Key result
Time-averaged ventricular segmentation yielded greater peak systolic left ventricular kinetic energy than time-resolved segmentation in healthy volunteers (4.16 vs 3.29 mJ; P=0.005).
Why the study?
Does time-resolved versus time-averaged ventricular segmentation affect kinetic energy calculations on 4D flow MRI in healthy volunteers and patients with cardiac disease?
Observational (n=15)
Does time-resolved versus time-averaged ventricular segmentation affect kinetic energy calculations on 4D flow MRI in healthy volunteers and patients with cardiac disease?
Absolute Event Rate: 4.16% vs 3.29%
p-value: p=0.005
Kinetic energy values calculated through time-averaged segmentation on 4D flow MRI are consistently greater than those from time-resolved segmentation, particularly during systole and in the left ventricle.
Segmentation choice may bias 4D flow KE estimates; leaves open validation in cardiac disease.
Purpose To measure the effects of using time‐resolved (TR) versus time‐averaged (TA) ventricular segmentation on four‐dimensional flow‐sensitive (4D flow) magnetic resonance imaging (MRI) kinetic energy (KE) calculations. Materials and Methods Right (RV) and left (LV) ventricular KE was calculated from 4D flow MRI data acquired at 3.0T in 10 healthy volunteers and five subjects with cardiac disease using TR and TA segmentation. KE was calculated from the mass of blood within the ventricles multiplied by the velocities squared. Differences in TR and TA KE and interobserver variability were quantified with Bland–Altman analysis. Results In healthy volunteers, peak systolic RV KE (KE RV ) were 4.89 ± 1.49 mJ using TR and 5.53 ± 1.62 mJ using TA segmentation ( P = 0.016); peak systolic LV KE (KE LV ) were 3.29 ± 0.96 mJ and 4.16 ± 1.26 mJ ( P = 0.005). Peak diastolic KE RV were 3.33 ± 0.90 mJ (TR) and 3.61 ± 1.12 mJ (TA) ( P = 0.082), while peak diastolic KE LV were 4.90 ± 1.49 mJ and 5.31 ± 1.59 mJ ( P = 0.044). In patient volunteers, peak systolic KE RV were 4.34 ± 3.78 mJ using TR and 4.88 ± 3.98 mJ using TA segmentation ( P = 0.26); peak systolic KE LV were 4.39 ± 4.21 mJ and 4.36 ± 3.84 mJ ( P = 0.91). Peak diastolic KE RV were 3.34 ± 2.08 mJ (TR) and 4.05 ± 1.12 mJ (TA) ( P = 0.08), while peak diastolic KE LV were 4.34 ± 5.11 mJ and 4.06 ± 3.47 mJ ( P = 0.75). Interobserver differences in KE LV were greater for TR than TA calculations; bias ranged from 3 ± 30% for TA peak systolic KE LV to 36 ± 30% for TR peak diastolic KE LV . Conclusion Although qualitatively similar, KE values calculated through TA segmentation were consistently greater than TR KE, with differences more pronounced during systole and in the LV. Level of Evidence: 2 J. Magn. Reson. Imaging 2017;45:821–828.
No takes yet. Share an insight, caveat, or question.
Hussaini et al. (2016) conducted an observational in Healthy and cardiac disease (n=15). Time-averaged (TA) ventricular segmentation vs. Time-resolved (TR) ventricular segmentation was evaluated on Peak systolic left ventricular kinetic energy in healthy volunteers (p=0.005). Time-averaged ventricular segmentation yielded greater peak systolic left ventricular kinetic energy than time-resolved segmentation in healthy volunteers (4.16 vs 3.29 mJ; P=0.005).
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: