childhood community acquired pneumonia (CAP) in the Etiology of Pneumonia in the Community study. STUDY DESIGN: Hospitalized children <18 years of age with CAP enrolled in the Etiology of Pneumonia in the Community study at 3 children's hospitals between January 2010 and June 2012 were included. Testing of blood and respiratory specimens used multiple modalities to identify typical and atypical bacterial, or viral infection. Study radiologists classified chest radiographs (consolidation, other infiltrates [interstitial and/or alveolar], pleural effusion) using modified World Health Organization pneumonia criteria. Infiltrate patterns were compared according to etiology of CAP. RESULTS: Among 2212 children, there were 1302 (59%) with consolidation with or without other infiltrates, 910 (41%) with other infiltrates, and 296 (13%) with pleural effusion. In 1795 children, at least 1 pathogen was detected. Among these patients, consolidation (74%) was the most frequently observed pattern (74% in typical bacterial CAP, 58% in atypical bacterial CAP, and 54% in viral CAP). Positive and negative predictive values of consolidation for typical bacterial CAP were 12% (95% CI 10%-15%) and 96% (95% CI 95%-97%) respectively. In a multivariable model, typical bacterial CAP was associated with pleural effusion (OR 7.3, 95% CI 4.7-11.2) and white blood cell ≥15 000/mL (OR 3.2, 95% CI 2.2-4.9), and absence of wheeze (OR 0.5, 95% CI 0.3-0.8) or viral detection (OR 0.2, 95% CI 0.1-0.4). CONCLUSIONS: Consolidation predicted typical bacterial CAP poorly, but its absence made typical bacterial CAP unlikely. Pleural effusion was the best predictor of typical bacterial infection, but too uncommon to aid etiology prediction.

Adults with symptoms of pneumonia: a prospective comparison of patients with and without infiltrates on chest radiography.

OBJECTIVE: Most studies on patients hospitalized with community-acquired pneumonia (CAP) require confirmation of an infiltrate by chest radiography, but in practice admissions are common among patients with symptoms of pneumonia without an infiltrate (SPWI). The aim of this research was to compare clinical characteristics, microbial etiology, and outcomes among patients with CAP and SPWI. METHODS: Adults suspected of CAP were prospectively recruited at Landspitali University Hospital over a 1-year period, 2018 to 2019. The study was population based. Those admitted with two or more of the following symptoms were invited to participate: temperature ≥38°C or ≤36°C, sweating, shaking/chills, chest pain, a new cough, or new onset of dyspnea. Primary outcome was mortality at 30 days and one year. RESULTS: Six hundred twenty-five cases were included, 409 with CAP and 216 with SPWI; median age was 75 (interquartile range [IQR] 64-84) and 315 (50.4%) were females. Patients with CAP were more likely to have fever (≥38.0°C) (66.9% [273/408]) vs. 49.3% (106/215), p < 0.001), a higher CRP (median 103 [IQR 34-205] vs. 55 (IQR 17-103), p < 0.001), identification of Streptococcus pneumoniae (18.0% [64/355]) vs. 6.3% (10/159) of tested, p = 0.002) and to receive antibacterial treatment (99.5% [407/409]) vs. 87.5% (189/216), p < 0.001) but less likely to have a respiratory virus detected (25.4% [33/130]) vs. 51.2% (43/84) of tested, p < 0.001). The adjusted odds ratios for 30-day and 1 year mortality of SPWI compared to CAP were 0.86 (95% CI 0.40-1.86) and 1.46 (95% CI 0.92-2.32), respectively. DISCUSSION: SPWI is a common cause of hospitalization and despite having fever less frequently, lower inflammatory markers, and lower detection rate of pneumococci than patients with CAP, mortality is not significantly different.

Effectiveness of 13-valent pneumococcal conjugate vaccine on radiological primary end-point pneumonia among cases of severe community acquired pneumonia in children: A prospective multi-site hospital-based test-negative study in Northern India.

INTRODUCTION: Community acquired pneumonia (CAP) is a leading cause of under-five mortality in India and Streptococcus pneumoniae is the main bacterial pathogen for it. Pneumococcal Conjugate Vaccine 13 (PCV13) has been introduced in a phased manner, in the national immunization program of India since 2017/2018. The primary objective of this study was to evaluate the effectiveness of PCV13 on chest radiograph (CXR)-confirmed pneumonia, in children hospitalized with WHO-defined severe CAP. METHODS: This prospective, multi-site test-negative study was conducted in a hospital-network situated in three districts of Northern India where PCV13 had been introduced. Children aged 2-23 months, hospitalized with severe CAP and with interpretable CXR were included after parental consent. Clinical data was extracted from hospital records. CXRs were interpreted by a panel of three independent blinded trained radiologists. Exposure to PCV13 was defined as ≥2 doses of PCV13 in children aged ≤ 12 months and ≥ 1 dose(s) in children > 12 months of age. Our outcome measures were CXR finding of primary endpoint pneumonia with or without other infiltrates (PEP±OI); vaccine effectiveness (VE) and hospital mortality. RESULTS: From 1st June 2017-30th April 2021, among 2711 children included, 678 (25.0%) were exposed to PCV1. CXR positive for PEP±OI on CXR was found in 579 (21.4%), of which 103 (17.8%) were exposed to PCV. Adjusted odds ratio (AOR) for PEP±OI among the exposed group was 0.69 (95% CI, 0.54-0.89, p = 0.004). Adjusted VE was 31.0% (95% CI: 11.0-44.0) for PEP±OI. AOR for hospital mortality with PEP±OI was 2.65 (95% CI: 1.27-5.53, p = 0.01). CONCLUSION: In severe CAP, children exposed to PCV13 had significantly reduced odds of having PEP±OI. Since PEP±OI had increased odds of hospital mortality due to CAP, countrywide coverage with PCV13 is an essential priority.

Community-acquired pneumonia - use of chest x-rays for diagnosis in family practice.

BACKGROUND: According to guidelines, the diagnosis of pneumonia should be confirmed by chest x-ray, ensuring appropriate management and wise use of antibiotics. Our study aimed to describe use of x-rays by family doctors and patients following diagnosis of pneumonia in primary care practices in the north of Israel. METHODS: This was a retrospective database study including adults diagnosed with pneumonia, assessing rates of referral and actual use of chest x-rays. We examined rates of referral for chest x-rays and rates of adherence to the referral, according to age, gender, smoking status, comorbidities and distance of residence from the radiology facility. RESULTS: During one year there were 4,230 diagnosed cases of pneumonia in the practice, of which 2,503 were referred for chest x-rays, and 1,920 adhered to the referral (45% of those diagnosed with pneumonia). The rate of referral was higher when the radiology facility was located in the same city as the family doctor compared to outside the city (69.7% and 53.2%, p < 0.001). Patients aged 40-64 were referred more than patients aged 18-39 or 65+ (61.5% vs. 56.5% and 58.3%, p = 0.03). Actual use of chest x-rays (considering both referral and adherence) was more likely when the radiology facility was in the same health centre or city than when it was outside the city [OR = 2.4; 95% CI: 2.1-2.8]; patients aged 65 + or 40-64 were more likely to adhere to the referral for x-ray than those aged 18-39 [OR = 1.3; 95% CI: 1.1-1.6, OR = 1.2; 95% CI: 1.0-1.4, respectively]. CONCLUSION: Accessibility of radiology facilities seems to be an important factor associated with both doctors' decisions and patients' adherence to the referral for chest x-rays.

Clinical and Imaging Characteristics of Primary Severe Community-Acquired Pneumonia Caused by Hypervirulent Klebsiella Pneumoniae.

BACKGROUND: To investigate the CT imaging features and microbial phenotypes of primary severe community-acquired pneumonia caused by hypervirulent Klebsiella pneumoniae (hvKp). METHODS: Patients diagnosed with primary hvKp pneumonia were included, and their clinical data were analyzed, including the baseline characteristics and CT imaging results. After hypermucoviscosity phenotyping, the strains, serological types, and virulence genes of hvKp were identified using multiplex PCR. RESULTS: Twelve patients with primary hvKp pneumonia were included (11 males, 1 female). All patients were infected via respiratory tract inhalation. Ten patients were long-term drinkers. Four patients (33.3%), who were long-term alcohol abusers, died within 30 days after diagnosis. No extrapulmonary metastatic infection was found in any patient. The imaging of lung lesions at the early disease stage exhibited an extensive consolidation in the lungs. As the disease progressed, the most common imaging features were pleural effusion (9/12), cavitation and necrosis (8/12), and pneumothorax (3/12). The serological typing of the capsular polysaccharides on hvKp strains were K1 (6/12) and K2 (6/12). Furthermore, the virulence genotyping showed rmpA (11/12), magA (11/12), ureA (12/12), mrkD (12/12), fim-1 (12/12), wabG (12/12), ybtS (12/12), and iucB (11/12). CONCLUSIONS: Primary severe community-acquired hvKp-associated pneumonia is more common in men, especially those with a long-term history of alcohol consumption. CT scanning at the early disease stage mostly showed extensive pulmonary consolidation, which was prone to be combined with cavitation, necrosis, and pleural effusion. K1 and K2 serotypes were identified among the hvKp strains, which were not prone to form extrapulmonary metastasis via the bloodstream.

Community-acquired round Pneumonia in a 63-year-old Female.

Round pneumonia is a radiological manifestation of pulmonary lesion. This is found as spherical or oval-shaped radio-opacity on chest X-ray. Round pneumonia has been reported in literature uncommonly. Round pneumonia was first time reported in the radiology literature in 1954 (Wagner et al., 1998). It was first recognized in children. In 1973, Rose and Ward reviewed 21 cases of round pneumonia in children. Radiological findings resembled pulmonary and mediastinal masses. Since then, time and again, round pneumonia has been reported in children; but, this is also found rarely in adults. There are many causes of round pneumonia in adults, for example, infectious and noninfectious. It may mimic pulmonary neoplasms due to its radiological appearance. Hence, the usual diagnostic challenge of round pneumonia is to differentiate pneumonia from bronchogenic carcinoma. Here we present an interesting case of round pneumonia in an adult female.

Early chest CT-scan in emergency patients affected by community-acquired pneumonia is associated with improved diagnosis consistency.

Chest CT-scan (CT) exceeds chest X-ray (CXR) to diagnose community-acquired pneumonia (CAP) but actual use and results remain unclear. We examine whether CT performed at ED visit improved ED diagnosis of CAP as compared to a final diagnosis of CAP at hospital discharge (gold standard diagnosis for the study), and how it impacts relevant clinical outcomes. This retrospective monocenter observational study was based on the analysis of the hospital database. Patients with a diagnosis of CAP in the ED (ICD-10 codes: J110, J111, from J12- to J18-, J440, J690, U0710, and U0711) were included. We compared ED patients who were diagnosed with CAP using CXR and CT. We measured diagnostic consistency, duration of ED visit, percentage of CXR and CT during hospital stay, hospital length-of-stay, ICU admission, and in-hospital mortality. Multivariate analysis was adjusted for CRB65 score by multiple logistic regression analysis for binary outcomes and by multivariate analysis of variance for continuous outcomes. We included 994 ED patients with an initial diagnosis of CAP (751 receiving CXR, 243 receiving CT). CT prescription in the ED increased over time ( P < 0.001). In patients admitted after ED, CT improved diagnosis consistency for CAP [88.2% vs. 80.9%; difference 7.3% (95% confidence interval 1.2-13.3%)] with a trend for lower hospital length-of-stay [10.2 vs. 12.2 days; difference -2.0 (95% confidence interval -3.9 to -0.1)], but not ICU admission ( P = 0.09) and in-hospital mortality ( P = 0.056). Diagnosis of patients admitted with CAP improved when CT was obtained at ED visit. These results should be reproduced at a larger scale to test whether early CT conserves healthcare resources.

Características radiográficas de la neumonía adquirida en la comunidad en el adulto inmunocompetente hospitalizado según el agente causal / Radiographic characteristics of community-acquired pneumonia in the immunocompetent adult hospitalized according to the etiologic agent

Resumen En la práctica clínica, la radiografía de tórax permite confirmar el diagnóstico y la extensión de la neumonía adquirida en la comunidad (NAC). Objetivos: Examinar las características radiográficas de la NAC según el agente causal y el grado de concordancia interobservador (CI) en la descripción de los hallazgos radiográficos. Métodos: Se evaluaron las radiografías de tórax de 300 pacientes adultos inmunocompetentes hospitalizados por NAC, tres residentes de radiología consignaron el patrón de los infiltrados pulmonares, su localización anatómica y extensión, la presencia de derrame pleural y otros hallazgos radiográficos. Se realizaron cultivos de esputo, hemocultivos, pruebas serológicas y técnicas de biología molecular de hisopado nasofaríngeo para identificar los principales patógenos respiratorios. Resultados: Las manifestaciones clínicas y los hallazgos de la radiografía de tórax fueron similares en las neumonías causadas por diferentes patógenos respiratorios: bacterias clásicas, virus respiratorios y microorganismos atípicos. En las neumonías bacterianas predominó el patrón de relleno alveolar de distribución lobar, en las neumonías vírales y atípicas predominó el patrón intersticial o mixto alvéolo-intersticial con opacidades en vidrio esmerilado. La CI fue satisfactoria (kappa > 0,6) para determinar el patrón principal de los infiltrados pulmonares, su localización anatómica y la presencia de derrame pleural, su localización y extensión. La CI fue moderada (kappa 0,4-0,6) para definir la extensión de la neumonía y detectar signos radiológicos asociados a congestión pulmonar. Conclusión: Los hallazgos de la radiografía de tórax no permitieron identificar con precisión el agente causal de la neumonía, siendo útil en la caracterización de los infiltrados pulmonares y para detectar complicaciones como el derrame paraneumónico.

In a clinical setting the chest radiograph is the reference standard in establishing the diagnosis of community-acquired pneumonia (CAP). Objectives: This study aimed to assess interobserver reliability (IR) of radiographic findings and the relationship to different respiratory pathogens in CAP. Methods: Chest radiographs of 300 immunocompetent adult patients hospitalized with pneumonia, obtained from a database, were reviewed by three residents of radiology without specific clinical information. Main pattern of pulmonary infiltrates, topographic localization, extent of pneumonia, presence of pleural fluid, thickened bronchial walls, lymphadenopathy and air bronchogram were scored. Sputum and blood cultures, serological tests and nasopharyngeal swab for respiratory virus detection by molecular diagnostic techniques were performed to identify the causative pathogen. Results: Clinical manifestations and chest X-ray findings were similar in pneumonias caused by different respiratory pathogens: classic bacteria, respiratory viruses and atypical microorganisms. The alveolar pattern of lobar distribution predominated in bacterial pneumonia; meanwhile, interstitial or mixed alveolar-interstitial pattern with ground glass opacities predominated in viral and atypical pneumonias. IR was fair to good (kappa > 0.6) for determining the main pattern of infiltrates, anatomical location and the presence of pleural effusion, their anatomical location and extension. IR was moderate (kappa 0.4-0.6) for determining the extent of pneumonia and signs of congestive heart failure. Conclusion: Simple features such as main pattern description, anatomical location, identifying the involved lobes and pleural fluid recognition showed fair to excellent interobserver reliability. Chest radiographs was of limited value in predicting the causative pathogen but were of beneficial use to characterize pulmonary infiltrates and to detect complications such as parapneumonic effusion.

High-resolution computed tomography features associated with differentiation of tuberculosis among elderly patients with community-acquired pneumonia: a multi-institutional propensity-score matched study.

While high-resolution computed tomography (HRCT) is increasingly performed, its role in diagnosing pulmonary tuberculosis (TB) among elderly patients with community-acquired pneumonia (CAP) has not been fully elucidated. This study aimed to determine HRCT features that can differentiate pulmonary TB from non-TB CAP in elderly patients. This study included consecutive elderly patients (age > 65 years) admitted to two teaching hospitals for pulmonary TB or non-TB pneumonia who met the CAP criteria of the American Thoracic Society/Infectious Diseases Society of America guidelines. After propensity score matching for clinical background between patients with pulmonary TB and those with non-TB CAP, their HRCT features were compared. This study included 151 patients with pulmonary TB and 238 patients with non-TB CAP. The presence of centrilobular nodules, air bronchograms, and cavities and the absence of ground-glass opacities and bronchial wall thickening were significantly associated with pulmonary TB. The negative predictive values of centrilobular nodules, air bronchograms, and cavities for pulmonary TB were moderate (70.6%, 67.9%, and 63.0%, respectively), whereas the positive predictive value of cavities was high (96.6%). In elderly patients, although some HRCT features could differentiate pulmonary TB from non-TB CAP, no useful findings could rule out pulmonary TB with certainty.

Lung Ultrasound Performed by Primary Care Physicians for Clinically Suspected Community-Acquired Pneumonia: A Multicenter Prospective Study.

PURPOSE: We investigated whether lung ultrasound (US) performed in primary care is useful and feasible for diagnosing community-acquired pneumonia (CAP) compared with chest radiography, as most previous research has been conducted in hospital settings. METHODS: We undertook a prospective observational cohort study of lung US performed in 12 primary care centers. Patients aged 5 years and older with symptoms suggesting CAP were examined with lung US (by 21 family physicians and 7 primary care pediatricians) and chest radiograph on the same day. We compared lung US findings with the radiologist's chest radiograph report as the reference standard, given that the latter is the most common imaging test performed for suspected CAP in primary care. The physicians had varied previous US experience, but all received a 5-hour lung US training program. RESULTS: The study included 82 patients. Compared with chest radiography, positive lung US findings (consolidation measuring >1 cm or a focal/asymmetrical B-lines pattern) showed a sensitivity of 87.8%, a specificity of 58.5%, a positive likelihood-ratio of 2.12, and a negative likelihood-ratio of 0.21. Findings were similar regardless of the physicians' previous US training or experience. We propose a practical algorithm whereby patients having consolidation measuring greater than 1 cm or normal findings on lung US could skip chest radiography, whereas patients with a B-lines pattern without consolidation (given its low specificity) would need chest radiography to ensure appropriate management. Lung US was generally performed in 10 minutes or less. CONCLUSION: Point-of-care lung US in primary care could be useful for investigating suspected CAP (avoiding chest radiography in most cases) and is likely feasible in daily practice, as short training programs appear sufficient and little time is needed to perform the scan.

Radiographic Imaging of Community-Acquired Pneumonia: A Case-Based Review.

The chest radiograph is the most common imaging examination performed in most radiology departments, and one of the more common indications for these studies is suspected infection. Radiologists must therefore be aware of less common radiographic patterns of pulmonary infection if they are to add value in the interpretation of chest radiographs for this indication. This review uses a case-based format to illustrate a range of imaging findings that can be associated with acute pulmonary infection and highlight findings that should prompt investigation for diseases other than community-acquired pneumonia to prevent misdiagnosis and delays in appropriate management.

Chest Radiographs Using a Context-Fusion Convolution Neural Network (CNN): Can It Distinguish the Etiology of Community-Acquired Pneumonia (CAP) in Children?

Clinical symptoms and inflammatory markers cannot reliably distinguish the etiology of CAP, and chest radiographs have abundant information related with CAP. Hence, we developed a context-fusion convolution neural network (CNN) to explore the application of chest radiographs to distinguish the etiology of CAP in children. This retrospective study included 1769 cases of pediatric pneumonia (viral pneumonia, n = 487; bacterial pneumonia, n = 496; and mycoplasma pneumonia, n = 786). The chest radiographs of the first examination, C-reactive protein (CRP), and white blood cell (WBC) were collected for analysis. All patients were stochastically divided into training, validation, and test cohorts in a 7:1:2 ratio. Automatic lung segmentation and hand-crafted pneumonia lesion segmentation were performed, from which three image-based models including a full-lung model, a local-lesion model, and a context-fusion model were built; two clinical characteristics were used to build a clinical model, while a logistic regression model combined the best CNN model and two clinical characteristics. Our experiments showed that the context-fusion model which integrated the features of the full-lung and local-lesion had better performance than the full-lung model and local-lesion model. The context-fusion model had area under curves of 0.86, 0.88, and 0.93 in identifying viral, bacterial, and mycoplasma pneumonia on the test cohort respectively. The addition of clinical characteristics to the context-fusion model obtained slight improvement. Mycoplasma pneumonia was more easily identified compared with the other two types. Using chest radiographs, we developed a context-fusion CNN model with good performance for noninvasively diagnosing the etiology of community-acquired pneumonia in children, which would help improve early diagnosis and treatment.

Factors associated with gravity-dependent distribution on chest CT in elderly patients with community-acquired pneumonia: a retrospective observational study.

Although lung involvement in aspiration pneumonia typically has a gravity-dependent distribution on chest images, which patient's conditions contribute to its radiological pattern has not been fully elucidated. This study was designed to determine the factors associated with the gravity-dependent distribution of community-acquired pneumonia (CAP) on chest computed tomography (CT). This retrospective study included elderly patients aged ≥ 65 years with CAP who underwent chest CT within 1 week before or after admission. The factors associated with lower lobe- and posterior-predominant distributions of ground glass opacity or airspace consolidation were determined. Of the 369 patients with CAP, 348 (94%) underwent chest CT. Multivariate analyses showed that impaired consciousness, a low Barthel index of activities of daily living, and high hemoglobin levels were associated with lower lobe-predominant distribution, while male sex and impaired consciousness were associated with posterior-predominant distribution. Cerebrovascular diseases were unrelated to these distributions. While male sex, impaired consciousness, high hemoglobin levels, low albumin levels, and the number of involved lobes were associated with in-hospital mortality, gravity-dependent distributions were not. Impaired consciousness might be the most significant predictor of aspiration pneumonia; however, the gravity-dependent distribution of this disease is unlikely to affect disease prognosis.

CT features of community-acquired pneumonia at the emergency department.

BACKGROUND: Chest computed tomography (CT) was reported to improve the diagnosis of community-acquired pneumonia (CAP) as compared to chest X-ray (CXR). The aim of this study is to describe the CT-patterns of CAP in a large population visiting the emergency department and to see if some of them are more frequently missed on CXR. MATERIALS AND METHODS: This is an ancillary analysis of the prospective multicenter ESCAPED study including 319 patients. We selected the 163 definite or probable CAP based on adjudication committee classification; 147 available chest CT scans were reinterpreted by 3 chest radiologists to identify CAP patterns. These CT-patterns were correlated to epidemiological, biological and microbiological data, and compared between false negative and true positive CXR CAP. RESULTS: Six patterns were identified: lobar pneumonia (51/147, 35%), including 35 with plurifocal involvement; lobular pneumonia (43/147, 29%); unilobar infra-segmental consolidation (24/147, 16%); bronchiolitis (16/147, 11%), including 4 unilobar bronchiolitis; atelectasis and bronchial abnormalities (8/147, 5.5%); interstitial pneumonia (5/147, 3.5%). Bacteria were isolated in 41% of patients with lobar pneumonia-pattern (mostly Streptococcus pneumoniae and Mycoplasma pneumonia) versus 19% in other patients (p = 0.01). Respiratory viruses were equally distributed within all patterns. CXR was falsely negative in 46/147 (31%) patients. Lobar pneumonia was significantly less missed on CXR than other patterns (p = 0.003), especially lobular pneumonia and unilobar infra-segmental consolidation, missed in 35% and 58% of cases, respectively. CONCLUSION: Lobar and lobular pneumonias are the most frequent CT-patterns. Lobar pneumonia is appropriately detected on CXR and mainly due to Streptococcus pneumoniae or Mycoplasma pneumoniae. Chest CT is very useful to identify CAP in other CT-patterns. Prior the COVID pandemic, CAP was rarely responsible for interstitial opacities on CT.