Improved Interobserver Agreement on Lung-RADS Classification of Solid Nodules Using Semiautomated CT Volumetry.

Background Classification of lung cancer screening CT scans depends on measurement of lung nodule size. Information about interobserver agreement is limited. Purpose To assess interobserver agreement in the measurements and American College of Radiology Lung CT Screening Reporting and Data System (Lung-RADS) classifications of solid lung nodules detected at lung cancer screening using manual measurements of average diameter and computer-aided semiautomated measurements of average diameter and volume (CT volumetry). Materials and Methods Two radiologists and one radiology resident retrospectively measured lung nodules from screening CT scans obtained between September 2016 and June 2018 with a Lung-RADS (version 1.0) classification of 2, 3, 4A, or 4B in the clinical setting. Average manual diameter and semiautomated computer-aided diameter and volume measurements were converted to the corresponding Lung-RADS categories. Interobserver agreement in raw measurements was assessed using intraclass correlation and Bland-Altman indexes, and interobserver agreement in Lung-RADS classification was assessed using bi-rater κ. Results One hundred twenty patients (mean age, 63 years ± 6 [standard deviation]; 67 women) were evaluated. All manual, semiautomated diameter, and semiautomated volume measurements were obtained by all three readers in 120 of 147 nodules (82%). Intraclass correlation coefficients were greater than or equal to 0.95 for all reader pairs using all measurement methods and were highest using volumetry. Bias and 95% limits of agreement for average diameter were smaller with semiautomated measurements than with manual measurements. κ values across all Lung-RADS classifications were greater than or equal to 0.81, with the lowest being for manual measurements and the highest being for volumetric measurements. Forty-three of 120 (36%) of the nodules were classified into a lower Lung-RADS category on the basis of volumetry compared with using manual diameter measurements by at least one reader, whereas the reverse occurred for four of 120 (3%) of the nodules. Conclusion Interobserver agreement was high with manual diameter measurements and increased with semiautomated CT volumetric measurements. Semiautomated CT volumetry enabled classification of more nodules into lower Lung CT Screening Reporting and Data System categories than manual or semiautomated diameter measurements. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Nishino in this issue.

Fat-Containing Hypermetabolic Masses on FDG PET/CT: A Spectrum of Benign and Malignant Conditions.

OBJECTIVE: This article focuses on identifying the imaging appearances of hypermetabolic fatty masses and masslike lesions on PET/CT and understanding the diagnostic challenges radiologists may face while interpreting findings of these lesions on PET/CT. This article provides an approach to aid in the diagnosis of these lesions and the appropriate management of patients. CONCLUSION: Both malignant and benign fat-containing masses and masslike lesions can show hypermetabolic activity on PET/CT. Although the differential diagnosis is broad, clinical history, anatomic location, and knowledge of anatomic variants and imaging features can help radiologists avoid misinterpretation of benign fatty lesions as malignancy.

Prevalence of pulmonary artery dilation in non-cystic fibrosis bronchiectasis: a computed tomography analysis from a cohort of the US Bronchiectasis and Nontuberculous Mycobacteria Research Registry.

Although pulmonary artery (PA) dilation is independently associated with significant morbidity and mortality in patients with pulmonary diseases irrespective of diagnosed pulmonary hypertension, its relationship with nontuberculous mycobacteria (NTM) is unknown. The Bronchiectasis and NTM Research Registry is a multicenter registry created to foster research in non-cystic fibrosis (CF) bronchiectasis and NTM lung disease. The majority of patients with non-CF bronchiectasis at Oregon Health & Science University have NTM infections. To determine the prevalence of PA dilation in these patients and its association with supplemental oxygen use, severity of bronchiectasis, tobacco use, and NTM in the sputum culture, we evaluated the chest computed tomography (CT) scans from 321 patients in a cross-sectional analysis. We measured the severity of bronchiectasis by applying modified Reiff criteria and measured the diameters of the PA and aorta (Ao), with PA dilation defined as a PA:Ao ratio >0.9. In our cohort, the mean age was 67.3 years and 83.2% were female. The mean modified Reiff score was 7.1, indicating moderate disease severity. Forty-two patients (13.1%) were found to have PA dilation. PA dilation was positively associated with the use of supplemental oxygen (P<0.001), but there was no association between PA dilation and NTM infection.

Prioritizing congenital syphilis control in south China: a decision analytic model to inform policy implementation.

BACKGROUND: Syphilis is a major public health problem in many regions of China, with increases in congenital syphilis (CS) cases causing concern. The Chinese Ministry of Health recently announced a comprehensive 10-y national syphilis control plan focusing on averting CS. The decision analytic model presented here quantifies the impact of the planned strategies to determine whether they are likely to meet the goals laid out in the control plan. METHODS AND FINDINGS: Our model incorporated data on age-stratified fertility, female adult syphilis cases, and empirical syphilis transmission rates to estimate the number of CS cases associated with prenatal syphilis infection on a yearly basis. Guangdong Province was the focus of this analysis because of the availability of high-quality demographic and public health data. Each model outcome was simulated 1,000 times to incorporate uncertainty in model inputs. The model was validated using data from a CS intervention program among 477,656 women in China. Sensitivity analyses were performed to identify which variables are likely to be most influential in achieving Chinese and international policy goals. Increasing prenatal screening coverage was the single most effective strategy for reducing CS cases. An incremental increase in prenatal screening from the base case of 57% coverage to 95% coverage was associated with 106 (95% CI: 101, 111) CS cases averted per 100,000 live births (58% decrease). The policy strategies laid out in the national plan led to an outcome that fell short of the target, while a four-pronged comprehensive syphilis control strategy consisting of increased prenatal screening coverage, increased treatment completion, earlier prenatal screening, and improved syphilis test characteristics was associated with 157 (95% CI: 154, 160) CS cases averted per 100,000 live births (85% decrease). CONCLUSIONS: The Chinese national plan provides a strong foundation for syphilis control, but more comprehensive measures that include earlier and more extensive screening are necessary for reaching policy goals.

Prevalence of pulmonary artery dilation in non-cystic fibrosis bronchiectasis: A CT analysis from a cohort of the US Bronchiectasis and Nontuberculous Mycobacteria Research Registry.

Although pulmonary artery (PA) dilation is independently associated with significant morbidity and mortality in patients with pulmonary diseases irrespective of diagnosed pulmonary hypertension, its relationship to nontuberculous mycobacteria (NTM) is unknown. To determine the prevalence of PA dilation in patients with NTM-predominant non-CF bronchiectasis, we evaluated the chest computed tomography (CT) scans from 321 patient in the United States based Bronchiectasis and NTM Research Registry. The majority of our cohort had NTM infection. We measured the severity of bronchiectasis using modified Reiff criteria and measured the diameters of the PA and aorta (Ao), with PA dilation defined as a PA:Ao ratio > 0.9. Forty-two patients (13%) were found to have PA dilation. PA dilation was positively associated with the use of supplemental oxygen (p < 0.001), but there was no association between PA dilation and NTM infection.

Endemic Thoracic Infections in Sub-Saharan Africa.

Although many of the thoracic infections endemic to Africa are also present around the world, this article focuses on entities that are emerging or disproportionately affect populations living in sub-Saharan Africa. Important emerging or reemerging viral and bacterial diseases that commonly affect the lung include dengue fever, plague, leptospirosis, and rickettsioses. Most parasitic infections endemic to Africa can also manifest within the thorax, including malaria, amebiasis, hydatid disease, schistosomiasis, paragonimiasis, ascariasis, strongyloidiasis and cysticercosis. Level of sanitation, interaction between humans and host animals, climate change, political instability, and global travel all affect the distribution and burden of these diseases.

Cost-effectiveness of screening for HIV in the era of highly active antiretroviral therapy.

BACKGROUND: The costs, benefits, and cost-effectiveness of screening for human immunodeficiency virus (HIV) in health care settings during the era of highly active antiretroviral therapy (HAART) have not been determined. METHODS: We developed a Markov model of costs, quality of life, and survival associated with an HIV-screening program as compared with current practice. In both strategies, symptomatic patients were identified through symptom-based case finding. Identified patients started treatment when their CD4 count dropped to 350 cells per cubic millimeter. Disease progression was defined on the basis of CD4 levels and viral load. The likelihood of sexual transmission was based on viral load, knowledge of HIV status, and efficacy of counseling. RESULTS: Given a 1 percent prevalence of unidentified HIV infection, screening increased life expectancy by 5.48 days, or 4.70 quality-adjusted days, at an estimated cost of 194 dollars per screened patient, for a cost-effectiveness ratio of 15,078 dollars per quality-adjusted life-year. Screening cost less than 50,000 dollars per quality-adjusted life-year if the prevalence of unidentified HIV infection exceeded 0.05 percent. Excluding HIV transmission, the cost-effectiveness of screening was 41,736 dollars per quality-adjusted life-year. Screening every five years, as compared with a one-time screening program, cost 57,138 dollars per quality-adjusted life-year, but was more attractive in settings with a high incidence of infection. Our results were sensitive to the efficacy of behavior modification, the benefit of early identification and therapy, and the prevalence and incidence of HIV infection. CONCLUSIONS: The cost-effectiveness of routine HIV screening in health care settings, even in relatively low-prevalence populations, is similar to that of commonly accepted interventions, and such programs should be expanded.

Cost-effectiveness of rapid point-of-care prenatal syphilis screening in sub-Saharan Africa.

BACKGROUND: Syphilis continues to be an important public health problem among pregnant women in sub-Saharan Africa with prevalence rates as high as 17%. Pregnant women are a critical population to screen to prevent the devastating consequences of infection to their unborn children. Although screening and appropriate treatment of infected pregnant women can prevent fetal and maternal complications, traditional screening algorithms requiring multiple tests have proven to be difficult to implement in resource-poor settings. We assess the cost-effectiveness of on-site prenatal syphilis screening with newly available rapid point-of-care screening tests in sub-Saharan Africa. METHODS: Data from the literature were used to model the acquisition and subsequent natural history of syphilis in pregnant sub-Saharan African women over the course of their lifetime. We assessed the health and economic outcomes associated with screening strategies that differed by the initial test [rapid plasma reagin (RPR), immunochromographic strip (ICS)], need for confirmation with Treponema pallidum hemagglutination assay, and number of visits required. Model outcomes include adverse pregnancy outcomes (miscarriage, low birth weight, congenital syphilis, stillbirth, and neonatal death), life expectancy, lifetime costs (2004 US dollars), and incremental cost-effectiveness ratios. RESULTS: With no screening, for a cohort of 1000 women with an average of 6 pregnancies in their lifetime, there were 256 cases of congenital syphilis, 583 low birth weight infants, and 170 stillbirths or neonatal deaths. The most effective and least costly strategy was one-visit rapid testing with ICS, which averted 178 cases of congenital syphilis, 43 low birth weight infants, and 37 perinatal deaths, and saved $170,030 per 1000 women compared with no screening. The choice between ICS and RPR was most influenced by test kit, labor and supply costs, and test sensitivity. RPR was preferred when the ICS cost more than doubled or ICS test sensitivity fell below 88%. CONCLUSIONS: Universal prenatal syphilis screening using rapid point-of-care tests will improve both maternal and infant outcomes and is cost-effective.

Quality assurance and quantitative imaging biomarkers in low-dose CT lung cancer screening.

After years of assessment through controlled clinical trials, low-dose CT screening for lung cancer is becoming part of clinical practice. As with any cancer screening test, those undergoing lung cancer screening are not being evaluated for concerning signs or symptoms, but are generally in good health and proactively trying to prevent premature death. Given the resultant obligation to achieve the screening aim of early diagnosis while also minimizing the potential for morbidity from workup of indeterminate but ultimately benign screening abnormalities, careful implementation of screening with conformance to currently recognized best practices and a focus on quality assurance is essential. In this review, we address the importance of each component of the screening process to optimize the effectiveness of CT screening, discussing options for quality assurance at each step. We also discuss the potential added advantages, quality assurance requirements and current status of quantitative imaging biomarkers related to lung cancer screening. Finally, we highlight suggestions for improvements and needs for further evidence in evaluating the performance of CT screening as it transitions from the research trial setting into daily clinical practice.

Cost-effectiveness of alternative management strategies for patients with solitary pulmonary nodules.

BACKGROUND: Positron emission tomography (PET) with 18-fluorodeoxyglucose (FDG) is a potentially useful but expensive test to diagnose solitary pulmonary nodules. OBJECTIVE: To evaluate the cost-effectiveness of strategies for pulmonary nodule diagnosis and to specifically compare strategies that did and did not include FDG-PET. DESIGN: Decision model. DATA SOURCES: Accuracy and complications of diagnostic tests were estimated by using meta-analysis and literature review. Modeled survival was based on data from a large tumor registry. Cost estimates were derived from Medicare reimbursement and other sources. TARGET POPULATION: All adult patients with a new, noncalcified pulmonary nodule seen on chest radiograph. TIME HORIZON: Patient lifetime. PERSPECTIVE: Societal. INTERVENTION: 40 clinically plausible combinations of 5 diagnostic interventions, including computed tomography, FDG-PET, transthoracic needle biopsy, surgery, and watchful waiting. OUTCOME MEASURES: Costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios. RESULTS OF BASE-CASE ANALYSIS: The cost-effectiveness of strategies depended critically on the pretest probability of malignancy. For patients with low pretest probability (26%), strategies that used FDG-PET selectively when computed tomography results were possibly malignant cost as little as 20 000 dollars per QALY gained. For patients with high pretest probability (79%), strategies that used FDG-PET selectively when computed tomography results were benign cost as little as 16 000 dollars per QALY gained. For patients with intermediate pretest probability (55%), FDG-PET strategies cost more than 220 000 dollars per QALY gained because they were more costly but only marginally more effective than computed tomography-based strategies. RESULTS OF SENSITIVITY ANALYSIS: The choice of strategy also depended on the risk for surgical complications, the probability of nondiagnostic needle biopsy, the sensitivity of computed tomography, and patient preferences for time spent in watchful waiting. In probabilistic sensitivity analysis, FDG-PET strategies were cost saving or cost less than 100 000 dollars per QALY gained in 76.7%, 24.4%, and 99.9% of computer simulations for patients with low, intermediate, and high pretest probability, respectively. CONCLUSIONS: FDG-PET should be used selectively when pretest probability and computed tomography findings are discordant or in patients with intermediate pretest probability who are at high risk for surgical complications. In most other circumstances, computed tomography-based strategies result in similar quality-adjusted life-years and lower costs.

Test performance of positron emission tomography and computed tomography for mediastinal staging in patients with non-small-cell lung cancer: a meta-analysis.

PURPOSE: To compare the diagnostic accuracy of computed tomography (CT) and positron emission tomography (PET) with 18-fluorodeoxyglucose (FDG) for mediastinal staging in patients with non-small-cell lung cancer and to determine whether test results are conditionally dependent (the sensitivity and specificity of FDG-PET depend on the presence or absence of enlarged mediastinal lymph nodes on CT). DATA SOURCES: Computerized search of MEDLINE, EMBASE, BIOSIS, and CancerLit through March 2003 and reference lists of retrieved studies and review articles. STUDY SELECTION: Studies in any language that examined FDG-PET for mediastinal staging in patients with known or suspected non-small-cell lung cancer, enrolled at least 10 participants (including at least 5 participants with mediastinal metastasis), and provided enough data to permit calculation of sensitivity and specificity for identifying lymph node involvement. DATA EXTRACTION: One reviewer (of non-English-language studies) or 2 reviewers (of English-language studies) independently evaluated studies for inclusion, rated methodologic quality, and abstracted relevant data. DATA SYNTHESIS: Thirty-nine studies met inclusion criteria. Methodologic quality varied, but few aspects of study quality affected diagnostic accuracy. The authors constructed summary receiver-operating characteristic curves for CT and FDG-PET. Positron emission tomography with 18-fluorodeoxyglucose was more accurate than CT for identifying lymph node involvement (P < 0.001). For CT, median sensitivity and specificity were 61% (interquartile range, 50% to 71%) and 79% (interquartile range, 66% to 89%), respectively. For FDG-PET, median sensitivity and specificity were 85% (interquartile range, 67% to 91%) and 90% (interquartile range, 82% to 96%), respectively. Fourteen studies provided information about the conditional test performance of CT and FDG-PET. Positron emission tomography with 18-fluorodeoxyglucose was more sensitive but less specific when CT showed enlarged lymph nodes (median sensitivity, 100% [interquartile range, 90% to 100%]; median specificity, 78% [interquartile range, 68% to 100%]) than when CT showed no lymph node enlargement (median sensitivity, 82% [interquartile range, 65% to 100%]; median specificity, 93% [interquartile range, 92% to 100%]; P = 0.002). CONCLUSIONS: Positron emission tomography with 18-fluorodeoxyglucose is more accurate than CT for mediastinal staging. Positron emission tomography with 18-fluorodeoxyglucose is more sensitive but less specific when CT shows enlarged mediastinal lymph nodes.

Systematic review: surveillance systems for early detection of bioterrorism-related diseases.

BACKGROUND: Given the threat of bioterrorism and the increasing availability of electronic data for surveillance, surveillance systems for the early detection of illnesses and syndromes potentially related to bioterrorism have proliferated. PURPOSE: To critically evaluate the potential utility of existing surveillance systems for illnesses and syndromes related to bioterrorism. DATA SOURCES: Databases of peer-reviewed articles (for example, MEDLINE for articles published from January 1985 to April 2002) and Web sites of relevant government and nongovernment agencies. STUDY SELECTION: Reports that described or evaluated systems for collecting, analyzing, or presenting surveillance data for bioterrorism-related illnesses or syndromes. DATA EXTRACTION: From each included article, the authors abstracted information about the type of surveillance data collected; method of collection, analysis, and presentation of surveillance data; and outcomes of evaluations of the system. DATA SYNTHESIS: 17,510 article citations and 8088 government and nongovernmental Web sites were reviewed. From these, the authors included 115 systems that collect various surveillance reports, including 9 syndromic surveillance systems, 20 systems collecting bioterrorism detector data, 13 systems collecting influenza-related data, and 23 systems collecting laboratory and antimicrobial resistance data. Only the systems collecting syndromic surveillance data and detection system data were designed, at least in part, for bioterrorism preparedness applications. Syndromic surveillance systems have been deployed for both event-based and continuous bioterrorism surveillance. Few surveillance systems have been comprehensively evaluated. Only 3 systems have had both sensitivity and specificity evaluated. LIMITATIONS: Data from some existing surveillance systems (particularly those developed by the military) may not be publicly available. CONCLUSIONS: Few surveillance systems have been specifically designed for collecting and analyzing data for the early detection of a bioterrorist event. Because current evaluations of surveillance systems for detecting bioterrorism and emerging infections are insufficient to characterize the timeliness or sensitivity and specificity, clinical and public health decision making based on these systems may be compromised.

A conceptual framework for evaluating information technologies and decision support systems for bioterrorism preparedness and response.

OBJECTIVES: The authors sought to develop a conceptual framework for evaluating whether existing information technologies and decision support systems (IT/DSSs) would assist the key decisions faced by clinicians and public health officials preparing for and responding to bioterrorism. METHODS: They reviewed reports of natural and bioterrorism related infectious outbreaks, bioterrorism preparedness exercises, and advice from experts to identify the key decisions, tasks, and information needs of clinicians and public health officials during a bioterrorism response. The authors used task decomposition to identify the subtasks and data requirements of IT/DSSs designed to facilitate a bioterrorism response. They used the results of the task decomposition to develop evaluation criteria for IT/DSSs for bioterrorism preparedness. They then applied these evaluation criteria to 341 reports of 217 existing IT/DSSs that could be used to support a bioterrorism response. MAIN RESULTS: In response to bioterrorism, clinicians must make decisions in 4 critical domains (diagnosis, management, prevention, and reporting to public health), and public health officials must make decisions in 4 other domains (interpretation of bioterrorism surveillance data, outbreak investigation, outbreak control, and communication). The time horizons and utility functions for these decisions differ. From the task decomposition, the authors identified critical subtasks for each of the 8 decisions. For example, interpretation of diagnostic tests is an important subtask of diagnostic decision making that requires an understanding of the tests' sensitivity and specificity. Therefore, an evaluation criterion applied to reports of diagnostic IT/DSSs for bioterrorism asked whether the reports described the systems' sensitivity and specificity. Of the 217 existing IT/DSSs that could be used to respond to bioterrorism, 79 studies evaluated 58 systems for at least 1 performance metric. CONCLUSIONS: The authors identified 8 key decisions that clinicians and public health officials must make in response to bioterrorism. When applying the evaluation system to 217 currently available IT/DSSs that could potentially support the decisions of clinicians and public health officials, the authors found that the literature provides little information about the accuracy of these systems.

Assessing the performance of a computer-based policy model of HIV and AIDS.

BACKGROUND: Model-based analyses, conducted within a decision analytic framework, provide a systematic way to combine information about the natural history of disease and effectiveness of clinical management strategies with demographic and epidemiological characteristics of the population. Among the challenges with disease-specific modeling include the need to identify influential assumptions and to assess the face validity and internal consistency of the model. METHODS AND FINDINGS: We describe a series of exercises involved in adapting a computer-based simulation model of HIV disease to the Women's Interagency HIV Study (WIHS) cohort and assess model performance as we re-parameterized the model to address policy questions in the U.S. relevant to HIV-infected women using data from the WIHS. Empiric calibration targets included 24-month survival curves stratified by treatment status and CD4 cell count. The most influential assumptions in untreated women included chronic HIV-associated mortality following an opportunistic infection, and in treated women, the 'clinical effectiveness' of HAART and the ability of HAART to prevent HIV complications independent of virologic suppression. Good-fitting parameter sets required reductions in the clinical effectiveness of 1st and 2nd line HAART and improvements in 3rd and 4th line regimens. Projected rates of treatment regimen switching using the calibrated cohort-specific model closely approximated independent analyses published using data from the WIHS. CONCLUSIONS: The model demonstrated good internal consistency and face validity, and supported cohort heterogeneities that have been reported in the literature. Iterative assessment of model performance can provide information about the relative influence of uncertain assumptions and provide insight into heterogeneities within and between cohorts. Description of calibration exercises can enhance the transparency of disease-specific models.