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Assessment of cardiac time intervals using high temporal resolution real‐time spiral phase contrast with UNFOLDed‐SENSE
Author(s) -
Kowalik Grzegorz T.,
Knight Daniel S.,
Steeden Jennifer A.,
Tann Oliver,
Odille Freddy,
Atkinson David,
Taylor Andrew,
Muthurangu Vivek
Publication year - 2015
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.25183
Subject(s) - spiral (railway) , temporal resolution , contrast (vision) , gold standard (test) , sliding window protocol , dimension (graph theory) , biomedical engineering , computer science , mathematics , nuclear magnetic resonance , medicine , physics , artificial intelligence , window (computing) , optics , mathematical analysis , pure mathematics , operating system
Purpose To develop a real‐time phase contrast MR sequence with high enough temporal resolution to assess cardiac time intervals. Methods The sequence utilized spiral trajectories with an acquisition strategy that allowed a combination of temporal encoding (Unaliasing by fourier‐encoding the overlaps using the temporal dimension; UNFOLD) and parallel imaging (Sensitivity encoding; SENSE) to be used (UNFOLDed‐SENSE). An in silico experiment was performed to determine the optimum UNFOLD filter. In vitro experiments were carried out to validate the accuracy of time intervals calculation and peak mean velocity quantification. In addition, 15 healthy volunteers were imaged with the new sequence, and cardiac time intervals were compared to reference standard Doppler echocardiography measures. For comparison, in silico, in vitro, and in vivo experiments were also carried out using sliding window reconstructions. Results The in vitro experiments demonstrated good agreement between real‐time spiral UNFOLDed‐SENSE phase contrast MR and the reference standard measurements of velocity and time intervals. The protocol was successfully performed in all volunteers. Subsequent measurement of time intervals produced values in keeping with literature values and good agreement with the gold standard echocardiography. Importantly, the proposed UNFOLDed‐SENSE sequence outperformed the sliding window reconstructions. Conclusion Cardiac time intervals can be successfully assessed with UNFOLDed‐SENSE real‐time spiral phase contrast. Real‐time MR assessment of cardiac time intervals may be beneficial in assessment of patients with cardiac conditions such as diastolic dysfunction. Magn Reson Med 73:749–756, 2015. © 2014 Wiley Periodicals, Inc.