- Workshop presentation
- Open Access
Accelerated dual-contrast quantitative first-pass perfusion MRI of the mouse heart with compressed sensing
© Naresh et al; licensee BioMed Central Ltd. 2013
- Published: 30 January 2013
- Late Gadolinium Enhancement
- Myocardial Blood Flow
- Compress Sense
- Arterial Input Function
- Infarct Zone
Myocardial blood flow (MBF) imaging in gene-modified mice may be used to elucidate molecular mechanisms that underlie coronary vascular function and dysfunction. First pass Gd-enhanced MRI is well-established in humans and has been recently investigated in mice[1–3]. The rapid heart rate and small size of the heart present challenges to performing quantitative first pass imaging in mice. A dual contrast acquisition simplifies the procedure (one Gd injection) and may provide more accurate results because the arterial input function (AIF) and tissue function (TF) are acquired under identical conditions. We developed a compressed sensing (CS)-accelerated first pass sequence for mice with a dual contrast acquisition.
MRI was performed on a 7T system (Bruker, Germany). C57Bl/6 mice were anesthetized with 1.25% isoflurane and maintained at 36±0.50C during MRI. Mice were imaged at rest (n=6), with the vasodilator ATL313 (25μg/kg) (n=6), and on day 1 post-myocardial infarction (MI) (n=6). A dual contrast saturation-recovery sequence with ky and time domain undersampling was used to acquire first-pass Gd-enhanced images. Two slices were acquired within a cardiac cycle, one to obtain the AIF and the other to obtain the TF. For both slices, the center (50%) of k-space was acquired at the Nyquist rate while higher spatial frequencies were randomly undersampled. The acceleration factors for the AIF and TF slices were 6 and 4, respectively. Other imaging parameters were: TE/TR=1.2/2.1ms, FOV=25.6x18-20.8mm2, resolution=200μm2, matrix=128x74-104, alpha=150, slice thickness=1mm, saturation delay=15/70ms for AIF/TF. A motion-compensated CS algorithm was used to reconstruct the undersampled images. Fermi function deconvolution quantified perfusion in the entire slice (Baseline and ATL313) or in the infarct and remote zones (Day 1 post-MI), where late gadolinium enhancement (LGE) defined the infarct zone.
Accelerated first-pass MRI using undersampling and CS enables the implementation of a dual-contrast method, which can quantify perfusion in the mouse heart over a wide range of MBF. MBF reserve can also be measured. These methods promise to prove useful in the assessment of therapies for MI, and may shed light on key molecular mechanisms that underlie coronary vascular dysfunction.
This work was funded in part by AHA Predoctoral Award 11PRE7440117, NIH R01 EB001763 and US-Israel Binational Science Foundation grant 2007290.
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.