Accelerated and high-resolution cardiac T₂ mapping through peripheral k-space sharing.

Area of Science:

• Cardiovascular Magnetic Resonance Imaging
• Quantitative MRI Techniques

Background:

• Cardiac T2 mapping is crucial for assessing myocardial tissue properties.
• Current techniques often require long acquisition times, limiting clinical applicability.
• High-spatial-resolution T2 mapping is desirable for detailed myocardial assessment.

Purpose of the Study:

• To develop and optimize a novel, accelerated cardiac T2 mapping technique.
• To achieve high spatial resolution and precision with reduced acquisition time.
• To validate the new technique against established methods in healthy volunteers and patients.

Main Methods:

• Implementation and optimization of the SKRATCH (Shared k-space Radial T2 Characterization of the Heart) technique.
• Evaluation of six SKRATCH variants (including different pulse sequences and breathing strategies) in phantoms and 22 healthy volunteers at 3T.
• Comparison with a navigator-gated reference technique for precision and spatial resolution assessment.
• Application of the optimal breath-held SKRATCH technique in patients with subacute myocardial infarction.

Main Results:

• The free-breathing SKRATCH technique reduced acquisition time by 52.4% while preserving precision and spatial resolution.
• The optimal breath-held SKRATCH technique showed homogenous T2 values comparable to the reference (39.9 ± 3.4 ms vs. 39.5 ± 3.4 ms).
• All myocardial infarction patients exhibited elevated T2 values in ischemic regions, demonstrating clinical utility.

Conclusions:

• The optimized SKRATCH technique enables accelerated, high-spatial-resolution cardiac T2 mapping.
• The method is validated in healthy volunteers and shows promise for clinical application in patients.
• SKRATCH offers a precise and efficient approach for quantitative assessment of myocardial tissue.