Chest X-ray Assessment Research Articles

Value of projectional imaging relative to cross-sectional imaging to assess catheter tip position in the superior vena cava: evaluation of reader variability.

The cavo-atrial junction (CAJ) is the most appropriate central venous catheters CVC tip location to reduce complications. Among chest X-ray (CXR) landmarks for tips assessment, only the pericardial reflection lies in the same plane as the vascular structures. We aimed to evaluate the observer variability to determine tip positioning on CXR, using CT as a gold standard. We retrospectively analyzed 107 CT scans of patients with port catheters (January-December 2021). The tip to CAJ distance (DCAJ) was measured on both projectional (PJ) and cross-sectional (CS) CT images by 2 × 2 observers (within and between evaluations). Observational statistics included paired t-tests, repeatability coefficients (RC), and intraclass correlation coefficients (ICC), with data visualized using Bland-Altman plots. All ICC were >0.9, indicating excellent reliability. The mean difference between observers comparing CS and PJ was 0.13 ± 0.80 cm (P = .10) with outer 95% confidence limits of 1.92 cm and -2.17 cm and an RC of 1.79 cm. CXR provides a reliable method for CVC tip localization, though assessment variability is ±2 cm. CXR assessment of CVC tips shows both intra- and inter-individual variability, due to challenges in identifying the CAJ and catheter tip . While considering the 3 cm anatomical zone around the CAJ acceptable, operators should be aware of the 2 cm variability resulting from CXR assessment. To account for this variability and avoid the risk of positioning the tip beyond 3 cm from the CAJ, operators should reduce the CXR-based acceptable zone to 1 cm around the CAJ, impacting approximately 30% of procedures.

Chest X-Ray-Based Telemedicine Platform for Pediatric Tuberculosis Diagnosis in Low-Resource Settings: Development and Validation Study.

Tuberculosis (TB) remains a major cause of morbidity and death worldwide, with a significant impact on children, especially those under the age of 5 years. The complex diagnosis of pediatric TB, compounded by limited access to more accurate diagnostic tests, underscores the need for improved tools to enhance diagnosis and care in resource-limited settings. This study aims to present a telemedicine web platform, BITScreen PTB (Biomedical Image Technologies Screen for Pediatric Tuberculosis), aimed at improving the evaluation of pulmonary TB in children based on digital chest x-ray (CXR) imaging and clinical information in resource-limited settings. The platform was evaluated by 3 independent expert readers through a retrospective assessment of a data set with 218 imaging examinations of children under 3 years of age, selected from a previous study performed in Mozambique. The key aspects assessed were the usability through a standardized questionnaire, the time needed to complete the assessment through the platform, the performance of the readers to identify TB cases based on the CXR, the association between the TB features identified in the CXRs and the initial diagnostic classification, and the interreader agreement of the global assessment and the radiological findings. The platform's usability and user satisfaction were evaluated using a questionnaire, which received an average rating of 4.4 (SD 0.59) out of 5. The average examination completion time ranged from 35 to 110 seconds. In addition, the study on CXR showed low sensitivity (16.3%-28.2%) but high specificity (91.1%-98.2%) in the assessment of the consensus case definition of pediatric TB using the platform. The CXR finding having a stronger association with the initial diagnostic classification was air space opacification (χ21>20.38, P<.001). The study found varying levels of interreader agreement, with moderate/substantial agreement for air space opacification (κ=0.54-0.67) and pleural effusion (κ=0.43-0.72). Our findings support the promising role of telemedicine platforms such as BITScreen PTB in enhancing pediatric TB diagnosis access, particularly in resource-limited settings. Additionally, these platforms could facilitate the multireader and systematic assessment of CXR in pediatric TB clinical studies.

WE-B-207-00: CT Lung Cancer Screening Part 1

The US National Lung Screening Trial (NLST) was a multi-center randomized, controlled trial comparing a low-dose CT (LDCT) to posterior-anterior (PA) chest x-ray (CXR) in screening older, current and former heavy smokers for early detection of lung cancer. Recruitment was launched in September 2002 and ended in April 2004 when 53,454 participants had been randomized at 33 screening sites in equal proportions. Funded by the National Cancer Institute this trial demonstrated that LDCT screening reduced lung cancer mortality. The US Preventive Services Task Force (USPSTF) cited NLST findings and conclusions in its deliberations and analysis of lung cancer screening. Under the 2010 Patient Protection and Affordable Care Act, the USPSTF favorable recommendation regarding lung cancer CT screening assisted in obtaining third-party payers coverage for screening. The objective of this session is to provide an introduction to the NLST and the trial findings, in addition to a comprehensive review of the dosimetry investigations and assessments completed using individual NLST participant CT and CXR examinations. Session presentations will review and discuss the findings of two independent assessments, a CXR assessment and the findings of a CT investigation calculating individual organ dosimetry values. The CXR assessment reviewed a total of 73,733 chest x-ray exams that were performed on 92 chest imaging systems of which 66,157 participant examinations were used. The CT organ dosimetry investigation collected scan parameters from 23,773 CT examinations; a subset of the 75,133 CT examinations performed using 97 multi-detector CT scanners. Organ dose conversion coefficients were calculated using a Monte Carlo code. An experimentally-validated CT scanner simulation was coupled with 193 adult hybrid computational phantoms representing the height and weight of the current U.S. population. The dose to selected organs was calculated using the organ dose library and the abstracted scan parameters. This session will review the results and summarize the individualized doses to major organs and the mean effective dose and CTDIvol estimate for 66,157 PA chest and 23,773 CT examinations respectively, using size-dependent computational phantoms coupled with Monte Carlo calculations. Learning Objectives: 1. Review and summarize relevant NLST findings and conclusions. 2. Understand the scope and scale of the NLST specific to participant dosimetry. 3. Provide a comprehensive review of NLST participant dosimetry assessments. 4. Summarize the results of an investigation providing individualized organ dose estimates for NLST participant cohorts.

WE-B-207-01: CT Lung Cancer Screening and the Medical Physicist: Background, Findings and Participant Dosimetry Summary of the National Lung Screening Trial (NLST)

The US National Lung Screening Trial (NLST) was a multi-center randomized, controlled trial comparing a low-dose CT (LDCT) to posterior-anterior (PA) chest x-ray (CXR) in screening older, current and former heavy smokers for early detection of lung cancer. Recruitment was launched in September 2002 and ended in April 2004 when 53,454 participants had been randomized at 33 screening sites in equal proportions. Funded by the National Cancer Institute this trial demonstrated that LDCT screening reduced lung cancer mortality. The US Preventive Services Task Force (USPSTF) cited NLST findings and conclusions in its deliberations and analysis of lung cancer screening. Under the 2010 Patient Protection and Affordable Care Act, the USPSTF favorable recommendation regarding lung cancer CT screening assisted in obtaining third-party payers coverage for screening. The objective of this session is to provide an introduction to the NLST and the trial findings, in addition to a comprehensive review of the dosimetry investigations and assessments completed using individual NLST participant CT and CXR examinations. Session presentations will review and discuss the findings of two independent assessments, a CXR assessment and the findings of a CT investigation calculating individual organ dosimetry values. The CXR assessment reviewed a total of 73,733 chest x-ray exams that were performed on 92 chest imaging systems of which 66,157 participant examinations were used. The CT organ dosimetry investigation collected scan parameters from 23,773 CT examinations; a subset of the 75,133 CT examinations performed using 97 multi-detector CT scanners. Organ dose conversion coefficients were calculated using a Monte Carlo code. An experimentally-validated CT scanner simulation was coupled with 193 adult hybrid computational phantoms representing the height and weight of the current U.S. population. The dose to selected organs was calculated using the organ dose library and the abstracted scan parameters. This session will review the results and summarize the individualized doses to major organs and the mean effective dose and CTDIvol estimate for 66,157 PA chest and 23,773 CT examinations respectively, using size-dependent computational phantoms coupled with Monte Carlo calculations. Learning Objectives: 1.Review and summarize relevant NLST findings and conclusions. 2.Understand the scope and scale of the NLST specific to participant dosimetry. 3.Provide a comprehensive review of NLST participant dosimetry assessments. 4.Summarize the results of an investigation providing individualized organ dose estimates for NLST participant cohorts.

WE-B-207-02: CT Lung Cancer Screening and the Medical Physicist: A Dosimetry Summary of CT Participants in the National Lung Cancer Screening Trial (NLST)

The US National Lung Screening Trial (NLST) was a multi-center randomized, controlled trial comparing a low-dose CT (LDCT) to posterior-anterior (PA) chest x-ray (CXR) in screening older, current and former heavy smokers for early detection of lung cancer. Recruitment was launched in September 2002 and ended in April 2004 when 53,454 participants had been randomized at 33 screening sites in equal proportions. Funded by the National Cancer Institute this trial demonstrated that LDCT screening reduced lung cancer mortality. The US Preventive Services Task Force (USPSTF) cited NLST findings and conclusions in its deliberations and analysis of lung cancer screening. Under the 2010 Patient Protection and Affordable Care Act, the USPSTF favorable recommendation regarding lung cancer CT screening assisted in obtaining third-party payers coverage for screening. The objective of this session is to provide an introduction to the NLST and the trial findings, in addition to a comprehensive review of the dosimetry investigations and assessments completed using individual NLST participant CT and CXR examinations. Session presentations will review and discuss the findings of two independent assessments, a CXR assessment and the findings of a CT investigation calculating individual organ dosimetry values. The CXR assessment reviewed a total of 73,733 chest x-ray exams that were performed on 92 chest imaging systems of which 66,157 participant examinations were used. The CT organ dosimetry investigation collected scan parameters from 23,773 CT examinations; a subset of the 75,133 CT examinations performed using 97 multi-detector CT scanners. Organ dose conversion coefficients were calculated using a Monte Carlo code. An experimentally-validated CT scanner simulation was coupled with 193 adult hybrid computational phantoms representing the height and weight of the current U.S. population. The dose to selected organs was calculated using the organ dose library and the abstracted scan parameters. This session will review the results and summarize the individualized doses to major organs and the mean effective dose and CTDIvol estimate for 66,157 PA chest and 23,773 CT examinations respectively, using size-dependent computational phantoms coupled with Monte Carlo calculations. Learning Objectives: 1. Review and summarize relevant NLST findings and conclusions. 2. Understand the scope and scale of the NLST specific to participant dosimetry. 3. Provide a comprehensive review of NLST participant dosimetry assessments. 4. Summarize the results of an investigation providing individualized organ dose estimates for NLST participant cohorts.

STANDARDISED ASSESSMENT OF ACUTE LOWER RESPIRATORY INFECTIONS (ALRI) IN A RANDOMISED FIELD TRIAL OF REDUCED AIR POLLUTION EXPOSURE

Introduction Pneumonia remains the principal cause of death of children under 5 in developing countries. Evidence from nearly 20 studies associates exposure to pollution from biomass fuels with increased risk of acute lower respiratory infections (ALRI). However, all these studies have been observational designs, very few with exposure assessment, and with inconsistent case ascertainment and definition. To strengthen this evidence, a randomised controlled trial (RCT) is currently underway in Guatemala to measure the effect of an improved stove on ALRI incidence. This provides the first opportunity to study health effects of air pollution in a randomised intervention, largely free of confounding which typically complicates interpretation in environmental epidemiology. This paper describes the methods used for standardised case-finding. Method The sample includes 500 children in a poor rural area of north-western Guatemala. At recruitment, children were aged less than 4 months, or in utero. Each child is being followed to age 18 months. Following baseline questionnaires, a random 50% of homes received plancha stoves-a well–accepted local product known to reduce indoor air pollution by up to 80–90%. Case finding is carried out at three levels: (a) household visits, (b) referral to a study physician, and (c) referral to the district hospital. Fieldworkers trained in IMCI case recognition visit each home weekly, using standard questions and examination (including respiratory rate) to identify possible ALRI cases. This process is very sensitive, but not very specific. Anthropological work was undertaken to identify symptom terms in the local (Mam) language with correct meanings. Children meeting ALRI criteria are referred to a physician, based in a community centre: this helps to maintain blindness of the physician to the intervention/control status of each child's home. Physician assessment utilises standardised clinical criteria, based on prior WHO studies and re-enforced through clinical training sessions. Such sessions are also carried out at regular intervals to maintain consistency. All children with signs of ALRI are referred for chest X-ray (CXR), and RSV antigen testing and pulse oximetry (PO) are carried out. The use of CXR and PO provide additional ‘objective’ assessment of each child, and RSV testing will allow comparison of IAP risk in bronchiolitis and pneumonia cases. Severely ill children are admitted to hospital, and additional clinical information collected at discharge. All deaths are being assessed by verbal autopsy. Conclusion Primary case definition is determined by the study physician, combining clinical findings, CXR, and hospital information, with PO providing a measure of severity. Independent, blind assessment of CXRs and verbal autopsy reports will also be available. Experience with this system of case finding will be reported, including numbers of ALRI cases treated at home and admitted, and %RSV positive. Also analysed will be the differences in numbers and characteristics of ALRI cases defined by (a) IMCI criteria at weekly visit, (b) physician examination with CXR, and (c) CXR findings only. Practical issues in maintaining standardised procedures, and referring children for CXR and admission in a rural population fearful of the hospital will also be reported.