Screening of asymptomatic children for tuberculosis is a lateral chest radiograph routinely indicated?

TB or not TB? Diagnostic Sensitivity, Specifity and Interobserver Agreement in the Radiological Diagnosis of Pulmonary Tuberculosis in Children

BACKGROUND

The differentiation between latent tuberculosis infection (LTBI) and tuberculosis (TB) relies on radiological changes. Confirming the diagnosis remains a challenge because typical findings are often missing in children. This study evaluates diagnostic sensitivity, specifity and interobserver agreement on the radiological diagnosis of TB by chest-x-rays in accordance to professional specialization and work experience.

METHODS

Chest x-rays of 120 children with proven tuberculosis infection were independently evaluated by general radiologists, paediatric radiologists and paediatric pulmonologists. Results were compared to a reference diagnosis created by group of experienced paediatric radiologists and paediatric pulmonologists. Primary endpoints were diagnostic sensitivity and specificity and interobserver variability defined as Krippendorfs alpha of thesel groups compared to the reference diagnosis.

RESULTS

Of the 120 chest x-rays 33 (27,5%) were diagnosed as TB by the reference standard . Paediatric pulmonologist had the highest diagnostic sensitivity (90%) but were less specific (71%) whereas general radiologist were less sensitive (68%) but more secific (95%). The best diagnostic accuracy was achieved by pediatric radiologists with a diagnostic sensitivity of 77% and specificity 95% respectively.

CONCLUSIONS

We demonstrated significant interobserver variability and relevant differences in sensitivity and specificity in the radiological diagnosis of TB between the groups. Paediatric radiologists showed the best diagnostic performance. As the diagnosis of pulmonary TB has significant therapeutic consequences for children they should be routinely involved in the diagnostic process.

Quality assurance of paediatric lateral chest radiographs

INTRODUCTION

Lateral chest radiographs aid in paediatric clinical practice in countries where the diagnosis of primary pulmonary tuberculosis (PTB) still relies heavily on the chest radiograph. This study aimed to create a validated quality assurance (QA) tool investigating the diagnostic performance of this projection by applying this to a database of lateral chest radiographs in children with suspected PTB.

METHOD

The QA tool was built to include a compilation of criteria from the different sources, accompanied by graphic representations and objective measurements where appropriate. Each defined criterion (radiographic error) was evaluated by implementing the QA tool on 300 radiographs, scored by three readers. The sample was subjected to two separate sets of data analysis, based on averages, and on majority decision methodology.

RESULTS

The QA tool was based on existing published criteria, as well as under-collimation and under-inspiration, two de novo criteria. For the total 900 reads, errors were categorized as patient-related in 681 (75.7%) and radiographer-related in 421 (46.8%) and 122 (13.6%) had no errors. The average number of errors per radiograph ranged from 0.9 to 4.7 errors out of the 11 quality factors reviewed. When considering the majority decision, the median errors per radiograph was 1 (IQR 1-2) (range 0-5). Inter-rater agreement varied for different criteria.

CONCLUSION

A novel QA tool for evaluating lateral chest radiographs was developed which requires further efforts of refinement regarding criteria such as exposure, field of view: under-collimation, and motion artifact, which remain subjective. The designed QA tool will allow comparison of radiograph quality before and after interventions. Furthermore, the tool can be used in tackling childhood PTB in low- and middle-income countries (LMICs) since the hallmark of the disease is lymphadenopathy, which is often depicted best on lateral chest radiographs.

Radiological patterns of childhood thoracic tuberculosis in a developed country: a single institution's experience on 217/255 cases

The incidence of tuberculosis is increasing in the developed world and children in particular represent a high-risk group for developing the disease. The aim of this review is to analyse the spectrum of radiological signs as reported in the recent literature, in light of our series over a 15-year period, to pinpoint the most common radiological patterns in a developed country and to determine the role played by the different chest imaging techniques in diagnosis improvement. Lung TB was present in 217 out of 255 patients (85 %): 146 patients were under 5 years of age (76 under 2 years) and 71 over 5 years (41 over 10 years). We describe different patterns differentiating adolescents and young adults from infants and children. Adolescents and young adult tuberculosis are apical and cavitary. Thoracic TB in infants and children is characterized by lymph node and parenchymal disease. In 21 cases with lymphadenopathies without lymph-bronchial diffusion (age range 2 months-7 years), CT identified the Ghon focus in 16/21 cases; chest X-ray never identified the Ghon focus. In our series, pleural TB was present in 8 cases out of 146 under 5 years of age, 5 cases out of 76 under 2 years, and 18 cases out of 71 over 5 years. Radiologists should be aware of typical patterns of tuberculosis, to provide an early diagnosis.

Radiological findings of pulmonary tuberculosis in indigenous patients in Dourados, MS, Brazil

OBJECTIVE

To describe the radiological findings of pulmonary tuberculosis in indigenous patients from the city of Dourados, MS, Brazil, according to age and sex.

MATERIALS AND METHODS

Chest radiographic images of 81 patients with pulmonary tuberculosis, acquired in the period from 2007 to 2010, were retrospectively analyzed by two radiologists in consensus for the presence or absence of changes. The findings in abnormal radiographs were classified according to the changes observed and they were correlated to age and sex. The data were submitted to statistical analysis.

RESULTS

The individuals' ages ranged from 1 to 97 years (mean: 36 years). Heterogeneous consolidations, nodules, pleural involvement and cavities were the most frequent imaging findings. Most patients (55/81 or 67.9%) were male, and upper lung and right lung were the most affected regions. Fibrosis, heterogeneous consolidations and involvement of the left lung apex were significantly more frequent in males (p < 0.05). Presence of a single type of finding at radiography was most frequent in children (p < 0.05).

CONCLUSION

Based on the hypothesis that indigenous patients represent a population without genetically determined resistance to tuberculosis, the present study may enhance the knowledge about how the pulmonary form of this disease manifests in susceptible individuals.

Clinical peculiarities of tuberculosis

The ongoing spread of tuberculosis (TB) in poor resource countries and the recently increasing incidence in high resource countries lead to the need of updated knowledge for clinicians, particularly for pediatricians. The purpose of this article is to provide an overview on the most important peculiarities of TB in children. Children are less contagious than adults, but the risk of progression to active disease is higher in infants and children as compared to the subsequent ages. Diagnosis of TB in children is more difficult than in adults, because few signs are associated with primary infection, interferon-gamma release assays and tuberculin skin test are less reliable in younger children, M. tuberculosis is more rarely detected in gastric aspirates than in smears in adults and radiological findings are often not specific. Treatment of latent TB is always necessary in young children, whereas it is recommended in older children, as well as in adults, only in particular conditions. Antimycobacterial drugs are generally better tolerated in children as compared to adults, but off-label use of second-line antimycobacterial drugs is increasing, because of spreading of multidrug resistant TB worldwide. Given that TB is a disease which often involves more than one member in a family, a closer collaboration is needed between pediatricians and clinicians who take care of adults.

Management of children exposed to Mycobacterium tuberculosis: a public health evaluation in West Java, Indonesia

OBJECTIVE

To investigate qualitatively and quantitatively the performance of a programme for managing the child contacts of adult tuberculosis patients in Indonesia.

METHODS

A public health evaluation framework was used to assess gaps in a child contact management programme at a lung clinic. Targets for programme performance indicators were derived from established programme indicator targets, the scientific literature and expert opinion. Compliance with tuberculosis screening, the initiation of isoniazid preventive therapy in children younger than 5 years, the accuracy of tuberculosis diagnosis and adherence to preventive therapy were assessed in 755 child contacts in two cohorts. In addition, 22 primary caregivers and 34 clinic staff were interviewed to evaluate knowledge and acceptance of child contact management. The cost to caregivers was recorded. Gaps between observed and target indicator values were quantified.

FINDINGS

THE GAPS BETWEEN OBSERVED AND TARGET PERFORMANCE INDICATORS WERE: 82% for screening compliance; 64 to 100% for diagnostic accuracy, 50% for the initiation of preventive therapy, 54% for adherence to therapy and 50% for costs. Many staff did not have adequate knowledge of, or an appropriate attitude towards, child contact management, especially regarding isoniazid preventive therapy. Caregivers had good knowledge of screening but not of preventive therapy and had difficulty travelling to the clinic and paying costs.

CONCLUSION

The study identified widespread gaps in the performance of a child contact management system in Indonesia, all of which appear amenable to intervention. The public health evaluation framework used could be applied in other settings where child contact management is failing.