3D localized <i>in vivo</i><sup>1</sup>H spectroscopy of human brain by using a hybrid of 1D‐hadamard with 2D‐chemical shift imaging

Gonen, Oded; Arias‐Mendoza, Fernando; Goelman, Gadi

doi:10.1002/mrm.1910370503

Cited by 47 publications

(56 citation statements)

References 32 publications

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“…1 H MR spectroscopic measurements can serve as estimates of neuronal cell viability, cell energetics, membrane turnover, gliosis, glycolysis, and inflammatory processes in vivo through levels of their respective surrogate markers, N-acetylaspartate (NAA), creatine, choline, myo-inositol, and lactate (10)(11)(12). Furthermore, because 1 H MR spectroscopy has shown variable changes among brain regions (13,14), its three-dimensional MR spectroscopic imaging variant is of great utility in the evaluation of an increasing number of clinical conditions. MR spectroscopic imaging improves diagnostic accuracy for differentiation between recurrent neoplastic brain lesions and therapy-related effects (15), for preoperative assignment of grades to gliomas (16), and for localization of an epileptogenic focus in the medial temporal lobe (17).…”

Section: Discussionmentioning

confidence: 99%

Anteroposterior Hippocampal Metabolic Heterogeneity: Three-dimensional Multivoxel Proton¹H MR Spectroscopic Imaging—Initial Findings

King¹,

Glodzik²,

Liu³

et al. 2008

Radiology

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Purpose:To quantify proton magnetic resonance (MR) spectroscopy-detectable metabolite concentrations along anteroposterior axis of hippocampus in healthy young and elderly subjects. Materials and Methods:Young (three women, three men; age range, 25-35 years) and elderly (four women, two men; age range, 68 -72 years) groups underwent MR imaging and proton MR spectroscopic imaging at 3 T in this HIPAA-compliant prospective study and gave institutional review board-approved written consent. Volume of interest was centered on and tilted parallel to hippocampal anteroposterior plane. Absolute N-acetylaspartate (NAA), choline, and creatine levels were obtained in each voxel, with phantom replacement. Results:Mean NAA, creatine, and choline concentrations in the young group were higher in posterior hippocampus (12.9 mmol/L Ϯ 2.0 [standard deviation], 7.8 mmol/L Ϯ 1.2, 2.3 mmol/L Ϯ 0.4, respectively) than anterior hippocampus (8.0 mmol/L Ϯ 1.1, 6.0 mmol/L Ϯ 1.4, 1.5 mmol/L Ϯ 0.2; P ϭ .005, .02, and .0002, respectively). In the elderly group, mean concentrations were higher in posterior hippocampus (8.6 mmol/L Ϯ 0.9, 5.6 mmol/L Ϯ 0.6, 1.5 mmol/L Ϯ 0.2, respectively) than anterior hippocampus (7.2 mmol/L Ϯ 1.0, 2.4 mmol/L Ϯ 0.3, 1.0 mmol/L Ϯ 0.2; P ϭ .006, .0001, .04, respectively). Mean concentrations were significantly higher in the young group (13.2 mmol/ L Ϯ 1.0, 7.4 mmol/L Ϯ 0.8, 2.1 mmol/L Ϯ 0.3, respectively) than in the elderly group (9.0 mmol/L Ϯ 1.0, 5.8 mmol/L Ϯ 0.8, 1.8 mmol/L Ϯ 0.3; P ϭ .0001, .01, .05, respectively). Posteroanterior metabolic gradients differed: NAA decreased faster in the young group (Ϫ1.0 mmol/L ⅐ cm Ϫ1 ) than the elderly group (Ϫ0.7 mmol/ L ⅐ cm Ϫ1 ); creatine and choline concentrations decreased faster in the elderly group (Ϫ0.8 and Ϫ0.058 mmol/ L ⅐ cm Ϫ1 , respectively) than the young group (Ϫ0.16 and Ϫ0.008 mmol/L ⅐ cm Ϫ1 , respectively). No left-right metabolic differences were found. Conclusion:Significant metabolic heterogeneity was observed between groups and along anteroposterior axis of healthy hippocampus in both groups. Age matching and consistent voxel placement are important for correct comparisons of both absolute metabolic levels and metabolite ratios in longitudinal intra-and intersubject cross-sectional studies. Note: This copy is for your personal, non-commercial use only. To order presentation-ready copies for distribution to your colleagues or clients, use the Radiology Reprints form at the end of this article.T he hippocampus, a part of the limbic system located on the floor of the temporal horn of the lateral ventricle (1), is crucial for memory consolidation, spatial cognition, perception of temporal ordering of events (2), mood regulation (3), and negative feedback inhibition of glucocorticoids (4). It is functionally connected to a wide range of cortical and subcortical brain regions, including the cingulate gyrus, orbitofrontal and temporal cortices, amygdala, olfactory cortex, and thalamic nuclei (5). Given this complex function and connectivity, it is not surpr...

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Section: Discussionmentioning

confidence: 99%

Anteroposterior Hippocampal Metabolic Heterogeneity: Three-dimensional Multivoxel Proton¹H MR Spectroscopic Imaging—Initial Findings

King¹,

Glodzik²,

Liu³

et al. 2008

Radiology

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“…The commercial software adjusted the homogeneity over a 9 lr cm ϫ 6 ap cm ϫ 4 is cm region encompassing both hippocampi angulated along the temporal poles. This VOI was then partitioned into 4 is slices each of 16 lr ϫ 16 ap in-plane resolution in a 4 is ϫ 16 lr ϫ 16 ap cm 3 FOV for nominal 1 cm 3 voxels, using a 1D Hadamard/2D-chemical-shiftimaging localization sequence (22). The data were processed with in-house-developed software.…”

Section: Methodsmentioning

confidence: 99%

Robust fully automated shimming of the human brain for high‐field ¹H spectroscopic imaging

Hetherington

Chu

Gonen

et al. 2006

Magnetic Resonance in Med

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Although a variety of methods have been proposed to provide automated adjustment of shim homogeneity, these methods typically fail or require large numbers of iterations in vivo when applied to regions with poor homogeneity, such as the temporal lobe. These limitations are largely due to 1) the limited accuracy of single evolution time measurements when full B 0 mapping studies are used, and 2) inaccuracies arising from projectionbased methods when the projections pass through regions where the inhomogeneity exceeds the order of the fitted parameters. To overcome these limitations we developed a novel B 0 mapping method using multiple evolution times with a novel unwrapping scheme in combination with a user-defined ROI selection tool. We used these methods at 4T on 10 control subjects to obtain high-resolution spectroscopic images of glutamate from the bilateral hippocampi. A variety of rapid automated shim mapping methods for the human brain based on acquisition of a limited number of columnar projections using phase mapping have been described for small localized volumes (1,2). Shen and colleagues (3,4) demonstrated the need for alternate projection geometries when shimming planar volumes. Although these methods have been successfully applied in regions of good homogeneity, such as the occipital lobe for single volume measurements (1,2) and for slices above the corpus callosum (3), they can fail or require large numbers of iterations in vivo when applied to regions with very poor B 0 homogeneity adjacent to air-filled sinuses, such as the temporal lobes. Intrinsic to these maps is the assumption that the B 0 inhomogeneity present in the entire sample or region of interest (ROI) can be accurately represented by the limited number of columns acquired, and that the columns are sufficiently narrow for there to be negligible inhomogeneity across them. However, this assumption fails when the spatial order of the inhomogeneity present (i.e., the order of the spherical harmonic terms that characterize the spatial symmetry of the inhomogeneity) exceeds the spatial order that is used or measurable in the columnar analysis model, or when the inhomogeneity changes very rapidly in relationship to the cross-sectional width of the column (5). In this case lower-order corrections in localized regions are then used to attempt to compensate for higher-order corrections that do not have the same spatial symmetry. The calculated shim corrections can either over-or underestimate the size of the adjustments required to provide "optimal" homogeneity over the entire target volume given the available currents.Alternatively, shim methods that utilize complete maps (5-9) as opposed to columnar projections can provide accurate maps over large regions without assumptions regarding the order of the inhomogeneity present. In these cases the residual inhomogeneity is minimized by using information from sampling a much greater extent of the target volume. For B 0 mapping, typically a single, relatively short phase evolution time is used becau...

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“…The advantages of using Hadamard encoding as a localization strategy have been fully discussed elsewhere (23,24,(31)(32)(33) Hadamard encoding is insensitive to B 1 imperfections and the repetition time; d) the method gives spectra with high signal-to-noise ratio per unit time; and e) data can be recovered if acquisition is interrupted. However, there are also limitations to the use of longitudinal Hadamard encoding.…”

Section: Discussionmentioning

confidence: 98%

Multiple-voxel double-quantum lactate-edited spectroscopy using two-dimensional longitudinal Hadamard encoding

Lei

Peeling

1999

Magn. Reson. Med.

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3D localized in vivo¹H spectroscopy of human brain by using a hybrid of 1D‐hadamard with 2D‐chemical shift imaging

Cited by 47 publications

References 32 publications

Anteroposterior Hippocampal Metabolic Heterogeneity: Three-dimensional Multivoxel Proton¹H MR Spectroscopic Imaging—Initial Findings

Anteroposterior Hippocampal Metabolic Heterogeneity: Three-dimensional Multivoxel Proton¹H MR Spectroscopic Imaging—Initial Findings

Robust fully automated shimming of the human brain for high‐field ¹H spectroscopic imaging

Multiple-voxel double-quantum lactate-edited spectroscopy using two-dimensional longitudinal Hadamard encoding

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3D localized in vivo1H spectroscopy of human brain by using a hybrid of 1D‐hadamard with 2D‐chemical shift imaging

Cited by 47 publications

References 32 publications

Anteroposterior Hippocampal Metabolic Heterogeneity: Three-dimensional Multivoxel Proton1H MR Spectroscopic Imaging—Initial Findings

Anteroposterior Hippocampal Metabolic Heterogeneity: Three-dimensional Multivoxel Proton1H MR Spectroscopic Imaging—Initial Findings

Robust fully automated shimming of the human brain for high‐field 1H spectroscopic imaging

Multiple-voxel double-quantum lactate-edited spectroscopy using two-dimensional longitudinal Hadamard encoding

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3D localized in vivo¹H spectroscopy of human brain by using a hybrid of 1D‐hadamard with 2D‐chemical shift imaging

Anteroposterior Hippocampal Metabolic Heterogeneity: Three-dimensional Multivoxel Proton¹H MR Spectroscopic Imaging—Initial Findings

Anteroposterior Hippocampal Metabolic Heterogeneity: Three-dimensional Multivoxel Proton¹H MR Spectroscopic Imaging—Initial Findings

Robust fully automated shimming of the human brain for high‐field ¹H spectroscopic imaging