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Left and right ventricular kinetic energy using time‐resolved versus time‐average ventricular volumes
Author(s) -
Hussaini Syed F.,
Rutkowski David R.,
RoldánAlzate Alejandro,
François Christopher J.
Publication year - 2017
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.25416
Subject(s) - diastole , cardiology , magnetic resonance imaging , medicine , nuclear medicine , blood flow , nuclear magnetic resonance , blood pressure , physics , radiology
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.