Improved accuracy and precision with three‐parameter simultaneous myocardial T1 and T2 mapping using multiparametric SASHA

Journal article

Purpose: To develop and validate a three-parameter model for improved precision multiparametric SAturation-recovery single-SHot Acquisition (mSASHA) cardiac T₁ and T₂ mapping with high accuracy in a single breath-hold.

Methods: The mSASHA acquisition consists of nine images of variable saturation recovery and T₂ preparation in 11 heartbeats with T₁ and T₂ values calculated using a three-parameter model. It was validated in simulations and phantoms at 3 T with comparison to a four-parameter joint T₁-T₂ technique. The mSASHA acquisition was compared with MOLLI, SASHA, and T₂-prepared balanced SSFP in 10 volunteers.

Results: The mSASHA technique had high accuracy in phantoms compared to spin echo, with −0.2 ± 0.3% T₁ error and −2.4 ± 1.3% T₂ error. The mSASHA coefficient of variation in phantoms for T₁ was similar to MOLLI (0.7 ± 0.2% for both) and T₂-prepared balanced SSFP for T₂ (1.3 ± 0.7% vs 1.4 ± 0.3%, adjusted p > .05 for both). In simulations, three-parameter mSASHA had higher precision than four-parameter joint T₁-T₂ for both T₁ and T₂ (46% and 11% reductions in T₁ and T₂ interquartile range for native myocardium). In vivo myocardial mSASHA T₁ was similar to SASHA (1523 ± 18 ms vs 1520 ± 18 ms) with similar coefficient of variation to both MOLLI and SASHA (3.3 ± 0.6% vs 3.1 ± 0.6% and 3.3 ± 0.5% respectively, adjusted p > .05 for all). Myocardial mSASHA T₂ was 37.1 ± 1.1 ms with similar precision to T₂-prepared balanced SSFP (6.7 ± 1.7% vs 6.0 ± 1.6%, adjusted p > .05).

Conclusion: Three-parameter mSASHA provides high-accuracy cardiac T₁ and T₂ quantification in a single breath-hold with similar precision to MOLLI and T₂-prepared balanced SSFP. Further study is required to both establish normative values and demonstrate clinical utility in patient populations.

Authors: Chow, K; Hayes, G; Flewitt, JA; Feuchter, P; Lydell, C

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Wiley
• Journal: Magnetic Resonance in Medicine
• Volume: 87
• Issue: 6
• Pages: 2775-2791
• Publication date: 2022-02-08
• Acceptance date: 2022-01-05
• DOI: 10.1002/mrm.29170
• EISSN: 1522-2594
• ISSN: 0740-3194
• Pmid: 35133018
• Language: English
• Keywords: cardiac MR; MOLLI; multiparametric mapping; SASHA; T1 mapping; T2 mapping