Coronary Artery Motion and Cardiac Phases: Dependency on Heart Rate—Implications for CT Image Reconstruction

Abstract

This study had institutional review board approval; written informed consent was obtained. The purpose was to prospectively determine the heart rate (HR) dependency of three-dimensional (3D) coronary artery motion by incorporating into analysis the durations of systole and diastole. Thirty patients (seven women, 23 men; mean age, 56.6 years +/- 12.7 [standard deviation]; HR: 45-100 beats per minute) underwent electrocardiographically gated 64-section computed tomographic (CT) coronary angiography to determine coronary motion velocities at bifurcation points. Significance of velocity differences (P < .05) was determined by using analysis of variance for repeated measures and Bonferroni post hoc tests. HR dependency was determined by using linear regression analysis. HR significantly affected 3D coronary motion (r = 0.47, P < .009) through nonproportional shortening of systole and diastole (r = -0.82, P < .001), leading to percentage reconstruction interval shifts of coronary velocity troughs and peaks (P < .01). Results suggest that image reconstruction algorithms at CT coronary angiography be adapted to the individual patient's HR.

Reconstruction of coronary arteries from X-ray angiography: A review

“…Specifically, this signal is used to assign cardiac phases to the collected X-ray images assuming a cyclic heart motion ( Figure 5). Typically, the phases of least motion, endsystole and end-diastole (Shechter et al, 2006;Husmann et al, 2007), are employed for gating to obtain a higher 3D reconstruction quality.…”

“…Because of the heart rate differences and other special conditions (e.g. arrhythmia) of the patients, the optimal cardiac phase for reconstruction is different between the patients (Husmann et al, 2007). Moreover, it is known that the reconstruction quality varies among different cardiac phases (Schäfer et al, 2006).…”

C-arm CT: Reconstruction of dynamic high contrast objects applied to the coronary sinus

“…in cardiac imaging, the true object motion is unknown. However, from physiology [14] or measurements using a CT scanner [15] general properties of the object motion can be derived and phases of rest or rapid motion can be identified. In cardiac imaging the motion characteristics are heart rate dependent.…”

“…The black line shows the mean velocity of points located on the coronary tree dependent on the motion phase according to [15]. As can be seen the velocity curve has two troughs, i.e.…”

“…If the two volumes are perfectly aligned the energy functional F will be minimized. The black line shows the relative mean velocity of points located on the coronary artery tree depending on the relative heart phase according to [15]. (a) shows a set of 10 equidistantly spaced rectangular gating functions including all projection images.…”