Dataset Information

Fully automated atlas-based method for prescribing 3D PRESS MR spectroscopic imaging: Toward robust and reproducible metabolite measurements in human brain.

ABSTRACT:

Purpose

To implement a fully automated atlas-based method for prescribing 3D PRESS MR spectroscopic imaging (MRSI).

Methods

The PRESS selected volume and outer-volume suppression bands were predefined on the MNI152 standard template image. The template image was aligned to the subject T₁ -weighted image during a scan, and the resulting transformation was then applied to the predefined prescription. To evaluate the method, H-1 MRSI data were obtained in repeat scan sessions from 20 healthy volunteers. In each session, datasets were acquired twice without repositioning. The overlap ratio of the prescribed volume in the two sessions was calculated and the reproducibility of inter- and intrasession metabolite peak height and area ratios was measured by the coefficient of variation (CoV). The CoVs from intra- and intersession were compared by a paired t-test.

Results

The average overlap ratio of the automatically prescribed selection volumes between two sessions was 97.8%. The average voxel-based intersession CoVs were less than 0.124 and 0.163 for peak height and area ratios, respectively. Paired t-test showed no significant difference between the intra- and intersession CoVs.

Conclusion

The proposed method provides a time efficient method to prescribe 3D PRESS MRSI with reproducible imaging positioning and metabolite measurements. Magn Reson Med 79:636-642, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

SUBMITTER: Bian W

PROVIDER: S-EPMC5670025 | biostudies-literature | 2018 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Fully automated atlas-based method for prescribing 3D PRESS MR spectroscopic imaging: Toward robust and reproducible metabolite measurements in human brain.

Bian Wei W Li Yan Y Crane Jason C JC Nelson Sarah J SJ

Magnetic resonance in medicine 20170503 2

<h4>Purpose</h4>To implement a fully automated atlas-based method for prescribing 3D PRESS MR spectroscopic imaging (MRSI).<h4>Methods</h4>The PRESS selected volume and outer-volume suppression bands were predefined on the MNI152 standard template image. The template image was aligned to the subject T<sub>1</sub> -weighted image during a scan, and the resulting transformation was then applied to the predefined prescription. To evaluate the method, H-1 MRSI data were obtained in repeat scan sessi ...[more]

PMID: 28470861

Similar Datasets

Project description:Perinatally acquired HIV (PHIV) has been associated with brain structural and functional deficiencies, and with poorer cognitive performance despite the advent of antiretroviral therapy (ART). However, investigation of brain metabolite levels in PHIV measured by proton magnetic resonance spectroscopy (MRS) methods, is still limited with often inconclusive or contradictory findings. In general, these MRS-based methods have used a single voxel approach that can only evaluate metabolite concentrations in a few select brain anatomical regions. Additionally, most of the published data have been on children perinatally infected with HIV with only a few studies examining adult populations, though not exclusively. Therefore, this prospective and cross-sectional study aims to evaluate metabolite differences at the whole-brain level, using a unique whole-brain proton magnetic resonance spectroscopy imaging (MRSI) method, in a group of PHIV infected young adults (N = 28) compared to age and gender matched control sample (N = 28), and to find associations with HIV clinical factors and neurocognitive scores. MRSI data were acquired on a 3T scanner with a TE of 70 ms. Brain metabolites levels of total N-acetylaspartate (tNAA), total choline (tCho) and total creatine (tCre), as well as ratios of tNAA/tCre, tCho/tCre, and tNAA/tCho, were obtained from the whole brain level and evaluated at the level of gray matter (GM) and white matter (WM) tissue types and anatomical regions of interest (ROI). Our results indicate extensive metabolic abnormalities throughout the brains of PHIV infected subjects with significantly elevated levels of tCre and tCho, notably in GM regions. Decreases in tNAA and ratios of tNAA/tCre and tNAA/tCho were also found mostly in WM regions. These metabolic alterations indicate increased glial activation, inflammation, neuronal dysfunction, and energy metabolism in PHIV infected individuals, which correlated with a reduction in CD4 cell count, and lower cognitive scores. Our findings suggest that significant brain metabolite alterations and associated neurological complications persist in the brains of those with PHIV on long-term ART, and advocates the need for continued monitoring of their brain health.

Project description:BackgroundAbsolute quantification of metabolites in MR spectroscopic imaging (MRSI) requires a stable reference signal of known concentration. The Electronic REference To access In vivo Concentrations (ERETIC) has shown great promise but has not been applied in patients and 3D MRSI. ERETIC hardware has not been integrated with receive arrays due to technical challenges, such as coil combination and unwanted coupling between multiple ERETIC and receive channels, for which we developed mitigation strategies.PurposeTo develop absolute quantification for whole-brain MRSI in glioma patients.Study typeProspective.PopulationFive healthy volunteers and three patients with isocitrate dehydrogenase mutant glioma (27% female). Calibration and coil loading phantoms.Field strength/sequenceA 3 T; Adiabatic spin-echo spiral 3D MRSI with real-time motion correction, Fluid Attenuated Inversion Recovery (FLAIR), Gradient Recalled Echo (GRE), Multi-echo Magnetization Prepared Rapid Acquisition of Gradient Echo (MEMPRAGE).AssessmentAbsolute quantification was performed for five brain metabolites (total N-acetyl-aspartate [NAA]/creatine/choline, glutamine + glutamate, myo-inositol) and the oncometabolite 2-hydroxyglutarate using a custom-built 4x-ERETIC/8x-receive array coil. Metabolite quantification was performed with both EREIC and internal water reference methods. ERETIC signal was transmitted via optical link and used to correct coil loading. Inductive and radiative coupling between ERETIC and receive channels were measured.Statistical testsERETIC and internal water methods for metabolite quantification were compared using Bland-Altman (BA) analysis and the nonparametric Mann-Whitney test. P < 0.05 was considered statistically significant.ResultsERETIC could be integrated in receive arrays and inductive coupling dominated (5-886 times) radiative coupling. Phantoms show proportional scaling of the ERETIC signal with coil loading. The BA analysis demonstrated very good agreement (3.3% ± 1.6%) in healthy volunteers, while there was a large difference (36.1% ± 3.8%) in glioma tumors between metabolite concentrations by ERETIC and internal water quantification.ConclusionOur results indicate that ERETIC integrated with receive arrays and whole-brain MRSI is feasible for brain metabolites quantification. Further validation is required to probe that ERETIC provides more accurate metabolite concentration in glioma patients.Evidence level2 TECHNICAL EFFICACY: Stage 1.

Project description:To develop a relevant pathophysiologic model of human immunodeficiency virus (HIV)-associated dementia by studying regional variations in metabolite levels measured with magnetic resonance (MR) spectroscopic imaging and their relationship to immunologic measures and cognitive dysfunction.This was a HIPAA-compliant, institutional review board-approved study involving written informed consent. Distributions of N-acetylaspartate (NAA), choline (Cho), and creatine (Cr) concentrations in 94 subjects (20 seronegative controls and 74 HIV-positive subjects; 34 of the HIV-positive subjects having HIV-associated dementia; 63 men, 31 women; mean age, 40 years) were determined with proton (hydrogen 1 [(1)H]) MR spectroscopic imaging. HIV-positive subjects underwent neuropsychological testing and blood and cerebrospinal fluid (CSF) analysis. Factor analysis was utilized to determine associations between metabolites across regions. Analysis of variance and t tests were used to isolate differences between cohorts.A "Cho factor" differentiated seronegative controls from HIV-infected cohorts, indicating elevated Cho levels across deep gray and white matter regions of HIV-positive individuals. An "NAA factor" differentiated those with dementia from those without and correlated best with psychomotor and executive function tests. A "Cr factor" indicated Cr elevations correlated with CSF monocyte chemoattractant protein-1 levels. NAA and Cr factor scores were strongly weighted to metabolite changes in white matter regions.These results highlight the importance of white matter involvement in HIV-associated dementia and support the current pathogenesis model of glial cell proliferation in HIV infection, denoted by regional Cho elevations, and neuronal dysfunction and/or death, denoted by NAA decreases, associated with dementia. Factor analysis of MR spectroscopic imaging data is a useful method for determining regional metabolic variations in HIV infection and its neuropsychological correlates.

Dataset Information

Fully automated atlas-based method for prescribing 3D PRESS MR spectroscopic imaging: Toward robust and reproducible metabolite measurements in human brain.

Purpose

Methods

Results

Conclusion

Publications

Fully automated atlas-based method for prescribing 3D PRESS MR spectroscopic imaging: Toward robust and reproducible metabolite measurements in human brain.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets