Free‐breathing simultaneous <i>T</i><sub>1</sub>, <i>T</i><sub>2</sub>, and <i>T</i><sub>2</sub><sup>∗</sup> quantification in the myocardium
Ingo Hermann, Peter Kellman, Ömer Burak Demirel, Mehmet Akçakaya, Lothar R. Schad, Sebastian Weingärtner
Abstract
Abstract Purpose To implement a free‐breathing sequence for simultaneous quantification of , , and for comprehensive tissue characterization of the myocardium in a single scan using a multi‐gradient‐echo readout with saturation and preparation pulses. Methods In the proposed Saturation And ‐prepared Relaxometry with Navigator‐gating (SATURN) technique, a series of multi‐gradient‐echo (GRE) images with different magnetization preparations was acquired during free breathing. A total of 35 images were acquired in 26.5 ± 14.9 seconds using multiple saturation times and preparation durations and with imaging at 5 echo times. Bloch simulations and phantom experiments were used to validate a 5‐parameter fit model for accurate relaxometry. Free‐breathing simultaneous , , and measurements were performed in 10 healthy volunteers and 2 patients using SATURN at 3T and quantitatively compared to conventional single‐parameter methods such as SASHA for , ‐prepared bSSFP, and multi‐GRE for . Results Simulations confirmed accurate fitting with the 5‐parameter model. Phantom measurements showed good agreement with the reference methods in the relevant range for in vivo measurements. Compared to single‐parameter methods comparable accuracy was achieved. SATURN produced in vivo parameter maps that were visually comparable to single‐parameter methods. No significant difference between , , and times acquired with SATURN and single‐parameter methods was shown in quantitative measurements (SATURN , , ; conventional methods: , , ; ) Conclusion SATURN enables simultaneous quantification of , , and in the myocardium for comprehensive tissue characterization with co‐registered maps, in a single scan with good agreement to single‐parameter methods.