Erschienen in:
24.07.2018 | Research Article
Improved 4D cardiac functional assessment for pediatric patients using motion-weighted image reconstruction
verfasst von:
Ziwu Zhou, Fei Han, Takegawa Yoshida, Kim-Lien Nguyen, John Paul Finn, Peng Hu
Erschienen in:
Magnetic Resonance Materials in Physics, Biology and Medicine
|
Ausgabe 6/2018
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Abstract
Objective
Our aim was to develop and evaluate a motion-weighted reconstruction technique for improved cardiac function assessment in 4D magnetic resonance imaging (MRI).
Materials and methods
A flat-topped, two-sided Gaussian kernel was used to weigh k-space data in each target cardiac phase and adjacent two temporal phases during the proposed phase-by-phase reconstruction algorithm. The proposed method (Strategy 3) was used to reconstruct 18 cardiac phases based on data acquired using a previously proposed technique [4D multiphase steady-state imaging with contrast enhancement (MUSIC) technique and its self-gated extension using rotating Cartesian k-space (ROCK-MUSIC) from 12 pediatric patients. As a comparison, the same data set was reconstructed into nine phases using a phase-by-phase method (Strategy 1), 18 phases using view sharing (Strategy 4), and 18 phases using a temporal regularized method (Strategy 2). Regional image sharpness and left ventricle volumetric measurements were used to compare the four reconstructions quantitatively.
Results
Strategies 1 and 4 generated significantly sharper images of static structures (P ≤ 0.018) than Strategies 2 and 3 but significantly more blurry (P ≤ 0.021) images of the heart. Left ventricular volumetric measurements from the nine-phase reconstruction (Strategy 1) correlated moderately (r < 0.8) with the 2D cine, whereas the remaining three techniques had a higher correlation (r > 0.9). The computational burden of Strategy 2 was six times that of Strategy 3.
Conclusion
The proposed method of motion-weighted reconstruction improves temporal resolution in 4D cardiac imaging with a clinically practical workflow.