Actual Dose-Reduction Strategies in Cardiac Computed Tomography

Abstract

Computed tomography (CT) in cardiac examination is a powerful imaging tool that has developed rapidly during the last decade and continues to increase its potential by bringing novel technologies. Due to its noninvasive character, cardiac CT became a largely used method in detecting coronary diseases or functional issues at the expense of conventional coronary angiography. The accuracy of images has also increased, especially since new generation dual-source multi-slice detectors were developed. Although there are continuous improvements that serve to gain better-quality images, thus increasing their diagnostic accuracy, there is an inconvenient that became a serious topic for debate in the current literature: exposure to higher doses of radiation during cardiac CT examinations. Fortunately, physicians and manufacturers are taking into consideration the need to apply new strategies for radiation dose-reduction. Thus, this objective can be achieved by using patient-tailored dose-reduction strategies and by modulating the technical features of the CT scanners in order to gather highquality images with minimal radiation exposure. The aim of this manuscript was to review the current literature data on dose-reduction strategies that are used for cardiovascular computed tomography scans.

Image Quality and Dose Reduction by Dual Source Computed Tomography Coronary Angiography: Protocol Comparison

“…Indeed, in retrospective ECG-gated CTCA, radiation dose has been considered very high 22,23 but, on the other hand, it is useful to assess cardiac function, since data acquisition covers all phases of the cardiac cycle; in addition, the flexibility and reliability of phase reconstruction is the highest when compared to other strategies. 24 The SAS mode is characterized by turning on the X-ray tube only at a predefined time point of the cardiac cycle, usually in mid-to-end diastole, while keeping the patient table stationary. This has resulted in a significant radiation dose reduction from over 20 mSv to around 2 mSv by confining the CT scan to the smallest possible window at only 1 distinct mid- Abbreviations: HR, heart rate; DLP, dose length product; SNR, signal to noise ratio; CNR, contrast to noise ratio; A, maximum intensity projections (MIP); B, curved multiplanar reformations (c-MPR)R; C, conventional angiography; d, 3D volume rendering images.…”