Skip to content

Advertisement

  • Poster presentation
  • Open Access

3D cardiac Chemical Shift Imaging of [1-13C] hyperpolarized acetate and pyruvate in pigs

  • 1, 2,
  • 2,
  • 3,
  • 3,
  • 4,
  • 1,
  • 2,
  • 3,
  • 2, 1,
  • 5, 6,
  • 7,
  • 2,
  • 8,
  • 1, 2 and
  • 2
Journal of Cardiovascular Magnetic Resonance201315 (Suppl 1) :P10

https://doi.org/10.1186/1532-429X-15-S1-P10

  • Published:

Keywords

  • Dynamic Nuclear Polarization
  • Chemical Shift Image
  • Cardiac Metabolism
  • Birdcage Coil
  • Short Axis Orientation

Background

13C Dynamic Nuclear Polarization (DNP) with rapid dissolution together with Magnetic Resonance Chemical Shift Imaging (CSI) have been used for non-invasive real-time metabolic assessment in cardiac experimental models on a clinical 3T scanner. Here, we report an in vivo comparison of hyperpolarized [1-13C] pyruvate and [1-13C] acetate perfusion and metabolism: a method based on a 3D Spiral CSI sequence is presented for obtaining spatially and spectrally-resolved information on whole heart cardiac metabolism.

Methods

In this work hyperpolarized [1-13C] pyruvate and [1-13C] acetate were injected in vivo to obtain spatially and spectrally resolved information of basal metabolism on whole heart in middle size animal models. Five healthy male farm pigs (38±2 kg) were studied in basal condition and subjected to imaging experiments performed on a 3T GE Signa HDx scanner using a 13C-quadrature birdcage coil (Rapid Biomedical). An HyperSense DNP polarizer (Oxford Inst.) was employed for the studies: a procedure for the hyperpolarization and dissolution of a large dose of TRIS-[1-13C]acetate water/glycerol mixture was set up while the preparation of a large dose of [1-13C] pyruvic acid was performed as recently published by this group. An anatomical region of interest covering the whole heart was first acquired with a proton reference scan and the metabolic information was then obtained using 3D IDEAL spiral CSI on the same region. Image re-slicing along cardiac short axis (SA) views and image fusion of 13C metabolite maps and anatomical 1H reference images were performed by PMOD software.

Results

A graph of the γ-variate and mono-exponential fitting of hyperpolarized [1-13C] acetate myocardial spectroscopic signals is reported in Figure 1 while a representative map in SA orientation through the heart is shown in Figure 2: [1-13C] acetate is extracted inside the heart and clearly detected in the heart-chambers and myocardial wall. Representative maps of spatial distribution of [1-13C]bicarbonate, [1-13C] lactate and [1-13C] pyruvate in SA orientation through the heart are also produced using hyperpolarized [1-13C] pyruvate.
Figure 1
Figure 1

13C dynamic spectra were acquired using a slice selective pulse-and-acquire sequence (bandwidth 5000 Hz, 2048 pts, 10° FA). A long-axis slice of 20 mm was selected during excitation. Spectra were acquired from the beginning of the injection of the hyperpolarized [1-13C] acetate, every 2 s, for 120 s. Diagrammatic representation of the γ-variate and mono-exponential fitting of cardiac spectroscopic signal to obtain rate constants (N=4).

Figure 2
Figure 2

Representative maps in SA view of the heart showing the in vivo spatial distribution of hyperpolarized TRIS-[1-13C] acetate in pigs; spectroscopic data were normalized to the maximum value of signal amplitude.

Conclusions

A comparison between acetate and pyruvate 13C-mapping has been realised as far as we know for the first time in pigs with this experimental approach. This ongoing study demonstrates the feasibility of whole-heart 13C-cardiac metabolic imaging in pigs for detecting and mapping cardiac metabolism in basal condition with hyperpolarized [1-13C]acetate in comparison with [1-13C] pyruvate.

This study is the first step towards the optimization of the [1-13C] acetate concentration and the acquisition sequence parameters to ensure suitable MR signals in myocardial tissue and to study its metabolic fate.

Funding

Self funding.

Authors’ Affiliations

(1)
Institute of Clinical Physiology, National Research Council, Pisa, Italy
(2)
Fondazione G. Monasterio CNR-Regione Toscana, Pisa, Italy
(3)
Scuola Superiore Sant'Anna, Pisa, Italy
(4)
Faculty of Physics, University of Pisa, Pisa, Italy
(5)
GE Healthcare, Hillerod, Denmark
(6)
Department of Electrical Engineering, Technical University of Denmark, Kongens Lyngby, Denmark
(7)
GE Global Research, Munich, Germany
(8)
Department of Information Engineering, University of Pisa, Pisa, Italy

Copyright

© Menichetti et al; licensee BioMed Central Ltd. 2013

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.

Advertisement