Prognostic Performance of Prospective versus Retrospective Electrocardiographic Gating in Coronary Computed Tomographic Angiography

DIAGNOSTIC REFERENCE LEVELS OF CARDIAC COMPUTED TOMOGRAPHY ANGIOGRAPHY IN A SINGLE MEDICAL CENTER IN TAIWAN: A 3-Y ANALYSIS

This study aimed to establish the diagnostic reference levels (DRLs) for coronary computed tomography angiography (CCTA) and coronary arterial calcium score (CACS) owing to a large variability in patient radiation dose and the lack of dose recommendations in Taiwan. Volume computed tomography dose index (CTDIvol) and dose-length product (DLP) were obtained using CCTAs and the CACS of 445 patients over a 3-y period in a single medical center in Taiwan. CCTAs were performed using routine protocols and 256-detector CT scanners. Electrocardiogram gating was retrospective. The obtained data were analyzed using Prism 6 to determine the 25th, 50th (median) and 75th DRL percentiles for CTDIvol and DLP. These DRL results were compared with existing DRLs from seven countries. The DRLs for CCTA determined from this survey were similar to the existing data from other countries. Such DRLs could provide a useful tool for the optimization of radiation dose for CCTA in Taiwan.

Discrepancies in Measurement of the Thoracic Aorta: JACC Review Topic of the Week

Clinicians often encounter discrepant measurements of the ascending aorta that impede, complicate, and impair appropriate clinical assessment-including key issues of presence or absence of aortic growth, rate of growth, and need for surgical intervention. These discrepancies may arise within a single modality (computed tomography scan, magnetic resonance imaging, or echocardiography) or between modalities. The authors explore the origins and significance of these discrepancies, revealing that some "truth" usually underlies all the discrepant measurements, which individually look at the ascending aorta with different perspectives and dimensional definitions. The authors conclude with a practical "question and answer" section that addresses common specific issues in interpretation and management of patients in the real-world setting.