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Background: Postacute Covid‐19 patients commonly present with respiratory symptoms; however, a noninvasive imaging method for quantitative characterization of respiratory patterns is lacking. Purpose: To evaluate if quantitative characterization of respiratory pattern on free‐breathing higher temporal resolution MRI stratifies patients by cardiopulmonary symptom burden. Study Type: Prospective analysis of retrospectively acquired data. Subjects: A total of 37 postacute Covid‐19 patients (25 male; median [interquartile range (IQR)] age: 58 [42–64] years; median [IQR] days from acute infection: 335 [186–449]). Field Strength/Sequence: 0.55 T/two‐dimensional coronal true fast imaging with steady‐state free precession (trueFISP) at higher temporal resolution. Assessment: Patients were stratified into three groups based on presence of no (N = 11), 1 (N = 14), or ≥2 (N = 14) cardiopulmonary symptoms, assessed using a standardized symptom inventory within 1 month of MRI. An automated lung postprocessing workflow segmented each lung in each trueFISP image (temporal resolution 0.2 seconds) and respiratory curves were generated. Quantitative parameters were derived including tidal lung area, rates of inspiration and expiration, lung area coefficient of variability (CV), and respiratory incoherence (departure from sinusoidal pattern) were. Pulmonary function tests were recorded if within 1 month of MRI. Qualitative assessment of respiratory pattern and lung opacity was performed by three independent readers with 6, 9, and 23 years of experience. Statistical Tests: Analysis of variance to assess differences in demographic, clinical, and quantitative MRI parameters among groups; univariable analysis and multinomial logistic regression modeling to determine features predictive of patient symptom status; Akaike information criterion to compare the quality of regression models; Cohen and Fleiss kappa (κ) to quantify inter‐reader reliability. Two‐sided 5% significance level was used. Results: Tidal area and lung area CV were significantly higher in patients with two or more symptoms than in those with one or no symptoms (area: 15.4 cm2 vs. 12.9 cm2 vs. 12.8 cm2; CV: 0.072, 0.067, and 0.058). Respiratory incoherence was significantly higher in patients with two or more symptoms than in those with one or no symptoms (0.05 vs. 0.043 vs. 0.033). There were no significant differences in patient age (P = 0.19), sex (P = 0.88), lung opacity severity (P = 0.48), or pulmonary function tests (P = 0.35–0.97) among groups. Qualitative reader assessment did not distinguish between groups and showed slight inter‐reader agreement (κ = 0.05–0.11). Data Conclusion: Quantitative respiratory pattern measures derived from dynamic higher‐temporal resolution MRI have potential to stratify patients by symptom burden in a postacute Covid‐19 cohort. Level of Evidence: 3 Technical Efficacy: Stage 3 [ABSTRACT FROM AUTHOR]

A variety of thoracic imaging modalities and techniques have been used to evaluate diseases of the trachea and central bronchi. This document evaluates evidence for the use of thoracic imaging in the evaluation of tracheobronchial disease, including clinically suspected tracheal or bronchial stenosis, tracheomalacia or bronchomalacia, and bronchiectasis. Appropriateness guidelines for initial imaging evaluation of tracheobronchial disease and for pretreatment planning or posttreatment evaluation are included. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation. [ABSTRACT FROM AUTHOR]

Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. A search for the underlying cause of infection typically includes radiological imaging as part of this investigation. This document focuses on thoracic and abdominopelvic causes of sepsis. In 2017, the global incidence of sepsis was estimated to be 48.9 million cases, with 11 million sepsis-related deaths (accounting for nearly 20% of all global deaths); therefore, understanding which imaging modalities and types of studies are acceptable or not acceptable is imperative. The 5 variants provided include the most commonly encountered scenarios in the setting of sepsis along with recommendations and data for each imaging study. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation. [ABSTRACT FROM AUTHOR]

The source of a majority (more than 80%) of high-consequence marine accidents can be attributed to compounded human and organizational errors (HOE). Recent examples include the Exxon Valdez tanker grounding (258,000 barrels of oil spilled), and the Occidental Piper Alpha platform explosions and fires (167 men killed). Currently, there is no structured quantitative approach to assist engineers, operators, and regulators of marine systems to either design HOE tolerant systems or to include considerations of HOE as an integral part of the design, construction, and operation of marine systems. The human element has generally been ignored.The objective of this dissertation is to introduce a quantitative modeling methodology to assess the impacts of HOE in operation of tankers and offshore platforms. This methodology includes a systematic approach to structuring critical elements that lead to accident scenarios and a quantitative modeling procedure to assess the impacts of operational risks under various operating conditions that can lead to these scenarios.The modeling methodology incorporates structuring accident scenarios into underlying, direct, and compounding factors. Diagrammatic representations of the unique factors leading to accident scenarios using influence diagrams are proposed. The diagrams are used to develop simplified general "templates" for that particular class of accident. The function of the templates are to form a basis that preserve the central causative mechanisms for a similar operation, yet do not preserve the unique aspects of the disaster being modeled.Insufficient and unreliable data linking complex effects of human errors to marine casualties has led to limitations in quantitative human error modeling. A quantitative measuring technique, the Human Error Safety Index Method (HESIM), has been proposed that measures organizational, task and system complexities, and environmental factors that affect operators abilities to perform decisions and actions to mitigate or aggravate accident events. These measurement techniques rely upon judgments and experiences of those familiar with the operations being modeled and objective data to formulate a "safety index". A methodology for coiiection of the objective data, the Human and Organizational Error Data Quantification System (HOEDQS), is also proposed. The HOEDQS allows updating of human errors such that there becomes a greater reliance upon objective data and less upon the judgmental indexing procedure.Two marine casualties were identified as case study examples for confirmation of the modeling procedures: the Exxon Valdez and Piper Alpha disasters. These casualties were selected because of the quality, completeness, accessibility, and availability of information related to the accident events. The unique aspects of each disaster are modeled and templates are developed. Quantitative analyses were performed on each operation to confirm that high risk levels were measured conditional upon the operating factors for each disaster. The results from this dissertation will be of interest to engineers, operators, managers, and regulators concerned with preventing and mitigating the effects of HOE to increase safety of marine systems.