Computerized MRS voxel registration and partial volume effects in single voxel 1H-MRS

Lee, Hedok; Caparelli, Elisabeth C.; Li, Haifang; Mandal, Amit Kumar; Smith, Shane; Zhang, Shaonan; Bilfinger, Thomas V.; Benveniste, Helene

doi:10.1016/j.mri.2013.04.001

Cited by 19 publications

(18 citation statements)

References 60 publications

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“…Of particular note is the need to specify the order of multiple voxel rotations (which do not commute) for voxels. A range of voxel overlaps have been shown previously, from 57% within-subject for a small (15 mm) 3 parietal voxel [7] to 86% for a slightly larger (20 mm) 3 posterior cingulate voxel [17]. There is some evidence that automated voxel placement protocols, which typically calculate voxel location parameters from parameters co-registering images to standard space within-session, can perform as well as human operators and remove some variance [17], and prospective voxel placement correction has been demonstrated with a navigator-based acquisition [18].…”

Section: Discussionmentioning

confidence: 81%

“…It is therefore somewhat surprising that the fidelity of voxel placement has only occasionally been investigated in the literature [7] [17]. In order to evaluate the repeatability of voxel placement for MEGA-PRESS GABA scans, this study calculated the DOC both within-subject and, after image co-registration, between-subject.…”

Section: Discussionmentioning

confidence: 99%

“…To date, a landmark-based approach is the main method for edited MRS voxel placement. Given the reliance on anatomical landmarks, it is therefore particularly important to assess the reproducibility of voxel placement in MRS studies [7], especially for edited MRS experiments.…”

Section: Introductionmentioning

confidence: 99%

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Voxel Placement Precision for GABA-Edited Magnetic Resonance Spectroscopy

Bai¹,

Harris²,

Gong³

et al. 2017

OJRad

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The purpose of the present study was to assess the reproducibility of voxel placement for GABA-edited MRS. GABA-edited MRS data were acquired in 13 healthy volunteers from (3 cm)3 voxel; and within the same session a second acquisition was independently prescribed. A three-dimensional voxel mask image was reconstructed in T1-image-space using the SVMask tool (in house software). Reproducibility of voxel placement was assessed using the Dice overlap coefficient, both within-subject and between-subject following co-registration of T1 images and transformation of voxel mask images to standard space. Within-subject overlap coefficients were 86% ± 5%. Between-subject overlap coefficients were 75% ± 10%. For the two voxel locations considered (occipital and sensorimotor), voxel overlap was very similar. Between-subject values are higher due to between-session effects, anatomical variability and volume mismatch in standard space. While surprisingly low in terms of volume overlap, the overlap coefficients correspond to acceptable linear displacements.

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Section: Discussionmentioning

confidence: 81%

Section: Discussionmentioning

confidence: 99%

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Voxel Placement Precision for GABA-Edited Magnetic Resonance Spectroscopy

Bai¹,

Harris²,

Gong³

et al. 2017

OJRad

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“…Voxel placement was performed by an operator who was blinded to the drug condition and drug condition was randomized to eliminate bias in voxel placement based on drug condition. Achieved voxel overlap (64%) did not differ between conditions and is on the order of that achieved by automated voxel placement [91], indicating excellent and stable within-subject reliability of voxel placement. Physiological data confirmed sympathomimetic drug activity, providing evidence of internal validity.…”

Section: Strengths and Limitationsmentioning

confidence: 81%

Psychostimulant drug effects on glutamate, Glx, and creatine in the anterior cingulate cortex and subjective response in healthy humans

White

Monnig

Walsh

et al. 2018

Neuropsychopharmacol

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Prescription psychostimulants produce rapid changes in mood, energy, and attention. These drugs are widely used and abused. However, their effects in human neocortex on glutamate and glutamine (pooled as Glx), and key neurometabolites such as N-acetylaspartate (tNAA), creatine (tCr), choline (Cho), and myo-inositol (Ins) are poorly understood. Changes in these compounds could inform the mechanism of action of psychostimulant drugs and their abuse potential in humans. We investigated the acute impact of two FDA-approved psychostimulant drugs on neurometabolites using magnetic resonance spectroscopy (H MRS). Single clinically relevant doses of d-amphetamine (AMP, 20 mg oral), methamphetamine (MA, 20 mg oral; Desoxyn®), or placebo were administered to healthy participants (n = 26) on three separate test days in a placebo-controlled, double-blinded, within-subjects crossover design. Each participant experienced all three conditions and thus served as his/her own control. H MRS was conducted in the dorsal anterior cingulate cortex (dACC), an integrative neocortical hub, during the peak period of drug responses (140-150 m post ingestion). D-amphetamine increased the level of Glu (p = .0001), Glx (p = .003), and tCr (p = .0067) in the dACC. Methamphetamine increased Glu in females, producing a significant crossover interaction pattern with gender (p = .02). Drug effects on Glu, tCr, and Glx were positively correlated with subjective drug responses, predicting both the duration of AMP liking (Glu: r = +.49, p = .02; tCr: r = +.41, p = .047) and the magnitude of peak drug high to MA (Glu: r = +.52, p = .016; Glx: r = +.42, p = .049). Neither drug affected the levels of tNAA, Cho, or Ins after correction for multiple comparisons. We conclude that d-amphetamine increased the concentration of glutamate, Glx, and tCr in the dACC in male and female volunteers 2/ hours after drug consumption. There was evidence that methamphetamine differentially affects dACC Glu levels in women and men. These findings provide the first experimental evidence that specific psychostimulants increase the level of glutamatergic compounds in the human brain, and that glutamatergic changes predict the extent and magnitude of subjective responses to psychostimulants.

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“…However, a relatively large voxel in MRSI may compromise gray matter (GM) and white matter (WM) or cerebral spinal fluid (CSF). Therefore, to report the concentrations in a standardized metabolite concentration unit, the partial volume effect and the relaxation effect must be considered . An additional nonwater suppression (NWS) scan, using the same experiment parameters, is necessary to obtain an unsuppressed water signal for calibration.…”

Section: Introductionmentioning

confidence: 99%