Cardiac Computed Tomography: Technology in Rapid Evolution

From resting electrocardiogram (ECG) to stress ECG, stress echocardiography, and nuclear perfusion imaging , noninvasive cardiovascular imaging has significantly improved the clinician’s ability to detect coronary artery disease (CAD). Yet, the holy grail of assessing CAD has been the direct visualization of the coronary arteries. Today, invasive cardiac catheterization and intravascular ultrasound remain the gold standards for detecting coronary stenosis and atherosclerotic plaques. These invasive procedures, however, carry significant costs and procedural risks. Therefore, the development of noninvasive imaging techniques capable of evaluating the coronary anatomy would have a huge impact in managing patients with suspected CAD or at risk of developing CAD.

Until now, noninvasive imaging of the coronary arteries has been a challenge. The coronary vessels are small and move with the cardiac cycle and with respiration, so any noninvasive technique would need to have tremendously high spatial and temporal resolution to obtain accurate images of the coronary tree. Over the past decade, hardware and software technological advances in computed tomography (CT) have met these challenges. Single-slice scanners with inadequate resolution for cardiac application have given way to the current generation multislice (up to 320-slice) scanners with submillimeter and almost heart-freezing temporal resolution, enabling accurate noninvasive assessment of coronary arteries.