Free-breathing 3D whole-heart joint T₁/T₂ mapping and water/fat imaging at 0.55 T

TY - JOUR

T1 - Free-breathing 3D whole-heart joint T1/T2 mapping and water/fat imaging at 0.55 T

AU - Si, Dongyue

AU - Crabb, Michael G

AU - Kunze, Karl P

AU - Littlewood, Simon J

AU - Prieto, Claudia

AU - Botnar, René M

N1 - Publisher Copyright: © 2024 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.

PY - 2024/10

Y1 - 2024/10

N2 - Purpose: To develop and validate a highly efficient motion compensated free-breathing isotropic resolution 3D whole-heart joint T 1/T 2 mapping sequence with anatomical water/fat imaging at 0.55 T. Methods: The proposed sequence takes advantage of shorter T 1 at 0.55 T to acquire three interleaved water/fat volumes with inversion-recovery preparation, no preparation, and T 2 preparation, respectively. Image navigators were used to facilitate nonrigid motion-compensated image reconstruction. T 1 and T 2 maps were jointly calculated by a dictionary matching method. Validations were performed with simulation, phantom, and in vivo experiments on 10 healthy volunteers and 1 patient. The performance of the proposed sequence was compared with conventional 2D mapping sequences including modified Look-Locker inversion recovery and T 2-prepared balanced steady-SSFP sequence. Results: The proposed sequence has a good T 1 and T 2 encoding sensitivity in simulation, and excellent agreement with spin-echo reference T 1 and T 2 values was observed in a standardized T 1/T 2 phantom (R 2 = 0.99). In vivo experiments provided good-quality co-registered 3D whole-heart T 1 and T 2 maps with 2-mm isotropic resolution in a short scan time of about 7 min. For healthy volunteers, left-ventricle T 1 mean and SD measured by the proposed sequence were both comparable with those of modified Look-Locker inversion recovery (640 ± 35 vs. 630 ± 25 ms [p = 0.44] and 49.9 ± 9.3 vs. 54.4 ± 20.5 ms [p = 0.42]), whereas left-ventricle T 2 mean and SD measured by the proposed sequence were both slightly lower than those of T 2-prepared balanced SSFP (53.8 ± 5.5 vs. 58.6 ± 3.3 ms [p < 0.01] and 5.2 ± 0.9 vs. 6.1 ± 0.8 ms [p = 0.03]). Myocardial T 1 and T 2 in the patient measured by the proposed sequence were in good agreement with conventional 2D sequences and late gadolinium enhancement. Conclusion: The proposed sequence simultaneously acquires 3D whole-heart T 1 and T 2 mapping with anatomical water/fat imaging at 0.55 T in a fast and efficient 7-min scan. Further investigation in patients with cardiovascular disease is now warranted.

AB - Purpose: To develop and validate a highly efficient motion compensated free-breathing isotropic resolution 3D whole-heart joint T 1/T 2 mapping sequence with anatomical water/fat imaging at 0.55 T. Methods: The proposed sequence takes advantage of shorter T 1 at 0.55 T to acquire three interleaved water/fat volumes with inversion-recovery preparation, no preparation, and T 2 preparation, respectively. Image navigators were used to facilitate nonrigid motion-compensated image reconstruction. T 1 and T 2 maps were jointly calculated by a dictionary matching method. Validations were performed with simulation, phantom, and in vivo experiments on 10 healthy volunteers and 1 patient. The performance of the proposed sequence was compared with conventional 2D mapping sequences including modified Look-Locker inversion recovery and T 2-prepared balanced steady-SSFP sequence. Results: The proposed sequence has a good T 1 and T 2 encoding sensitivity in simulation, and excellent agreement with spin-echo reference T 1 and T 2 values was observed in a standardized T 1/T 2 phantom (R 2 = 0.99). In vivo experiments provided good-quality co-registered 3D whole-heart T 1 and T 2 maps with 2-mm isotropic resolution in a short scan time of about 7 min. For healthy volunteers, left-ventricle T 1 mean and SD measured by the proposed sequence were both comparable with those of modified Look-Locker inversion recovery (640 ± 35 vs. 630 ± 25 ms [p = 0.44] and 49.9 ± 9.3 vs. 54.4 ± 20.5 ms [p = 0.42]), whereas left-ventricle T 2 mean and SD measured by the proposed sequence were both slightly lower than those of T 2-prepared balanced SSFP (53.8 ± 5.5 vs. 58.6 ± 3.3 ms [p < 0.01] and 5.2 ± 0.9 vs. 6.1 ± 0.8 ms [p = 0.03]). Myocardial T 1 and T 2 in the patient measured by the proposed sequence were in good agreement with conventional 2D sequences and late gadolinium enhancement. Conclusion: The proposed sequence simultaneously acquires 3D whole-heart T 1 and T 2 mapping with anatomical water/fat imaging at 0.55 T in a fast and efficient 7-min scan. Further investigation in patients with cardiovascular disease is now warranted.

UR - http://www.scopus.com/inward/record.url?scp=85196109582&partnerID=8YFLogxK

U2 - 10.1002/mrm.30139

DO - 10.1002/mrm.30139

M3 - Article

C2 - 38872384

SN - 0740-3194

VL - 92

SP - 1511

EP - 1524

JO - Magnetic Resonance in Medicine

JF - Magnetic Resonance in Medicine

IS - 4

ER -