Compressed sensing to accelerate magnetic resonance spectroscopic imaging

Evaluation and application to <sup>23</sup>Na-imaging of mouse hearts

Mahon L. Maguire, Sairam Geethanath, Craig A. Lygate, Vikram Kodibagkar, Jürgen E. Schneider

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Background: Magnetic Resonance Spectroscopic Imaging (MRSI) has wide applicability for non-invasive biochemical assessment in clinical and pre-clinical applications but suffers from long scan times. Compressed sensing (CS) has been successfully applied to clinical <sup>1</sup>H MRSI, however a detailed evaluation of CS for conventional chemical shift imaging is lacking. Here we evaluate the performance of CS accelerated MRSI, and specifically apply it to accelerate <sup>23</sup>Na-MRSI on mouse hearts in vivo at 9.4 T. Methods: Synthetic phantom data representing a simplified section across a mouse thorax were used to evaluate the fidelity of the CS reconstruction for varying levels of under-sampling, resolution and signal-to-noise ratios (SNR). The amplitude of signals arising from within a compartment, and signal contamination arising from outside the compartment relative to noise-free Fourier-transformed (FT) data were determined. Simulation results were subsequently verified experimentally in phantoms and in three mouse hearts in vivo. Results: CS reconstructed MRSI data are scaled linearly relative to absolute signal intensities from the fully-sampled FT reconstructed case (R<sup>2</sup> > 0.8, p-value < 0.001). Higher acceleration factors resulted in a denoising of the reconstructed spectra, but also in an increased blurring of compartment boundaries, particularly at lower spatial resolutions. Increasing resolution and SNR decreased cross-compartment contamination and yielded signal amplitudes closer to the FT data. Proof-of-concept high-resolution, 3-fold accelerated <sup>23</sup>Na-amplitude maps of murine myocardium could be obtained within ∼23 mins. Conclusions: Relative signal amplitudes (i.e. metabolite ratios) and absolute quantification of metabolite concentrations can be accurately determined with up to 5-fold under-sampled, CS-reconstructed MRSI. Although this work focused on murine cardiac <sup>23</sup>Na-MRSI, the results are equally applicable to other nuclei and tissues (e.g. <sup>1</sup>H MRSI in brain). Significant reduction in MRSI scan time will reduce the burden on the subject, increase scanner throughput, and may open new avenues for (pre-) clinical metabolic studies.

Original languageEnglish (US)
Article number42
JournalJournal of Cardiovascular Magnetic Resonance
Volume17
Issue number1
DOIs
StatePublished - Jun 15 2015

Fingerprint

Magnetic Resonance Imaging
Signal-To-Noise Ratio
Noise
Myocardium
Thorax
Brain

Keywords

  • Chemical shift imaging
  • Compressed sensing
  • Magnetic resonance spectroscopic imaging
  • Mouse
  • Sodium

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Radiology Nuclear Medicine and imaging
  • Radiological and Ultrasound Technology
  • Family Practice

Cite this

Compressed sensing to accelerate magnetic resonance spectroscopic imaging : Evaluation and application to <sup>23</sup>Na-imaging of mouse hearts. / Maguire, Mahon L.; Geethanath, Sairam; Lygate, Craig A.; Kodibagkar, Vikram; Schneider, Jürgen E.

In: Journal of Cardiovascular Magnetic Resonance, Vol. 17, No. 1, 42, 15.06.2015.

Research output: Contribution to journalArticle

@article{0d8ebe9b05b442d7b943d9836b8f209d,
title = "Compressed sensing to accelerate magnetic resonance spectroscopic imaging: Evaluation and application to 23Na-imaging of mouse hearts",
abstract = "Background: Magnetic Resonance Spectroscopic Imaging (MRSI) has wide applicability for non-invasive biochemical assessment in clinical and pre-clinical applications but suffers from long scan times. Compressed sensing (CS) has been successfully applied to clinical 1H MRSI, however a detailed evaluation of CS for conventional chemical shift imaging is lacking. Here we evaluate the performance of CS accelerated MRSI, and specifically apply it to accelerate 23Na-MRSI on mouse hearts in vivo at 9.4 T. Methods: Synthetic phantom data representing a simplified section across a mouse thorax were used to evaluate the fidelity of the CS reconstruction for varying levels of under-sampling, resolution and signal-to-noise ratios (SNR). The amplitude of signals arising from within a compartment, and signal contamination arising from outside the compartment relative to noise-free Fourier-transformed (FT) data were determined. Simulation results were subsequently verified experimentally in phantoms and in three mouse hearts in vivo. Results: CS reconstructed MRSI data are scaled linearly relative to absolute signal intensities from the fully-sampled FT reconstructed case (R2 > 0.8, p-value < 0.001). Higher acceleration factors resulted in a denoising of the reconstructed spectra, but also in an increased blurring of compartment boundaries, particularly at lower spatial resolutions. Increasing resolution and SNR decreased cross-compartment contamination and yielded signal amplitudes closer to the FT data. Proof-of-concept high-resolution, 3-fold accelerated 23Na-amplitude maps of murine myocardium could be obtained within ∼23 mins. Conclusions: Relative signal amplitudes (i.e. metabolite ratios) and absolute quantification of metabolite concentrations can be accurately determined with up to 5-fold under-sampled, CS-reconstructed MRSI. Although this work focused on murine cardiac 23Na-MRSI, the results are equally applicable to other nuclei and tissues (e.g. 1H MRSI in brain). Significant reduction in MRSI scan time will reduce the burden on the subject, increase scanner throughput, and may open new avenues for (pre-) clinical metabolic studies.",
keywords = "Chemical shift imaging, Compressed sensing, Magnetic resonance spectroscopic imaging, Mouse, Sodium",
author = "Maguire, {Mahon L.} and Sairam Geethanath and Lygate, {Craig A.} and Vikram Kodibagkar and Schneider, {J{\"u}rgen E.}",
year = "2015",
month = "6",
day = "15",
doi = "10.1186/s12968-015-0149-6",
language = "English (US)",
volume = "17",
journal = "Journal of Cardiovascular Magnetic Resonance",
issn = "1097-6647",
publisher = "BioMed Central",
number = "1",

}

TY - JOUR

T1 - Compressed sensing to accelerate magnetic resonance spectroscopic imaging

T2 - Evaluation and application to 23Na-imaging of mouse hearts

AU - Maguire, Mahon L.

AU - Geethanath, Sairam

AU - Lygate, Craig A.

AU - Kodibagkar, Vikram

AU - Schneider, Jürgen E.

PY - 2015/6/15

Y1 - 2015/6/15

N2 - Background: Magnetic Resonance Spectroscopic Imaging (MRSI) has wide applicability for non-invasive biochemical assessment in clinical and pre-clinical applications but suffers from long scan times. Compressed sensing (CS) has been successfully applied to clinical 1H MRSI, however a detailed evaluation of CS for conventional chemical shift imaging is lacking. Here we evaluate the performance of CS accelerated MRSI, and specifically apply it to accelerate 23Na-MRSI on mouse hearts in vivo at 9.4 T. Methods: Synthetic phantom data representing a simplified section across a mouse thorax were used to evaluate the fidelity of the CS reconstruction for varying levels of under-sampling, resolution and signal-to-noise ratios (SNR). The amplitude of signals arising from within a compartment, and signal contamination arising from outside the compartment relative to noise-free Fourier-transformed (FT) data were determined. Simulation results were subsequently verified experimentally in phantoms and in three mouse hearts in vivo. Results: CS reconstructed MRSI data are scaled linearly relative to absolute signal intensities from the fully-sampled FT reconstructed case (R2 > 0.8, p-value < 0.001). Higher acceleration factors resulted in a denoising of the reconstructed spectra, but also in an increased blurring of compartment boundaries, particularly at lower spatial resolutions. Increasing resolution and SNR decreased cross-compartment contamination and yielded signal amplitudes closer to the FT data. Proof-of-concept high-resolution, 3-fold accelerated 23Na-amplitude maps of murine myocardium could be obtained within ∼23 mins. Conclusions: Relative signal amplitudes (i.e. metabolite ratios) and absolute quantification of metabolite concentrations can be accurately determined with up to 5-fold under-sampled, CS-reconstructed MRSI. Although this work focused on murine cardiac 23Na-MRSI, the results are equally applicable to other nuclei and tissues (e.g. 1H MRSI in brain). Significant reduction in MRSI scan time will reduce the burden on the subject, increase scanner throughput, and may open new avenues for (pre-) clinical metabolic studies.

AB - Background: Magnetic Resonance Spectroscopic Imaging (MRSI) has wide applicability for non-invasive biochemical assessment in clinical and pre-clinical applications but suffers from long scan times. Compressed sensing (CS) has been successfully applied to clinical 1H MRSI, however a detailed evaluation of CS for conventional chemical shift imaging is lacking. Here we evaluate the performance of CS accelerated MRSI, and specifically apply it to accelerate 23Na-MRSI on mouse hearts in vivo at 9.4 T. Methods: Synthetic phantom data representing a simplified section across a mouse thorax were used to evaluate the fidelity of the CS reconstruction for varying levels of under-sampling, resolution and signal-to-noise ratios (SNR). The amplitude of signals arising from within a compartment, and signal contamination arising from outside the compartment relative to noise-free Fourier-transformed (FT) data were determined. Simulation results were subsequently verified experimentally in phantoms and in three mouse hearts in vivo. Results: CS reconstructed MRSI data are scaled linearly relative to absolute signal intensities from the fully-sampled FT reconstructed case (R2 > 0.8, p-value < 0.001). Higher acceleration factors resulted in a denoising of the reconstructed spectra, but also in an increased blurring of compartment boundaries, particularly at lower spatial resolutions. Increasing resolution and SNR decreased cross-compartment contamination and yielded signal amplitudes closer to the FT data. Proof-of-concept high-resolution, 3-fold accelerated 23Na-amplitude maps of murine myocardium could be obtained within ∼23 mins. Conclusions: Relative signal amplitudes (i.e. metabolite ratios) and absolute quantification of metabolite concentrations can be accurately determined with up to 5-fold under-sampled, CS-reconstructed MRSI. Although this work focused on murine cardiac 23Na-MRSI, the results are equally applicable to other nuclei and tissues (e.g. 1H MRSI in brain). Significant reduction in MRSI scan time will reduce the burden on the subject, increase scanner throughput, and may open new avenues for (pre-) clinical metabolic studies.

KW - Chemical shift imaging

KW - Compressed sensing

KW - Magnetic resonance spectroscopic imaging

KW - Mouse

KW - Sodium

UR - http://www.scopus.com/inward/record.url?scp=84935875545&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84935875545&partnerID=8YFLogxK

U2 - 10.1186/s12968-015-0149-6

DO - 10.1186/s12968-015-0149-6

M3 - Article

VL - 17

JO - Journal of Cardiovascular Magnetic Resonance

JF - Journal of Cardiovascular Magnetic Resonance

SN - 1097-6647

IS - 1

M1 - 42

ER -