A whole-heart coronary imaging approach allowing interactive selection of the acquisition window increased lumen-to-myocardium contrast-to-noise ratio by 30% compared to a standard fixed window.
Observational (n=8)
No
Does a whole-heart coronary imaging approach with flexible trigger delay improve coronary visualization and sharpness compared to a standard fixed window in healthy subjects?
A flexible acquisition window with interactive trigger delay selection improves coronary MRI visualization and sharpness compared to standard fixed-window techniques.
Effect estimate: 30% increase
p-value: p=<0.005
Coronary magnetic resonance imaging (MRI) requires a correctly timed trigger delay derived from a scout cine scan to synchronize k-space acquisition with the quiescent period of the cardiac cycle. However, heart rate changes between breath-held cine and free-breathing coronary imaging may result in inaccurate timing errors. Additionally, the determined trigger delay may not reflect the period of minimal motion for both left and right coronary arteries or different segments. In this work, we present a whole-heart coronary imaging approach that allows flexible selection of the trigger delay timings by performing k-space sampling over an enlarged acquisition window. Our approach addresses coronary motion in an interactive manner by allowing the operator to determine the temporal window with minimal cardiac motion for each artery region. An electrocardiogram-gated, k-space segmented 3D radial stack-of-stars sequence that employs a custom rotation angle is developed. An interactive reconstruction and visualization platform is then employed to determine the subset of the enlarged acquisition window for minimal coronary motion. Coronary MRI was acquired on eight healthy subjects (5 male, mean age = 37 ± 18 years), where an enlarged acquisition window of 166-220 ms was set 50 ms prior to the scout-derived trigger delay. Coronary visualization and sharpness scores were compared between the standard 120 ms window set at the trigger delay, and those reconstructed using a manually adjusted window. The proposed method using manual adjustment was able to recover delineation of five mid and distal right coronary artery regions that were otherwise not visible from the standard window, and the sharpness scores improved in all coronary regions using the proposed method. This paper demonstrates the feasibility of a whole-heart coronary imaging approach that allows interactive selection of any subset of the enlarged acquisition window for a tailored reconstruction for each branch region.
Kawaji et al. (Thu,) conducted a observational in Healthy (n=8). Flexible acquisition window and trigger delay (manually adjusted window) vs. Standard 120 ms window set at the trigger delay was evaluated on Lumen-to-myocardium contrast-to-noise ratio (CNR) (30% increase, p=<0.005). A whole-heart coronary imaging approach allowing interactive selection of the acquisition window increased lumen-to-myocardium contrast-to-noise ratio by 30% compared to a standard fixed window.