The recognition that nearly every other heart failure patient has preserved systolic function, as measured by ejection fraction (EF), has spurred the need for evaluating both systolic and diastolic function of the heart [1]. Although breath-held cine steady-state free precession (SSFP) imaging of the left ventricle (LV) in the short axis orientation acquired at frame rates on the order of 20-30 fps is clinically accepted as an accurate and reproducible tool for the measurement of LV systolic function [2], the evaluation of LV diastolic function continues to be in the domain of echocardiography, partly due to the high frame rates (> 100 fps) achievable with echo. Echocardiographic measurement of blood flow velocities across the mitral valve or mitral annular tissue velocities during the filling period of the cardiac cycle, often serve as surrogate indices of LV diastolic function. The purposes of this report are to: 1) report a respiratory-triggered, high frame rate (60-80 fps) cine SSFP imaging of the LV acquired during free breathing; 2) define two MRI based diastolic functional indices extracted from the change in LV volume across the cardiac cycle as well as the rate of change of LV volume (dV/dt) during the early (E) and late (A, or atrial) filling periods, and 3) compare the LV volume based indices to traditional measures of diastolic function measured using echo or MR phase contrast imaging, e.g., E/A ratio. 23 subjects (9 F, age: 46 ± 12 yrs) provided written informed consent to participate in this prospective IRB approved study. All underwent MRI and echocardiographic imaging in a single imaging session without getting off of the scanner table bed. MRI: All subjects were imaged at 1.5 T (Philips, Achieva) with VCG gating using a 32 channel cardiac coil for signal reception. A custom respiratory-triggered, free breathing SSFP cine imaging sequence with the following acquisition parameters was used to obtain a stack of contiguous high frame LV short axis cine SSFP images [3]: TR/TE/flip: 3.2 ms/1.5 ms/55˚; acquired temporal resolution: 14.6 ± 2.2 ms/phase; acquired spatial resolution: 2.25 x 2.25 x 10 mm³; parallel imaging factor: 2. MR Q-flow: Flow across the tips of the mitral leaflet was assessed using phase contrast MRI with a maximum velocity encoding value of 200 cm/s. Echocardiography: Immediately before or after MR examination, E/A ratio of the trans-mitral flow during diastole was measured using echo (Philips Healthcare, IE 33) without patient getting off of the scan table to minimize physiologic variation between MR and echo measurements. Data Analysis: An expert observer drew a contour circumscribing the LV cavity (endocardial contour) at end-diastole of each slice position which was subsequently propagated to all frames by a semi-automated algorithm. After review and adjustment (if necessary) of propagated contours by an experienced observer, LV volume at each cardiac phase was calculated using the Simpson’s method. The raw LV volume curve was up-sampled by a factor of 4, and the derivative of the time-volume curve was used to estimate both the blood volume change as well as the peak volume rate of LV filling during the early (EFP) and late filling periods (LFP) of diastole [4] (Figure 1) using custom-written software in MATLAB™. We defined two MR volume based indices: (a) ratio of the blood volume change during EFP to during LFP– V_EFP/V_LFP, and (b) ratio of early peak filling rate to the late peak filling rate - R_EFP/R_LFP. MR volume curve based diastolic function indices correlated with Doppler trans-mitral velocity based estimates (Figure 2). The volume rate based index R_EFP/R_LFP correlated better than the volume index V_EFP/V_LFP with Doppler E/A ratio (Figure 2). MRI phase velocity based estimation of E/A ratio, while correlated well REFP/RLFP (r² = 0.65 vs 0.68, Figure 3), was consistently lower than R_EFP/R_LFP, and V_EFP/V_LFP. Furthermore, E/A ratio from phase contrast velocity measurements were in close agreement with E/A ratio from Doppler (Figure 4). The relative change in volume, and peak volume-rate of the LV between the early and late filling periods of the cardiac cycle as measured from high-frame rate cine SSFP imaging, correlate well with conventional echo-based E/A ratio used to assess diastolic function. The results from this pilot study suggest that it is feasible to evaluate both systolic and diastolic function with a single set of high-temporal resolution cine SSFP images acquired during free breathing. The potential utility of this method has to be tested in a cohort of heart failure patients.