- Poster presentation
- Open Access
Regional left ventricular myocardial T1 and velocity mapping: elevated extracellular volume fraction is associated with altered myocardial velocities
© Collins et al.; licensee BioMed Central Ltd. 2014
- Published: 16 January 2014
- Myocardial Fibrosis
- Gadobenate Dimeglumine
- Myocardial Velocity
- Extracellular Volume Fraction
- Tissue Phase Mapping
Non-ischemic cardiomyopathy (NICM) is a common cause of left ventricular (LV) dysfunction and may be associated with myocardial fibrosis. Global LV systolic function may underestimate the impact of fibrosis on myocardial function and is insensitive to regional abnormalities in myocardial motion. Advances in cardiac MRI have enabled quantification of myocardial fibrosis through the calculation of the gadolinium extracellular volume fraction (Ve) using T1 mapping techniques employing the modified look-locker inversion recovery (MOLLI) correction. In addition, tissue phase mapping (TPM) enables assessment of regional myocardial velocities. The purpose of this study was to evaluate the impact of regional myocardial fibrosis on regional myocardial velocities. We hypothesize that regional scar will correlate with reduced regional systolic and diastolic velocities.
CMR was performed in 38 patients (22 men, avg age 48.2 ± 18.6 yrs) with NICM on a 1.5T scanner (MAGNETOM Aera or Avanto, Siemens AG, Healthcare Sector, Erlangen, Germany). TPM was performed using a black-blood prepared cine phase-contrast sequence with tri-directional phase encoding in the short axis orientation (venc = 25 cm/sec, temp res = 24 msec, spatial res = 2.9 × 2.4 mm, thickness = 8 mm). T1 mapping was performed in identical slice positions using a MOLLI sequence comprised of three inversion pulses with single shot bSSFP diastolic readouts using a 3, 3, 5 schema with three recovery heart beats between inversion pulses (spatial res = 2.3 × 1.8 mm, thickness = 8 mm). T1 mapping images were acquired before and 10 to 25 minutes after 0.2 mmol/kg gadobenate dimeglumine (Multihance, Bracco Diagnostics, Monroe, NJ) injection. The Ve fraction was calculated as originally described by Jerosch-Harold. A reduced LV ejection fraction (EF) was defined as <50%. Analysis was based on a 16-segment AHA model.
The association of elevated regional myocardial Ve with reduced myocardial velocities independent of LVEF suggests a closely interrelated regional tissue structure-function relationship in patients with NICM.
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. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.