T 2 measurement of the human myocardium using a T 2 ‐prepared transient‐state trueFISP sequence

A fast and motion‐insensitive technique suitable for myocardial BOLD contrast imaging is presented. The method, termed T 2 ‐TrueFISP, combines T 2 magnetization preparation with steady‐state free precession (SSFP) imaging for T 2 relaxation mapping of the myocardium in healthy volunteers. The T 2 contrast‐to‐noise ratio (CNR) was optimized with the use of transient‐state TrueFISP readout and half‐Fourier readout with linear phase encoding. Single‐slice myocardial T 2 ‐weighted image was obtained within one heartbeat, and a single slice T 2 map of the myocardium was obtained in under 5–7 s. A respiratory navigator‐gating method was incorporated for serial measurements and signal averaging, with the subjects breathing freely. The mean myocardial T 2 relaxation time measured in 12 healthy volunteers was 54 ± 5.7 ms. Regional variations of T 2 values across the myocardium were 7%. Temporal variations across serial T 2 measurements in a transmural region covering ∼0.5 cc of the left ventricular (LV) wall were 3.6% without signal averaging (number of excitations (NEX) = 1) and 1.7% with signal averaging (NEX = 10). According to our preliminary results, the T 2 ‐TrueFISP method is expected to provide a robust and sensitive tool for clinical application of myocardial BOLD contrast imaging. Magn Reson Med 57:960–966, 2007. © 2007 Wiley‐Liss, Inc.