Free-breathing, motion-corrected, highly efficient whole heart T2 mapping at 3T with hybrid radial-cartesian trajectory

Purpose To develop and test a time‐efficient, free‐breathing, whole heart T2 mapping technique at 3.0T. Methods ECG‐triggered three‐dimensional (3D) images were acquired with different T2 preparations at 3.0T during free breathing. Respiratory motion was corrected with a navigator‐guided motion correction framework at near perfect efficiency. Image intensities were fit to a monoexponential function to derive myocardial T2 maps. The proposed 3D, free breathing, motion‐corrected (3D‐FB‐MoCo) approach was studied in ex vivo canine hearts and kidneys, healthy volunteers, and canine subjects with acute myocardial infarction (AMI). Results Ex vivo T2 values from proposed 3D T2‐prep gradient echo were not different from two‐dimensional (2D) spin echo (P = 0.7) and T2‐prep balanced steady‐state free precession (bSSFP) (P = 0.7). In healthy volunteers, compared with 3D‐FB‐MoCo and breath‐held 2D T2‐prep bSSFP (2D‐BH), non–motion‐corrected (3D‐FB‐Non‐MoCo) myocardial T2 was longer, had a larger coefficient of variation (COV), and had a lower image quality (IQ) score (T2 = 40.3 ms, COV = 38%, and IQ = 2.3; all P