Accelerated two-dimensional cine DENSE cardiovascular magnetic resonance using compressed sensing and parallel...

Area of Science:

• Cardiovascular Imaging
• Medical Physics
• Biomedical Engineering

Background:

• Cine Displacement Encoding with Stimulated Echoes (DENSE) enables quantitative cardiac mechanics analysis but suffers from long acquisition times.
• Compressed sensing (CS) combined with parallel imaging (PI) offers a potential solution for accelerating image acquisition by reconstructing images from undersampled data.
• Developing CS-PI methods for cine DENSE is crucial for improving clinical efficiency and patient comfort.

Purpose of the Study:

• To develop and validate CS-PI accelerated acquisition and reconstruction techniques for cine DENSE.
• To assess the accuracy of these accelerated methods for cardiac imaging using retrospective undersampling.
• To demonstrate the feasibility of prospectively accelerated 2D cine DENSE imaging within a single breathhold.

Main Methods:

• Implemented an accelerated cine DENSE sequence using variable-density spiral k-space sampling and golden angle time-resolved acquisitions.
• Combined a Block LOw-rank Sparsity with Motion-guidance (BLOSM) CS method with sensitivity encoding (SENSE) for reconstructing undersampled spiral data.
• Evaluated image quality, displacement, and strain accuracy by comparing fully-sampled acquisitions with retrospectively and prospectively accelerated data in healthy volunteers and patients.

Main Results:

• BLOSM-SENSE demonstrated lower or similar relative root mean square error (rRMSE) compared to SENSE alone at rate-2 and rate-4 accelerations.
• BLOSM-SENSE showed improved correlation and agreement with reference data for myocardial displacement and strain compared to SENSE, particularly at higher acceleration rates.
• Prospectively accelerated cine DENSE (rate-2 and rate-4) yielded good image quality and accurate functional parameters.

Conclusions:

• CS-PI accelerated spiral cine DENSE with 2D displacement encoding is feasible for rapid cardiac imaging.
• Acquisition times can be reduced to a single breathhold (8-14 heartbeats) without compromising image quality or accuracy.
• This technique enables high-quality assessment of myocardial displacement and circumferential strain, enhancing clinical utility.