Reproducibility and observer variability of tissue phase mapping for the quantification of regional myocardial velocities.
To systematically investigate the reproducibility of global and segmental left ventricular (LV) velocities derived from tissue phase mapping (TPM). Breath held and ECG synchronized TPM data (spatial/temporal resolution = 2 × 2 mm(2)/20.8 ms) were acquired in 18 healthy volunteers. To analyze scan-rescan variability, TPM was repeated in all subjects during a second visit separated by 16 ± 5 days. Data analysis included LV segmentation, and quantification of global and regional (AHA 16-segment modal) metrics of LV function [velocity-time curves, systolic and diastolic peak and time-to-peak (TTP) velocities] for radial (Vr), long-axis (Vz) and circumferential (VΦ) LV velocities. Mean velocity time curves in basal, mid-ventricular, and apical locations showed highly similar LV motion patterns for all three velocity components (Vr, VΦ, Vz) for scan and rescan. No significant differences for both systolic and diastolic peak and TTP myocardial velocities were observed. Segmental analysis revealed similar regional peak Vr and Vz during both systole and diastole except for three LV segments (p = 0.045, p = 0.033, and p = 0.009). Excellent (p < 0.001) correlations between scans and rescan for peak Vr (R(2) = 0.92), peak Vz (R(2) = 0.90), radial TTP (R(2) = 0.91) and long-axis TTP (R(2) = 0.88) confirmed good agreement. Bland-Altman analysis demonstrated excellent intra-observer and good inter-observer analysis agreement but increased variability for long axis peak velocities. TPM based analysis of global and regional myocardial velocities can be performed with good reproducibility. Robustness of regional quantification of long-axis velocities was limited but spatial velocity distributions across the LV could reliably be replicated.
Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Avenue Suite 1600, Chicago, IL, 60611, USA.
Kai
K
Lin
Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Avenue Suite 1600, Chicago, IL, 60611, USA.
Varun
V
Chowdhary
Division of Cardiology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
Keith H
KH
Benzuly
Division of Cardiology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
Clyde W
CW
Yancy
Department of Pathology and Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
Jon W
JW
Lomasney
Division of Cardiology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
Vera H
VH
Rigolin
Division of Cardiology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
Allen S
AS
Anderson
Division of Cardiology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
Jane
J
Wilcox
Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Avenue Suite 1600, Chicago, IL, 60611, USA.
James
J
Carr
Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Avenue Suite 1600, Chicago, IL, 60611, USA. mmarkl@northwestern.edu.|Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, USA. mmarkl@northwestern.edu.
Michael
M
Markl
D000328:Adult; D062485:Breath Holding; D004562:Electrocardiography; D005260:Female; D064368:Healthy Volunteers; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D015588:Observer Variation; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013997:Time Factors; D016277:Ventricular Function, Left
Function; Left ventricle; Reproducibility; Tissue phase mapping; Velocity