Purpose A new form of functional imaging has been proposed in the form of 4DCT-ventilation. Because 4DCTs are acquired as part of routine care for lung cancer patients, calculating ventilation maps from 4DCTs provides spatial lung function information without added dosimetric or monetary cost to the patient. Before 4DCT-ventilation is implemented it needs to be clinically validated. Pulmonary function tests (PFTs) provide a clinically established way of evaluating lung function. The purpose of our work was to perform a clinical validation by comparing 4DCT-ventilation metrics with PFT data. Methods and Materials Ninety-eight lung cancer patients with pre-treatment 4DCT and PFT data were included in the study. PFT metrics used to diagnose obstructive lung disease were recorded: forced expiratory volume in 1 second (FEV1) and FEV1/forced vital capacity (FEV1/FVC). 4DCT data sets and spatial registration were used to compute 4DCT-ventilation images using a density-change based and a Jacobian-based model. The ventilation maps were reduced to single metrics intended to reflect the degree of ventilation obstruction. Specifically, we computed the coefficient of variation (CoV) (standard deviation/mean), ventilation V20 (volume of lung ≤20% ventilation), and correlated the ventilation metrics with PFT data. Regression analysis was used to determine whether 4DCT-ventilation data could predict for normal versus abnormal lung function using PFT thresholds. Results Correlation coefficients comparing 4DCT-ventilation to PFT data ranged from 0.63–0.72 with the best agreement between FEV1 and CoV. 4DCT-ventilation metrics were able to significantly delineate between clinically normal versus abnormal PFT results. Conclusions Validation of 4DCT-ventilation with clinically relevant metrics is essential. We demonstrate good global agreement between PFTs and 4DCT-ventilation, indicating that 4DCT ventilation provides a reliable assessment of lung function. 4DCT-ventilation enables exciting opportunities to assess lung function and create functional avoidance radiotherapy plans. The current work presents supporting evidence for the integration of 4DCT-ventilation into clinical trials.
As highly visible representatives and guardians of society, law enforcement officers (LEOs) are very public figures. Injury or death in the line of duty, whether due to accidents or intentional acts of violence, is an occupational hazard for LEOs. Targeted assaults on police officers, referred to as ambushes in previous literature, are a particularly perplexing problem with significant implications for society at large. In the summer of 2016, the latest in a series of high-profile acts of violence aimed at police occurred, leading to increased examination of the acts themselves and their causes. This article examines recent trends in assaults on LEOs, focusing on predatory rather than reactive attacks, and applies a threat assessment model to a case of targeted violence against police. We use State of Washington v. Christopher Monfort (2015), a prosecution for arson, assault with intent to murder, and murder, as a case example, to examine how the threat assessment model, and the concepts of affective versus predatory violence help in understanding targeted violence against LEOs, assessing its risk, and managing it. Copyright © 2016 John Wiley & Sons, Ltd.
This chapter examines the law enforcement role when responding to an event involving lone-actor violence. This role can be proactive and preventive, with federal, state, and local agencies forming partnerships to facilitate communication and intelligence-sharing. This is an ongoing process to enhance cross-systems collaboration to assess, intervene, and manage individuals of concern before an act of violence occurs. Later in the chapter, the reactive nature of the law enforcement response is covered, starting with the immediate response to an event with a discussion regarding tactics used to locate and neutralize threats and arrange for a medical response. General concepts such as incident management and notification/incorporation of outside agencies are discussed, as well as the emotional toll that first responders experience. The early stages of the criminal investigation are then covered, highlighting the need for both a central overarching investigative organization as well as robust local participation.
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