Image courtesy of Vital Images.

Utilization of 64-slice multidetector CT (MDCT) to depict a 3D representation of shear stress distribution along coronary lumen might be useful for assessing the role of shear stress in atherosclerotic plaque formation for its progression or regression, according to a presentation at the American Heart Association conference held this week in Orlando, Fla.

Yusaku Fukumoto of Shuto General Hospital in Yanai, Japan and Masunori Matsuzaki of Yamaguchi University in Ube, Japan, were lead investigators for the study.

Prior to the study, the researchers knew that shear stress is one of the important physical factors in the process of arterial vessel, which is subjected to lower shear stress. It is most likely to be assessed with plaque information. However, noninvasive visualization of shear stress distribution along the coronary lumen in vivo has been technically difficult.

The study sought to develop a noninvasive way of color mapping of shear stress in the coronary artery using a 64-slice MDCT, and to preliminarily evaluate its clinical feasibility.

They used a three-step method:

• 3D luminal mesh polygens are reconstructed from the images of MDCT in vivo;
• Colorized mapping of shear stress distribution with a finite element method; and
• A relationship between the degree of shear stress and the site of plaque accumulation within the coronary artery was examined.

Fukumoto and colleagues acquired 3D images using a Toshiba Medical Systems’ Aquilion 64-slice MDCT. The spatial resolution of the mesh polygen was approximately 0.05mm². The computational fluid dynamic simulation was performed with the finite element model. Then, color mapping of shear stress distribution was performed, the researchers said.

The researchers concluded that “a noninvasive color-mapping of shear stress along the coronary artery in vivo could be represented by using 64-slice MDCT.”

Additionally, atherosclerotic plaque formation was observed in the distal inner curvature of the bended site and in the outer side of the bifurcation with a large daughter vessel. The colorized mapping revealed that shear stress tended to be lower at the site of plaque accumulation within the coronary artery.