Phase analysis detects heterogeneity of myocardial deformation on cine MRI

Abstract

Objectives. Myocardial scar will lead to heterogeneous left ventricular deformation. We hypothesized that a myocardial scar will display an elevated standard deviation (SD) of phase and that this effect could be compared with mechanical dispersion. Design. Thirty patients (three women and 27 men) were investigated over 4–8 weeks after ST-elevation myocardial infarction treated with percutaneous coronary intervention. Seventeen had a scar area > 75% in at least one antero- or inferoseptal segment (scar) and 13 had a scar area < 1% (non-scar). The phase delays of velocity, displacement, and strain were measured in the longitudinal direction, tangential to the endocardial outline, and in the radial direction, perpendicular to the tangent. Results. The SD of phase in radial measurements differentiated scar patients from those without scar (p < 0.01), while longitudinal measurements did so only for longitudinal strain. Likewise, the SD for radial measurements of time to peak for segmental velocity, displacement, and strain performed better than longitudinal measurements and equal to the results of phase. Conclusion. Phase dispersion in deformation imaging may be used for detecting heterogeneous left ventricular contraction.

Key words::

• cardiac function tests
• magnetic resonance imaging
• myocardial strain
• phase analysis
• mechanical dispersion

Acknowledgements

We gratefully acknowledge Johan Kihlberg, RN, and the MRI technicians at CMIV for scanning the patients and Elisabeth Logander, RN, for coordinating patient recruitment. Professor Gianni Pedrizzetti, University of Trieste, and Rolf Baumann, chief technology officer of Tomtec, provided fruitful discussions on issues regarding phase.

Funding

Futurum – the Academy for healthcare, Jonkoping County Council [grant 5339], the Swedish Heart Lung Foundation [grant 20120449], the Medical Research Council of Southeast Sweden [grant 4138], and CMIV, Linkoping University.

Financial disclosures

None.

Declaration of interest: The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper.