Validation of in vivo 2D displacements from spiral cine DENSE at 3T

Journal of Cardiovascular Magnetic Resonance

Research

David K Powell¹  Gregory J Wehner¹  Brandon K Fornwalt²  Frederick H Epstein³  Sean M Hamlet⁴  Jonathan D Suever⁵  Walter Dimitri Mojsejenko⁵  Jonathan D Grabau⁵  Linyuan Jing⁵  Christopher M Haggerty⁵  Xiaodong Zhong⁶ 

[1]Department of Biomedical Engineering, University of Kentucky, 741 S Limestone, BBSRB B353, 40509, Lexington, KY, USA

[2]Department of Biomedical Engineering, University of Kentucky, 741 S Limestone, BBSRB B353, 40509, Lexington, KY, USA

[3]Department of Pediatrics, University of Kentucky, Lexington, USA

[4]Departments of Physiology and Medicine, University of Kentucky, Lexington, USA

[5]Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA

[6]Department of Electrical Engineering, University of Kentucky, Lexington, USA

[7]Department of Pediatrics, University of Kentucky, Lexington, USA

[8]MR R&D Collaborations, Siemens Healthcare, Atlanta, GA, USA

关键词: DENSE;    Displacement;    Cardiac mechanics;    Spiral;    Strain;    Torsion;    3T;    Cardiovascular magnetic resonance;   

DOI  :  10.1186/s12968-015-0119-z

 received in 2014-04-11, accepted in 2015-01-13,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundDisplacement Encoding with Stimulated Echoes (DENSE) encodes displacement into the phase of the magnetic resonance signal. Due to the stimulated echo, the signal is inherently low and fades through the cardiac cycle. To compensate, a spiral acquisition has been used at 1.5T. This spiral sequence has not been validated at 3T, where the increased signal would be valuable, but field inhomogeneities may result in measurement errors. We hypothesized that spiral cine DENSE is valid at 3T and tested this hypothesis by measuring displacement errors at both 1.5T and 3T in vivo.MethodsTwo-dimensional spiral cine DENSE and tagged imaging of the left ventricle were performed on ten healthy subjects at 3T and six healthy subjects at 1.5T. Intersection points were identified on tagged images near end-systole. Displacements from the DENSE images were used to project those points back to their origins. The deviation from a perfect grid was used as a measure of accuracy and quantified as root-mean-squared error. This measure was compared between 3T and 1.5T with the Wilcoxon rank sum test. Inter-observer variability of strains and torsion quantified by DENSE and agreement between DENSE and harmonic phase (HARP) were assessed by Bland-Altman analyses. The signal to noise ratio (SNR) at each cardiac phase was compared between 3T and 1.5T with the Wilcoxon rank sum test.ResultsThe displacement accuracy of spiral cine DENSE was not different between 3T and 1.5T (1.2 ± 0.3 mm and 1.2 ± 0.4 mm, respectively). Both values were lower than the DENSE pixel spacing of 2.8 mm. There were no substantial differences in inter-observer variability of DENSE or agreement of DENSE and HARP between 3T and 1.5T. Relative to 1.5T, the SNR at 3T was greater by a factor of 1.4 ± 0.3.ConclusionsThe spiral cine DENSE acquisition that has been used at 1.5T to measure cardiac displacements can be applied at 3T with equivalent accuracy. The inter-observer variability and agreement of DENSE-derived peak strains and torsion with HARP is also comparable at both field strengths. Future studies with spiral cine DENSE may take advantage of the additional SNR at 3T.

【 授权许可】

Unknown   
© Wehner et al.; licensee BioMed Central. 2015. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.