Free‐breathing, non‐<scp>ECG</scp>, simultaneous myocardial <scp>T<sub>1</sub></scp>, <scp>T<sub>2</sub></scp>, <scp>T<sub>2</sub></scp>*, and fat‐fraction mapping with motion‐resolved cardiovascular MR multitasking
Tianle Cao, Nan Wang, Alan C. Kwan, Hsu‐Lei Lee, Xianglun Mao, Yibin Xie, Kim‐Lien Nguyen, Caroline M. Colbert, Fei Han, Pei Han, Hui Han, Anthony Christodoulou, Debiao Li
Abstract
Purpose To develop a free‐breathing, non‐electrocardiogram technique for simultaneous myocardial T 1 , T 2 , T 2 *, and fat‐fraction (FF) mapping in a single scan. Methods The MR Multitasking framework is adapted to quantify T 1 , T 2 , T 2 *, and FF simultaneously. A variable TR scheme is developed to preserve temporal resolution and imaging efficiency. The underlying high‐dimensional image is modeled as a low‐rank tensor, which allows accelerated acquisition and efficient reconstruction. The accuracy and/or repeatability of the technique were evaluated on static and motion phantoms, 12 healthy volunteers, and 3 patients by comparing to the reference techniques. Results In static and motion phantoms, T 1 /T 2 /T 2 */FF measurements showed substantial consistency ( R > 0.98) and excellent agreement (intraclass correlation coefficient > 0.93) with reference measurements. In human subjects, the proposed technique yielded repeatable T 1 , T 2 , T 2 *, and FF measurements that agreed with those from references. Conclusions The proposed free‐breathing, non‐electrocardiogram, motion‐resolved Multitasking technique allows simultaneous quantification of myocardial T 1 , T 2 , T 2 *, and FF in a single 2.5‐min scan.