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Rapid breath‐hold assessment of myocardial velocities using spiral UNFOLD‐ed SENSE tissue phase mapping
Author(s) -
Kowalik Grzegorz T.,
Muthurangu Vivek,
Khushnood Abbas,
Steeden Jennifer A.
Publication year - 2016
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.25218
Subject(s) - scanner , spiral (railway) , computer science , acceleration , image quality , noise (video) , artificial intelligence , nuclear medicine , biomedical engineering , computer vision , physics , image (mathematics) , medicine , mathematics , mathematical analysis , classical mechanics
Purpose To develop and validate a rapid breath‐hold tissue phase mapping (TPM) sequence. Materials and Methods The sequence was based on an efficient uniform density spiral acquisition, combined with data acceleration. A novel acquisition and reconstruction strategy enabled combination of UNFOLD (2×) and SENSE (3×): UNFOLD‐ed SENSE. The sequence was retrospectively cardiac‐gated, and a graphics processing unit (GPU) was used for rapid “online” reconstruction. The optimal UNFOLD parameters for the data were calculated using an in silico model. The technique was validated on a 1.5T MR scanner in 15 patients with known aortic valve disease, against a respiratory self‐navigated free‐breathing TPM technique. Quantitative image quality measures (velocity‐to‐noise and edge sharpness) were made as well as calculation of longitudinal, radial, and tangential myocardial velocities in the left ventricle. Results The proposed breath‐hold TPM data took eight heartbeats to acquire. The breath‐hold TPM images had significantly higher edge sharpness ( P = 0.0014) than the self‐navigated TPM images, but with significantly lower velocity‐to‐noise ratio ( P < 0.0001). There was excellent agreement ( r > 0.94) in the longitudinal, radial, and tangential velocities between the self‐navigated data and the proposed breath‐hold TPM sequence. Conclusion We demonstrate the feasibility of using spiral UNFOLD‐ed SENSE to measure myocardial velocities using a rapid breath‐hold spiral TPM sequence. This novel technique might enable accurate measurement of myocardial velocities, in a short scan time, which is especially important in a busy clinical workflow. J. MAGN. RESON. IMAGING 2016;44:1003–1009.