Left and right ventricular kinetic energy using time‐resolved versus time‐average ventricular volumes

• Published in: Journal of magnetic resonance imaging Vol. 45; no. 3; pp. 821 - 828
• Main Authors: Hussaini, Syed F., Rutkowski, David R., Roldán‐Alzate, Alejandro, François, Christopher J.
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.03.2017
• Subjects: 4D flow MRI; Adolescent; Adult; Algorithms; Blood Flow Velocity; cardiac function; cardiac magnetic resonance; Child; Coronary artery disease; Data acquisition; Energy consumption; Energy measurement; Energy Transfer; Heart diseases; Humans; Image Interpretation, Computer-Assisted - methods; Image processing; Image segmentation; Kinetic energy; Magnetic resonance imaging; Mathematical analysis; Middle Aged; Myocardial Contraction; NMR; Nuclear magnetic resonance; Reproducibility of Results; Resonance; Sensitivity and Specificity; Stroke Volume; Systole; Ventricle; Ventricular Dysfunction - diagnostic imaging; Ventricular Dysfunction - physiopathology; Young Adult; 4D flow MRI; cardiac function; kinetic energy; cardiac magnetic resonance
• ISSN: 1053-1807; 1522-2586
• DOI: 10.1002/jmri.25416

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 (KERV) were 4.89 ± 1.49 mJ using TR and 5.53 ± 1.62 mJ using TA segmentation (P = 0.016); peak systolic LV KE (KELV) were 3.29 ± 0.96 mJ and 4.16 ± 1.26 mJ (P = 0.005). Peak diastolic KERV were 3.33 ± 0.90 mJ (TR) and 3.61 ± 1.12 mJ (TA) (P = 0.082), while peak diastolic KELV were 4.90 ± 1.49 mJ and 5.31 ± 1.59 mJ (P = 0.044). In patient volunteers, peak systolic KERV were 4.34 ± 3.78 mJ using TR and 4.88 ± 3.98 mJ using TA segmentation (P = 0.26); peak systolic KELV were 4.39 ± 4.21 mJ and 4.36 ± 3.84 mJ (P = 0.91). Peak diastolic KERV were 3.34 ± 2.08 mJ (TR) and 4.05 ± 1.12 mJ (TA) (P = 0.08), while peak diastolic KELV were 4.34 ± 5.11 mJ and 4.06 ± 3.47 mJ (P = 0.75). Interobserver differences in KELV were greater for TR than TA calculations; bias ranged from 3 ± 30% for TA peak systolic KELV to 36 ± 30% for TR peak diastolic KELV. 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.