Chest tuberculosis: Radiological review and imaging recommendations

Chest X-ray Bone Suppression for Improving Classification of Tuberculosis-Consistent Findings

Chest X-rays (CXRs) are the most commonly performed diagnostic examination to detect cardiopulmonary abnormalities. However, the presence of bony structures such as ribs and clavicles can obscure subtle abnormalities, resulting in diagnostic errors. This study aims to build a deep learning (DL)-based bone suppression model that identifies and removes these occluding bony structures in frontal CXRs to assist in reducing errors in radiological interpretation, including DL workflows, related to detecting manifestations consistent with tuberculosis (TB). Several bone suppression models with various deep architectures are trained and optimized using the proposed combined loss function and their performances are evaluated in a cross-institutional test setting using several metrics such as mean absolute error (MAE), peak signal-to-noise ratio (PSNR), structural similarity index measure (SSIM), and multiscale structural similarity measure (MS-SSIM). The best-performing model (ResNet-BS) (PSNR = 34.0678; MS-SSIM = 0.9828) is used to suppress bones in the publicly available Shenzhen and Montgomery TB CXR collections. A VGG-16 model is pretrained on a large collection of publicly available CXRs. The CXR-pretrained model is then fine-tuned individually on the non-bone-suppressed and bone-suppressed CXRs of Shenzhen and Montgomery TB CXR collections to classify them as showing normal lungs or TB manifestations. The performances of these models are compared using several performance metrics such as accuracy, the area under the curve (AUC), sensitivity, specificity, precision, F-score, and Matthews correlation coefficient (MCC), analyzed for statistical significance, and their predictions are qualitatively interpreted through class-selective relevance maps (CRMs). It is observed that the models trained on bone-suppressed CXRs (Shenzhen: AUC = 0.9535 ± 0.0186; Montgomery: AUC = 0.9635 ± 0.0106) significantly outperformed (p < 0.05) the models trained on the non-bone-suppressed CXRs (Shenzhen: AUC = 0.8991 ± 0.0268; Montgomery: AUC = 0.8567 ± 0.0870).. Models trained on bone-suppressed CXRs improved detection of TB-consistent findings and resulted in compact clustering of the data points in the feature space signifying that bone suppression improved the model sensitivity toward TB classification.

Mediastinal lymphadenopathy: a practical approach

Introduction: Mediastinal lymphadenopathy is secondary to various benign and malignant etiologies. There is a variation in the underlying cause in different demographic settings. The initial clue to the presence of enlarged mediastinal lymph nodes is through thoracic imaging modalities. Malignancy (Lung cancer, lymphoma, and extrathoracic cancer) and granulomatous conditions (sarcoidosis and tuberculosis) are the most common causes. For a confident diagnosis, the clinician must choose from several available options and integrate the clinical, radiological, and pathology findings. An accurate diagnosis is necessary for optimal management.Areas covered: We performed a search of the PUBMED database to identify relevant articles on the causes, imaging modalities, and interventional modalities to diagnose these conditions. We discuss a practical approach toward the evaluation of a patient with mediastinal lymphadenopathy.Expert opinion: Mediastinal lymphadenopathy is a commonly encountered clinical problem. Treating physicians need to be aware of the clinico-radiological manifestations of the common diagnostic entities. Selecting an appropriate tissue diagnosis modality is crucial, with an intent to use the least invasive technique with good diagnostic yield. Endosonographic modalities (EBUS-TBNA, EUS-FNA, and EUS-B-FNA) have emerged as the cornerstone to most patients' diagnosis. An accurate diagnosis translates into favorable treatment outcomes.

Choosing Wisely: Computed Tomography in the Diagnosis of Adolescents With Intrathoracic Tuberculosis

In a retrospective study of adolescents with intrathoracic tuberculosis (TB), 26 out of the 81 (32%) patients had undergone chest computed tomography (CT). Chest CT was considered unnecessary in 7 (27%), necessary in 7 (27%), and possibly/probably helpful in 12 (46%). Promptly obtaining specimens for sputum smear microscopy, molecular testing, as well as culture for Mycobacterium tuberculosis could avoid several unnecessary CTs.

Diagnosis Based on Detection of CXCL10 in Urine as Biomarker for The Determining Diagnosis of Active Lung Tuberculosis

Tuberculosis diagnosis is an important component in decreasing TB incidence and prevalence. Because of the difficulty to collect sputum in some cases, urine specimens are used as it is easier to garner. One of the biomarkers in urine that can be used to diagnose pulmonary TB is IP-10, which can be represented by the CXCL10 gene. The study aims to determine the accuracy of diagnosis based on detection of the CXCL10 gene in urine as a biomarker for the patients with suspected pulmonary TB in Dr. Soetomo Hospital in Surabaya from November 2019 until March 2020. Thus, this is an observative laboratory research with a cross-sectional study. CXCL10 gene was examined using PCR for 36 urine samples, and then, the data, together with the medical records of clinical manifestations of pulmonary TB, GeneXpert MTB /RIF, blood count, and thorax radiograph, were processed using IBM SPSS Statistics 26. The results of the GeneXpert MTB/RIF and thorax radiograph criteria show positive results of pulmonary TB, which were 44.4% and 69.4% respectively. CXCL10 gene was not found in all urine of healthy people (negative), while 2.8% (1/36 samples) positive CXCL10 gene was found in a patient with positive GeneXpert, also with negative clinical manifestations and urine culture. In this study, the accuracy of diagnosis based on detection of the CXCL10 gene in urine for diagnosis of active pulmonary TB was 2.8%. Future research is needed to improve the methods, among them are bigger size of urine samples and clearer medical history of patients. 

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.

Pre-HAART CD4+ T-lymphocytes as biomarkers of post-HAART immune recovery in HIV-infected children with or without TB co-infection

BACKGROUND

Infection with the Human Immunodeficiency Virus (HIV) dramatically increases the risk of developing active tuberculosis (TB). Several studies have indicated that co-infection with TB increases the risk of HIV progression and death. Sub-Saharan Africa bears the brunt of these dual epidemics, with about 2.4 million HIV-infected people living with TB. The main objective of our study was to assess whether the pre-HAART CD4+ T-lymphocyte counts and percentages could serve as biomarkers for post-HAART treatment immune-recovery in HIV-positive children with and without TB co-infection.

METHODS

The data analyzed in this retrospective study were collected from a cohort of 305 HIV-infected children being treated with HAART. A Lehmann family of ROC curves were used to assess the diagnostic performance of pre- HAART treatment CD4+ T-lymphocyte count and percentage as biomarkers for post-HAART immune recovery. The Kaplan-Meier estimator was used to compare differences in post-HAART recovery times between patients with and without TB co-infection.

RESULTS

We found that the diagnostic performance of both pre-HARRT treatment CD4+ T-lymphocyte count and percentage was comparable and achieved accuracies as high as 74%. Furthermore, the predictive capability of pre-HAART CD4+ T-lymphocyte count and percentage were slightly better in TB-negative patients. Our analyses also indicate that TB-negative patients have a shorter recovery time compared to the TB-positive patients.

CONCLUSIONS

Pre-HAART CD4+ T-lymphocyte count and percentage are stronger predictors of immune recovery in TB-negative pediatric patients, suggesting that TB co-infection complicates the treatment of HIV in this cohort. These findings suggest that the detection and treatment of TB is essential for the effectiveness of HAART in HIV-infected pediatric patients.

Hiding in plain sight: Diagnosing pleural tuberculosis using lung ultrasound

Introduction

Diagnosing pleural tuberculosis can be difficult in patients with ambiguous presentation, especially in resource-limited health centres. Thus, lung ultrasound had been studied as a novel method in helping clinicians to diagnose this condition.

Case presentation

A 48-year-old woman presented with worsening dyspnoea and orthopnoea for one week. She had also experienced weight loss, minimal dry cough and right-sided pleuritic chest pain for several weeks. A chest radiograph showed a right lower zone pleural effusion with no apparent lung consolidation. Lung ultrasound showed a right apical consolidation and right lower zone septated pleural effusion. Pleural fluid investigations showed exudative features of mixed lymphocytic, mesothelial and neutrophilic cellular components. Tuberculin skin test was strongly positive. She was subsequently treated for pleural tuberculosis. One month after treatment, her symptoms had improved considerably.

Discussion

Lung ultrasound has been found to be more effective than chest radiograph in detecting consolidation and diagnosing pneumonia. The portability and efficacy of today's ultrasound machines, including the handheld types, show that lung ultrasound is a practical, reliable and valuable diagnostic tool in managing pulmonary conditions including tuberculosis, provided that the operators are adequately trained.

Conclusion

Lung ultrasound in tuberculosis is the next frontier for clinicians and researchers.

Isolated thoracic duct injury from blunt force trauma

Isolated thoracic duct injury is an uncommon clinical event and is rare in the setting of trauma. We describe a case of an isolated thoracic duct injury resulting in the development of bilateral chylothorax following a motor vehicle collision in the absence of any other definable injury. We outline the initial patient presentation and diagnosis. After failing a trial of conservative management the patient underwent lymphangiography followed by thoracic duct ligation with pleurodesis. This case highlights the importance of recognizing thoracic duct injury following trauma.

Dual-Energy Computed Tomography Lung in patients of Pulmonary Tuberculosis

Objectives

The objective of this study was to characterize findings of high-resolution computed tomography (HRCT) and dual-energy CT (DECT) (80 keV, 140 keV, and mixed) in pulmonary tuberculosis (TB) patients and to compare and correlate HRCT and DECT findings.

Material and Methods

This cross-sectional study was conducted on 67 patients of 18-65 years of age who were suspected cases of pulmonary TB with signs and symptoms of cough, fever, hemoptysis, sputum, night sweats, and weight loss with positive sputum AFB examinations/bronchoalveolar lavage. All the patients subjected to HRCT scan and followed with DECT scan. Comparison of various imaging techniques (DECT 80 keV, DECT 140 keV, and DECT mixed) with HRCT was done for detecting lung findings and data so obtained were subjected to statistical analysis.

Results

On comparing the various imaging techniques with HRCT for detecting consolidation, tree in bud pattern, cavitary lesions, ground-glass opacity, bronchiectasis, atelectasis, nodules, granuloma, peribronchial thickening, and fibrosis, the maximum agreement of HRCT was found with DECT 80 keV and minimum agreement was found with DECT 140 keV.

Conclusion

The study concluded that DECT 80 keV monochromatic reconstructions among 80 keV, mixed, and 140 keV monochromatic reconstructions in lung parenchyma window settings are a faster and better analytical tool for the assessment of findings of pulmonary TB when compared with HRCT.

Unilateral Nonconfluent Cluster of Micronodules: Atypical Radiologic Appearance of Pulmonary Tuberculosis in an Immunocompetent Patient

Active pulmonary tuberculosis involving the lung parenchyma is typically seen on CT as consolidation, centrilobular nodules with tree-in-bud branching, cavitating lesions, and miliary nodules. However, some atypical CT patterns of granulomatous disease including tuberculosis have been recently described, namely, clusters of nodules without confluence or with confluence. We present a case of a patient who was found to have nonconfluent clusters of micronodules in the right lung with negative sputum culture for tuberculosis. There were also incidental findings of the partial duplex system of the left kidney with mild-to-moderate hydronephrosis in the lower moiety with proximal hydroureter. The urine culture was then positive for mycobacterium tuberculosis; hence, he was commenced on antituberculous medications. A repeated CT scan revealed significant improvement of the aforementioned clusters of micronodules and left hydronephrosis. In the present case, we would like to highlight the atypical appearances of pulmonary tuberculosis in the form of nonconfluent micronodules on HRCT despite negative sputum workup, with the concurrent active genitourinary tuberculosis.

Risk of tuberculosis with anti-tumor necrosis factor-alpha therapy in patients with psoriasis and psoriatic arthritis in Indian population

Anti-tumor necrosis factor-alpha (TNF-α) immunotherapy has revolutionized the treatment of inflammatory diseases, such as psoriasis and psoriatic arthritis. However, a major concern is that patients receiving this therapy have an increased risk of infection, particularly of reactivation of latent tuberculosis (TB). There were an estimated 10.4 million new cases of tuberculosis in 2016, worldwide, and India has one of the largest TB case burden with an estimated incidence of 2.79 million cases of TB in the same year. Anti-TNF agents like etanercept and infliximab are available in India approved for psoriasis and psoriatic arthritis. But long-term use of these agents possesses a risk of reactivation of latent TB. In this review article, we assessed the risk of TB with anti-TNF therapy especially in patients with psoriasis and psoriatic arthritis in India. At the end of the article, we have also suggested a recommendation for screening of latent tuberculosis and its management, before starting anti-TNF-α therapy.

A Panel of CircRNAs in the Serum Serves as Biomarkers for Mycobacterium tuberculosis Infection

Tuberculosis (TB), one of the ancient and deadliest diseases, is a chronic immune disorder caused by Mycobacterium tuberculosis (Mtb) infection. Due to the lack of ideal diagnostic and therapeutic markers, TB is still posing a major health, social, and economic burden worldwide. Circular RNA (circRNA), a newly discovered endogenous RNA, is abundant and stable in the cytoplasm and has tissue specificity. More and more studies suggested circRNA is involved in a variety of human pathological and physiological processes. Recently, several studies have confirmed circRNAs not only existed in the serum but also could serve as ideal biomarkers for detecting diseases since the circRNAs have continuous, stable, and covalently closed circular structures and are not easily degraded by nucleases. In this study, we screened the circRNA expression profiles in active TB serum samples and healthy volunteers serum samples by circRNA microarrays. Then, we performed qRT-PCR to verified the dysregulated circRNAs and ROC curve analysis to evaluate the value of circRNAs for TB diagnosis. The results showed circRNA_051239, circRNA_029965, and circRNA_404022 could serve as biomarkers for TB diagnosis.

Delayed Isolation of Active Pulmonary Tuberculosis in Hospitalized Patients: A Pivotal Role of Radiologic Evaluation

OBJECTIVE. The purpose of this study was to determine factors related to delayed isolation of patients hospitalized with active pulmonary tuberculosis (TB). MATERIALS AND METHODS. A total of 130 immunocompetent hospitalized patients with active pulmonary TB who had positive sputum culture results from January 2015 to December 2017 were reviewed. Delayed isolation of pulmonary TB was defined as failure to initiate airborne isolation within the first 3 days of hospitalization. Clinical and microbiologic characteristics of the patients and radiologic features on chest radiography (n = 130) and chest CT (n = 118) were retrospectively reviewed. Findings were compared between patients with early isolation and those with delayed isolation. Univariate and multivariate analyses were performed to determine independent predictors of delayed isolation. RESULTS. Forty-four patients (34%) had delayed isolation after initial hospitalization. On univariate and multivariate analyses, atypical presentation of active pulmonary TB on CT (odds ratio, 7.203; 95% CI, 2.203-23.551; p = 0.001) and concurrent lung parenchymal diseases on CT (odds ratio, 14.605; 95% CI, 3.274-65.155; p < 0.001) were significant predictors of delayed isolation of patients with active pulmonary TB. CONCLUSION. Awareness of the factors related to delayed diagnosis of active pulmonary TB is important to avoid an unexpected in-hospital outbreak of TB and control the disease. Atypical presentation of active pulmonary TB and concurrent lung parenchymal diseases on CT are significant factors related to delayed isolation of hospitalized patients with active pulmonary TB.

Impact of Diabetes Mellitus on Radiological Presentation of Pulmonary Tuberculosis in Otherwise Non-Immunocompromised Patients: A Systematic Review

BACKGROUND

Studies on the influence of diabetes mellitus on the radiological presentation of pulmonary tuberculosis performed so far yielded inconsistent results. We aimed to summarize the relevant evidence on this topic systematically.

METHODS

We systematically searched PubMed/MEDLINE (1980-2016) and the references of related articles (English-language reports) for observational studies that compared the radiological presentation of pulmonary tuberculosis in diabetes and non-diabetes patients.

RESULTS

A total of fifteen studies that enrolled 2,020 diabetic patients and 5,280 controls were included in this systematic review. None of the included studies showed any significant difference in the upper lobe involvement and or in bilateral disease between diabetes and non-diabetes patients. However, lower lung field cavitary disease was found to be more frequent (relative risks ranging from 2.76, 95% CI 2.28-3.35 to 4.47, 95% CI 2.62-7.62) in patients with poor glycemic control (HbA1C >9%). Similarly, a significantly higher proportion of cavitary disease in diabetes patients was reported by 7 out of 15 studies, the meta-analysis of cavities of any size/site also showed the significantly higher risk of cavitary disease in diabetes patients (p-value = 0.0008). Three studies stratified the presence of cavities by diabetes control status, finding a higher proportion of cavities in uncontrolled diabetic patients (relative risks ranging from 1.85, 95%CI 1.34-2.55 to 3.59, 95%CI 2.53-5.11). One out of four studies found a significantly higher proportion of nodular infiltrations in diabetes versus non-diabetes patients.

CONCLUSION

While there is no difference in localization of lung lesions between patients with diabetes and non-diabetes, our review found that the risk of cavitary disease is relatively higher in diabetes patients. It is essential for researchers to unify the criteria for diabetes diagnosis, patient selection, and radiographic severity and stratify the results by the potentially confounding factors.

Developing and verifying automatic detection of active pulmonary tuberculosis from multi-slice spiral CT images based on deep learning

OBJECTIVE

Diagnosis of tuberculosis (TB) in multi-slice spiral computed tomography (CT) images is a difficult task in many TB prevalent locations in which experienced radiologists are lacking. To address this difficulty, we develop an automated detection system based on artificial intelligence (AI) in this study to simplify the diagnostic process of active tuberculosis (ATB) and improve the diagnostic accuracy using CT images.

DATA

A CT image dataset of 846 patients is retrospectively collected from a large teaching hospital. The gold standard for ATB patients is sputum smear, and the gold standard for normal and pneumonia patients is the CT report result. The dataset is divided into independent training and testing data subsets. The training data contains 337 ATB, 110 pneumonia, and 120 normal cases, while the testing data contains 139 ATB, 40 pneumonia, and 100 normal cases, respectively.

METHODS

A U-Net deep learning algorithm was applied for automatic detection and segmentation of ATB lesions. Image processing methods are then applied to CT layers diagnosed as ATB lesions by U-Net, which can detect potentially misdiagnosed layers, and can turn 2D ATB lesions into 3D lesions based on consecutive U-Net annotations. Finally, independent test data is used to evaluate the performance of the developed AI tool.

RESULTS

For an independent test, the AI tool yields an AUC value of 0.980. Accuracy, sensitivity, specificity, positive predictive value, and negative predictive value are 0.968, 0.964, 0.971, 0.971, and 0.964, respectively, which shows that the AI tool performs well for detection of ATB and differential diagnosis of non-ATB (i.e. pneumonia and normal cases).

CONCLUSION

An AI tool for automatic detection of ATB in chest CT is successfully developed in this study. The AI tool can accurately detect ATB patients, and distinguish between ATB and non- ATB cases, which simplifies the diagnosis process and lays a solid foundation for the next step of AI in CT diagnosis of ATB in clinical application.

Spectrum of imaging findings in pulmonary infections. Part 2: Fungal, mycobacterial, and parasitic

Chest radiography is generally the first imaging modality used for the evaluation of pneumonia. It can establish the presence of pneumonia, determine its extent and location, and assess the response to treatment. Computed tomography is not used for the initial evaluation of pneumonia, but it may be used when the response to treatment is unusually slow. It helps to identify complications, detect any underlying chronic pulmonary disease, and characterise complex pneumonias. Although not diagnostic, certain imaging findings may suggest a particular microbial cause over others. Knowledge of whether pneumonia is community-acquired or nosocomial, as well as the age and immune status of the patient, can help to narrow the differential diagnoses. The purpose of this article is to briefly review the various pulmonary imaging manifestations of pathogenic organisms. This knowledge, along with the clinical history and laboratory investigations of the patient, may help to guide the treatment of pneumonia.

Pediatric Chest MRI: A Review

Chest radiographs and CT scans have been the cornerstone of pulmonary imaging given their advantages of being rapid and easily available techniques. However, a significant concern with their use in the pediatric population is the associated ionisation radiation. The use of magnetic resonance imaging (MRI) in pulmonary imaging has lagged behind its adoption in other organ systems. Previously, the lung parenchyma was considered difficult to evaluate by magnetic resonance due to low proton density in the pulmonary tissue, susceptibility artefacts within the lungs, and respiratory motion artefacts. However, in recent years, there have been a multitude of technical advancements to overcome these limitations. MRI can be an excellent radiation-free alternative in patients who require protracted follow-up like in cases such as cystic fibrosis, complicated pneumonias, tuberculosis and mediastinal neoplasms. An added advantage of MRI is that it can provide functional information in addition to the structural information provided by traditional imaging techniques. One of the major reasons of limited use of MRI despite its established utility is the lack of clarity regarding its indications, and a paucity of data on tailored MRI protocols customised to clinical needs. This article aims to review the basic MRI techniques, indications and terminologies used in chest imaging, with special emphasis on imaging findings of common pathologies in the pediatric population.

Chest Tuberculosis in Children

Chest is the commonest site of involvement by tuberculosis (TB) in children; lungs being the most frequently affected region, followed by nodes, pleura and chest wall. It is difficult to diagnose TB in children due to lack of overt symptoms and difficulty in obtaining samples for microbiological confirmation. Hence various imaging modalities play an important role in diagnostic algorithm as well as in follow-up after treatment. Standardization of chest radiograph reporting in context of clinically suspected TB is the need of the hour so as to suggest a proper diagnosis and avoid over-diagnosis. This article aims to discuss the imaging features of chest tuberculosis according to the site of involvement on various imaging modalities in the pediatric population.

Miliary tuberculosis presenting as a choroidal mass and a tuberculosis screening review

Anti-tumor necrosis factor alpha (anti-TNF) therapy is a standard of care in the management of many inflammatory conditions. However, anti-TNF pharmaceuticals increases the risk of reactivating tuberculosis making screening for latent tuberculosis infection (LTBI) a requirement prior to initiating therapy. Case: A middle-aged male from China with a past medical history of LTBI and Crohn's disease, previously on infliximab, presented to the United States for a second opinion on his abdominal pain. He also reported new onset visual changes. Ophthalmology evaluation revealed a 4 cm choroid mass of his left eye and a CT scan of the abdomen showed diffuse lymphadenopathy and lesions in his liver, spleen, and lung. He was admitted for treatment of miliary tuberculosis. Discussion: Immunocompromised patients are a unique population that brings challenges to LTBI testing. Conclusion: Clinicians should know the most up to date screening tools for LTBI and diagnostic workup for active tuberculosis infection.

A case-report of a pulmonary tuberculosis with lymphadenopathy mimicking a lymphoma

Clinical and radiological manifestations of tuberculosis (TB) are heterogeneous, and differential diagnosis can include both benign and malignant diseases (e.g., sarcoidosis, metastatic diseases, and lymphoma). Diagnostic dilemmas can delay appropriate therapy, favoring Mycobacterium tuberculosis transmission. We report on a case of TB in an immunocompetent, Somalian 22-year-old boy admitted in the respiratory unit of an Italian university hospital. His symptoms and clinical signs were thoracic pain, weight loss, latero-cervical, mediastinal, and abdominal lymphadenopathy. Smear microscopy and PCR were negative for Mycobacterium tuberculosis. The unclear histological pattern, the unusual clinical presentation, the CT scan signs, the BAL lymphocytes suggested the suspicion a lymphoma. Culture conversion proved Mycobacterium tuberculosis infection. This case report highlights the risk of misdiagnosis in patients with generalized lympho-adenopathy and pulmonary infiltrates, particularly in Africans young patients.

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.

Tuberculosis and biologics in rheumatology: A special situation

India has a huge patient burden of rheumatic diseases (RDs) including rheumatoid arthritis. The use of biologics has transformed the treatment paradigm for RD; however, biologic treatment-related infections (especially tuberculosis [TB]) are an area of potential concern for TB-endemic nations like India. Anti-tumor necrosis factor (TNF) therapy impairs the physiological TNF-mediated signaling and may cause reactivation and dissemination of latent TB infection (LTBI). Careful screening is, thus, crucial in RD patients who are about to commence anti-TNF treatment. To date, there is no consensus available for the screening, evaluation and treatment of LTBI as well as on the drug dosage and duration regimen (monotherapy or combination therapy) in the Indian population. An evidence-based algorithm for LTBI screening and management in RD patients undergoing biologic disease-modifying anti-rheumatic drug therapy is suggested in this review for Indian rheumatologists. The proposed algorithm guides physicians through a step-wise screening approach, including medical history, tuberculin skin test, interferon gamma release assay, chest radiograph and management of LTBI with isoniazid therapy or its combination with rifampicin. Further, the provided algorithm can aid the national bodies (such as National TB Control Program) in formulating recommendations for LTBI in this high-risk population.

Deep Learning at Chest Radiography: Automated Classification of Pulmonary Tuberculosis by Using Convolutional Neural Networks

Purpose To evaluate the efficacy of deep convolutional neural networks (DCNNs) for detecting tuberculosis (TB) on chest radiographs. Materials and Methods Four deidentified HIPAA-compliant datasets were used in this study that were exempted from review by the institutional review board, which consisted of 1007 posteroanterior chest radiographs. The datasets were split into training (68.0%), validation (17.1%), and test (14.9%). Two different DCNNs, AlexNet and GoogLeNet, were used to classify the images as having manifestations of pulmonary TB or as healthy. Both untrained and pretrained networks on ImageNet were used, and augmentation with multiple preprocessing techniques. Ensembles were performed on the best-performing algorithms. For cases where the classifiers were in disagreement, an independent board-certified cardiothoracic radiologist blindly interpreted the images to evaluate a potential radiologist-augmented workflow. Receiver operating characteristic curves and areas under the curve (AUCs) were used to assess model performance by using the DeLong method for statistical comparison of receiver operating characteristic curves. Results The best-performing classifier had an AUC of 0.99, which was an ensemble of the AlexNet and GoogLeNet DCNNs. The AUCs of the pretrained models were greater than that of the untrained models (P < .001). Augmenting the dataset further increased accuracy (P values for AlexNet and GoogLeNet were .03 and .02, respectively). The DCNNs had disagreement in 13 of the 150 test cases, which were blindly reviewed by a cardiothoracic radiologist, who correctly interpreted all 13 cases (100%). This radiologist-augmented approach resulted in a sensitivity of 97.3% and specificity 100%. Conclusion Deep learning with DCNNs can accurately classify TB at chest radiography with an AUC of 0.99. A radiologist-augmented approach for cases where there was disagreement among the classifiers further improved accuracy. ^© RSNA, 2017.

Treatment Outcomes of Patients Treated for Pulmonary Tuberculosis after Undergoing Gastrectomy

Gastrectomy is a proxy of malnutrition, which may lead to increased risk for developing pulmonary tuberculosis (TB). Malabsorption in gastrectomy patients could lead to low serum levels of rifampicin, which may be related to higher treatment failure. However, there is limited information on treatment outcomes of TB in patients who have undergone gastrectomy. This study aims to determine treatment outcomes and adverse effects in patients treated for TB after undergoing gastrectomy for gastric cancer. During the study period, 112 patients were treated for active TB that developed after gastrectomy for gastric cancer. Among them, we selected 15 patients who were culture positive at initial diagnosis and had evidence of active TB on imaging studies; namely, the remaining 97 patients without initial culture or imaging studies were excluded. We thus performed a case-control study of gastric cancer patients treated for TB after undergoing gastrectomy (n = 15). The control group was defined as age- and sex-matched TB patients who had not received gastrectomy (n = 45). Treatment failure in clinical, microbiological aspects, and adverse events were analyzed. Patients who had undergone gastrectomy exhibited higher 4-month clinical failure rates, compared to non-gastrectomy patient: 4 (26.7%) vs. 1 (2.2%), P = 0.012. Gastrointestinal adverse effects were more frequent in patients with gastrectomy, compared to non-gastrectomy patients: 9 (60%) vs. 5 (11.1%), P < 0.001. In conclusion, patients treated for TB after undergoing gastrectomy are associated with higher rates of gastrointestinal adverse events and treatment failure.

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.

Pediatric Body Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) is a radiation-free imaging modality with excellent contrast resolution and multiplanar capabilities. Since ionizing radiation is an important concern in the pediatric population, MRI serves as a useful alternative to computed tomography (CT) and also provides additional clues to diagnosis, not discernible on other investigations. Magnetic resonance cholangiopancreatography (MRCP), urography, angiography, enterography, dynamic multiphasic imaging and diffusion-weighted imaging provide wealth of information. The main limitations include, long scan time, need for sedation/anesthesia, cost and lack of widespread availability. With the emergence of newer sequences and variety of contrast agents, MRI has become a robust modality and may serve as a one-stop shop for both anatomical and functional information.

Factors influencing development and mortality of acute respiratory failure in hospitalized patient with active pulmonary tuberculosis: a 10-year retrospective review

BACKGROUND

Pulmonary tuberculosis with acute respiratory failure is fatal and is a burden in the intensive care units and leads to mortality. This retrospective study identifies the factors influencing the development of pulmonary tuberculosis requiring mechanical ventilation (TBMV) and mortality in the hospitalized patients with pulmonary tuberculosis.

METHODS

The medical records of hospitalized adult patients with pulmonary tuberculosis were retrospectively reviewed. Demographic data, clinical presentations, radiographic findings, biochemical tests, and clinical outcomes were collected. Data were compared by Student's t-test and Chi-square test between groups. Select variables that were statistically significant with P values <0.1 were introduced into a forward, stepwise, logistic regression model. Odds ratios (ORs) and their 95% confidence intervals (CIs) identified the independent influencing factors in the development of TBMV and mortality.

RESULTS

Of 268 enrolled patients, 185 (69.0%) were male. The patients were equally divided between the TBMV and non-TBMV groups. The shorter duration of illness (OR, 0.99; 95% CI, 0.98-0.99), underlying disease of AIDS (OR, 14.55; 95% CI, 1.71-123.91), presentation of fever (OR, 2.11; 95% CI, 1.20-3.71) and dyspnea (OR, 3.51; 95% CI, 2.02-6.11), large amount of acid fast bacilli on sputum smear (OR, 3.76; 95% CI, 1.90-7.47), lower serum albumin level (OR, 0.39; 95% CI, 0.26-0.59), and delayed initiation of anti-tuberculosis agents (OR, 1.06; 95% CI, 1.00-1.12) were independent factors to develop TBMV. Male gender (OR, 2.16; 95% CI, 1.01-4.61), consolidation pattern on chest X-ray (OR, 2.41; 95% CI, 1.17-4.98), and lower serum albumin (OR, 0.39; 95% CI, 0.21-0.71) were correlated to mortality.

CONCLUSIONS

The incidence and mortality rate of TBMV patients were high. Acute tuberculous pneumonia, underlying disease of AIDS, amount of acid fast bacilli, and delayed administration of anti-tuberculosis agents were independent risk factors to develop TBMV. Male gender, consolidation on chest X-ray, and low serum albumin were significantly related to mortality.

Immunoglobulin G response to mammalian cell entry 1A (Mce1A) protein as biomarker of active tuberculosis

Cell wall components are major determinants of virulence of Mycobacterium tuberculosis and they contribute to the induction of both humoral and cell-mediated immune response. The mammalian cell entry protein 1A (Mce1A), in the cell wall of M. tuberculosis, mediates entry of the pathogen into mammalian cells. Here, we examined serum immunoglobulin levels (IgA, IgM and total IgG) against Mce1A as a potential biomarker for diagnosis and monitoring tuberculosis (TB) treatment response. Serum samples of 39 pulmonary TB patients and 65 controls (15 healthy household contacts, 19 latently infected household contacts, 13 non-TB and 18 leprosy patients) were screened by ELISA. The median levels of all immunoglobulin classes were significantly higher in TB patients when compared with control groups. The positive test results for IgA, IgM and total IgG were 62, 54 and 82%, respectively. For comparison, routine sputum smear examination diagnosed only 26 (67%) of 39 TB cases. Sensitivities of IgA, IgM and IgG test were 59, 51.3 and 79.5%, respectively, while the specificities observed were 77.3, 83.3 and 84.4%, respectively. A significant decrease compared with baseline was also shown after TB treatment. These results suggest that circulating total IgG antibody to Mce1A could be a complementary tool to diagnosis pulmonary TB.

Protocol for studying cough frequency in people with pulmonary tuberculosis

INTRODUCTION

Cough is a key symptom of tuberculosis (TB) as well as the main cause of transmission. However, a recent literature review found that cough frequency (number of coughs per hour) in patients with TB has only been studied once, in 1969. The main aim of this study is to describe cough frequency patterns before and after the start of TB treatment and to determine baseline factors that affect cough frequency in these patients. Secondarily, we will evaluate the correlation between cough frequency and TB microbiological resolution.

METHODS

This study will select participants with culture confirmed TB from 2 tertiary hospitals in Lima, Peru. We estimated that a sample size of 107 patients was sufficient to detect clinically significant changes in cough frequency. Participants will initially be evaluated through questionnaires, radiology, microscopic observation drug susceptibility broth TB-culture, auramine smear microscopy and cough recordings. This cohort will be followed for the initial 60 days of anti-TB treatment, and throughout the study several microbiological samples as well as 24 h recordings will be collected. We will describe the variability of cough episodes and determine its association with baseline laboratory parameters of pulmonary TB. In addition, we will analyse the reduction of cough frequency in predicting TB cure, adjusted for potential confounders.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the ethics committees at each participating hospital in Lima, Peru, Asociación Benéfica PRISMA in Lima, Peru, the Universidad Peruana Cayetano Heredia in Lima, Peru and Johns Hopkins University in Baltimore, USA. We aim to publish and disseminate our findings in peer-reviewed journals. We also expect to create and maintain an online repository for TB cough sounds as well as the statistical analysis employed.

Pulmonary Infections: Imaging with CT

Computed tomography (CT) plays a key role in various kinds of pulmonary infections especially in immunocompromised patients, owing to its much higher sensitivity and specificity than the traditionally performed chest X-ray. CT permits the detection of the main infectious pattern and associated findings with high confidence and allows for the precise assessment of all involved structures, to potentially guide a bronchoalveolar lavage or another diagnostic procedure, and to ensure a reliable follow-up. It may be performed at a carefully chosen dose, which may nearly reach that of a chest X-ray in specific situations. The importance of post-processing tools is undeniable in some conditions, in particular for the evaluation of micronodules in the immunocompromised population. The wide spectrum of features of specific organisms according to the immune status, such as in aspergillosis or tuberculosis, must be known, as well as the potential of atypical presentations in case of Pneumocystis jirovecii (PCP) pneumonia when occurring in non-HIV immunocompromised patients. In all cases, underlying disorders must be considered as well as all the differential diagnoses. Overall, CT definitely helps clinicians to diagnose pulmonary infections and to make treatment decisions, especially in vulnerable patients.