A Water Relaxation Atlas for Age- and Region-Specific Metabolite Concentration Correction at 3 T

Authors

Gizeaddis Lamesgin Simegn, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Yulu Song, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Saipavitra Murali-Manohar, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Helge J. Zöllner, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Christopher W. Davies-Jenkins, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Dunja Simicic, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Kathleen E. Hupfeld, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Aaron T. Gudmundson, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Emlyn Muska, Center for Cognitive Aging and Memory (CAM), McKnight Brain Institute, Department of Clinical and Health Psychology, University of Florida, Gainesville, Florida, USA.
Emily Carter, Center for Cognitive Aging and Memory (CAM), McKnight Brain Institute, Department of Clinical and Health Psychology, University of Florida, Gainesville, Florida, USA.
Steve C. Hui, Developing Brain Institute, Children's National Hospital, Washington, DC, USA.
Vivek Yedavalli, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Georg Oeltzschner, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Douglas C. Dean, Waisman Center, University of WI-Madison, Madison, Wisconsin, USA.
Can Ceritoglu, Center for Imaging Science and Institute for Computational Medicine, Department of Biomedical Engineering, JHU, Baltimore, Maryland, USA.
J Tilak Ratnanather, F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA.
Eric Porges, Center for Cognitive Aging and Memory (CAM), McKnight Brain Institute, Department of Clinical and Health Psychology, University of Florida, Gainesville, Florida, USA.
Richard Edden, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.

Document Type

Journal Article

Publication Date

1-1-2025

Journal

NMR in biomedicine

Volume

38

Issue

1

DOI

10.1002/nbm.5300

Keywords

MRS; Relaxometry atlas; aging; brain parcels; metabolite quantification; relaxation times

Abstract

Metabolite concentration estimates from magnetic resonance spectroscopy (MRS) are typically quantified using water referencing, correcting for relaxation-time differences between metabolites and water. One common approach is to correct the reference signal for differential relaxation within three tissue compartments (gray matter, white matter, and cerebrospinal fluid) using fixed literature values. However, water relaxation times (T and T) vary between brain locations and with age. MRS studies, even those measuring metabolite levels across the lifespan, often ignore these effects, because of a lack of reference data. The purpose of this study is to develop a water relaxometry atlas and to integrate location- and age-appropriate relaxation values into the MRS analysis workflow. One hundred one volunteers (51 men, 50 women; ~10 male, and 10 female participants per decade from the 20s to 60s) were recruited. T-weighted MPRAGE images ((1-mm) isotropic resolution) were acquired. Whole-brain water T and T measurements were made with DESPOT ((1.4 mm) isotropic resolution) at 3T. T and T maps were registered to the JHU MNI-SS/EVE atlas using affine and LDDMM transformation. The atlas's 268 parcels were reduced to 130 by combining homologous parcels. Mean T and T values were calculated for each parcel in each subject. Linear models of T and T as functions of age were computed, using age - 30 as the predictor. Reference atlases of "age-30-intercept" and age-slope for T and T were generated. The atlas-based workflow was integrated into Osprey, which co-registers MRS voxels to the atlas and calculates location- and age-appropriate water relaxation parameters for quantification. The water relaxation aging atlas revealed significant regional and tissue differences in water relaxation behavior across adulthood. Using location- and subject-appropriate reference values in the MRS analysis workflow removes a current methodological limitation and is expected to reduce quantification biases associated with water-referenced tissue correction, especially for studies of aging.

APA Citation

Simegn, Gizeaddis Lamesgin; Song, Yulu; Murali-Manohar, Saipavitra; Zöllner, Helge J.; Davies-Jenkins, Christopher W.; Simicic, Dunja; Hupfeld, Kathleen E.; Gudmundson, Aaron T.; Muska, Emlyn; Carter, Emily; Hui, Steve C.; Yedavalli, Vivek; Oeltzschner, Georg; Dean, Douglas C.; Ceritoglu, Can; Ratnanather, J Tilak; Porges, Eric; and Edden, Richard, "A Water Relaxation Atlas for Age- and Region-Specific Metabolite Concentration Correction at 3 T" (2025). GW Authored Works. Paper 6458.
https://hsrc.himmelfarb.gwu.edu/gwhpubs/6458

Department

Radiology