Echoplanar chemical shift imaging

Guimarães, A.R.; Baker, John R.; Jenkins, Bruce G.; Lee, P.L.; Weisskoff, Robert M.; Rosen, Bruce R.; González, Ramón

doi:10.1002/(sici)1522-2594(199905)41:5<877::aid-mrm4>3.0.co;2-3

Cited by 32 publications

(13 citation statements)

References 26 publications

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“…As typically implemented for brain measurements, MRS is performed for a single voxel placed within a region of interest in the brain. However, metabolites can be measured in larger areas of tissue, whole slices, and even whole brain volumes with spectroscopic chemical shift imaging (CSI) (Brown et al, 1982;(Kuker et al, 2004;Guimaraes et al, 1999).…”

Section: Magnetic Resonance Spectroscopymentioning

confidence: 99%

Advances in white matter imaging: A review of in vivo magnetic resonance methodologies and their applicability to the study of development and aging

Wozniak

Lim

2006

Neuroscience & Biobehavioral Reviews

240

180

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Several newer magnetic resonance imaging (MRI) techniques are increasingly being applied to the study of white matter development and pathology across the lifespan. These techniques go beyond traditional macrostructural volumetric methods and provide valuable information about underlying tissue integrity and organization at the microstructural and biochemical levels. We first provide an overview of white matter development and discuss the role of white matter and myelin in cognitive function. We also review available studies of development that have employed traditional volumetric measures. Then, we discuss the contributions of four newer imaging paradigms to our understanding of brain development and aging. These paradigms are Diffusion Tensor Imaging (DTI), Magnetization Transfer Imaging (MTI), T2-Relaxography, and Magnetic Resonance Spectroscopy (MRS). Studies examining brain development during childhood and adulthood as well as studies of the effects of aging are discussed.

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Section: Magnetic Resonance Spectroscopymentioning

confidence: 99%

Advances in white matter imaging: A review of in vivo magnetic resonance methodologies and their applicability to the study of development and aging

Wozniak

Lim

2006

Neuroscience & Biobehavioral Reviews

240

180

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“…Significant efforts have been made in the last several decades to achieve fast, high-resolution MR spectroscopic imaging (MRSI), through the development of fast sequences (1)(2)(3)(4)(5)(6)(7)(8)(9)(10) and advanced image reconstruction methods (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25). SPICE (SPectroscopic Imaging by exploiting spatiospectral CorrElation) is a relatively new approach that we recently proposed to achieve high-resolution MRSI with good signal-to-noise ratio (SNR) and speed (26).…”

Section: Introductionmentioning

confidence: 99%

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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“…The multishot spectroscopic imaging method presented here has some features in common with that proposed by Guimaraes et al (14), which is essentially the generalization using echo-planar spatial encoding to N temporal samples of what has become known as the Dixon method (20,21). The method described here differs from this in several ways.…”

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confidence: 95%

“…The time penalty associated with a multishot trajectory is often acceptable when the geometric integrity of the image is important, as is the case for MRSI data that will ultimately be registered to highresolution anatomic images. Although a multishot strategy is traditionally applied to the spatial domain, it is equally applicable to the temporal domain (11,14).The multishot spectroscopic imaging method presented here has some features in common with that proposed by Guimaraes et al (14), which is essentially the generalization using echo-planar spatial encoding to N temporal samples of what has become known as the Dixon method (20,21). The method described here differs from this in several ways.…”

mentioning

confidence: 99%

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Volumetric multishot echo‐planar spectroscopic imaging

Tyszka

Mamelak

2001

Magnetic Resonance in Med

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Rapid volumetric magnetic resonance spectroscopic imaging (MRSI) is potentially of great relevance to the diagnosis and treatment of focal cerebral diseases such as cancer and epilepsy. A strategy for volumetric multishot echo-planar spectroscopic imaging (MEPSI) is described which allows whole-brain metabolite mapping in approximately 20 min. A multishot trajectory is used in both the spatial and temporal domains which reduces the accumulated phase during each echo train and tolerates conventional Fourier reconstruction without regridding. Also described is a generalized correction for phase discontinuities arising from the multishot acquisition of the time domain, which is independent of the spatial k-space trajectory and is therefore also applicable to multishot spiral MRSI. Whole-brain, lipid-suppressed MEPSI data were acquired from five normal subjects. The mean signal-to-noise ratios (SNRs) (؎SE) for the n-acetylaspartate (NAA), choline (Cho), and creatine (Cr) maps across all subjects were 21.3 ؎ 1.8, 11.7 ؎ 0.6, and 9.2 ؎ 0.6, respectively, with a computed voxel size of 2. Rapid, noninvasive volumetric mapping of cerebral metabolites is a potentially valuable tool for the diagnosis and treatment of focal diseases of the human brain. Magnetic resonance spectroscopic imaging (MRSI) generates maps of the spatial distribution of a limited set of high-concentration metabolites within a slab or volume of material. The clinical value of MRSI has been demonstrated for focal diseases such as brain tumors (1-3), prostate cancer (4 -6), and epilepsy (7-9). The majority of MRSI implementations for brain imaging generate data resolved in two spatial dimensions and one spectral dimension.The application of echo-planar and spiral k-space trajectories has significantly reduced total imaging time for volumetric MRSI (10 -16). Typical acquisition times using these methods are tens of minutes, compared to several hours for an equivalent dataset if conventional phase encoding is used.Echo-planar data acquisition, though rapid, is sensitive to timing inaccuracies, eddy-currents, concomitant gradient effects, and main-field inhomogeneities. A great deal of effort has been invested in correcting these artifacts in conventional, nonspectroscopic EPI, and this experience can be applied to the correction of echoplanar MRSI (17)(18)(19). A multishot approach to spatial data acquisition is well established in both echo-planar and spiral imaging for reducing cumulative phase effects during the readout period of the sequence. These phase effects typically cause spatial geometric distortion of the echo-planar image and are not trivially corrected (17,19). The time penalty associated with a multishot trajectory is often acceptable when the geometric integrity of the image is important, as is the case for MRSI data that will ultimately be registered to highresolution anatomic images. Although a multishot strategy is traditionally applied to the spatial domain, it is equally applicable to the temporal domain (11,14).The multishot spectro...

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Echoplanar chemical shift imaging

Cited by 32 publications

References 26 publications

Advances in white matter imaging: A review of in vivo magnetic resonance methodologies and their applicability to the study of development and aging

Advances in white matter imaging: A review of in vivo magnetic resonance methodologies and their applicability to the study of development and aging

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

Volumetric multishot echo‐planar spectroscopic imaging

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Echoplanar chemical shift imaging

Cited by 32 publications

References 26 publications

Advances in white matter imaging: A review of in vivo magnetic resonance methodologies and their applicability to the study of development and aging

Advances in white matter imaging: A review of in vivo magnetic resonance methodologies and their applicability to the study of development and aging

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

Volumetric multishot echo‐planar spectroscopic imaging

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Product

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