2D free‐breathing dual navigator‐gated cardiac function validated against the 2D breath‐hold acquisition

Abstract

Purpose To develop and validate a free‐breathing cardiac cine acquisition, with potential to simplify cardiac MR studies, provide registered slices, and increase spatial resolution. Materials and Methods A 2D free‐breathing (FB) navigator‐gated cine radial acquisition for cardiac function was developed that used two navigators (one placed prior to the QRS, and another 500 msec after the QRS complex, after systole) to provide complete motion‐compensated assessment of systole, without loss of end‐diastole. Eleven subjects were studied. Results The 2D FB method provided results visually and quantitatively similar to the 2D breath‐hold (BH) methods. Comparison of volumes measured with FB to those measured by standard 2D BH cine resulted in mean bias ± 2 standard deviations of 1.0 mL ± 13.7 mL, 1.1 mL ± 7.6 mL, 3.0 g ± 18.8 g, and 0.3% ± 2.5%, for end‐diastolic volume, end‐systolic volume, left ventricular (LV) mass, and ejection fraction, respectively. Slice misregistration was identified in four (36%) of the BH studies, but none (0%) of the FB studies. In subjects with slice misregistration, there was greater discordance in LV volume measurements (P < 0.05 for end‐diastolic mass). Conclusion The FB cine acquisition provided results qualitatively and quantitatively similar to 2D BH methods with improved slice registration. J. Magn. Reson. Imaging 2008;28:773–777.