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- Open Access
Reproducibility of peak and time to peak velocity measurements with a high resolution spiral phase velocity mapping (PVM) sequence
© Simpson et al; licensee BioMed Central Ltd. 2013
- Published: 30 January 2013
- Peak Velocity
- Tissue Doppler Imaging
- Entire Cardiac Cycle
- Spiral Phase
- Atrial Systole
Myocardial PVM may be used to assess peak velocities and the times to those peaks (TTP) in order to characterise healthy and pathological regional heart motion . However data on the reproducibility of the technique is limited. A previous breathhold (low resolution) study investigated reproducibility for peak radial and circumferential velocities ; however that of TTP measurements was not presented. A higher resolution, navigator-gated study showed that MR had better reproducibility than tissue Doppler imaging for peak and TTP velocity measurements, but only longitudinal velocities were considered . All previous studies have used prospective cardiac gating and late diastolic (atrial systole) peak and TTP velocities have not been investigated. This study presents a comprehensive assessment of the reproducibility of myocardial PVM for assessing peak and TTP velocities throughout the entire cardiac cycle.
An efficient navigator-gated spiral trajectory PVM sequence (1.4 x 1.4 mm acquired spatial resolution, 21 ms acquired temporal resolution; nominal acquisition duration 53 heartbeats) was used to scan basal, mid-ventricular and apical short-axis slices in ten healthy volunteers on two separate occasions. Retrospective cardiac gating was implemented, allowing analysis of all major velocity peaks throughout the cardiac cycle, including atrial systole. The reproducibility of peak velocities and their TTP values was assessed by Bland Altman analysis. Analysis of TTP vales was repeated after normalisation to a fixed systolic and diastolic length.
Mean +/- SD values for all peak velocities and TTP velocities, along with their corresponding interstudy reproducibility (mean +/- signed differences between the two scans)
Peak velocity (cm/s)
Interstudy reproducibility (cm/s)
Interstudy reproducibility (ms)
TTP (normalised) (ms)
Interstudy reproducibility (normalised)(ms)
1st systolic peak
2nd systolic peak
High temporal resolution myocardial PVM with retrospective cardiac gating is a highly reproducible technique for measuring all peak velocities in the cardiac cycle, including those in atrial systole. Absolute and normalised systolic TTP values have comparable reproducibility. However the reproducibility of diastolic TTP values is improved following normalisation to a fixed systolic and diastolic length. This is particularly apparent for the late diastolic peak representing atrial systole.
The authors acknowledge the support of Heart Research UK, Imperial College London and NIHR Royal Brompton Cardiovascular Biomedical Research Unit.
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.