Markus Henningsson1,2. 1. Division of Diagnostics and Specialist Medicine, Department of Health, Medicine and Caring Sciences (HMV), Linköping University, Linköping, Sweden. 2. Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden.
Abstract
PURPOSE: To implement and evaluate a new dictionary-based technique for native myocardial T1 and T2 mapping using Cartesian sampling. METHODS: The proposed technique (Multimapping) consisted of single-shot Cartesian image acquisitions in 10 consecutive cardiac cycles, with inversion pulses in cycle 1 and 5, and T2 preparation (TE: 30 ms, 50 ms, and 70 ms) in cycles 8-10. Multimapping was simulated for different T1 and T2 , where entries corresponding to the k-space centers were matched to acquired data. Experiments were performed in a phantom, 16 healthy subjects, and 3 patients with cardiovascular disease. RESULTS: Multimapping phantom measurements showed good agreement with reference values for both T1 and T2 , with no discernable heart-rate dependency for T1 and T2 within the range of myocardium. In vivo mean T1 in healthy subjects was significantly higher using Multimapping (T1 = 1114 ± 14 ms) compared to the reference (T1 = 991 ± 26 ms) (p < 0.01). Mean Multimapping T2 (47.1 ± 1.3 ms) and T2 spatial variability (5.8 ± 1.0 ms) was significantly lower compared to the reference (T2 = 54.7 ± 2.2 ms, p < 0.001; spatial variability = 8.4 ± 2.0 ms, p < 0.01). Increased T1 and T2 was detected in all patients using Multimapping. CONCLUSIONS: Multimapping allows for simultaneous native myocardial T1 and T2 mapping with a conventional Cartesian trajectory, demonstrating promising in vivo image quality and parameter quantification results.
PURPOSE: To implement and evaluate a new dictionary-based technique for native myocardial T1 and T2 mapping using Cartesian sampling. METHODS: The proposed technique (Multimapping) consisted of single-shot Cartesian image acquisitions in 10 consecutive cardiac cycles, with inversion pulses in cycle 1 and 5, and T2 preparation (TE: 30 ms, 50 ms, and 70 ms) in cycles 8-10. Multimapping was simulated for different T1 and T2 , where entries corresponding to the k-space centers were matched to acquired data. Experiments were performed in a phantom, 16 healthy subjects, and 3 patients with cardiovascular disease. RESULTS: Multimapping phantom measurements showed good agreement with reference values for both T1 and T2 , with no discernable heart-rate dependency for T1 and T2 within the range of myocardium. In vivo mean T1 in healthy subjects was significantly higher using Multimapping (T1 = 1114 ± 14 ms) compared to the reference (T1 = 991 ± 26 ms) (p < 0.01). Mean Multimapping T2 (47.1 ± 1.3 ms) and T2 spatial variability (5.8 ± 1.0 ms) was significantly lower compared to the reference (T2 = 54.7 ± 2.2 ms, p < 0.001; spatial variability = 8.4 ± 2.0 ms, p < 0.01). Increased T1 and T2 was detected in all patients using Multimapping. CONCLUSIONS: Multimapping allows for simultaneous native myocardial T1 and T2 mapping with a conventional Cartesian trajectory, demonstrating promising in vivo image quality and parameter quantification results.