Posterior-anterior Chest X-ray Research Articles

Examination of Radiological Findings and Clinical Parameters in Paediatric Patients with Covid-19

Objective: It was aimed to evaluate the relationship between imaging techniques and clinical and laboratory parameters in paediatric COVID-19 patients.
 Methods: Our study included 187 patients under the age of 18 whose diagnosis of COVID-19 was confirmed by PCR test. Demographic, clinical, laboratory and radiological imaging findings of the patients were reviewed retrospectively from their file records.
 Results: 57.2% of the patients were male and the mean age was 110.1±67.4 months. A pulmonary finding associated with COVID-19 was detected in 21 (12%) of 175 patients who underwent Posterior-anterior (PA) chest X-ray. The most common findings were consolidation (n=16; 9.1%), bilateral ground-glass appearance (n=11; 6.3%), and atelectasis (n=5; 2.9%), respectively. Computed lung tomography was performed in 67 of the patients. The presence of a pulmonary finding associated with COVID-19 was detected in 28 (41.8%) of these patients. The three most common findings were consolidation (n=16; 23.9%), bilateral ground glass appearance (n=16; 23.9%), and atelectasis (n=15; 22.4%), respectively. It was determined that for patients with imaging findings on PA X-ray needed more paediatric intensive care, the length of their hospital stay was longer, comorbid diseases were present, their cough and tachypnea complaints were more pronounced (p

Diagnosis of Latent Tuberculosis Infection in Hemodialysis Patients: TST versus T-SPOT.TB.

Hemodialysis (HD) patients should be screened for latent tuberculosis (TB) infection. We aimed to determine the frequency of latent TB infection in HD patients and to compare the effectiveness of the tests used. The files of 56 HD patients followed between 1 January 2021 and 1 October 2022 were retrospectively analyzed. Demographic data, the presence of the Bacillus Calmette-Guerin (BCG) vaccine, whether or not the patients had previously received treatment for TB before, the status of encountering a patient with active TB of patients over 18 years of age, without active tuberculosis and who had a T-SPOT.TB test or a Tuberculin Skin Test (TST) were obtained from the patient files. The presence of previous TB in a posterior-anterior (PA) chest X-ray was obtained by evaluating PA chest X-rays taken routinely. Of the patients, 60.7% (n = 34) were male and their mean age was 60.18 ± 14.85 years. The mean duration of dialysis was 6.43 ± 6.03 years, and 76.8% (n = 43) had 2 BCG scars. The T-SPOT.TB test was positive in 32.1% (n = 18). Only 20 patients (35.7%) had a TST and all had negative results. While the mean age of those with positive T-SPOT.TB results was higher (p = 0.003), the time taken to enter HD was shorter (p = 0.029). T-SPOT.TB test positivity was higher in the group that had encountered active TB patients (p = 0.033). However, no significant difference was found between T-SPOT.TB results according to BCG vaccine, albumin, urea and lymphocyte levels. Although T-SPOT.TB test positivity was higher in patients with a previous TB finding in a PA chest X-ray, there was no statistically significant difference (p = 0.093). The applicability of the TST in the diagnosis of latent TB infection in HD patients is difficult and it is likely to give false-negative results. The T-SPOT.TB test is not affected by the BCG vaccine and immunosuppression. Therefore, using the T-SPOT.TB test would be a more appropriate and practical approach in the diagnosis of latent TB in HD patients.

Premature Deaths Due to Silicosis in Turkey, 2006-2017: A Twelve-Year Longitudinal Study.

Background Deaths due to epidemics of silicosis still continue to be reported both in developing and developed countries, and silica exposure from different sectors remains an important occupational health concern.Aims To identify characteristics of silicosis cases by focusing on a developing country and evaluate the frequency of and factors related to premature deaths and also reveal preventable causes of premature deaths in silicosis.Study Design Retrospective cohort.Methods We reviewed the records of 9769 patients who were diagnosed with occupational diseases in İstanbul Occupational Diseases Hospital between 2006 and 2017. According to International Classification of Diseases (ICD)-10 codes, 1473 silicosis cases were detected. The sociodemographic characteristics, job characteristics, comorbidities, serological, functional, and radiological data, and follow-up time were obtained from the medical records. Mortality data were gathered from The National Death Notification System of Ministry of Health.ResultsThe study examined 9769 cases diagnosed with an occupational disease, and 15.0% (n = 1473) of them were diagnosed with silicosis. The median age of silicosis patients was 40.0 years, and 26.9% of them were child labor when they started to work in dusty industries. Child labor was mostly seen among dental technicians (57.7%), denim sandblasters (46.4%), and miners (37.0%). In the follow-up period, 26.3% of Teflon sandblasters, 11.1% of coal miners, 8.6% of denim sandblasters had died before their average life expectancy, and the years of loss of life was 26.0 ± 11.6 years all over the group. Premature death was associated with occupation [hazard ratio (Teflon sandblasting): 3.93, CI: 1.43-10.78; hazard ratio (marble production): 4.4, CI: 1.02-19.21]; large opacities in posterior anterior chest X-ray [hazard ratio: 2.14, CI: 1.18-3.86]; tuberculosis [hazard ratio: 2.60, CI: 1.42-4.76]; and reduction in forced vital capacity (forced vital capacity% ≤80) during diagnosis [hazard ratio: 4.43, CI: 2.22-8.83].Conclusion: More than a quarter of silicosis cases are those who start working in dusty industries at an early age. Factors associated with premature death in patients with silicosis are patient occupation, large opacities on chest X-ray, tuberculosis, and pulmonary function loss at diagnosis.

Tuberculosis detection from chest x-rays for triaging in a high tuberculosis-burden setting: an evaluation of five artificial intelligence algorithms

Artificial intelligence (AI) algorithms can be trained to recognise tuberculosis-related abnormalities on chest radiographs. Various AI algorithms are available commercially, yet there is little impartial evidence on how their performance compares with each other and with radiologists. We aimed to evaluate five commercial AI algorithms for triaging tuberculosis using a large dataset that had not previously been used to train any AI algorithms. Individuals aged 15 years or older presenting or referred to three tuberculosis screening centres in Dhaka, Bangladesh, between May 15, 2014, and Oct 4, 2016, were recruited consecutively. Every participant was verbally screened for symptoms and received a digital posterior-anterior chest x-ray and an Xpert MTB/RIF (Xpert) test. All chest x-rays were read independently by a group of three registered radiologists and five commercial AI algorithms: CAD4TB (version 7), InferRead DR (version 2), Lunit INSIGHT CXR (version 4.9.0), JF CXR-1 (version 2), and qXR (version 3). We compared the performance of the AI algorithms with each other, with the radiologists, and with the WHO's Target Product Profile (TPP) of triage tests (≥90% sensitivity and ≥70% specificity). We used a new evaluation framework that simultaneously evaluates sensitivity, proportion of Xpert tests avoided, and number needed to test to inform implementers' choice of software and selection of threshold abnormality scores. Chest x-rays from 23 954 individuals were included in the analysis. All five AI algorithms significantly outperformed the radiologists. The areas under the receiver operating characteristic curve were 90·81% (95% CI 90·33-91·29) for qXR, 90·34% (89·81-90·87) for CAD4TB, 88·61% (88·03-89·20) for Lunit INSIGHT CXR, 84·90% (84·27-85·54) for InferRead DR, and 84·89% (84·26-85·53) for JF CXR-1. Only qXR (74·3% specificity [95% CI 73·3-74·9]) and CAD4TB (72·9% specificity [72·3-73·5]) met the TPP at 90% sensitivity. All five AI algorithms reduced the number of Xpert tests required by 50% while maintaining a sensitivity above 90%. All AI algorithms performed worse among older age groups (>60 years) and people with a history of tuberculosis. AI algorithms can be highly accurate and useful triage tools for tuberculosis detection in high-burden regions, and outperform human readers. Government of Canada.

Nanodot Optically Stimulated Luminescence Dosimeter for Entrance Surface Dose measurement at selected Health Clinic in Perak, Malaysia

The aimed of this study is to evaluate patient dosimetry received from Posterior Anterior Chest X-ray (PA-CXR) examination performed at community clinics in Perak using a nanodot Al2O3:C Optically Stimulated Luminescence dosimeter (OSLD). Four clinics were involved in this research namely Simpang Health Clinic, Buntong Health Clinic, Teluk Intan Health Clinic and Pengkalan Hulu Health Clinic. The ESD was measured by placing the OSLD on polymethylmethacrylate (PMMA) slabs that resembling a human body specifically lung. These clinics were selected as they were excluded from the first and second national dose survey conducted in Malaysia since 1993-1995 and 2005-2009 respectively. Previously, the recommended guidance level for PA-CXR entrance surface dose (ESD) was set at 0.9 mGy. We compare the ESD measured with OSL and guidance level set under the second national dose survey which utilized LiF:Mg, Ti thermoluminescence dosimeter (TLD). The results indicated that the 3rd quartile ESD measured using OSLD were ranged 0.271 mGy – 0.368 mGy which 30% lesser than the recommended guidance level.

Abstract 13493: Mechanism and Prognostic Significance of Cardiothoracic Ratio in Patients With Heart Failure With Preserved Ejection Fraction - Insights From Pursuit-hfpef Registry -

Introduction: The cardiothoracic ratio (CTR) is a widely accepted method of quantifying cardiac size, and carries prognostic information in acquired heart disease. However, little is described in the underlying mechanism and prognostic value in heart failure with preserved ejection fraction (HFpEF). Methods: Analysis was performed from a prospective multicenter observational registry for HFpEF (PURSUIT-HFpEF Registry) conducted in the Osaka region of Japan. A total of 871 patients hospitalized for acute HF (diagnosed by using Framingham criteria) met the inclusion criteria: a left ventricular ejection fraction (LVEF) ≥50% and brain natriuretic peptide (BNP) ≥100 pg/ml. We included 629 patients (age, 81±9 years; men, 46%; atrial fibrillation, 37%) whose follow-up data after survival discharge were available and whose CTR were measured from posterior-anterior chest X-ray. The endpoint was defined as the composite of death, re-hospitalization for HF, and cerebrovascular accident. Results: Median CTR at discharge was 56% (interquartile range: 51-61%). Comparison with echocardiographic data revealed that CTR significantly correlated with increased left atrial size (left atrial volume; r = 0.39, p <0.001) and LV filling pressure (E/e’ ratio; r = 0.13, p = 0.002), but not with LV size (LV end-diastolic volume; r = -0.014; LV end-systolic volume: r = -0.002) and LVEF (r = -0.035). Age (r = 0.16, p <0.001) and log-transformed N-terminal-pro-BNP value (r = 0.21, p <0.001) were also correlated with CTR. Female patients exhibited more higher CTR than male patients (54±7 vs. 58±7%, p <0.001). During a median follow-up of 15 months, 257 patients experienced the endpoint. When patients were classified into the CTR quartile groups, there was a positive correlation between the incidence rate and the quartiles (Q1, 31.0%; Q2, 39.5%; Q3, 35.7%; Q4 55.8%, p <0.001). After adjustment for age and gender, Cox regression analysis revealed that CTR at discharge was a significant predictor of the composite endpoint (hazard ratio per quartile increase; 1.23; 95% confidence interval, 1.10-1.39; p = 0.006). Conclusions: CTR was not associated with LV size but left atrial size in patients with HFpEF. Increased CTR at discharge predicted unfavorable prognosis in patients with HFpEF.

Smartphone evaluation of postero-anterior chest x-rays: An inter-observer study.

Posterior-anterior chest x-ray (PA-CXR) is among the most commonly used imaging methods in the diagnosis both in the emergency departments (ED) and the other clinics. The aim of the present study was to evaluate the diagnostic reliability of PA-CXRs sent via a smartphone. This study was conducted as an inter-observer study. PA-CXRs were photographed with a smartphone and they were sent to two separate participants (emergency medicine specialists one with 4 years experience and another with 3) via the WhatsApp application. And the participants evaluated to these images on their mobile phone. A poor concordance was determined in a ratio of 3/8 and good concordance was detected in a ratio of 3/8 between the two participants (p < 0.05). It was observed that only the mediastinum assessments could be an alternative to the gold standard (p < 0.01). We may conclude that the assessments done via a smartphone (photographing and sharing) may not be reliable.

A STORY OF EXTRAORDİNARY ABDOMİNALLY PERFORATİTON

Pneumoperitoneum is the result of a gastrointestinal (GI) tract perforation in more than 90% of cases. Perforation of the stomach or duodenum caused by peptic ulcer is considered the most common cause of pneumoperitoneum. In this article, we present a case of pneumoperitoneum associated with sigmoid colon perforation, which is the result of the patient trying to create a laxative effect by inserting the hose attached to the wash basin into his rectum and opening the water afterwards. An 89 years old male patient was brought to the emergency department with complaints of abdominal pain starting about 2 hours ago. The patient's abdominal ultrasonography showed free fluid up to 10 cm in the lower abdomen. Posterior anterior chest X-ray and direct standing abdominal X-ray of the patient had subdiaphragmatic free air and images with free fluid, pneumoperitoneum and perforation were obtained in contrast enhanced abdominal tomography. As a result of surgery performed by general surgery it was seen approximately 30 cm proximal from the rectumthat there was a 4 cm perforation in the sigmoid colon. We must consider pneumoperitoneum, which is the result of colon perforation especially in elderly patients with acute abdominal pain, to be definitely among our differential diagnoses.

Review of Evidence for Using Chest X-Rays for Active Tuberculosis Screening in Long-Term Care in Canada.

Background: People living in long-term care facilities (LTCF) are at high risk to develop active tuberculosis primarily as a result of reactivation of a latent TB infection, or endemic transmission between residents. Current national guidelines in Canada are to use a posterior-anterior and lateral chest X-ray to screen for TB for those over 65 years old, upon admission to a LTCF.Objective: To assess the available evidence for cost benefits of universal chest X-ray screening for new LTCF residents.Methodology: We conducted a search for all articles published until September 2018, in PubMed and WorlCat databases, in English, using a combination of key words: chest X-ray, chest radiography or CXR, long-term care, elderly, screening, and tuberculosis. We also reviewed publicly available guidelines for screening new residents to LTCF from across Canada. We report on a qualitative synthesis of the evidence in the documents retrieved.Results: The final review yielded four cost-effectiveness studies (2 of 4 conducted in countries with low incidence), one systematic review, one recommendation/editorial, and one cohort study. We found that in a tuberculosis low-incidence country the CXR cost per identified case was $672,298 CAD. Enacting a more targeted screening program, perhaps one that tests only those who previously had TB, or other high-risk medical conditions may enhance the cost-effectiveness.Recommendations: We suggest reviewing the screening policy for active TB in people entering LTCF, which is based on a CXR. The results indicate that a targeted search for active TB in people with symptoms or other high-risk medical conditions may be more cost-effective.

Conventional vs invert-grayscale X-ray for diagnosis of pneumothorax in the emergency setting

Introduction: Pneumothorax is a pathologic condition in which air is accumulated between the visceral and parietal pleura. After clinical suspicion, in order to diagnose the severity of the condition, imaging is necessary. By using the help of Picture Archiving and Communication Systems (PACS) direct conventional X-rays are converted to gray-scale and this has become a preferred method among many physicians.Methods: Our study design was a case-control study with cross-over design study. Posterior-anterior chest X-rays of patients were evaluated for pneumothorax by 10 expert physicians with at least 3years of experience and who have used inverted gray-scale posterior anterior chest X-ray for diagnosing pneumothorax.Results: The study included posterior anterior chest X-ray images of 268 patients of which 106 were diagnosed with spontaneous pneumothorax and 162 patients used as a control group. The sensitivity of Digital-conventional X-rays was found to be higher than that of inverted gray-scale images (95% CI (2,08–5,04), p<0,01). There was no statistically significant difference between the gold standard and digital-conventional images (95% CI (0,45–2,17), p=0,20), while the evaluations of the gray-scale images were found to be less sensitive for diagnosis (95% CI (3,16–5,67) p<0,01).Conclusion: Inverted gray-scale imaging is not a superior imaging modality over digital-conventional X-ray for the diagnosis of pneumothorax. Prospective studies should be performed where diagnostic potency of inverted gray-scale radiograms is tested against gold standard chest CT. Further research should compare inverted grayscale to lung ultrasound to assess them as alternatives prior to CT.

Clinical practitioners' knowledge of ionizing radiation doses in diagnostic radiology examinations in calabar

Observation has shown a preponderance of irrelevant, unjustified and perhaps unnecessary radiological requests in the study area. The consequences of this on the patients' doses and population collective dose may be dire.To assess Clinicians/Referrers' knowledge of radiation doses of patients undergoing radiological examinations.A prospective, non-experimental, cross-sectional survey of clinicians (except radiologists) in various hospitals in Calabar metropolis, Cross River State, Nigeria, was conducted. A pretested and validated questionnaire was designed to extract responses on rating of effective doses for commonly requested imaging examinations, using the value for the posterior-anterior (PA) chest x-ray as reference. Questions on radiosensitivity of different organs, imaging modalities that use ionizing radiation and considerations for the choice of ionizing radiation (IR) based examinations were included. Participants were also asked for their preferred methods of filling any knowledge gap on IR issues. Responses were presented in simple percentages.A total of 104 respondents, made up of 63.5% males and 36.5% females participated in the study. At least 70% and 42% of the respondents, respectively, were aware that Ultrasound and Magnetic Resonance Imaging were not IR based modalities. About 67.3% of the respondents did not know the doses of commonly requested radiological examinations. This result was not dependent on clinicians' demography. A total of 61.5% of the respondents referred patients for IR examinations even when the result was unlikely to alter their diagnosis or treatment; but to reassure the patient (98.8% ), meet expectations of patients (35%) or to give the patient the feeling of being taken seriously (75%).Participating Clinicians in this study have showed poor knowledge of radiation doses of commonly requested radiological examinations. Most participants suggested improvement of their knowledge of radiation doses through continuous medical education and by the provision of referral guidelines.

Gelsolin and Progression of Aortic Arch Calcification in Chronic Hemodialysis Patients.

Background:Vascular calcification (VC) is a key process associated with cardiovascular mortality in dialysis patients. Gelsolin is an actin-binding protein that can modulate inflammation, correlated inversely with hemodialysis (HD) mortality and involved in bone calcification homeostasis. In this report, we aim to characterize progression in aortic arch calcification (AAC) and investigate its association with gelsolin.Methods: 184 HD patients were enrolled and their annual posterior-anterior chest X-ray films (CXR) in 2009 and 2013 were examined. The severity of AAC was classified as grade 0 to 3. Blood levels of gelsolin were measured by ELISA kits. Biographic and biochemical data at baseline were analyzed with status of AAC at baseline and changes after 4 years.Results: At baseline, 60% of the patients had detectable AAC on CXR. After 4 years, 77% had AAC. Patients with grade 1 and 2 AAC had increased risk of progression (Odds ratio [OR] 2~3, P=0.001) compared to those with grade 0 at baseline. Compared to those with no AAC, patients with AAC progression had older age, lower gelsolin, higher waist circumference and prevalence of vascular disease. Regression analysis confirmed baseline gelsolin (odds ratio 0.845, 95% confidence interval [0.734-0.974]) and waist circumference as the independent factors associated with AAC progression. Gelsolin is positively correlated with serum albumin and negatively with tumor necrosis factor-alpha.Conclusion: Our study demonstrated that HD patients with grades 1 or 2 baseline AAC are at increased risk of further progression compared to those with grade 0. We also found lower blood levels of gelsolin associated with progressive AAC. Further investigation into the mechanistic roles of gelsolin in vascular calcification may provide new understanding of this key process.

Evaluation of Chest X-ray and Thoracic Computed Tomography in Patients with Suspected Tuberculosis.

To investigate if there is any correlation between positive findings detected by posterior-anterior (PA) chest radiograph and thoracic computerized tomography (CT) in cases with suspected lung tuberculosis (TB) due to positive tuberculin skin test (TST) results. This is a retrospective evaluation of the medical files of patients who visited the Department of Pediatrics, Istanbul University, Istanbul Faculty of Medicine from 2006, through 2011 as outpatients and had positive TST (>15mm) results. A total of 326 patients were included in the study; 45.7% (n=149) were girls, and the mean age was 9.0±4.1 y (range: 1-17 y). In total, 14.4% (n=47) had TB findings, all of which were in the form of hilar lymphadenopathy. Among the 47 cases with TB findings in PA chest X-ray, 45 (95.7%) also had findings in thoracic CT. Only 2 (4.3%) patients had normal thoracic CT results although their PA chest X-ray results were positive. Evaluation for pulmonary TB in children with positive isolated TSTs should be made primarily with PA chest X-ray. A routine thoracic CT scan is not necessary for asymptomatic patients with only hilar lymphadenopathy findings in PA chest radiographs.

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.

Comparison of radiological findings of chest x-ray with echocardiography in determination of the heart size.

Background:Heart size is an important and effective parameter in chest X-ray (CXR) interpretation. Studies indicate that, especially in middle-aged men, increased cardiothoracic ratio (CTR) is associated with ischemic heart disease (IHD) and increased rate of morbidity and mortality. The CXR is the most common imaging examination of the heart.Objectives:A good quality posterior-anterior (PA) chest radiograph is an important indicator of the cardiac size. Nowadays, CXR has given its place to more advanced approaches such as two-dimensional echocardiography. However, CXR is still more accessible and feasible for most of the physicians. This study was designed to compare the findings of CXR and echocardiography in determination of the heart size.Patients and Methods:This cross-sectional study was carried out from 2006 to 2007. A total of 197 patients entered the study. The cases had been undergone PA CXR and 2-D echocardiography maximum within two days.Results:Of participants, 24.9% had cardiomegaly according to the findings of CXR and 50.8% based on echocardiography. There was a statistically significant difference between the mean size of Right Ventricular End Diastolic Diameter in the patients with cardiothoracic ratio < 50% and ≥ 50% (P = 0.002) as well as Left Ventricular End Diastolic Diameter (P = 0.023). Also, a statistically significant difference was seen between echocardiography and CXR findings with regard to determination of the heart size (P = 0.003). Nonetheless, it is noteworthy that sensitivity and specificity of CXR findings in the diagnosis of cardiomegaly were 34%, and 84.5%, respectively.Conclusions:CTR is the most common method of describing the heart size. Increased CTR in CXR is associated with poor prognosis, which is suggestive of importance and necessity of early diagnosis. Although CXR may not have the same diagnostic accuracy as echocardiography, its easy accessibility and high specificity in diagnosis of cardiomegaly is very helpful, which can play an important and a cost-benefit role, particularly in screening the enlarged heart size. Moreover, according to the statistics released by Medical Council of Iran, most of Iranian physicians are general practitioners and a few of them are cardiologist.

Absent pulmonary valve syndrome with left lung atresia.

Absent pulmonary valve syndrome (APVS) is a rare anomaly characterized by the absence of the pulmonary valve. The absence of the pulmonary valve, along with the hypoplasia of the pulmonary annulus, leads to aneurysmal dilatation of the pulmonary artery and its branches. Other consequences include pulmonary stenosis and pulmonary insufficiency (1). The 3-day-old baby presented with cyanosis and tachypnea. He had to and fro murmurs at the upper left sternal region, as well as hepatomegaly. The electrocardiogram showed right ventricular hypertrophy. The posterior-anterior chest X-ray showed opaque left hemithorax with cardiac displacement (Figure 1). Upon echocardiographic examination, the following findings were noted: the right cardiac chambers were dilated and left ventricular hypoplasia was present (Video 1. See corresponding video/movie images at www.balkanmedicaljournal.org). A large subaortic ventricular septal defect and a main pulmonary artery aneurysm were seen (Video 2. See corresponding video/movie images at www.balkanmedicaljournal.org). Hypoplastic pulmonary annulus and absent pulmonary valve leaflets were present (Figure 2). Moderate pulmonary stenosis (peak systolic gradient was 45 mmHg) and mild pulmonary regurgitation were present (Video 3. See corresponding video/movie images at www.balkanmedical-journal.org). The aortic arc was left sided and no patent ductus arteriosus was seen. In addition to the echocardiographic findings, atresia of the left pulmonary artery was observed with computed tomography (Figures 3, ​,4).4). The patient died due to respiratory failure on fourth day after birth. FIG. 1 Posterior-anterior chest X-ray showed opaque left hemithorax with cardiac displacement FIG. 2 Hypoplastic pulmonary annulus and absent pulmonary valve leaflets FIG. 3 CT 3D reconstruction of aneurysmal pulmonary arteries FIG. 4 Left pulmonary artery atresia Absent pulmonary valve syndrome is a rare anomaly, which is characterized by aneurysmal dilatation of the pulmonary artery, depending on atresia or dysplasia of the pulmonary valve leaflets. The disease is usually associated with tetralogy of Fallot. Due to the absence of pulmonary valve leaflets, pulmonary regurgitation and mild pulmonary stenosis were seen (2). Respiratory distress signs could be seen to varying degrees due to compression of the airway with the pulmonary artery. In the severe forms, due to complete obstruction of the trachea or bronchi, rapid progress can be seen in the neonatal period. More severe forms of the disease may result in death during the newborn period due to the pressure effect exerted by the pulmonary artery on the tracheobronchial structures. The patient presented herein had an absence of the pulmonary valve, together with the non-restrictive ventricular septal defect. Also, mild pulmonary valve stenosis and insufficiency, widened pulmonary artery, and atresia of the left pulmonary artery were seen. Although catheterization could not be performed during the early stage, as the patient had severe respiratory dysfunction, computed tomography confirmed the presence of a widened pulmonary artery and atresia of the left pulmonary artery. Also, arterial branches from the abdominal or thoracic aorta supplying the left lung could not be detected with computed tomography. The combination of APVS with atresia of the left pulmonary artery is extremely rare (3). Early diagnosis and supportive treatment in the newborn period are important for the survival of these severely affected infants.

An investigation on patient dose in screen-film diagnostic radiology in Lhasa City, Xizang Autonomous Region, China

This study aimed to investigate patient dose in diagnostic screen-film radiographic examinations in the city of Lhasa, China. Seven out of the twenty-six hospitals registered with the Lhasa Health Bureau were included in the investigation. The entrance surface air Kerma (ESAK) of seven conventional screen-film radiology X-ray equipment in these hospitals was measured with a QA dosimeter in September 2012. The X-ray examinations were divided into three categories: PA (posterior-anterior) chest, upper/lower limb, and AP (anterior-posterior) lumbar spine. For each category, ESAKs were calculated and analyzed. The mean ESAK was 0.6 mGy for PA chest, 0.3 mGy for upper/lower limb, and 1.8 mGy for AP lumbar spine. In addition, the mean ESAK value recorded for PA chest X-ray examinations exceeded the corresponding value recommended by the International Atomic Energy Agency (0.4 mGy).

Ventricular Arrhythmias After Left Ventricular Assist Device

Despite advances in medical therapy, heart failure remains one of the major causes of hospitalizations and deaths in the United States. Approximately 5.7 million patients have heart failure, and it is the direct cause of death for 57 000 individuals annually.1 Although the combination of optimal medical therapy, implantable cardioverter-defibrillators (ICDs), and cardiac resynchronization therapy has reduced mortality rates, an estimated 50% of patients with heart failure still die within 5 years of diagnosis.1 Heart transplant is often the best therapeutic option for patients with end-stage heart failure; however, there has been a stable plateau of ≈2200 transplants/y in the United States due largely to limitations in organ availability.1 For patients who are facing unfavorably long wait times for heart transplantation, left ventricular assist devices (LVAD) have become a lifesaving option as a bridge to transplant. Currently, one quarter to one third of all heart transplant recipients are bridged with mechanical circulatory support before transplantation.2 Much of this support is in the form of permanent LVADs—surgically implanted mechanical assist devices that unload the left ventricle and can function in ambulatory patients (Figure 1). The use of permanent LVADs as destination therapy has increased dramatically, with evidence that they benefit patients with end-stage heart failure, despite noncandidacy for heart transplantation. Since the seminal Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure destination therapy trial in 2001, ≈1578 destination therapy LVADs have been implanted, with implant rates increasing rapidly.3,4 Figure 1. Examples of implantable cardioverter-defibrillators (ICDs) with 2 different types of left ventricular assist devices (LVADs). Posterior-anterior chest x-ray projections of biventricular ICDs in the presence of HVAD ( A ) and Heartmate II ( B ) models of LVAD. Development of LVADs dates to 1969 when the world’s first total artificial heart was implanted by Dr …