Dataset Information

Comparison of In Vivo and Ex Vivo MRI of the Human Hippocampal Formation in the Same Subjects.

ABSTRACT: Multiple techniques for quantification of hippocampal subfields from in vivo MRI have been proposed. Linking in vivo MRI to the underlying histology can help validate and improve these techniques. High-resolution ex vivo MRI can provide an intermediate modality to map information between these very different imaging modalities. This article evaluates the ability to match information between in vivo and ex vivo MRI in the same subjects. We perform rigid and deformable registration on 10 pairs of in vivo (3 T, 0.4 × 0.4 × 2.6 mm3) and ex vivo (9.4 T, 0.2 × 0.2 × 0.2 mm3) scans, and describe differences in MRI appearance between these modalities qualitatively and quantitatively. The feasibility of using this dataset to validate in vivo segmentation is evaluated by applying an automatic hippocampal subfield segmentation technique (ASHS) to in vivo scans and comparing SRLM (stratum/radiatum/lacunosum/moleculare) surface to manual tracing on corresponding ex vivo scans (and in 2 cases, histology). Regional increases in thickness are detected in ex vivo scans adjacent to the ventricles and were not related to scanner, resolution differences, or susceptibility artefacts. Satisfactory in vivo/ex vivo registration and subvoxel accuracy of ASHS segmentation of hippocampal SRLM demonstrate the feasibility of using this dataset for validation, and potentially, improvement of in vivo segmentation methods.

SUBMITTER: Wisse LEM

PROVIDER: S-EPMC6075210 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature

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Comparison of In Vivo and Ex Vivo MRI of the Human Hippocampal Formation in the Same Subjects.

Wisse L E M LEM Adler D H DH Ittyerah R R Pluta J B JB Robinson J L JL Schuck T T Trojanowski J Q JQ Grossman M M Detre J A JA Elliott M A MA Toledo J B JB Liu W W Pickup S S Das S R SR Wolk D A DA Yushkevich P A PA

Cerebral cortex (New York, N.Y. : 1991) 20171101 11

Multiple techniques for quantification of hippocampal subfields from in vivo MRI have been proposed. Linking in vivo MRI to the underlying histology can help validate and improve these techniques. High-resolution ex vivo MRI can provide an intermediate modality to map information between these very different imaging modalities. This article evaluates the ability to match information between in vivo and ex vivo MRI in the same subjects. We perform rigid and deformable registration on 10 pairs of ...[more]

PMID: 27664967

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Project description:Context and objectiveThe myokine irisin has been proposed to regulate energy homeostasis. Little is known about its association with metabolic parameters and especially with parameters influencing pathways of lipid metabolism. In the context of a clinical trial, an exploratory post hoc analysis has been performed in healthy subjects to determine whether simvastatin and/or ezetimibe influence serum irisin levels. The direct effects of simvastatin on irisin were also examined in primary human skeletal muscle cells (HSKMCs).Design and participantsA randomized, parallel 3-group study was performed in 72 men with mild hypercholesterolemia and without apparent cardiovascular disease. Each group of 24 subjects received a 14-day treatment with either simvastatin 40 mg, ezetimibe 10 mg, or their combination.ResultsBaseline irisin concentrations were not significantly correlated with age, BMI, estimated GFR, thyroid parameters, glucose, insulin, lipoproteins, non-cholesterol sterols, adipokines, inflammation markers and various molecular markers of cholesterol metabolism. Circulating irisin increased significantly in simvastatin-treated but not in ezetimibe-treated subjects. The changes were independent of changes in LDL-cholesterol and were not correlated with changes in creatine kinase levels. In HSKMCs, simvastatin significantly increased irisin secretion as well as mRNA expression of its parent peptide hormone FNDC5. Simvastatin significantly induced cellular reactive oxygen species levels along with expression of pro- and anti-oxidative genes such as Nox2, and MnSOD and catalase, respectively. Markers of cellular stress such as atrogin-1 mRNA and Bax protein expression were also induced by simvastatin. Decreased cell viability and increased irisin secretion by simvastatin was reversed by antioxidant mito-TEMPO, implying in part that irisin is secreted as a result of increased mitochondrial oxidative stress and subsequent myocyte damage.ConclusionsSimvastatin increases irisin concentrations in vivo and in vitro. It remains to be determined whether this increase is a result of muscle damage or a protective mechanism against simvastatin-induced cellular stress.Trial registrationClinicalTrials.gov NCT00317993 NCT00317993.

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Dataset Information

Comparison of In Vivo and Ex Vivo MRI of the Human Hippocampal Formation in the Same Subjects.

Publications

Comparison of In Vivo and Ex Vivo MRI of the Human Hippocampal Formation in the Same Subjects.

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