A subspace approach to high‐resolution spectroscopic imaging

Lam, Fan; Liang, Zhi Pei

doi:10.1002/mrm.25168

Cited by 120 publications

(191 citation statements)

References 41 publications

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“…has emerged as a promising technique for high-resolution MRSI (178). The technique takes advantage of a unique property of spectroscopic signals known as the partial separability (PS), which indicates that high-dimensional spectroscopic signals reside in a very low-dimensional subspace.…”

Section: P-mrsi Methodsmentioning

confidence: 99%

Assessing tissue metabolism by phosphorous-31 magnetic resonance spectroscopy and imaging: a methodology review

Liu

2017

Quant. Imaging Med. Surg.

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Many human diseases are caused by an imbalance between energy production and demand.Magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) provide the unique opportunity for in vivo assessment of several fundamental events in tissue metabolism without the use of ionizing radiation. Of particular interest, phosphate metabolites that are involved in ATP generation and utilization can be quantified noninvasively by phosphorous-31 ( 31 P) MRS/MRI. Furthermore, 31 P magnetization transfer (MT) techniques allow in vivo measurement of metabolic fluxes via creatine kinase (CK) and ATP synthase. However, a major impediment for the clinical applications of 31 P-MRS/MRI is the prohibitively long acquisition time and/or the low spatial resolution that are necessary to achieve adequate signal-to-noise ratio. P-MRS/MRI techniques. Applications of these techniques to the investigation of a specific physiology/pathology will be discussed without detailed description. Interested readers are referred to recent review articles on the applications of 31 P-MRS/MRI in metabolic characterization of skeletal muscle (10-12), heart (13), brain (14), and liver (11), as well as in diseases such as cancer (15), heart failure (16), and obesity and diabetes (17,18). Historical perspectiveThe use of 31 P-MRS for metabolic investigations dates back to 1960. Cohn and Hughes were the first to obtain a high-resolution 31 P spectrum of a solution of ATP (19). In addition, they also observed a dependence of the chemical shifts of the phosphorus nuclei of ATP on the pH of the solution. In parallel to the early development of MRI methods by Lauterbur (20), the entire 1970s also witnessed the rapid advance of 31 P-MRS in metabolic investigation of a broad range of biological systems. In 1973, Moon and Richards performed the first 31 P-MRS study that measured intracellular pH in human red blood cells (21). In the following year, Henderson and colleagues obtained the first 31 P spectrum of ATP from human red blood cells (22). At the same time, the Oxford team led by Radda performed the first experiment to acquire 31 P spectra from an intact organ, i.e., the excised and superfused muscle of rat hindlimb (23). The first in vivo 31 P-MRS study was performed on mouse brain by Chance et al. (24). Within the short span of one decade, organelles including mitochondria (25,26) and chromaffin granules (27), cells including Escherichia coli (28), yeast (29), and hepatocytes (30), and organs including skeletal muscle (31,32), heart (33-35), brain (36), kidney (37), and liver (38,39) have all been studied using 31 P-MRS.It is worth noting that most of these organ studies were performed on excised organs to avoid the need for spatial localization. Although Lauterbur has demonstrated the feasibility of imaging water protons (20), it was considered impractical for 31 P imaging of living systems because of the low sensitivity and difficulties with spectral resolution.The 1980s began with the publication of two important studies that aimed a...

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Section: P-mrsi Methodsmentioning

confidence: 99%

Assessing tissue metabolism by phosphorous-31 magnetic resonance spectroscopy and imaging: a methodology review

Liu

2017

Quant. Imaging Med. Surg.

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“…Sampling Consideration-Given a subspace with dimension L, the number of spatial encodings in (i.e., N 1 ) theoretically has at least to be greater than L. This is easy to satisfy since L is typically a small number with the field inhomogeneity effects removed (26,28). In practice, however, a sufficiently large N 1 is needed for effective field inhomogeneity correction and nuisance signal removal.…”

Section: Methods Practical Implementationsmentioning

confidence: 99%

“…SPICE exploits the spatiotemporal partial separability (PS) of high-dimensional spectroscopic signals and models the spatiotemporal function ρ (r; t) (the Fourier counterpart of the underlying spatiospectral function of interest as (26)(27)(28)(29) [1]…”

Section: Theory Subspace Modelmentioning

confidence: 99%

“…1 For image reconstruction from and (expressed as ), we incorporate low-rank models on ρ m and ρ ns (based on the PS representation in Eq. [1]) and use the following imaging equation (26,27,30) [4]…”

Section: Image Reconstructionmentioning

confidence: 99%

“…If the contribution of the nuisance signals is negligible (or removed from the data in preprocessing (29) Subspace Estimation-According to Eqs. [3] and [4], Φ can be easily estimated from (e.g., through singular value decomposition (26,27)) in the absence of field inhomogeneity. In the presence of non-negligible field inhomogeneity, as it is the case for in vivo experiments, its effects need to be removed (28).…”

Section: Image Reconstructionmentioning

confidence: 99%

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High‐resolution ¹H‐MRSI of the brain using SPICE: Data acquisition and image reconstruction

Lam

Clifford

et al. 2016

Magnetic Resonance in Med

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Purpose-To develop data acquisition and image reconstruction methods to enable highresolution 1 H MR spectroscopic imaging (MRSI) of the brain, using the recently proposed subspace-based spectroscopic imaging framework called SPICE (SPectroscopic Imaging by exploiting spatiospectral CorrElation).Theory and Methods-SPICE is characterized by the use of a subspace model for both data acquisition and image reconstruction. For data acquisition, we propose a novel spatiospectral encoding scheme that provides hybrid data sets for determining the subspace structure and for image reconstruction using the subspace model. More specifically, we use a hybrid chemical shift imaging (CSI)/echo-planar spectroscopic imaging (EPSI) sequence for two-dimensional (2D) MRSI and a dual-density, dual-speed EPSI sequence for three-dimensional (3D) MRSI. For image reconstruction, we propose a method that can determine the subspace structure and the highresolution spatiospectral reconstruction from the hybrid data sets generated by the proposed sequences, incorporating field inhomogeneity correction and edge-preserving regularization.Results-Phantom and in vivo brain experiments were performed to evaluate the performance of the proposed method. For 2D MRSI experiments, SPICE is able to produce high SNR spatiospectral distributions with an approximately 3 mm nominal in-plane resolution from a 10-min acquisition. For 3D MRSI experiments, SPICE is able to achieve an approximately 3 mm inplane and 4 mm through-plane resolution in about 25 min.Conclusion-Special data acquisition and reconstruction methods have been developed for highresolution 1 H-MRSI of the brain using SPICE. Using these methods, SPICE is able to produce spatiospectral distributions of 1 H metabolites in the brain with high spatial resolution, while maintaining a good SNR. These capabilities should prove useful for practical applications of SPICE.

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Encoding and Decoding with Prior Knowledge: From SLIM to SPICE

Lam

Liang

2015

eMagRes

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A subspace approach to high‐resolution spectroscopic imaging

Cited by 120 publications

References 41 publications

Assessing tissue metabolism by phosphorous-31 magnetic resonance spectroscopy and imaging: a methodology review

Assessing tissue metabolism by phosphorous-31 magnetic resonance spectroscopy and imaging: a methodology review

High‐resolution ¹H‐MRSI of the brain using SPICE: Data acquisition and image reconstruction

Encoding and Decoding with Prior Knowledge: From SLIM to SPICE

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A subspace approach to high‐resolution spectroscopic imaging

Cited by 120 publications

References 41 publications

Assessing tissue metabolism by phosphorous-31 magnetic resonance spectroscopy and imaging: a methodology review

Assessing tissue metabolism by phosphorous-31 magnetic resonance spectroscopy and imaging: a methodology review

High‐resolution 1H‐MRSI of the brain using SPICE: Data acquisition and image reconstruction

Encoding and Decoding with Prior Knowledge: From SLIM to SPICE

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High‐resolution ¹H‐MRSI of the brain using SPICE: Data acquisition and image reconstruction