Advances in Imaging Chest Tuberculosis: Blurring of Differences Between Children and Adults

Pediatric tuberculosis in Mexico: A retrospective analysis of 100 patients

Background

Analyzing the epidemiology and clinical manifestations of pediatric tuberculosis in endemic regions is crucial to meet the goal of ending tuberculosis. The objective was to assess the various clinical scenarios of tuberculosis in a large pediatric cohort in Mexico.

Methods

This retrospective study from a pediatric referral center in Mexico included patients diagnosed with tuberculosis from 2012 to 2021. We analyzed clinical data and diagnostic study results, including demographic characteristics, underlying medical conditions, BCG vaccination, clinical presentation, imaging findings, microbiologic data, treatment, and clinical outcomes. Basic descriptive statistics and Chi-squared analysis were performed to summarize the metadata of pediatric patients with different clinical presentations of tuberculosis and evaluate their association with mortality, respectively.

Results

A total of 100 patients were included with a mean age of 7.76 years ± 1.49 years. The most prevalent clinical presentation was pulmonary tuberculosis (n = 51). Only 51 patients were immunized with Bacillus Calmette-Guérin vaccine. The most commons symptoms were fever, cough and weight loss. Among patients with meningeal tuberculosis (n = 14), the most common clinical signs were seizures, fever, and vomiting. Cure was achieved in 52 patients, 12 patients died, and 36 continue in treatment. Clinical presentation of tuberculosis (p-value = 0.009) and immunodeficiency (p-value = 0.015) were significantly associated with mortality.

Conclusions

Increasing the visibility of tuberculosis is imperative to end this disease. We report relevant clinical data of a large pediatric tuberculosis cohort, stratified by the different forms of disease. A high index of suspicion of tuberculosis is required for a timely diagnosis and treatment initiation, particularly among immunocompromised individuals, in whom mortality is higher.

Comparison of chest radiographs against minimum intensity projection reconstruction computed tomography scans for detection of airway stenosis in children with lymphobronchial tuberculosis

BACKGROUND

Ideally, suspected airway compression in symptomatic children with lymphobronchial tuberculosis (TB) would be diagnosed using modern computed tomography (CT) assisted by coronal minimum intensity projection (MinIP) reconstructions. However, in TB-endemic regions with limited resources, practitioners rely on conventional radiography for diagnosing TB and its complications. Furthermore, airway compression detected on conventional radiographs would upgrade a patient into the severe category according to the new World Health Organization guidelines, precluding the patient from shorter treatment protocols. The accuracy of conventional radiographs in the context of detecting airway compression in children with TB has not been specifically evaluated against an imaging gold standard.

OBJECTIVE

We aimed to compare frontal chest radiographs against thick-slab angled coronal CT MinIP in identifying airway stenosis at ten specific sites and to determine observer agreement between the modalities regarding the degree of stenosis.

MATERIALS AND METHODS

This retrospective cross-sectional study compared chest radiographs with standardized angled coronal CT MinIP in children with symptomatic lymphobronchial TB at ten predetermined airway locations. Chest radiographs were evaluated by one pediatric radiologist and CT MinIP reconstructions were independently interpreted by three readers. Sensitivity and specificity were calculated using CT MinIP as the gold standard. Stenosis was graded as 1 for mild (1-50%), 2 for moderate (51-75%), 3a for severe (76-99%), and 3b for total occlusion (100%). Agreement between the two modalities regarding severity of stenosis was calculated using the kappa coefficient for each affected site.

RESULTS

A total of 37 patients were included in the study. The median age of patients was 14.3 months (interquartile range 8.0-23.2). Three hundred and seventy individual bronchi (10 from each of the 37 patients) were evaluated for stenosis. Chest radiographs showed that 31 out of 37 (84%) patients had stenosis in at least one of ten evaluated sites, most commonly the left main bronchus and bronchus intermedius, and this was confirmed via CT MinIP. The gold standard (CT MinIP) demonstrated stenosis in at least one of ten sites in all 37 patients (100%). Left main bronchus stenosis was detected by chest radiography with a 92.9% sensitivity and 100% specificity. Sensitivity and specificity for bronchus intermedius stenosis were 80% and 75%, respectively. There was substantial agreement for grade of stenosis between chest radiographs and CT (kappa=0.67) for the left main bronchus and moderate agreement (kappa=0.58) for the bronchus intermedius. Severe stenosis was found in 78 bronchi on CT compared to 32 bronchi (Grade 3a: 9, Grade 3b: 23) on chest radiographs.

CONCLUSION

The diagnosis of pulmonary TB in children continues to rely heavily on imaging, and we have shown that in young children, chest radiographs had a high sensitivity and specificity for detecting airway stenosis at certain anatomical sites, when adequately visualized, resulting from tuberculous lymph node compression at left main bronchus and bronchus intermedius. For most sites, the interobserver agreement was poor. Stenosis of the left main bronchus and bronchus intermedius should be the focus of chest radiograph interpretation and can assist both diagnosis and classification of patients for treatment.

Diagnostic performance of a novel ESAT6-CFP10 skin test for tuberculosis infection in school tuberculosis outbreak in China

Background

The ESAT6-CFP10 (EC) skin test is recommended by the World Health Organization for latent tuberculosis infection (LTBI). However, it is still unknown how the EC skin test performs in students during a school tuberculosis outbreak.

Methods

We conducted an epidemiological investigation to assess the performance of the EC skin test in this high-risk population.

Results

A total of 9 active student patients were confirmed in the same class as the index case, with an incidence rate of 18.0% (9/50). Among the 50 close contacts, 14 (28%) were over 15 years old and had a chest X-ray (CXR), and none of them had abnormal CXR findings. The rates of positive tuberculin skin test (TST) ≥ 5 mm and < 10 mm, ≥ 10 mm and < 15 mm, and ≥ 15 mm were 12.0% (6/50), 16.0% (8/50), and 10.0% (5/50), respectively. On the second screening, 44 students with the same class as the index case had the EC skin test, of which 31 (70.5%) had positive EC tests. All patients had negative sputum smear results, of whom 4 (44.4%) had positive Xpert results; three had a TST induration diameter between 5 mm and 10 mm, but all of them had an EC diameter > 15 mm; 5 (55.6%) had abnormal CXR results, but all the confirmed patients had abnormal CT results; Except for four cases that were diagnosed by Xpert, the remaining five were confirmed by CT scan.

Conclusion

The novel EC skin test performed well in students during the school tuberculosis outbreak. In some special conditions, such as when the index case is bacteriologically positive for tuberculosis and the rate of LTBI is higher than the average for the local same-age group, secondary screening is recommended 2-3 months after the first screening. Furthermore, we cannot ignore the role of CT in the diagnosis of early student tuberculosis.

CT Scan Differences of Pulmonary TB According to Presence of Pleural Effusion

BACKGROUND

Subpleural micronodules and interlobular septal thickening are common CT scan findings in TB pleural effusion. These CT scan features could help us differentiate between TB pleural effusion and nonTB empyema.

RESEARCH QUESTION

Does the frequency of subpleural micronodules and interlobular septal thickening correlate with the presence of pleural effusion in patients with pulmonary TB?

STUDY DESIGN AND METHODS

CT scan findings of pulmonary TB, micronodules and their distribution (peribronchovascular, septal, subpleural, centrilobular, and random), large opacity (consolidation/macronodule), cavitation, tree-in-buds, bronchovascular bundle thickening, interlobular septal thickening, lymphadenopathy, and pleural effusion were retrospectively analyzed. Patients were divided into two groups according to the presence of pleural effusion. Clinicoradiologic findings of the two groups were then analyzed. We presented Benjamini-Hochberg critical value for multiple testing correction of CT scan findings, with a false discovery rate of 0.05.

RESULTS

Of a total of 338 consecutive patients diagnosed with pulmonary TB who underwent CT scans, 60 were excluded because of coexisting pulmonary diseases. The frequency of subpleural nodules (47/68, 69% in pulmonary TB with pleural effusion vs 30/210, 14% in pulmonary TB without effusion, P < .001, Benjamini-Hochberg [B-H] critical value = 0.0036) and interlobular septal thickening (55/68, 81% vs 134/210, 64%, P = .009, B-H critical value = 0.0107) was significantly higher in the group of patients with pulmonary TB with pleural effusion than in the group without pleural effusion. In contrast, tree-in-buds (20/68, 29% vs 101/210, 48%, P = .007, B-H critical value = 0.0071) were less frequently seen in patients with pulmonary TB with pleural effusion.

INTERPRETATION

Subpleural nodules and septal thickening were more common in pulmonary TB patients with pleural effusion than in those without pleural effusion. TB involvement of the lymphatics in the peripheral interstitium could be associated with the development of pleural effusion.

Imaging recommendations and algorithms for pediatric tuberculosis: part 1-thoracic tuberculosis

Tuberculosis (TB) remains a global health problem and is the second leading cause of death from a single infectious agent, behind the novel coronavirus disease of 2019. Children are amongst the most vulnerable groups affected by TB, and imaging manifestations are different in children when compared to adults. TB primarily involves the lungs and mediastinal lymph nodes. Clinical history, physical examination, laboratory examinations and various medical imaging tools are combined to establish the diagnosis. Even though chest radiography is the accepted initial radiological imaging modality for the evaluation of children with TB, this paper, the first of two parts, aims to discuss the advantages and limitations of the various medical imaging modalities and to provide recommendations on which is most appropriate for the initial diagnosis and assessment of possible complications of pulmonary TB in children. Practical, evidence-based imaging algorithms are also presented.

Chest Imaging for Pulmonary TB—An Update

The diagnosis of pulmonary tuberculosis (PTB) in children is challenging. Difficulties in acquiring suitable specimens, pauci-bacillary load, and limitations of current diagnostic methods often make microbiological confirmation difficult. Chest imaging provides an additional diagnostic modality that is frequently used in clinical practice. Chest imaging can also provide insight into treatment response and identify development of disease complications. Despite widespread use, chest radiographs are usually non-specific and have high inter- and intra-observer variability. Other diagnostic imaging modalities such as ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) can provide additional information to substantiate diagnosis. In this review, we discuss the radiological features of PTB in each modality, highlighting the advantages and limitations of each. We also address newer imaging technologies and potential use.

A proposed CT classification of progressive lung parenchymal injury complicating pediatric lymphobronchial tuberculosis: From reversible to irreversible lung injury

Lymphobronchial tuberculosis (LBTB) is tuberculous lymphadenopathy affecting the airways, which is particularly common in children with primary TB. Airway compression by lymphadenopathy causes downstream parenchymal pathology, which may ultimately result in irreversible lung destruction, if not treated timeously. Computed tomography (CT) is considered the "gold standard" for detecting mediastinal lymph nodes in children with TB. CT is also the best way of imaging the airways of children with LBTB. The CT findings of the parenchymal complications and associations of LBTB on CT have been described, but no severity classification was provided to aid management decisions. Identifying the parenchymal complications of LBTB and recognizing their severity has clinical relevance. Using prior publications on LBTB and post obstructive lung injury we have used an image bank of CT scans in children with pulmonary TB, presenting with airway symptoms, to create a CT severity staging of lung injury in LBTB. The staging focuses on distinguishing nonsalvageable destruction (nonenhancing or cavitated lung) from salvageable lung parenchymal disease (enhancing and noncavitated) to inform the management decisions, which range from bronchoscopic airway clearance to surgical decompression of the compressing nodes.

High rate of transmission in a pulmonary tuberculosis outbreak in a junior high school in China, 2020

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School tuberculosis outbreaks are common in China

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Students with PPD ≥ 15 mm are recommended to have prophylactic treatment

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More attention should be paid to students with PPD ≥ 10 mm and < 15 mm in school TB outbreaks

Background

School tuberculosis outbreaks are common in China. This study aimed to introduce a new screening process to help control outbreaks.

Methods

An epidemiological investigation into a school-based tuberculosis outbreak was conducted in order to identify the origin of the infection, and how it was transmitted.

Results

In total, 10 confirmed active tuberculosis cases were diagnosed among student contacts in the index case's class, giving an incidence rate of 19.2% (10/52). Three were found through a proactive visit and seven through screening. Of the nine secondary cases, two had purified protein derivation of tuberculin (PPD) ≥ 15 mm or blister (confirmed by computed tomography (CT) scan before preventive therapy), five had TST ≥ 10 mm and < 15 mm (two with abnormal chest radiography scan and three with positive T-SPOT tests, confirmed by CT) and two with PPD ≥ 5 mm and < 10 mm (confirmed by CT scan through proactive visit).

Conclusion

Further to our results based on this school outbreak, a new screening process is recommended that involves conducting interferon gamma release assays on those students with PPD ≥ 5 mm and < 15 mm if there are three or more active tuberculosis patients in the class with an epidemiological link. Furthermore, a CT scan is recommended for students who have had a recent tuberculosis infection before they have preventive therapy.

Chest CT Scan for the Diagnosis of Pediatric Pulmonary TB: Radiological Findings and Its Diagnostic Significance

Diagnosing active TB in children remains a clinical challenge, due to difficulties in achieving a definite microbiological confirmation, aspecific clinical manifestation, low sensitivity of chest radiography (CXR). For this reason, the use of chest computed tomography (CT) scan to evaluate suspected TB pediatric cases is increasing. We retrospectively reviewed records of patients aged <16 years diagnosed with active TB at the Pediatric Infectious Disease Unit of the Catholic University of the Sacred Heart to describe CT findings and to evaluate the need for its execution for diagnosis. In 41 cases, 7 CXR were normal (17.1%) while no CT scan was evaluated as negative. In 19 cases (46.3%), CXR was considered non-probable TB pulmonary, compared with 11 of 37 cases (29.7%) of CT. In 15 cases (36.6%) CXR was described as probable for TB pulmonary, instead 26 of the 37 cases evaluated by CT (70.3%) were classified as probable TB. We describe CT findings in patients with pediatric TB. We confirmed that CT can improve the diagnostic accuracy. In particular, the comparison between the CT and CXR ability in detecting cases of pulmonary TB in accordance with the proposed radiological probability criteria, showed a superiority of CT in detecting probable TB pictures (70.3%) compared with 36.6% of the x-Ray.

Chest imaging in paediatric pulmonary TB

Tuberculosis (TB) remains a significant cause of death from an infectious disease worldwide. The diagnosis of pulmonary TB in children is often challenging as children present with non-specific clinical symptoms, have difficulties providing specimens and have a low bacillary load. Radiological imaging supports a clinical diagnosis of pulmonary TB in children, can assess response to treatment and evaluate complications of TB. However, radiological signs on plain radiographs are often non-specific and inter-observer variability in the interpretation contribute to the difficulties in radiological interpretation and diagnosis. The goal of this review is to discuss the advantages and features of cross-sectional imaging such as ultrasound, Computed tomography (CT) and Magnetic resonance imaging (MRI) in diagnosing pulmonary TB (PTB) and its complications in children.

Reliability of chest radiograph interpretation for pulmonary tuberculosis in the screening of childhood TB contacts and migrant children in the UK

AIM

To determine interobserver agreement between paediatric radiologists interpreting tuberculosis (TB) screening chest radiographs (CXR) in children in the UK, and the TB detection rate.

MATERIALS AND METHODS

A retrospective review was undertaken of electronic request, notes, and CXRs (>7 years) in children exposed to an infectious case of TB and new entrants to the UK, at a tertiary children's hospital. Included were those with positive Mantoux/interferon gamma release assay (IGRA), positive culture, or high clinical suspicion of TB. CXR reports were categorised as normal, abnormal without features of TB, or abnormal with features of pulmonary TB. Three paediatric radiologists from a dedicated paediatric radiology department evaluated available CXRs, aware of the TB screening indication, using a published CXR reporting tool and blinded to the initial CXR report and to each other. A majority decision was collated, and considered lymphadenopathy and miliary nodules as diagnostic of primary TB. Interobserver agreement was calculated using Cohen's kappa.

RESULTS

One hundred and forty-eight children underwent TB screening with a CXR. One hundred and twenty-five had available CXR reports and case notes, which indicated 20/125 (16%) had CXR features of TB. One hundred and twenty-one of the 125 had CXRs available to for panel review. Twenty of these 121 (17%) yielded a majority decision of pulmonary TB. Inter-reader agreement was moderate in all aspects (kappa 0.4-0.6).

CONCLUSION

The high percentage of pulmonary TB on CXR (16% original reports; 17% by panel review) suggests that it is worthwhile investigating childhood TB contacts; however, the routine use and recommendation for CXR is questionable because of only moderate interpretation reliability (kappa 0.5), even by experts.

Imaging of thoracic tuberculosis in children: current and future directions

Tuberculosis continues to be an important cause of morbidity and mortality worldwide. It is the leading cause of infection-related deaths worldwide. Children are amongst the high-risk groups for developing tuberculosis and often pose a challenge to the clinicians in making a definitive diagnosis. The newly released global tuberculosis report from World Health Organization reveals a 50% increase in fatality from tuberculosis in children. Significantly, diagnostic and treatment algorithms of tuberculosis for children differ from those of adults. Bacteriologic confirmation of the disease is often difficult in children; hence radiologists have an important role to play in early diagnosis of this disease. Despite advancing technology, the key diagnostic imaging modalities for primary care and emergency services, especially in rural and low-resource areas, are chest radiography and ultrasonography. In this article, we discuss various diagnostic imaging modalities used in diagnosis and treatment of tuberculosis and their indications. We highlight the use of US as point-of-care service along with mediastinal US and rapid MRI protocols, especially in mediastinal lymphadenopathy and thoracic complications. MRI is the ideal modality in high-resource areas when adequate infrastructure is available. Because the prevalence of tuberculosis is highest in lower-resource countries, we also discuss global initiatives in low-resource settings.

Standardized radiographic interpretation of thoracic tuberculosis in children

There is a lack of standardized approach and terminology to classify the diverse spectrum of manifestations in tuberculosis. It is important to recognize the different clinical and radiographic patterns to guide treatment. As a result of changing epidemiology, there is considerable overlap in the radiologic presentations of primary tuberculosis and post-primary tuberculosis. In this article we promote a standardized approach in clinical and radiographic classification for children suspected of having or diagnosed with childhood tuberculosis. We propose standardized terms to diminish confusion and miscommunication, which can affect management. In addition, we present pitfalls and limitations of imaging.

Intrathoracic tuberculous lymphadenopathy in children: a guide to chest radiography

Making the diagnosis of pulmonary tuberculosis in children can be difficult because microbiological confirmation is not often achieved. Diagnosis is therefore often based on clinical features in combination with chest radiograph findings. Chest radiographs can demonstrate lymphadenopathy of the hilar and para-tracheal regions on the anteroposterior view, and subcarinal lymphadenopathy on the lateral view. However poor interobserver agreement has been reported for radiologist and clinician assessment of lymphadenopathy. This might reflect the lack of standardised imaging criteria for diagnosis as well as radiologists' objectives for achieving sensitivity rather than specificity. In this paper the authors provide a pictorial aid of chest radiographs in children with culture-confirmed tuberculosis to help clinicians identify lymph node enlargement in primary pulmonary tuberculosis. This collection of images comprises chest radiographs accompanied by schematics and either CT or MRI scan confirmation of pathological lymph node enlargement at the positions commonly affected in tuberculosis.

Recommendations for the diagnosis of pediatric tuberculosis

Tuberculosis (TB) is still the world's second most frequent cause of death due to infectious diseases after HIV infection, and this has aroused greater interest in identifying and managing exposed subjects, whether they are simply infected or have developed one of the clinical variants of the disease. Unfortunately, not even the latest laboratory techniques are always successful in identifying affected children because they are more likely to have negative cultures and tuberculin skin test results, equivocal chest X-ray findings, and atypical clinical manifestations than adults. Furthermore, they are at greater risk of progressing from infection to active disease, particularly if they are very young. Consequently, pediatricians have to use different diagnostic strategies that specifically address the needs of children. This document describes the recommendations of a group of scientific societies concerning the signs and symptoms suggesting pediatric TB, and the diagnostic approach towards children with suspected disease.

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.

Tuberculosis in children

Tuberculosis (TB) is a major, but often unrecognised, cause of disease and death in young children from countries with high TB incidence rates among adults. It is also relevant to paediatricians in low-incidence countries, such as Australia, because of increased international travel, immigration and refugee resettlement. This manuscript provides a brief overview of the global TB disease burden, the natural history of disease in children, and offers guidance on the prevention, diagnosis and treatment of TB in children.

Tuberculosis in children

Many clinicians regard tuberculosis as an adult pulmonary disease, but tuberculosis (TB) is a major cause of disease, both pulmonary and extrapulmonary, and death in young children from TB-endemic countries, especially in areas affected by poverty, social disruption, and human immunodeficiency virus (HIV) infection. This article reviews the disease burden and the natural history of disease in children with TB. It also provides guidance regarding the diagnosis, treatment, and prevention of TB in children.

Left main bronchus compression as a result of tuberculous lymphnode compression of the right-sided airways with right lung volume loss in children

RATIONALE

The superior mediastinal space is confined by the sterno-manubrium anteriorly and the vertebral column posterior. An abnormal relationship between the superior mediastinal structures may result in compression of the left main bronchus. In patients with right-sided pneumonectomy an exaggerated compensatory response may lead to stretching and compression of the remainder of the intra-thoracic airway. Lymphobronchial TB mimics pneumonectomy when it causes compression of the bronchus intermedius, between nodal lymphnode groups with resultant volume loss in the right lung and displacement of the mediastinum to the right. The left main bronchus may be at risk of compression due to rotation and displacement of the major vessels.

AIM

To report pediatric cases of right-sided lymphobronchial TB with volume loss, demonstrate the use of angle measurements to quantify mediastinal dynamics and support a pathogenetic theory for left main bronchus compression.

MATERIALS AND METHODS

CT scans in children with TB and right lung volume loss, were compared retrospectively with controls using angle measurements based on descriptions of the aorta-carinal syndrome and the post-pneumonectomy syndrome. The Mann-Whitney U-test was used to compare groups.

RESULTS

The "Pulmonary bifurcation angle" between the main pulmonary arteries reached statistical significance (P = 0.025). The "Pulmonary outflow tract rotation" angle (pulmonary trunk with the mid sagittal plane) approached statistical significance (P = 0.078). The left main bronchus ranged from complete obliteration in two patients to 0.7 cm. In 16 of 30 patients the size was reduced to less than 75% of expected.

CONCLUSION

In children with right lung volume loss from TB, the compression of the contralateral bronchus is due to narrowing of the pulmonary artery bifurcation angle as the main trunk rotates towards the midline. This is comparable to the post-pneumonectomy syndrome.

The application of anti-ESAT-6 monoclonal antibody fluorescent probe in ex vivo near-infrared fluorescence imaging in mice with pulmonary tuberculosis

Here, we aimed to assess the feasibility of anti-ESAT-6 monoclonal antibody (mAb) coupling with IR783 and rhodamine fluorescent probe in the detection of ESAT-6 expression in tuberculosis tissue of mice using near-infrared fluorescence imaging. IR783 and rhodamine were conjugated to the anti-ESAT-6 mAb or IgG. Mice in the experimental group were injected with fluorescence-labeled mAb probe, and mice in the control group were injected with fluorescence-labeled non-specific IgG antibody. Twenty-four hours later, the lung tissue of mice was examined using ex vivo near-infrared fluorescence imaging. In addition, the contrast-to-noise ratio (CNR) was calculated by measuring the signal intensities of the pulmonary lesions, normal lung tissue and background noise. The frozen lung tissue section was examined under fluorescence microscopy and compared with hemoxylin and eosin (HE) staining. The ex vivo near-infrared fluorescence imaging showed that the fluorescence signal in the lung tuberculosis lesions in the experimental group was significantly enhanced, whereas there was only a weak fluorescence signal or even no fluorescence signal in the control group. CNR values were 64.40 ± 7.02 (n = 6) and 8.75 ± 3.87 (n = 6), respectively (t = 17.01, p < 0.001). The fluorescence accumulation distribution detected under fluorescence microscopy was consistent with HE staining of the tuberculosis region. In conclusion, anti-ESAT-6 mAb fluorescent probe could target and be applied in specific ex vivo imaging of mice tuberculosis, and may be of further use in tuberculosis in living mice.

Diagnosis, treatment and prevention of tuberculosis in children

In Australia, tuberculosis notification rates have plateaued at a low level and disease is highly concentrated in immigrant communities where children may be affected. Many clinicians regard tuberculosis as an adult disease, hence it is rarely considered in the differential diagnosis of sick children. This paper provides a brief overview of the natural history of the disease in children to demonstrate the importance of taking a careful tuberculosis exposure history. It also provides guidance regarding the diagnosis, treatment and prevention of tuberculosis in children. The management of paediatric cases is not difficult if important differences with adult disease are carefully considered; these differences are discussed in detail.

Updated diagnosis and treatment of childhood tuberculosis

BACKGROUND

Childhood tuberculosis (TB) accounts for a significant proportion of the global tuberculosis disease burden. However, current and previous efforts to develop better diagnostic, therapeutic, and preventive interventions have focused on TB in adults, and childhood TB has been relatively neglected. The purpose of this review is to provide an update on the diagnostic and therapeutic recommendations for childhood TB with an emphasis on intrathoracic disease.

DATA SOURCES

The literature from a range of sources was reviewed and synthesized to provide an overview of the contemporary approaches for the diagnosis and treatment of childhood TB.

RESULTS

This review summarizes the clinical, radiological, bacteriological, and immunological approaches to diagnose TB infection and disease in children. In addition, we summarize the updated guidelines for the treatment of TB in children.

CONCLUSIONS

The development of better diagnostic and therapeutic methods for childhood TB remains a significant challenge. As the strategies for diagnosis and treatment of childhood TB continue to improve and the knowledge base increases, the implementation of these strategies will be crucial.

Characteristic magnetic resonance imaging low T2 signal intensity of necrotic lung parenchyma in children with pulmonary tuberculosis

PURPOSE

To show that necrotic areas of the lung demonstrated on computed tomographic scanning in children with primary pulmonary tuberculosis (TB) may be of low signal intensity on T2.

MATERIALS AND METHODS

Review of magnetic resonance imaging scans (T1/T2/STIR/postgadolinium T1) in 6 children scanned because of low-density necrotic areas demonstrated on computed tomography scanning prior to bronchoscopic confirmation of pulmonary TB.

RESULTS

Abnormalities included airspace consolidation in 6 children (100%); central necrosis in 6 children (100%); nodules in 2 children (33.3%); and lymphadenopathy in 6 children (100%). Low T2 signal in the areas of necrosis was demonstrated in all 6 children (100%) and in an area of at least 2 × 2 cm; 1 child also showed an area of high signal (16.67%). Airspace consolidation demonstrated T2 high signal in all the children (100%). Both children with nodules demonstrated at least 1 nodule with a low signal in addition to the majority of high-signal nodules. Post gadolinium, the consolidation and all high-signal nodules demonstrated enhancement, whereas the areas of lung necrosis and low signal nodules showed no enhancement.

CONCLUSION

Lung parenchymal necrosis in primary pulmonary TB in children may be of low signal intensity on T2 and STIR magnetic resonance imaging. This may be distal to lymphobronchial obstruction and is probably due to the caseating necrosis.

CT features of lymphobronchial tuberculosis in children, including complications and associated abnormalities

BACKGROUND

Lymphobronchial tuberculosis (TB) is tuberculous lymphadenopathy involving the airways, which is particularly common in children.

OBJECTIVE

To describe CT findings of lymphobronchial TB in children, the parenchymal complications and associated abnormalities.

MATERIALS AND METHODS

CT scans of children with lymphobronchial TB were reviewed retrospectively. Lymphadenopathy, bronchial narrowing, parenchymal complications and associations were documented.

RESULTS

Infants comprised 51% of patients. The commonest site of lymphadenopathy was the subcarinal mediastinum (97% of patients). Bronchial compression was seen in all children (259 bronchi, of these 28% the bronchus intermedius) with severe or complete stenosis in 23% of affected bronchi. Parenchymal complications were present in 94% of patients, including consolidation (88%), breakdown (42%), air trapping (38%), expansile pneumonia (28%), collapse (17%) and bronchiectasis (9%), all predominantly on the right side (63%). Associated abnormalities included ovoid lesions, miliary nodules, pleural disease and intracavitary bodies.

CONCLUSION

Airway compression was more severe in infants and most commonly involved the bronchus intermedius. Numerous parenchymal complications were documented, all showing right-side predominance.

Not all children with nodular interstitial lung patterns in South Africa have TB-A rare case of paediatric "Bird Fanciers' disease"

Bird Fancier's disease is an allergic alveolitis that is rare in children. We describe the relevance of adequate history for making the diagnosis in children and the difficulty distinguishing this entity on chest radiographs and CT from imaging patterns caused by infections such as tuberculosis and HIV in developing countries. Pediatr. Pulmonol. 2011; 46:1134-1136. © 2011 Wiley Periodicals, Inc.

Paediatric radiology seen from Africa. Part I: providing diagnostic imaging to a young population

Paediatric radiology requires dedicated equipment, specific precautions related to ionising radiation, and specialist knowledge. Developing countries face difficulties in providing adequate imaging services for children. In many African countries, children represent an increasing proportion of the population, and additional challenges follow from extreme living conditions, poverty, lack of parental care, and exposure to tuberculosis, HIV, pneumonia, diarrhoea and violent trauma. Imaging plays a critical role in the treatment of these children, but is expensive and difficult to provide. The World Health Organisation initiatives, of which the World Health Imaging System for Radiography (WHIS-RAD) unit is one result, needs to expand into other areas such as the provision of maintenance servicing. New initiatives by groups such as Rotary and the World Health Imaging Alliance to install WHIS-RAD units in developing countries and provide digital solutions, need support. Paediatric radiologists are needed to offer their services for reporting, consultation and quality assurance for free by way of teleradiology. Societies for paediatric radiology are needed to focus on providing a volunteer teleradiology reporting group, information on child safety for basic imaging, guidelines for investigations specific to the disease spectrum, and solutions for optimising imaging in children.

Paediatric radiology seen from Africa. Part II: recognising research advantages in a developing country

Radiologists in developing countries cite numerous reasons for poor research output including heavier workloads, poor remuneration (resulting in "brain drain"), poor infrastructure, language barriers, lack of modern imaging equipment, and a disease spectrum that may be of little interest to journals and readers in the developed world. On the other hand, large populations of patients suffering from distinctive diseases, cost-effective healthcare systems, and a set-up with highly centralised tertiary referral hospitals, may be seen as advantages to those willing to tap into this as a data source for research. The lack of resources may even stimulate cost-effective innovations relevant to the needs of poor communities. This paper challenges preconceived ideas and identifies advantages for radiologists in developing countries to producing good research and publications. It also cautions against "annexation of sites" by stakeholders from developed countries, and suggests simple solutions to maximise research output without a significant financial cost.

Chest radiographic findings in primary pulmonary tuberculosis: observations from high school outbreaks

Objective

To describe the radiographic findings of primary pulmonary tuberculosis (TB) in previously healthy adolescent patients.

Materials and Methods

The Institutional Review Board approved this retrospective study, with a waiver of informed consent from the patients. TB outbreaks occurred in 15 senior high schools and chest radiographs from 58 students with identical strains of TB were analyzed by restriction fragment length polymorphism analysis by two independent observers. Lesions of nodule(s), consolidation, or cavitation in the upper lung zones were classified as typical TB. Mediastinal lymph node enlargement; lesions of nodule(s), consolidation, or cavitation in lower lung zones; or pleural effusion were classified as atypical TB. Inter-observer agreement for the presence of each radiographic finding was examined by kappa statistics.

Results

Of 58 patients, three (5%) had normal chest radiographs. Cavitary lesions were present in 25 (45%) of 55 students. Lesions with upper lung zone predominance were observed in 27 (49%) patients, whereas lower lung zone predominance was noted in 18 (33%) patients. The remaining 10 (18%) patients had lesions in both upper and lower lung zones. Pleural effusion was not observed in any patient, nor was the mediastinal lymph node enlargement. Hilar lymph node enlargement was seen in only one (2%) patient. Overall, 37 (67%) students had the typical form of TB, whereas 18 (33%) had TB lesions of the atypical form.

Conclusion

The most common radiographic findings in primary pulmonary TB by recent infection in previously healthy adolescents are upper lung lesions, which were thought to be radiographic findings of reactivation pulmonary TB by remote infection.