 Introduction/Background Patients who present with acute chest pain in the setting of nonspecific signs and symptoms, and a low pretest probability for coronary disease, remain an important clinical management dilemma. This is largely related to the competing imperatives of the medical and legal implications of an undiagnosed acute cardiac event as well as the impact on patient flow and hospital use of efficaciously triaging such low-risk cardiac patients, especially in the emergency room [1]. In the current era, there is great imperative to bring to bear a range of advances, including improved clinical algorithms such as the HEART (history electrocardiogram age risk factors troponin) scoring system [2-5], newer biochemical tests, such as high sensitivity troponins [6-11], and newer advanced imaging modalities, such as coronary artery CT [12-14]. Patient management approaches are exploring integration of these procedure advances in the context of clinical decision units/observational units [15,16]. This publication will focus on the evidence for use of individual imaging approaches, in the context of an integrated decision-making setting. All elements are essential: 1) timing, 2) reconstructions/reformats, and 3) 3-D renderings. Standard CTs with contrast also include timing issues and recons/reformats. Only in CTA, however, is 3-D rendering a required element. This corresponds to the definitions that CMS has applied to the Current Procedural Terminology codes. Reprint requests to: publications@acr.org Acute Nonspecific Chest Pain OR Discussion of Procedures by Variant Variant 1: Acute nonspecific chest pain; low probability of coronary artery disease. Initial imaging.
Acute Nonspecific Chest Pain Low Probability of Coronary Artery Disease PCAs.  Introduction/Background Patients who present with acute chest pain in the setting of nonspecific signs and symptoms, and a low pretest probability for coronary disease, remain an important clinical management dilemma. This is largely related to the competing imperatives of the medical and legal implications of an undiagnosed acute cardiac event as well as the impact on patient flow and hospital use of efficaciously triaging such low-risk cardiac patients, especially in the emergency room [1]. In the current era, there is great imperative to bring to bear a range of advances, including improved clinical algorithms such as the HEART (history electrocardiogram age risk factors troponin) scoring system [2-5], newer biochemical tests, such as high sensitivity troponins [6-11], and newer advanced imaging modalities, such as coronary artery CT [12-14]. Patient management approaches are exploring integration of these procedure advances in the context of clinical decision units/observational units [15,16]. This publication will focus on the evidence for use of individual imaging approaches, in the context of an integrated decision-making setting. All elements are essential: 1) timing, 2) reconstructions/reformats, and 3) 3-D renderings. Standard CTs with contrast also include timing issues and recons/reformats. Only in CTA, however, is 3-D rendering a required element. This corresponds to the definitions that CMS has applied to the Current Procedural Terminology codes. Reprint requests to: publications@acr.org Acute Nonspecific Chest Pain OR Discussion of Procedures by Variant Variant 1: Acute nonspecific chest pain; low probability of coronary artery disease. Initial imaging.