CT coronary angiography: 256-slice and 320-detector row scanners

Abstract

Multidetector computed tomography (MDCT) has rapidly evolved from 4-detector row systems in 1998 to 256-slice and 320-detector row CT systems. With smaller detector element size and faster gantry rotation speed, spatial and temporal resolution of the 64-detector MDCT scanners have made coronary artery imaging a reliable clinical test. Wide-area coverage MDCT, such as the 256-slice and 320-detector row MDCT scanners, has enabled volumetric imaging of the entire heart free of stair-step artifacts at a single time point within one cardiac cycle. It is hoped that these improvements will be realized with greater diagnostic accuracy of CT coronary angiography. Such scanners hold promise in performing a rapid high quality "triple rule-out" test without high contrast load, improved myocardial perfusion imaging, and even four-dimensional CT subtraction angiography. These emerging technical advances and novel applications will continue to change the way we study coronary artery disease beyond detecting luminal stenosis.

Fig. 1

Whole intracoronary endothelial shear stress (ESS) mapping from single-heartbeat 320-detector row CT (Toshiba Aquilion One Dynamic Volume CT; Tochigi, Japan) after injection of 80 mL of iopamidol, 370 mg I/mL (Isovue-370; Bracco Diagnostics, Princeton, NJ), followed by 40 mL of normal saline injected with a dual injector (EZEM Empower CTA DUAL Injector; EZEM Inc., Lake Success, NY). Three-dimensional volume-rendered images generated from Vitrea 4.1 software (Vital Images, Minnetonka, MN) (left side). Corresponding ESS maps (right side). Simulated blood flow uses a computational fluid dynamic technique. (Adapted from Ramkumar et al. [59]; with permission)