CCTA growing pains

Coronary CT angiography (CCTA) holds tremendous promise for cardiac imaging, but growing pains still exist. Two of the top stories from the last month demonstrate both the recent advancements in CCTA and some of the challenges limiting its use.

On the positive side, researchers from Yonsei University College of Medicine, Seoul, Korea, found objective CCTA image quality could be significantly improved and radiation doses reduced by combining iterative reconstruction with automatic tube potential selection featuring tube current modulation (APSCM).

The study, published in the August issue of Radiology, showed the potential benefits of using APSCM over the commonly used body mass index-based protocol. APSCM automatically selects appropriate kilovolt and milliampere second settings for each patient to maintain a set contrast-to-noise ratio selected by the user. At the same time, the study also wanted to determine the effect of sonogram-affirmed iterative reconstruction (SAFIRE) compared with traditional filtered back projection (FBP).

The retrospective analysis included more than 380 patients, and found that the combination of APSCM and SAFIRE resulted in a 29 percent decrease in image noise and a 41 percent increase in signal-to-noise ratio compared with the FBP group. It also edged out the BMI-based protocol group for objective measures of quality.

Less heartening news came from a study in the September issue of Academic Radiology, which found CCTA, when used as a decision-making test, may lead cardiac surgeons to overestimate coronary artery disease (CAD) severity similar to rates reported for cardiologists and radiologists. The current reference standard for diagnosing CAD, catheter coronary angiogram (CCA), costs more than CCTA and is more invasive, but authors Aine M. Kelly, MD, MS, University of Michigan Hospitals, Ann Arbor, and colleagues explained that cardiac surgeons aren’t as confident basing decisions on CCTA.

“Surgeons' confidence with CCTA may remain low until its use is routinely introduced into surgical training and they become just as familiar with it, as they are for CCA,” they wrote.

As researchers continue to refine the appropriate use of CCTA and the technique becomes more familiar, confidence in the technology can only grow.

Evan Godt
Editor – Health Imaging