Poster presentation
Open Access
Volume 14 Supplement 1
Abstracts of the 15th Annual SCMR Scientific Sessions: 2012
Inter-study variability in CMR measurements of right ventricular volume, mass and ejection fraction in tetralogy of fallot: a prospective observational study
Journal of Cardiovascular Magnetic Resonance201214(Suppl 1):P104
https://doi.org/10.1186/1532-429X-14-S1-P104
© Blalock et al; licensee BioMed Central Ltd. 2012
Published: 1 February 2012
Background
Cardiac MRI (CMR) is commonly used for serial monitoring of right ventricular (RV) size and function in patients with repaired tetralogy of Fallot (TOF). However, the inter-study variability of these measurements is not known, which hinders accurate interpretation of serial changes. In this study we prospectively assessed the inter-study variability of CMR measurements of RV size and function in TOF patients.
Methods
Patients with repaired TOF referred for a clinically indicated CMR examination at our institution were prospectively enrolled. ECG-gated steady-state free precession cine imaging of ventricular long- and short-axis planes was obtained on a 1.5 T scanner. Immediately after the conclusion of the examination, patients returned for a second study performed by a different technologist. Ventricular size and function data from both short-axis image sets were analyzed by a single observer and compared using Bland-Altman analysis with calculation of a repeatability coefficient (2SD of difference between studies), and intra-class correlation coefficient (ICC).
Results
Between March 2009 and April 2010, 30 patients with repaired TOF (median age 23.5 years, 53% male) were enrolled. Mean RV end-diastolic volume was 158.1±48 ml and mean RV ejection fraction was 57.1±6. Estimates of repeatability coefficient and ICC are summarized in the table. CMR measurements were highly reproducible between studies for quantification of RV end-diastolic volume (repeatability coefficient 24.1 ml, ICC 0.99), ejection fraction (repeatability coefficient 5.8%, ICC 0.94), and mass (repeatability coefficient 9.7 g, ICC 0.93). ICC values were not different between RV and LV for most parameters except mass, for which they were higher for the LV (0.99 vs 0.93, p=0.004). ICC values for all the CMR parameters were not influenced by the presence of a transannular patch.
Table 1
Inter-study variability in CMR measurements
LV | RV | p value comparing ICC between LV/RV | |||
|---|---|---|---|---|---|
Repeatability (2SD of difference between studies) | Intra-class correlation coefficient | Repeatability (2SD of difference between studies) | Intra-class correlation coefficient | ||
End-diastolic volume | 17.2 ml | 0.98 | 24.1 ml | 0.99 | 0.8 |
End-systolic volume | 12.3 ml | 0.98 | 17.7 ml | 0.98 | 0.7 |
Stroke volume | 17.0 ml | 0.93 | 21.9 ml | 0.95 | 0.65 |
Ejection fraction | 6.6% | 0.84 | 5.8% | 0.94 | 0.07 |
Mass | 11.6 g | 0.99 | 9.7 g | 0.93 | 0.004 |
Conclusions
CMR measurements of RV and LV size and function in repaired TOF patients are highly reproducible between studies. These data will aid in interpretation of serial changes and may be useful for sample size calculation in clinical trials.
Funding
None.
Authors’ Affiliations
(1)
Department of Cardiology, Children's Hospital Boston
(2)
Department of Pediatrics, Harvard Medical School
Copyright
© Blalock et al; licensee BioMed Central Ltd. 2012
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.
