Chest tuberculosis: Radiological review and imaging recommendations

Utility of preoperative 18F-flurodeoxyglucose PET/CT scanning in preoperative evaluation and surgical planning for pulmonary tuberculosis

OBJECTIVE

The objective of this study was to investigate the utility of preoperative 18F-FDG PET/CT scanning in preoperative evaluation and surgical planning for pulmonary tuberculosis.

METHODS

The study involved a retrospective analysis of clinical data and preoperative chest 18F-FDG PET/CT data of 24 patients with pulmonary tuberculosis who underwent pneumonectomy at the Shanghai Public Health Clinical Center between December 2017 and January 2022.

RESULTS

All 24 patients successfully underwent chest 18F-FDG PET/CT imaging, and complete data pertaining to the maximum standardized uptake value, mean standardized uptake value, minimum standardized uptake value, total lesion glycolysis, and metabolic tumor volume were obtained. Surgical excision plans were finalized using the chest 18F-FDG PET/CT findings along with the conventional chest CT scans. Pneumonectomy was successfully completed in all 24 patients, and these included 13 cases of pulmonary lobectomy, two cases of total pneumonectomy, one case of combined pulmonary lobectomy, one case of segmentectomy, and seven cases of pulmonary wedge resection. The actual surgical procedures had a conformity rate of 100% to the preoperative surgical plans that were made. The intraoperative bronchial stump embedding rate was 69% (11/18 cases), the incidence rate of postoperative air leakage was 3.8% (1/24 cases), and there were no reported cases of postoperative bronchopleural fistula or death.

CONCLUSION

Preoperative 18F-FDG PET/CT scans had significant utility in surgical planning, the selection of surgical methods, and the formulation of postoperative antituberculosis treatment courses for patients with pulmonary tuberculosis. The use of 18F-FDG PET/CT shows considerable promise in being promoted clinically for the surgical management of patients with pulmonary tuberculosis.

Clinical Features and Predictors of Treatment Outcome in Patients with Ocular Tuberculosis from the Netherlands and Indonesia: The OculaR TB in Low versus High Endemic Countries (ORTEC) Study

PURPOSE

To describe and compare clinical features, treatment approaches, and treatment outcomes of ocular tuberculosis (OTB) patients in the Netherlands, a low tuberculosis (TB)-endemic country, and Indonesia, a high TB-endemic country. We also aimed to identify predictors of treatment outcomes.

METHODS

A medical chart review of 339 OTB patients (n = 93 from the Netherlands and n = 246 from Indonesia) was performed. The primary outcome was response to treatment, whether with or without anti-tubercular treatment, after six months of treatment initiation (good versus poor responders).

RESULTS

Indonesian OTB patients displayed a higher prevalence of chest radiograph findings indicative of TB infection (p < 0.001) and concurrent active systemic TB (p = 0.011). Indonesian cohort exhibited a more acute and severe disease profile, including uveitis duration ≤ 3 months (p < 0.001), blindness (p < 0.001), anterior chamber (AC) cells ≥ 2+ (p < 0.001), and posterior synechiae (p < 0.001). Overall proportions of good responders to treatment were 67.6% in the Netherlands and 71.5% in Indonesia. Presence of AC cell ≥ 2+ (adjusted odds ratio (aOR): 2.12, 95% CI: 1.09-4.14), choroidal lesions other than serpiginous-like choroiditis (SLC) or tuberculoma (aOR: 4.47, 95% CI: 1.18-16.90), and retinal vasculitis (aOR: 2.32, 95% CI: 1.10-4.90) at baseline were predictors for poor response to treatment.

CONCLUSIONS

Despite a more severe initial clinical presentation in the Indonesian cohort, the overall treatment outcomes of OTB was comparable in both cohorts. Three baseline clinical features were identified as predictors of treatment outcomes.

Identification of Factors Determining Patterns of Serum C-Reactive Protein Level Reduction in Response to Treatment Initiation in Patients with Drug-Susceptible Pulmonary Tuberculosis

Background: Serum C-reactive protein (CRP) levels vary depending on radiological and bacteriological findings at the time of tuberculosis (TB) diagnosis. However, the utility of this biomarker in monitoring response to anti-TB treatment and identifying patients at risk of treatment failure is not well established. Objectives: This study evaluated the impact of patients' baseline characteristics and anti-TB drug plasma exposure on the early reduction in serum CRP levels and its relationship with treatment response. Methods: We enrolled 42 patients with drug-susceptible pulmonary TB, who received a standard six-month regimen. The plasma concentrations of four anti-TB drugs were analysed using LC-MS/MS. Clinically relevant data, including serum CRP levels before and 10-12 days after treatment initiation (CRP10-12d), were obtained from electronic medical records and patient questionnaires. Results: In 10-12 days, the median serum CRP level decreased from 21.9 to 6.4 mg/L. Lower body mass index, positive sputum-smear microscopy results, and lung cavitations at diagnosis were related to higher biomarker levels at both time points; smoking had a more pronounced effect on serum CRP10-12d levels. Variability in anti-TB drug plasma exposure did not significantly affect the reduction in serum CRP levels. The serum CRP10-12d levels, or fold change from the baseline, did not predict the time to sputum culture conversion. Conclusions: Disease severity and patient characteristics may influence the pattern of early CRP reduction, while anti-TB drug plasma exposure had no significant effect at this stage. These early changes in serum CRP levels were not a predictor of response to anti-TB therapy.

A Rare Case of Metastatic Adenocarcinoma Masquerading as Disseminated Tuberculosis

A 68-year-old female with no known comorbidities presented with a three-month history of abdominal pain, nausea, vomiting aggravated by food intake, dry cough, gastro-oesophageal reflux disease, breathlessness, low-grade fever, and significant weight loss. Initial investigations including a plain radiograph of the erect abdomen and contrast-enhanced computed tomography abdomen showed irregular concentric thickening of the large bowel along with proximal dilation of small bowel loops which was suggestive of subacute intestinal obstruction secondary to abdominal tuberculosis (TB). The patient also complained of persistent dry cough for which a chest radiograph and computed tomography (CT) thorax were done which showed features suggestive of pulmonary TB. Conservative management was initiated for subacute intestinal obstruction but persistent cough led to further evaluation with bronchoscopy and transbronchial lung biopsy, revealing invasive mucin-secreting adenocarcinoma. A subsequent PET-CT scan confirmed a large mass in the ileocecal region causing obstruction, multiple iliac lymph nodes, pancreatic and skeletal deposits, and lung opacities indicative of lymphangitis carcinomatosis. Despite the recommendation for exploratory laparotomy, the patient opted for conservative management due to her age and associated risks. This case highlights the importance of clinical symptoms and signs mimicking disseminated TB. Concomitant presence of chronic diseases with overlapping symptoms can lead to diagnostic dilemmas.

Identification of Nontuberculous Mycobacterium and Mycobacterium tuberculosis Complex in Sputum Patients with Suspected Tuberculosis

BACKGROUND

Pulmonary tuberculosis (TB) is predominantly caused by Mycobacterium tuberculosis complex (MTBC) and can also involve nontuberculous mycobacteria (NTM). These pathogens pose significant global health challenges, particularly in developing countries. Differentiating between MTBC and NTM in clinical specimens is often difficult using conventional acid-fast staining methods, leading to an underestimation of NTM prevalence in TB-endemic regions. This study aims to identify mycobacterial species in sputum samples from patients suspected of having TB, utilizing polymerase chain reaction (PCR) assays and gene sequencing techniques.

METHODS

We collected 111 sputum samples from patients at Dr. Wahidin Sudirohusodo Central General Hospital, Hasanuddin University Hospital, and Makassar Community Lung Health Center. The samples were analyzed at the Clinical Microbiology Laboratory of Hasanuddin University using standard microscopy and molecular detection techniques. Descriptive statistics were employed to summarize patient demographics, infection characteristics, and outcomes.

RESULTS

We collected sputum from suspected TB patients with an average age of 50.86 years. We found 16.2% (n = 18) acid-fast bacteria in 111 patients with suspected pulmonary TB, and molecularly, we identified 17.1% (n = 19) Mycobacterium species by multiplex PCR. Three sputum samples tested positive for NTM. Phylogenetic analysis, based on 16S rRNA gene sequencing, revealed similarities between the samples and known mycobacterial species.

CONCLUSIONS

The study underscores the challenges in differentiating between MTBC and NTM, highlighting the necessity for molecular diagnostic approaches. Notably, we found NTM in sputum samples from patients previously treated for TB. These findings can serve as a reference for improving diagnostic accuracy and preventing misdiagnosis of mycobacterial infections.

Tuberculosis Diagnosis: Current, Ongoing, and Future Approaches

Tuberculosis (TB) remains an impactful infectious disease, leading to millions of deaths every year. Mycobacterium tuberculosis causes the formation of granulomas, which will determine, through the host-pathogen relationship, if the infection will remain latent or evolve into active disease. Early TB diagnosis is life-saving, especially among immunocompromised individuals, and leads to proper treatment, preventing transmission. This review addresses different approaches to diagnosing TB, from traditional methods such as sputum smear microscopy to more advanced molecular techniques. Integrating these techniques, such as polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP), has significantly improved the sensitivity and specificity of M. tuberculosis identification. Additionally, exploring novel biomarkers and applying artificial intelligence in radiological imaging contribute to more accurate and rapid diagnosis. Furthermore, we discuss the challenges of existing diagnostic methods, including limitations in resource-limited settings and the emergence of drug-resistant strains. While the primary focus of this review is on TB diagnosis, we also briefly explore the challenges and strategies for diagnosing non-tuberculous mycobacteria (NTM). In conclusion, this review provides an overview of the current landscape of TB diagnostics, emphasizing the need for ongoing research and innovation. As the field evolves, it is crucial to ensure that these advancements are accessible and applicable in diverse healthcare settings to effectively combat tuberculosis worldwide.

Coccidioidomycosis and Histoplasmosis in Immunocompetent Individuals: A Comprehensive Review of Clinical Features, Diagnosis, and Management

Coccidioidomycosis and histoplasmosis are endemic mycoses caused by the Coccidioides species and Histoplasma capsulatum, respectively. While these fungal infections are often associated with immunocompromised individuals, they pose significant risks to immunocompetent hosts. This review comprehensively analyzes these infections in immunocompetent individuals, focusing on clinical features, diagnostic approaches, and management strategies. The current understanding of coccidioidomycosis and histoplasmosis in immunocompetent individuals includes their clinical presentations, diagnostic methodologies, and treatment options. A literature review encompassed recent studies, clinical guidelines, and expert opinions. Data were analyzed to highlight critical aspects of the clinical manifestations, diagnostic processes, and management of these infections in immunocompetent patients. Coccidioidomycosis typically presents with pulmonary symptoms that may range from mild to severe and can include chronic and disseminated forms. Histoplasmosis also presents a spectrum of pulmonary symptoms with the potential for extrapulmonary dissemination. Diagnostic approaches for both infections involve clinical evaluation, serological tests, culture, and imaging studies. Management strategies include antifungal therapies such as fluconazole and itraconazole for coccidioidomycosis and itraconazole and amphotericin B for histoplasmosis, with treatment duration and monitoring tailored to the severity of the infection. Coccidioidomycosis and histoplasmosis can significantly affect immunocompetent individuals, with clinical presentations varying widely from mild to severe. Accurate diagnosis and appropriate management are crucial for optimal outcomes. This review underscores the importance of awareness and timely intervention in managing these endemic mycoses and highlights the need for continued research into better diagnostic and therapeutic approaches.

Imaging of Pulmonary Miliary Tuberculosis With Multiple Intracranial Tuberculomas

Tuberculosis, caused by Mycobacterium tuberculosis, is a widely spread disease complex affecting multiple organs. It is a type of communicable disease disproportionately affecting low and middle-income countries. The imaging modality of choice for pulmonary tuberculosis is computed tomography, and for brain lesions, it is a contrast-enhanced magnetic resonance imaging study. This report presents the case of a 73-year-old male patient who was diagnosed with tuberculosis on radiography and was started anti-tubercular treatment for the same and later developed multiple tuberculomas. This report showcases the imaging findings and emphasizes the need for timely and undisrupted treatment for tuberculosis management to prevent further complications like brain tuberculomas as developed in our case.

Post-tubercular Left Lung Destruction With Compensatory Hyperinflation of the Right Lung: A Complicated Case

Hyperinflation is the rise in functional residual capacity, i.e., the volume of air left in the lung after normal expiration. One lung is wholly damaged and nonfunctional, while the other lung increases its surface area to compensate for the loss of the respiratory system. Pulmonary tuberculosis (TB) is a respiratory disease caused by Mycobacterium tuberculosis, primarily targeting the lungs. However, if left untreated, it could lead to life-threatening conditions, such as systemic manifestations, and increase the mortality rate. When TB causes severe damage to one lung, the other lung may compensate by hyperinflating excessively to keep the body's oxygenation levels healthy. It was seen in the case of a 60-year-old male who presented to the Outpatient Department (OPD) with complaints of hearing loss, blood-tinged sputum, and cough. In investigations, compensatory hyperinflation was seen. TB and hyperinflation of the lung are not associated together, and hyperinflation is not a clinical sign of TB. This distinction is what distinguishes this particular case.

Post-tuberculosis respiratory impairment in Gambian children and adolescents: A cross-sectional analysis

BACKGROUND

Although post-tuberculosis lung disease (PTLD) is a known consequence of pulmonary tuberculosis (pTB), few studies have reported the prevalence and spectrum of PTLD in children and adolescents.

METHODS

Children and adolescent (≤19 years) survivors of pTB in the Western Regions of The Gambia underwent a respiratory symptom screening, chest X-ray (CXR) and spirometry at TB treatment completion. Variables associated with lung function impairment were identified through logistic regression models.

RESULTS

Between March 2022 and July 2023, 79 participants were recruited. The median age was 15.6 years (IQR: 11.8, 17.9); the majority, 53/79 (67.1%), were treated for bacteriologically confirmed pTB, and 8/79 (10.1%) were children and adolescents living with HIV. At pTB treatment completion, 28/79 (35.4%) reported respiratory symptoms, 37/78 (47.4%) had radiological sequelae, and 45/79 (57.0%) had abnormal spirometry. The most common respiratory sequelae were cough (21/79, 26.6%), fibrosis on CXR (22/78, 28.2%), and restrictive spirometry (41/79, 51.9%). Age at TB diagnosis over ten years, undernutrition and fibrosis on CXR at treatment completion were significantly associated with abnormal spirometry (p = .050, .004, and .038, respectively).

CONCLUSION

Chronic respiratory symptoms, abnormal CXR, and impaired lung function are common and under-reported consequences of pTB in children and adolescents. Post-TB evaluation and monitoring may be necessary to improve patient outcomes.

Characteristics of culture-negative subclinical pulmonary tuberculosis: a single-center observation

BACKGROUND

Little is known about culture-negative subclinical pulmonary tuberculosis (TB), and its diagnosis remains challenging. Therefore, this study aimed to identify the characteristics and the extent of disease associated with culture-negative subclinical pulmonary TB.

METHODS

This retrospective cohort study was conducted on immunocompetent individuals with subclinical pulmonary TB at a university hospital in Thailand from January 2014 to December 2019. Subclinical pulmonary TB was diagnosed based on the presence of radiographic abnormalities consistent with TB in the absence of TB symptoms. All subjects demonstrated significant improvement or resolution of radiographic abnormalities following the completion of treatment. At least two negative sputum cultures were needed to fulfill the definition of culture-negative pulmonary TB. Data were analyzed using univariate and multiple logistic regression analyses to determine the characteristics of those with culture-negative subclinical pulmonary TB compared to culture-positive ones.

RESULTS

Out of the 106 individuals identified with subclinical pulmonary TB, 84 met the criteria for inclusion in the analysis. The study found lower radiographic extent and increasing age were key attributes of culture-negative subclinical pulmonary TB. The odds ratios (95% confidence interval) were 7.18 (1.76 to 29.35) and 1.07 (1.01 to 1.13), respectively. They tend to have lower rates of bilateral involvement in both chest x-ray (8.5% vs. 32.0%, p=0.006) and computed tomography (15.4% vs. 42.9%, p=0.035). However, no other specific radiographic findings were identified.

CONCLUSIONS

People with culture-negative subclinical pulmonary TB were likely to have less radiographic -severity, reflecting early disease. Nevertheless, no radiographic patterns, except for unilaterality, were related to culture-negative subclinical pulmonary TB.

Chronic pulmonary aspergillosis incidence in newly detected pulmonary tuberculosis cases during follow-up

BACKGROUND

Chronic pulmonary aspergillosis (CPA) is known to complicate patients with post-tubercular lung disease. However, some evidence suggests that CPA might co-exist in patients with newly-diagnosed pulmonary tuberculosis (P.TB) at diagnosis and also develop during therapy. The objective of this study was to confirm the presence of CPA in newly diagnosed P.TB at baseline and at the end-of-TB-therapy.

MATERIALS AND METHODS

This prospective longitudinal study included newly diagnosed P.TB patients, followed up at third month and end-of-TB-therapy with symptom assessment, anti-Aspergillus IgG antibody and imaging of chest for diagnosing CPA.

RESULTS

We recruited 255 patients at baseline out of which 158 (62%) completed their follow-up. Anti-Aspergillus IgG was positive in 11.1% at baseline and 27.8% at end-of-TB-therapy. Overall, proven CPA was diagnosed in 7% at baseline and 14.5% at the end-of-TB-therapy. Around 6% patients had evidence of aspergilloma in CT chest at the end-of-TB-therapy.

CONCLUSIONS

CPA can be present in newly diagnosed P.TB patients at diagnosis and also develop during anti-tubercular treatment. Patients with persistent symptoms or developing new symptoms during treatment for P.TB should be evaluated for CPA. Whether patients with concomitant P.TB and CPA, while receiving antitubercular therapy, need additional antifungal therapy, needs to be evaluated in future studies.

Clinical presentation, management, and outcome of suspected central nervous system infections in Indonesia: a prospective cohort study

BACKGROUND

Little is known about the etiology, clinical presentation, management, and outcome of central nervous system (CNS) infections in Indonesia, a country with a high burden of infectious diseases and a rising prevalence of HIV.

METHODS

We included adult patients with suspected CNS infections at two referral hospitals in a prospective cohort between April 2019 and December 2021. Clinical, laboratory, and radiological assessments were standardized. We recorded initial and final diagnoses, treatments, and outcomes during 6 months of follow-up.

RESULTS

Of 1051 patients screened, 793 were diagnosed with a CNS infection. Patients (median age 33 years, 62% male, 38% HIV-infected) presented a median of 14 days (IQR 7-30) after symptom onset, often with altered consciousness (63%), motor deficits (73%), and seizures (21%). Among HIV-uninfected patients, CNS tuberculosis (TB) was most common (60%), while viral (8%) and bacterial (4%) disease were uncommon. Among HIV-infected patients, cerebral toxoplasmosis (41%) was most common, followed by CNS TB (19%), neurosyphilis (15%), and cryptococcal meningitis (10%). A microbiologically confirmed diagnosis was achieved in 25% of cases, and initial diagnoses were revised in 46% of cases. In-hospital mortality was 30%, and at six months, 45% of patients had died, and 12% suffered from severe disability. Six-month mortality was associated with older age, HIV, and severe clinical, radiological and CSF markers at presentation.

CONCLUSION

CNS infections in Indonesia are characterized by late presentation, severe disease, frequent HIV coinfection, low microbiological confirmation and high mortality. These findings highlight the need for earlier disease recognition, faster and more accurate diagnosis, and optimized treatment, coupled with wider efforts to improve the uptake of HIV services.

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.

Relevance of the correlation between tomography findings and laboratory test results in the accuracy of the diagnosis of pulmonary tuberculosis

Objective

To evaluate the correlation between multidetector computed tomography (MDCT) findings and laboratory test results in patients with pulmonary tuberculosis (PTB).

Materials and Methods

A total of 57 patients were evaluated. Patients with suspected PTB were divided into groups according to the final diagnosis (confirmed or excluded), and the groups were compared in terms of sociodemographic variables, clinical symptoms, tomography findings, and laboratory test results.

Results

Among the patients with a confirmed diagnosis of PTB, small pulmonary nodules with a peribronchovascular distribution were significantly more common in the patients with a positive sputum smear microscopy result (47.4% vs. 8.3%; p = 0.046), as were a miliary pattern (36.8% vs. 0.0%; p = 0.026), septal thickening (84.2% vs. 41.7%; p = 0.021), and lymph node enlargement (52.6% vs. 8.3%; p = 0.020). Small pulmonary nodules with a centrilobular distribution were significantly more common among the culture-positive patients (75.0% vs. 35.7%; p = 0.045), as was a tree-in-bud pattern (91.7% vs. 42.9%; p = 0.014). A tree-in-bud pattern, one of the main tomography findings characteristic of PTB, had a sensitivity, specificity, positive predictive value, and negative predictive value of 71.0%, 73.1%, 75.9%, and 67.9%, respectively.

Conclusion

MDCT presented reliable predictive values for the main tomography findings in the diagnosis of PTB, being a safe tool for the diagnosis of PTB in patients with clinical suspicion of the disease. It also appears to be a suitable tool for the selection of patients who are candidates for more complex, invasive examinations from among those with high clinical suspicion of PTB and a negative sputum smear microscopy result.

Circular RNAs in tuberculosis: From mechanism of action to potential diagnostic biomarker

Tuberculosis (TB), caused by Mycobacterium tuberculosis (M. tuberculosis), continues to be a major global health concern. Understanding the molecular intricacies of TB pathogenesis is crucial for developing effective diagnostic and therapeutic approaches. Circular RNAs (circRNAs), a class of single-stranded RNA molecules characterized by covalently closed loops, have recently emerged as potential diagnostic biomarkers in various diseases. CircRNAs have been demonstrated to modulate the host's immunological responses against TB, specifically by reducing monocyte apoptosis, augmenting autophagy, and facilitating macrophage polarization. This review comprehensively explores the roles and mechanisms of circRNAs in TB pathogenesis. We also discuss the growing body of evidence supporting their utility as promising diagnostic biomarkers for TB. By bridging the gap between fundamental circRNA biology and TB diagnostics, this review offers insights into the exciting potential of circRNAs in combatting this infectious disease.

Unveiling the Clinical Diversity in Nontuberculous Mycobacteria (NTM) Infections: A Comprehensive Review

Once considered rare, nontuberculous mycobacterial (NTM) infections have garnered increasing attention in recent years. This comprehensive review provides insights into the epidemiology, clinical diversity, diagnostic methods, treatment strategies, prevention, and emerging research trends in NTM infections. Key findings reveal the global prevalence of NTM infections, their diverse clinical presentations affecting respiratory and extra-pulmonary systems, and the diagnostic challenges addressed by advances in microbiological, radiological, and immunological methods. Treatment complexities, especially drug resistance and patient adherence, are discussed, along with the vulnerability of special populations. The importance of early detection and management is underscored. Prospects in NTM research, including genomics, diagnostics, drug development, and multidisciplinary approaches, promise to enhance our understanding and treatment of these infections. This review encapsulates the multifaceted nature of NTM infections, offering a valuable resource for clinicians, researchers, and public health professionals.

Evolving role of chest radiographs for diagnosis of pediatric pulmonary tuberculosis

Chest radiographs (CXR) have played an important and evolving role in diagnosis, classification and management of pediatric pulmonary tuberculosis (TB). During the pre-chemotherapy era, CXR aided in determining infectiousness, mainly to guide isolation practices, by detecting calcified and non-calcified lymphadenopathy. The availability of TB chemotherapy from the mid-1900s increased the urgency to find accurate diagnostic tools for what had become a treatable disease. Chest radiographs provided the mainstay of diagnosis in children, despite high inter-reader variability limiting its accuracy. The development of cross-sectional imaging modalities, such as computed tomography, provided more accurate intra-thoracic lymph node assessment, but these modalities have major availability, cost and radiation exposure disadvantages. As a consequence, CXR remains the most widely used modality for childhood  pulmonary TB diagnosis, given its relatively low cost and accessibility. Publication of the revised 2022 World Health Organization Consolidated TB guidelines added practical value to CXR interpretation in children, by allowing the selection of children for shorter TB treatment using radiological signs of severity of disease, that have high reliability. This article provides a review of the historical journey and evolving role of CXR in pediatric pulmonary TB.

Tips and Tricks in Thoracic Radiology for Beginners: A Findings-Based Approach

This review has the purpose of illustrating schematically and comprehensively the key concepts for the beginner who approaches chest radiology for the first time. The approach to thoracic imaging may be challenging for the beginner due to the wide spectrum of diseases, their overlap, and the complexity of radiological findings. The first step consists of the proper assessment of the basic imaging findings. This review is divided into three main districts (mediastinum, pleura, focal and diffuse diseases of the lung parenchyma): the main findings will be discussed in a clinical scenario. Radiological tips and tricks, and relative clinical background, will be provided to orient the beginner toward the differential diagnoses of the main thoracic diseases.

A case report of a 16-year-old male with extrapulmonary tuberculosis presenting as multiloculated mediastinal, pleural, and paravertebral fluid collections with chest pain, Eldoret, Kenya

Key Clinical Message

Extrapulmonary TB presenting as multiloculated pleural fluid collections is rare in persons less than 18 years of age, but it can occur. High index of suspicion is important in establishing early diagnosis and treatment to reduce morbidity and mortality.

Abstract

We present a case report of an immunocompetent African young man who presented with persistent chest pain and fever, and was diagnosed with extrapulmonary tuberculosis (EPTB) following chest CT scan, pleural biopsy histopathology examination, and Ziehl-Neelsen (ZN) staining, and pleural fluid Gene Xpert studies.

Necrotising pneumonia caused by Curvularia hawaiiensis (syn. Bipolaris hawaiiensis) and Mycobacterium tuberculosis coinfection in a patient with ascariasis: a case report and review

INTRODUCTION

Curvularia hawaiiensis (formerly Bipolaris hawaiiensis) is a plant pathogen often isolated from soil and vegetative material. However, only a few cases of opportunistic invasive infections in humans have been described.

CASE

A 16-year-old female patient without comorbidities was admitted to the emergency department because of fever and chest pain. We described the first coinfection of Curvularia hawaiiensis and Mycobacterium tuberculosis necrotising pneumonia.

DISCUSSION

Multiple infections can alter immune responses. However, immunosuppression is the most critical risk factor for infection with species of the genus Curvularia. Therefore, it is crucial to carefully examine patients with tuberculosis, as they may rarely be coinfected with unusual fungi.

Superimposed Pulmonary Tuberculosis (PTB) in a 26-Year-Old Female with No Underlying Co-Morbidities Recovering from COVID-19-Case Report

Tuberculosis before the COVID-19 pandemic is said to have killed more people globally than any other communicable disease and is ranked the 13th cause of death, according to the WHO. Tuberculosis also still remains highly endemic, especially in LIMCs with a high burden of people living with HIV/AIDS, in which it is the leading cause of mortality. Given the risk factors associated with COVID-19, the cross similarities between tuberculosis and COVID-19 symptoms, and the paucity of data on how both diseases impact each other, there is a need to generate more information on COVID-19-TB co-infection. In this case report, we present a young female patient of reproductive age with no underlying comorbidities recovering from COVID-19, who later presented with pulmonary tuberculosis. It describes the series of investigations performed and treatments given during the follow-up. There is a need for more surveillance for possible COVID-19-TB co-infection cases and further research to understand the impact of COVID-19 on tuberculosis and vice versa, especially in LMICs.

Evolution of tuberculosis diagnostics: From molecular strategies to nanodiagnostics

Tuberculosis has remained a global concern for public health affecting the lives of people for ages. Approximately 10 million people are affected by the disease and 1.5 million succumb to the disease worldwide annually. The COVID-19 pandemic has highlighted the role of early diagnosis to win the battle against such infectious diseases. Thus, advancement in the diagnostic approaches to provide early detection forms the foundation to eradicate and manage contagious diseases like tuberculosis. The conventional diagnostic strategies include microscopic examination, chest X-ray and tuberculin skin test. The limitations associated with sensitivity and specificity of these tests demands for exploring new techniques like probe-based assays, CRISPR-Cas and microRNA detection. The aim of the current review is to envisage the correlation between both the conventional and the newer approaches to enhance the specificity and sensitivity. A significant emphasis has been placed upon nanodiagnostic approaches manipulating quantum dots, magnetic nanoparticles, and biosensors for accurate diagnosis of latent, active and drug-resistant TB. Additionally, we would like to ponder upon a reliable method that is cost-effective, reproducible, require minimal infrastructure and provide point-of-care to the patients.

An Insight into Advances in Developing Nanotechnology Based Therapeutics, Drug Delivery, Diagnostics and Vaccines: Multidimensional Applications in Tuberculosis Disease Management

Tuberculosis (TB), one of the deadliest contagious diseases, is a major concern worldwide. Long-term treatment, a high pill burden, limited compliance, and strict administration schedules are all variables that contribute to the development of MDR and XDR tuberculosis patients. The rise of multidrug-resistant strains and a scarcity of anti-TB medications pose a threat to TB control in the future. As a result, a strong and effective system is required to overcome technological limitations and improve the efficacy of therapeutic medications, which is still a huge problem for pharmacological technology. Nanotechnology offers an interesting opportunity for accurate identification of mycobacterial strains and improved medication treatment possibilities for tuberculosis. Nano medicine in tuberculosis is an emerging research field that provides the possibility of efficient medication delivery using nanoparticles and a decrease in drug dosages and adverse effects to boost patient compliance with therapy and recovery. Due to their fascinating characteristics, this strategy is useful in overcoming the abnormalities associated with traditional therapy and leads to some optimization of the therapeutic impact. It also decreases the dosing frequency and eliminates the problem of low compliance. To develop modern diagnosis techniques, upgraded treatment, and possible prevention of tuberculosis, the nanoparticle-based tests have demonstrated considerable advances. The literature search was conducted using Scopus, PubMed, Google Scholar, and Elsevier databases only. This article examines the possibility of employing nanotechnology for TB diagnosis, nanotechnology-based medicine delivery systems, and prevention for the successful elimination of TB illnesses.

The Performance of Computer-Aided Detection Digital Chest X-ray Reading Technologies for Triage of Active Tuberculosis Among Persons With a History of Previous Tuberculosis

BACKGROUND

Digital chest X-ray (dCXR) computer-aided detection (CAD) technology uses lung shape and texture analysis to determine the probability of tuberculosis (TB). However, many patients with previously treated TB have sequelae, which also distort lung shape and texture. We evaluated the diagnostic performance of 2 CAD systems for triage of active TB in patients with previously treated TB.

METHODS

We conducted a retrospective analysis of data from a cross-sectional active TB case finding study. Participants ≥15 years, with ≥1 current TB symptom and complete data on history of previous TB, dCXR, and TB microbiological reference (Xpert MTB/RIF) were included. dCXRs were evaluated using CAD4TB (v.7.0) and qXR (v.3.0). We determined the diagnostic accuracy of both systems, overall and stratified by history of TB, using a single threshold for each system that achieved 90% sensitivity and maximized specificity in the overall population.

RESULTS

Of 1884 participants, 452 (24.0%) had a history of previous TB. Prevalence of microbiologically confirmed TB among those with and without history of previous TB was 12.4% and 16.9%, respectively. Using CAD4TB, sensitivity and specificity were 89.3% (95% CI: 78.1-96.0%) and 24.0% (19.9-28.5%) and 90.5% (86.1-93.3%) and 60.3% (57.4-63.0%) among those with and without previous TB, respectively. Using qXR, sensitivity and specificity were 94.6% (95% CI: 85.1-98.9%) and 22.2% (18.2-26.6%) and 89.7% (85.1-93.2%) and 61.8% (58.9-64.5%) among those with and without previous TB, respectively.

CONCLUSIONS

The performance of CAD systems as a TB triage tool is decreased among persons previously treated for TB.

Pre-treatment chest X-ray stability duration and tuberculosis disease in San Diego, California, 2012–2017

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Chest X-rays are essential in public health screening for tuberculosis (TB) disease.

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Chest X-ray stability duration is the time between two unchanged chest X-rays.

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Pre-treatment stability of 4–6 months was not negatively related to active TB.

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Patients screened overseas (B1 notification) were less likely to develop active TB.

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Future study may consider other settings and thresholds for empiric treatment.

Background

Overseas screening for tuberculosis (TB) has sought to reduce the burden of active TB in the United States. The duration of time between two unchanged, or stable, chest X-rays (CXRs) taken four to six months apart has been considered clinically useful in the evaluation of suspected pulmonary TB disease, but this relationship has not been previously quantified.

Objective

To investigate the association between pre-treatment CXR stability duration and future clinical or culture-confirmed (Class 3) diagnosis of pulmonary TB in San Diego, California, USA.

Methods

This retrospective record review included County of San Diego TB clinic patients with abnormal CXR results who were started on treatment between 2012 and 2017; multivariable logistic regression was used to analyze the clinical data.

Results

Pre-treatment CXR stability duration of at least four months was not significantly associated with a Class 3 pulmonary TB diagnosis (adjusted odds ratio [AOR], 0.83; 95 % confidence interval [CI], 0.20–3.48), nor was pre-treatment CXR stability duration of at least six months (AOR, 0.97; 95 % CI, 0.30–3.10). Similar results were obtained when four-to-six-month stability was considered (AOR, 0.78; 95 % CI, 0.16–3.89). Patients screened overseas (B1 notification) were less likely to develop Class 3 TB (unadjusted OR, 0.15; 95 % CI 0.05–0.44).

Conclusion

Pre-treatment chest X-ray stability duration was not associated with excluding Class 3 pulmonary TB in this setting, and CXR stability duration cut points may not be as clinically informative as previously understood, but overseas screening is likely an important step in reducing active TB disease burden in the U.S.

Extra-pulmonary Tuberculosis among Tuberculosis Patients Visiting a Tertiary Care Centre: A Descriptive Cross-sectional Study

Introduction

Tuberculosis outside of the lung is extrapulmonary tuberculosis. The diagnosis of extrapulmonary tuberculosis is not easy in a community setting even in district hospitals. Clinical symptoms and radiological diagnosis are effective for the diagnosis of pulmonary and extra-pulmonary cases. The aim of the study is to find out the prevalence of extra-pulmonary tuberculosis among tuberculosis patients visiting a tertiary care centre.

Methods

This was a descriptive cross-sectional study conducted among the patient visiting a tertiary care centre from August 2019 to January 2020 after taking ethical approval from Institutional Review Committe (Reference number: 86) which observed different clinicoradiological and laboratory features in patients with extrapulmonary tuberculosis to address their respective accuracy and usability in measuring the burden of tuberculosis. The interview was taken for the symptoms, and then radiological and laboratory data were collected. Convenience sampling was used. Point estimate and 95% confidence interval were calculated.

Results

Out of 60 patients with tuberculosis, 39 (65%) (62.83-67.17, 95% Confidence Interval) were diagnosed with extrapulmonary tuberculosis. Among them, 30 (76.9%) were with pleural effusions followed by lymphadenopathy in 9 (23.07%).

Conclusions

The prevalence of extra-pulmonary tuberculosis was found to be higher as compared to the study done in similar settings.

Keywords

extrapulmonary; pulmonary; tuberculosis.

Challenges in diagnosis and treatment of tuberculosis in elderly

Tuberculosis (TB) is a major infectious disease worldwide. Early diagnosis and prompt treatment reduces the transmission, morbidity and mortality in tuberculosis. Elderly (age >65 years) have many risk factors to develop tuberculosis. Recent survey in India showed incidence of TB higher in elderly. They may not have classical symptoms, clinical and radiological signs of TB which can lead to delayed diagnosis or misdiagnosis. In addition, elderly have many comorbid and coexisting diseases which make diagnosis and treatment of TB challenging. Comorbidities, poor general health status and other medications may lead to increased drug adverse reactions and poor adherence to treatment in elderly. Hence special emphasis should be given to elderly for early diagnosis and treatment. Elderly with multiple comorbidities require individualized approach for better outcome.

A scoring system developed from a nomogram to differentiate active pulmonary tuberculosis from inactive pulmonary tuberculosis

Purpose

This study aimed to develop and validate a scoring system based on a nomogram of common clinical metrics to discriminate between active pulmonary tuberculosis (APTB) and inactive pulmonary tuberculosis (IPTB).

Patients and methods

A total of 1096 patients with pulmonary tuberculosis (PTB) admitted to Wuhan Jinyintan Hospital between January 2017 and December 2019 were included in this study. Of these patients with PTB, 744 were included in the training cohort (70%; 458 patients with APTB, and 286 patients with IPTB), and 352 were included in the validation cohort (30%; 220 patients with APTB, and 132 patients with IPTB). Data from 744 patients from the training cohort were used to establish the diagnostic model. Routine blood examination indices and biochemical indicators were collected to construct a diagnostic model using the nomogram, which was then transformed into a scoring system. Furthermore, data from 352 patients from the validation cohort were used to validate the scoring system.

Results

Six variables were selected to construct the prediction model. In the scoring system, the mean corpuscular volume, erythrocyte sedimentation rate, albumin level, adenosine deaminase level, monocyte-to-high-density lipoprotein ratio, and high-sensitivity C-reactive protein-to-lymphocyte ratio were 6, 4, 7, 5, 5, and 10, respectively. When the cut-off value was 15.5, the scoring system for recognizing APTB and IPTB exhibited excellent diagnostic performance. The area under the curve, specificity, and sensitivity of the training cohort were 0.919, 84.06%, and 86.36%, respectively, whereas those of the validation cohort were 0.900, 82.73, and 86.36%, respectively.

Conclusion

This study successfully constructed a scoring system for distinguishing APTB from IPTB that performed well.

Semantic segmentation of bone structures in chest X-rays including unhealthy radiographs: A robust and accurate approach

The chest X-ray is a widely used medical imaging technique for the diagnosis of several lung diseases. Some nodules or other pathologies present in the lungs are difficult to visualize on chest X-rays because they are obscured byoverlying boneshadows. Segmentation of bone structures and suppressing them assist medical professionals in reliable diagnosis and organ morphometry. But segmentation of bone structures is challenging due to fuzzy boundaries of organs and inconsistent shape and size of organs due to health issues, age, and gender. The existing bone segmentation methods do not report their performance on abnormal chest X-rays, where it is even more critical to segment the bones. This work presents a robust encoder-decoder network for semantic segmentation of bone structures on normal as well as abnormal chest X-rays. The novelty here lies in combining techniques from two existing networks (Deeplabv3+ and U-net) to achieve robust and superior performance. The fully connected layers of the pre-trained ResNet50 network have been replaced by an Atrous spatial pyramid pooling block for improving the quality of the embedding in the encoder module. The decoder module includes four times upsampling blocks to connect both low-level and high-level features information enabling us to retain both the edges and detail information of the objects. At each level, the up-sampled decoder features are concatenated with the encoder features at a similar level and further fine-tuned to refine the segmentation output. We construct a diverse chest X-ray dataset with ground truth binary masks of anterior ribs, posterior ribs, and clavicle bone for experimentation. The dataset includes 100 samples of chest X-rays belonging to healthy and confirmed patients of lung diseases to maintain the diversity and test the robustness of our method. We test our method using multiple standard metrics and experimental results indicate an excellent performance on both normal and abnormal chest X-rays.

Uncertainty Quantification in Segmenting Tuberculosis-Consistent Findings in Frontal Chest X-rays

Deep learning (DL) methods have demonstrated superior performance in medical image segmentation tasks. However, selecting a loss function that conforms to the data characteristics is critical for optimal performance. Further, the direct use of traditional DL models does not provide a measure of uncertainty in predictions. Even high-quality automated predictions for medical diagnostic applications demand uncertainty quantification to gain user trust. In this study, we aim to investigate the benefits of (i) selecting an appropriate loss function and (ii) quantifying uncertainty in predictions using a VGG16-based-U-Net model with the Monto-Carlo (MCD) Dropout method for segmenting Tuberculosis (TB)-consistent findings in frontal chest X-rays (CXRs). We determine an optimal uncertainty threshold based on several uncertainty-related metrics. This threshold is used to select and refer highly uncertain cases to an expert. Experimental results demonstrate that (i) the model trained with a modified Focal Tversky loss function delivered superior segmentation performance (mean average precision (mAP): 0.5710, 95% confidence interval (CI): (0.4021,0.7399)), (ii) the model with 30 MC forward passes during inference further improved and stabilized performance (mAP: 0.5721, 95% CI: (0.4032,0.7410), and (iii) an uncertainty threshold of 0.7 is observed to be optimal to refer highly uncertain cases.

Chest X-ray findings in drug-sensitive and drug-resistant pulmonary tuberculosis patients in Uganda

Background

Methods

Results

Conclusions

An infant of 26 weeks gestation with congenital miliary tuberculosis complicated by chronic lung disease requiring CPAP was diagnosed on Day 104 of life: congenital tuberculosis was confirmed by detection of calcified ovaries in his mother

INTRODUCTION

Early diagnosis of tuberculosis (TB) in infants is important but is commonly missed because the symptoms are often non-specific.

CASE PRESENTATION

A Nepalese male infant born at 26 weeks gestation and weighing 1227 g (97th centile) was admitted to the neonatal intensive care unit (NICU) immediately after birth for the management of his prematurity. After extubation on Day 8, his oxygen saturation became unstable and he required nasal continuous positive airway pressure with oxygen for 3 months. On Day 104, further detailed evaluation was required because there was no improvement in his respiratory condition. A computed tomography (CT) scan demonstrated scattered miliary nodules in both lung fields. Acid-fast staining for the mycobacteria and TB polymerase chain reaction (PCR) of the sputum obtained directly by laryngeal aspiration confirmed Mycobacterium tuberculosis. On Day 105, he was therefore transferred to a tertiary care hospital for further intensive care. Pathology findings suggested placental involvement with TB owing to chronic endometrial infection. In addition, a maternal abdominal CT scan demonstrated bilateral calcified lesions in the ovaries. He completed antituberculous chemotherapy and was discharged 3 months later. At 18 months of age there are no sequelae and his development is almost normal. None of the infants or medical personnel who were exposed in the NICU developed secondary TB.

CONCLUSION

In neonates with persistent respiratory distress, neonatologists should consider TB infection as a differential diagnosis.

ABBREVIATIONS

CLD: chronic lung disease; CRP: C-reactive protein; CT: computed tomography; IGRA: interferon-γ release assay; IVF-ET: in vitro fertilisation-embryo transfer; N-CPAP: nasal continuous positive airway pressure; NICU: neonatal intensive care unit; PCR: polymerase chain reaction; PROM: premature rupture of membranes; TB: tuberculosis; WBC: white blood cells.

Data Mining for ICD-10 Admission Diagnoses Preceding Tuberculosis within 1 Year among Non-HIV and Non-Diabetes Patients

Delayed diagnosis of tuberculosis (TB) increases mortality and extends the duration of disease transmission. This study aimed to identify significant ICD-10 admission diagnoses preceding TB. All hospital electronic medical records from fiscal year 2015 to 2020 in the Songkhla Province, Thailand were retrieved. After excluding diabetes and HIV patients, a case-control analysis was performed. Exposures of interest were ICD-10 diagnoses on admissions 1–12 months prior to the visit during which TB was detected. Incident cases of respiratory tuberculosis (A15.0–A16.9) that had been admitted with at least one such exposure were chosen. For every case, controls were retrieved from weekly concurrent OPD patients who had the same 10-year interval of age, sex, and preceding admission and discharge week as the case. The 10 most common comorbidities during hospitalization preceding TB with their relative odds ratios (RORs) and 95% confidence intervals were identified. These included five significant exposures related to lower respiratory infection without adequate TB investigation. Significant RORs ranged from 3.10 (unspecified pneumonia) to 34.69 (hemoptysis). Full TB investigation was not performed due to problems with health insurance. In conclusion, the physicians should be informed about this pitfall, and the insurance system should be revised accordingly.

Unusual sites of tuberculosis mimicking skeletal metastases: A case report

The incidence of skeletal tuberculosis is about 1%-5% of all tuberculous infections. The most common sites are the spine, hip, knee, foot, elbow, hand, and shoulder, whereas the sternum, ribs, sternoclavicular joint, and calvaria are rarely affected. Because of the emergence of skeletal tuberculosis in therapeutic management, radiologists need to be aware of the imaging findings in pulmonary and extrapulmonary tuberculosis. Conventional X-ray plays an important role in diagnosing pulmonary and skeletal tuberculosis. Tuberculosis is known as the ‘great mimicker’, however, thus computed tomography and magnetic resonance imaging may provide additional details that assist the radiologist in distinguishing this tubercular infection from others. We report the case of a young male patient with skeletal tuberculosis who presented with general weakness, paraplegia, and a calvarial mass.

Deep learning-based pulmonary tuberculosis automated detection on chest radiography: large-scale independent testing

BACKGROUND

It is critical to have a deep learning-based system validated on an external dataset before it is used to assist clinical prognoses. The aim of this study was to assess the performance of an artificial intelligence (AI) system to detect tuberculosis (TB) in a large-scale external dataset.

METHODS

An artificial, deep convolutional neural network (DCNN) was developed to differentiate TB from other common abnormalities of the lung on large-scale chest X-ray radiographs. An internal dataset with 7,025 images was used to develop the AI system, including images were from five sources in the U.S. and China, after which a 6-year dynamic cohort accumulation dataset with 358,169 images was used to conduct an independent external validation of the trained AI system.

RESULTS

The developed AI system provided a delineation of the boundaries of the lung region with a Dice coefficient of 0.958. It achieved an AUC of 0.99 and an accuracy of 0.948 on the internal data set, and an AUC of 0.95 and an accuracy of 0.931 on the external data set when it was used to detect TB from normal images. The AI system achieved an AUC of more than 0.9 on the internal data set, and an AUC of over 0.8 on the external data set when it was applied to detect TB, non-TB abnormal and normal images.

CONCLUSIONS

We conducted a real-world independent validation, which showed that the trained system can be used as a TB screening tool to flag possible cases for rapid radiologic review and guide further examinations for radiologists.

Lightweight YOLOv4 with Multiple Receptive Fields for Detection of Pulmonary Tuberculosis

The characteristics of pulmonary tuberculosis are complex, and the cost of manual screening is high. The detection model based on convolutional neural network is an essential method for assisted diagnosis with artificial intelligence. However, it also has the disadvantages of complex structure and a large number of parameters, and the detection accuracy needs to be further improved. Therefore, an improved lightweight YOLOv4 pulmonary tuberculosis detection model named MIP-MY is proposed. Firstly, over 300 actual cases are selected to make a common dataset by professional physicians, which is used to evaluate the performance of the model. Subsequently, by introducing the inverted residual channel attention and the pyramid pooling module, a new structure of MIP is created and used as the backbone extractor of MIP-MY, which could further decrease the number of parameters and fuse context information. Then the multiple receptive field module is added after the three effective feature layers of the backbone extractor, which effectively enhances the information extraction ability of the deep feature layer and reduces the miss detection rate of small pulmonary tuberculosis lesions. Finally, the pulmonary tuberculosis detection model MIP-MY with lightweight and multiple receptive field characteristics is constructed by combining each improved modules with multiscale structure. Compared to the original YOLOv4, the model parameters of MIP-MY is reduced by 47%, while the mAP value is raised to 95.32% and the miss detection rate is decreased to 6%. It is verified that the model can effectively assist radiologists in the diagnosis of pulmonary tuberculosis.

The Diagnostic Deceiver: Radiological Pictorial Review of Tuberculosis

Tuberculosis (TB) is a bacterial infection with Mycobacterium tuberculosis; it is a public health problem worldwide and one of the leading causes of mortality. Since December 2019, the COVID-19 pandemic has created unprecedented health challenges and disrupted the TB health services, especially in high-burden countries with ever-increasing prevalence. Extrapulmonary and even pulmonary TB are an important cause of nonspecific clinical and radiological manifestations and can masquerade as any benign or malignant medical case, thus causing disastrous conditions and diagnostic dilemmas. Clinical manifestations and routine laboratory tests have limitations in directing physicians to diagnose TB. Medical-imaging examinations play an essential role in detecting tissue abnormalities and early suspecting diagnosis of TB in different organs. Radiologists and physicians should be familiar with and aware of the radiological manifestations of TB to contribute to the early suspicion and diagnosis of TB. The purpose of this article is to illustrate the common radiologic patterns of pulmonary and extrapulmonary TB. This article will be beneficial for radiologists, medical students, chest physicians, and infectious-disease doctors who are interested in the diagnosis of TB.

Differentiating between drug-sensitive and drug-resistant tuberculosis with machine learning for clinical and radiological features

Background

Tuberculosis (TB) drug resistance is a worldwide public health problem that threatens progress made in TB care and control. Early detection of drug resistance is important for disease control, with discrimination between drug-resistant TB (DR-TB) and drug-sensitive TB (DS-TB) still being an open problem. The objective of this work is to investigate the relevance of readily available clinical data and data derived from chest X-rays (CXRs) in DR-TB prediction and to investigate the possibility of applying machine learning techniques to selected clinical and radiological features for discrimination between DR-TB and DS-TB. We hypothesize that the number of sextants affected by abnormalities such as nodule, cavity, collapse and infiltrate may serve as a radiological feature for DR-TB identification, and that both clinical and radiological features are important factors for machine classification of DR-TB and DS-TB.

Methods

We use data from the NIAID TB Portals program (https://tbportals.niaid.nih.gov), 1,455 DR-TB cases and 782 DS-TB cases from 11 countries. We first select three clinical features and 26 radiological features from the dataset. Then, we perform Pearson's chi-squared test to analyze the significance of the selected clinical and radiological features. Finally, we train machine classifiers based on different features and evaluate their ability to differentiate between DR-TB and DS-TB.

Results

Pearson's chi-squared test shows that two clinical features and 23 radiological features are statistically significant regarding DR-TB vs. DS-TB. A ten-fold cross-validation using a support vector machine shows that automatic discrimination between DR-TB and DS-TB achieves an average accuracy of 72.34% and an average AUC value of 78.42%, when combing all 25 statistically significant features.

Conclusions

Our study suggests that the number of affected lung sextants can be used for predicting DR-TB, and that automatic discrimination between DR-TB and DS-TB is possible, with a combination of clinical features and radiological features providing the best performance.

Metaheuristic based Optimization Methods for the Segmentation of Tuberculosis Sputum Smear Images

Tuberculosis (TB) is a worldwide health crisis and second primary infectious disease that causes death. An attempt has been made to detect the presence of bacilli in sputum smears. The smear images recorded under standard image acquisition protocol are segmented by metaheuristic-based methods. Morphological operators are embedded in Ant Colony Optimization (ACO) and Particle Swarm Optimization (PSO) segmentation to retain concavity of rod-shaped bacilli. Results demonstrate that hybrid ACO segmentation is able to retain the shape of bacilli in TB images. Segmented images are validated with ground truth using overlap, distance and probability-based measures. Significant shape-based features such as area, perimeter, compactness, shape factor and tortuosity are extracted from the segmented images. It is observed that hybrid method preserves more edges, detects the presence of bacilli and facilitates direct segmentation with reduced number of redundant searches to generate edges. Thus this hybrid ACO-morphology segmentation technique aid in the diagnostic relevance of TB images.

Clinico-radiological and bronchoscopic predictors of microbiological yield in sputum negative tuberculosis in Pakistan

To determine association of clinico-radiological factors and radiological activity with diagnostic yield in sputum-smear negative tuberculosis (TB). Prospective observational study in Military Hospital Rawalpindi from July to December 2018. Adult patients having no contraindications to bronchoscopy were included. HIV positive patients and those on anti-tuberculosis therapy for more than one week were excluded. High-Resolution Computed tomography (HRCT) findings were classified based on active and inactive tuberculosis features. Washings were sent for Acid-Fast Bacillus (AFB) smear, GeneXpert assay and cultures. Out of 215 patients, 42.3% (91) were diagnosed with microbiological or histological evidence of TB. On univariate analysis, cavitation (p-value <0.001), soft-tissue nodules (p-value 0.04), and endobronchial mucosal changes (p-value 0.02) were associated with culture positivity. Presence of cavitation (OR= 4.10; CI= 2.18,7.73; p-value<0.001) was the only independent predictor of microbiological yield. Diagnostic yield was 70%, 50%, 12.5% and 8.6% in patients with definitely active, probably active, indeterminate and inactive tuberculosis HRCT features respectively. Sensitivity, specificity, positive predictive value and negative predictive value of HRCT active TB were 95.38% (95% CI 87.10 -99.04), 48.00 % (95% CI 39.78 -56.30), 44.29% (95% CI 40.31 -48.33), 96.00 % (95%CI 88.70 -98.66) respectively. There was no significant association between age groups, smoking status and gender with diagnosis of tuberculosis in our study. Radiological activity and certain visualized bronchoscopic changes were associated with good diagnostic performance and can be used as predictive factors in diagnosis of active smear negative tuberculosis.

A case of tuberculosis of the rare azygos lobe of the right lung

Background

The azygos lobe is a rare anatomical variant seen in the upper lobe of right lung. It occurs during embryological development due to the failure of posterior cardinal vein to migrate supero-medially. It is often an incidental finding on imaging and is asymptomatic in majority of cases. Tuberculosis involving the azygos lobe is extremely rare. Only a few cases of tuberculosis involving the azygos lobe have been reported in literature.

Case presentation

We present a rare case report of tuberculosis infection involving the azygos lobe in a 57-year-old male with history of chronic cough, fever, hemoptysis, and weight loss.

Conclusions

The azygos lobe is usually asymptomatic, but it may be misdiagnosed as bulla, lung cyst, or abscess. In rare cases it may be associated with certain pathology such as tuberculosis, other infections, and lung cancer. Hence, it is pertinent for a radiologist to be aware of this variant when reporting chest imaging cases.

Magnetic resonance imaging in response assessment of mediastinal tuberculous lymphadenopathy: Going beyond size

Background:

Assessment of response to antitubercular treatment (ATT) in mediastinal tuberculous lymph nodes (LNs) is challenging. Gold standard techniques such as biopsy and culture involve invasive procedures. Radiographic persistence of mediastinal LNs even after completion of ATT poses a treatment dilemma. In this study, we evaluated the changes in signal intensity (SI) and apparent diffusion coefficient (ADC) values of mediastinal LNs on magnetic resonance imaging (MRI), for response assessment to ATT.

Materials and Methods:

After institute ethics approval, a retrospective analysis of MRI images of 22 patients with 55 mediastinal tuberculous LNs was done. Clinically responsive patients of mediastinal tuberculous LNs who underwent chest MRI prior to ATT, or within 1 month of starting ATT, and second MRI performed at least after 2 months of start of the treatment were included. LN size, T1 and T2 signal characteristics (homogenously/heterogeneously and hyperintense or hypointense), T2 and T1 SI ratio, ADC values, and contrast enhancement characteristics were compared. Paired t-test and McNemar test were performed at a significance level of α =0.05.

Results:

Size of LN reduced, but 45 LNs measured >8 mm in second MRI. There was statistically significant decrease in the T2 and T1 SI ratios in second MRI, P = 0.026 and 0.008, respectively. No statistically significant difference was found in ADC values, P = 0.31.

Conclusions:

Decrease in T2 and T1 SI ratios of mediastinal tuberculous LNs can be used as a noninvasive imaging parameter to suggest response to ATT. However, ADC value is not a useful indicator of treatment response.

COVID-19 and pulmonary tuberculosis - A diagnostic dilemma

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Meanwhile, pulmonary tuberculosis(TB) is one of the most common infective lung diseases in developing nations. The concurrence of pulmonary TB and COVID-19 can lead to poor prognosis, owing to the pre-existing lung damage caused by TB. Case presentation: We describe the imaging findings in 3 cases of COVID-19 pneumonia with co-existing pulmonary TB on HRCT thorax. The concurrence of COVID-19 and pulmonary TB can be a diagnostic dilemma. Correct diagnosis and prompt management is imperative to reduce mortality and morbidity. Hence it is pertinent for imaging departments to identify and report these distinct entities when presenting in conjunction.

Dilemma of diagnosing thoracic sarcoidosis in tuberculosis endemic regions: An imaging-based approach. Part 1

Sarcoidosis is a multi-systemic disorder of unknown etiology, although commonly believed to be immune-mediated. Histologically, it is characterized by noncaseating granuloma which contrasts against the caseating granuloma seen in tuberculosis (TB), an infectious disease that closely mimics sarcoidosis, both clinically as well as radiologically. In TB-endemic regions, the overlapping clinico-radiological manifestations create significant diagnostic dilemma, especially since the management options are markedly different in the two entities. Part 1 of this review aims to summarize the clinical, laboratory, and imaging features of sarcoidosis, encompassing both typical and atypical manifestations, in an attempt to distinguish between the two disease entities.

Dilemma of diagnosing thoracic sarcoidosis in tuberculosis-endemic regions: An imaging-based approach. Part 2

The second part of the review discusses the role of different existing imaging modalities in the evaluation of thoracic sarcoidosis, including chest radiograph, computed tomography, magnetic resonance imaging, endobronchial ultrasound, and positron emission tomography. While summarizing the advantages and pitfalls of each imaging modality, the authors propose imaging recommendations and an algorithm to be followed in the evaluation of clinically suspected case of sarcoidosis in tuberculosis-endemic regions.