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Single heartbeat cardiac tagging for the evaluation of transient phenomena
Author(s) -
Herzka Daniel A.,
Derbyshire J. Andrew,
Kellman Peter,
McVeigh Elliot R.
Publication year - 2005
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.20719
Subject(s) - heartbeat , beat (acoustics) , cardiac cycle , computer science , temporal resolution , artificial intelligence , cardiac imaging , valsalva maneuver , steady state free precession imaging , image resolution , computer vision , physics , magnetic resonance imaging , medicine , optics , cardiology , blood pressure , radiology , computer security
Many cardiac abnormalities are of a transient nature, creating a beat‐to‐beat variation in myocardial function. This work presents the cardiac imaging technique for the measurement of regional function during transient cardiac phenomena. All information necessary for the reconstruction of a cine loop is acquired within a single heartbeat, avoiding the temporal blurring introduced by segmented imaging due to the assumption of cardiac cycle periodicity. This method incorporates a gradient‐optimized, high‐efficiency EPI‐SSFP sequence and TSENSE parallel imaging. For acquisitions with readout resolutions of 128,160, 192, and 256 points, the technique produced images with average temporal resolution of 35, 39, 43, and 52 ms and average spatial resolutions of 2.65, 2.12, 1.77, and 1.32 mm in the readout direction, respectively, and 2.88 and 2.08 mm in the phase encode direction for acceleration rates of 3 and 4, respectively. Local apparent strains in the single slice and measurements of ventricular end‐systolic and end‐diastolic areas were used as quantitative measures to validate the single heartbeat technique. To demonstrate the utility of the sequence, movie loops were acquired for multiple heartbeats in non‐breath‐held acquisitions as well as during a Valsalva maneuver. A heartbeat‐interleaved acquisition allowed for the reconstruction of nonaccelerated images from R contiguous heartbeats. Images reconstructed from such data displayed tag blurring and reduced tag persistence due to motion and interheartbeat variability. Images acquired during the Valsalva maneuver demonstrated apparent beat‐to‐beat variability, visible both in the images and as changing strain patterns and ventricular volumes. Magn Reson Med, 2005. Published 2005 Wiley‐Liss, Inc.