DENSE and HARP: two views on the same technique of phase-based strain imaging

Area of Science:

• Cardiovascular Imaging
• Biomedical Engineering
• Medical Physics

Background:

• Harmonic phase (HARP) and displacement encoding with stimulated echoes (DENSE) are key techniques in cardiac motion analysis.
• Historically, HARP evolved from myocardial tagging, while DENSE originated from stimulated echo and displacement encoding principles.

Purpose of the Study:

• To critically evaluate and compare the imaging and reconstruction strategies of DENSE and HARP.
• To elucidate the actual differences and similarities between these two prominent phase-based strain imaging techniques.

Main Methods:

• A detailed point-by-point discussion comparing HARP and DENSE methodologies.
• Examination of the historical development and recent advancements in both techniques.
• Analysis of imaging and reconstruction strategies employed by HARP and DENSE.

Main Results:

• Apparent differences between HARP and DENSE are largely non-existent upon closer examination.
• Both techniques have evolved, incorporating similar improvements and diminishing distinct features.
• The underlying principles and applications show significant overlap.

Conclusions:

• HARP and DENSE are often treated as distinct, but a more unified approach is warranted.
• Merging the frameworks of HARP and DENSE simplifies understanding of their respective advantages and disadvantages.
• A generalized framework enhances comprehension of phase-based strain imaging beyond individual techniques.