Gaspar Andreia S, Silva Nuno A, Ferreira António M, Nunes Rita G
Instituto de Sistemas e Robótica-Lisboa and Departamento de Bioengenharia, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal.
Hospital da Luz Learning Health, Luz Saúde, Lisboa, Portugal.
Magn Reson Med. 2024 Aug;92(2):741-750. doi: 10.1002/mrm.30080. Epub 2024 Mar 25.
To develop an open-source prototype of myocardial T1 mapping (Open-MOLLI) to improve accessibility to cardiac T1 mapping and evaluate its repeatability. With Open-MOLLI, we aim to enable faster implementation and testing of sequence modifications and to facilitate inter-scanner and cross-vendor reproducibility studies.
Open-MOLLI is an inversion-recovery sequence using a balanced SSFP (bSSFP) readout, with inversion and triggering schemes based on the 5(3)3 MOLLI sequence, developed in Pulseq. Open-MOLLI and MOLLI sequences were acquired in the ISMRM/NIST phantom and 21 healthy volunteers. In 18 of those subjects, Open-MOLLI and MOLLI were repeated in the same session (test-retest).
Phantom T1 values were comparable between methods, specifically for the vial with reference T1 value most similar to healthy myocardium T1 (T1 = 1027 ms): T1 = 1011 ± 24 ms versus T1 = 1009 ± 20 ms. In vivo T1 estimates were similar between Open-MOLLI and MOLLI (T1 = 1004 ± 33 ms vs. T1 = 998 ± 52 ms), with a mean difference of -17 ms (p = 0.20), despite noisier Open-MOLLI weighted images and maps. Repeatability measures were slightly higher for Open-MOLLI (RC = 3.0% vs. RC = 4.4%).
The open-source sequence Open-MOLLI can be used for T1 mapping in vivo with similar mean T1 values to the MOLLI method. Open-MOLLI increases the accessibility to cardiac T1 mapping, providing also a base sequence to which further improvements can easily be added and tested.
开发一种心肌T1映射的开源原型（Open-MOLLI），以提高心脏T1映射的可及性并评估其可重复性。通过Open-MOLLI，我们旨在实现序列修改的更快实施和测试，并促进不同扫描仪和跨供应商的可重复性研究。
Open-MOLLI是一种使用平衡稳态自由进动（bSSFP）读出的反转恢复序列，其反转和触发方案基于在Pulseq中开发的5(3)3 MOLLI序列。在ISMRM/NIST体模和21名健康志愿者中采集了Open-MOLLI和MOLLI序列。在其中18名受试者中，在同一会话中重复采集Open-MOLLI和MOLLI（重测）。
两种方法的体模T1值具有可比性，特别是对于参考T1值与健康心肌T1最相似的小瓶（T1 = 1027 ms）：T1 = 1011±24 ms与T1 = 1009±20 ms。Open-MOLLI和MOLLI的体内T1估计值相似（T1 = 1004±33 ms对T1 = 998±52 ms），平均差异为-17 ms（p = 0.20），尽管Open-MOLLI加权图像和图谱噪声更大。Open-MOLLI的重复性测量值略高（相关系数RC = 3.0%对RC = 4.4%）。
开源序列Open-MOLLI可用于体内T1映射，其平均T1值与MOLLI方法相似。Open-MOLLI提高了心脏T1映射的可及性，还提供了一个基础序列，可轻松添加和测试进一步的改进。
