Clinical Feasibility of Free-Breathing Volumetric Comprehensive Tissue Characterization via the Multi-parametric SAVA Technique.

Abstract

Background: Volumetric, one-stop cardiovascular magnetic resonance parametric mapping techniques have been developed and continue to evolve; however, clinical adoption remains limited by insufficient evidence supporting their feasibility in routine practice and the need to demonstrate agreement with established standard techniques.

Purpose: To validate three-dimensional free-breathing mSAVA for comprehensive myocardial tissue characterization, including pre-/post-contrast T₁, T₂, ECV, and synthesized bright-blood (BB-) and dark-blood (DB-) LGE in patients, and to compare its performance with conventional T₁ mapping, T₂ mapping, and phase-sensitive inversion recovery (PSIR) techniques.

Methods: We deployed mSAVA in a clinical hospital setting and had it operated by radiologists. A total of 40 patients (22 males, age range: 17-67 years) with various cardiac diseases referred for CMR evaluation underwent mSAVA imaging along with standard clinical sequences, including MOLLI for native/post-contrast T₁ mapping, mGraSE for T₂ mapping, and PSIR. The study was approved by the institutional review board, and written informed consent was obtained from all participants before imaging. We evaluated the clinical feasibility of mSAVA, its agreement with established conventional techniques, and its ability to synthesize LGE.

Results: Of 40 enrolled patients, 2 had non-diagnostic mSAVA images and 7 lacked post-contrast scans or had atypical cardiac anatomy. In the remaining 31 patients (17 male; age range, 17-67 years), mSAVA required 6.1±1.7min of free-breathing acquisition to obtain whole-heart joint T₁/T₂ maps, compared with 1.5min for MOLLI T₁ mapping and 1.7min for mGraSE T₂ mapping over three slices. mSAVA showed strong correlation for post-contrast T₁ and ECV, and moderate correlation for native T₁ and T₂ with conventional clinical standards, and similarly characterized scar-remote tissue differences. The 3D post-contrast T₁/T₂ maps also enabled retrospective synthesis of bright-blood and dark-blood LGE. Synthesized BB-LGE demonstrated good accuracy for detecting enhancement compared with PSIR, whereas synthesized DB-LGE showed moderate precision and variable scar depiction.

Conclusion: This initial clinical study suggests that free-breathing, one-stop mSAVA is a promising technique for comprehensive CMR tissue characterization, particularly in patients unable to perform breath-holds, in scenarios requiring multiple quantitative measurements, or when whole-heart coverage is desired. Further clinical studies are warranted to establish its references and its clinical value.