NeuroimAging – Grégoria Kalpouzos group

Our research focuses on the effects of normal and pathological aging on structural, molecular, mechanical and functional brain integrity, in relation to cognition. We also study genetic, physiological and lifestyle factors that modulate age-related brain and cognitive changes. We use a broad range of Magnetic Resonance Imaging (MRI) techniques and positron emission tomography. We also develop deep learning methods that we apply to neuroimaging.

Part of the:

Department of Neurobiology, Care Sciences and Society

Decorative image showing three profiles with visible brains.

Grégoria Kalpouzos Team

Farshad Falahati

Research Infrastructure Specialist

Email: farshad.falahati@ki.se

Håkan Fischer

Affiliated to Research

Email: hakan.fischer@ki.se

Jonatan Gustavsson

Affiliated to Research

Email: jonatan.gustavsson@ki.se

Our research focuses on the effects of ageing on structural, molecular and functional brain integrity, in relation to cognition. We also study genetic, physiological and lifestyle factors that modulate age-related brain and cognitive changes. We use a broad range of Magnetic Resonance Imaging (MRI) techniques and positron emission tomography.

Research focus

The focus of our research is two-fold: we study (1) the effects of normal and pathological aging on structural, molecular, biomechanical and functional brain integrity, in relation to cognition, (2) genetic, physiological and lifestyle factors that modulate age-related brain and cognitive changes.

We use a broad range of magnetic resonance imaging techniques (MRI) and positron emission tomography (PET). To reach a better understanding of the neural underpinnings of cognitive performance, we use advanced techniques and methods such as:

Novel markers of brain aging and neurodegeneration (e.g., brain iron using quantitative susceptibility mapping with MRI, biomechanical viscoelastic properties of the brain tissue using magnetic resonance elastography, fluid biomarkers of neurodegeneration such as p-Tau181, neurofilament light)
Multimodal neuroimaging where we integrate several neuroimaging modalities together
Deep learning approaches applied to neuroimaging data

brain imaging.

Average elastogram of 23 individuals showing cerebral stiffness in pascals. Image: Grégoria Kalpouzos

Projects

ElastAge

We investigate the biomechanical properties of the brain tissue in normal aging and preclinical Alzheimer's disease using Magnetic Resonance Elastography. We study the molecular and microstructural neural underpinnings of the viscoelastic parameters of the brain tissue, and relate it to brain activity and cognition.

This is a collaborative project between KI/ARC, the Royal Institute of Technology in Stockholm (KTH)/Division of Biomedical Imaging (Rodrigo Moreno, Christoffer Olsson), the Memory Clinic of Karolinska University Hospital Solna (Zuzana Ištvánfyová, Francesca Mangialasche, Göran Hagman, Miia Kivipelto), and KI/Clinical Neuroscience (Tobias Granberg).

PI: Grégoria Kalpouzos

Relaxometry of the brain project IronAge, of which Grégoria Kalpouzos is the PI.

Relaxometry of the brain (IronAge project). Image: Grégoria Kalpouzos

IronAge

High iron load in the brain, deleterious to brain integrity and cognitive performance, has been observed in normal and pathological aging. We investigate the impact of brain iron on neural activity and cognitive performance in aging. Another aim is to uncover the genetic, physiological and lifestyle determinants of brain iron accumulation.

The project is funded by the Swedish Research Council, Alzheimerfonden and Karolinska Institutet (KI grant and KID funding).

PI: Grégoria Kalpouzos

Deep learning model.

Manual and deep-learning-based automated segmentation of midbrain nuclei. Image: Grégoria Kalpouzos

Brain Iron and microbleeds: a deep-learning approach

We assess the role of brain iron and microbleeds in cognitive and physical function in a population-based study on aging (SNAC-K). One aspect of this project is the automated segmentation of iron-rich small nuclei using deep learning.

This project is funded by the Swedish Research Council.

PI: Grégoria Kalpouzos

Collaborations

The group collaborates with the other research groups at ARC on particular projects, notably involving neuroimaging:

Long-COVID19 project (Research group leader and PI Erika Jonsson Laukka), where our collaborative focus lies in the characterization of the olfactory bulbs on high-resolution 3T MR images.

Image of the brain and blue arrows showing olfactory bulbs.

Manual tracing of olfactory bulbs on T2 MR sequence with spatial resolution 0.2 x 0.2 x 1 mm3. Image: Grégoria Kalpouzos

Lifestyle, brain pathology and cognitive reserve in cognitive decline and dementia, and role of cerebral small vessel disease in cognitive aging (Research group leader and PI Chengxuan Qiu), using SNAC-K MRI data.
StoneAge project (PI Goran Papenberg), which is an additional follow-up of IronAge, aims to link brain iron accumulation, neuroinflammation (using positron emission tomography) and cognition in older age.

The group also collaborates with the Division Clinical Geriatrics of NVS, notably on sleep in normal and pathological aging, in relation to brain integrity and cognition (PI Shireen Sindi).

National collaborations

Karolinska University Hospital, memory clinic Solna (Zuzana Istvánfyová, Francesca Mangialasche, Göran Hagman, Miia Kivipelto)
Royal Institute of Technology in Stockholm (KTH), Division of Biomedical Imaging (Rodrigo Moreno, Christoffer Olsson)
Umeå University (Ana Virel)
Örebro University (Jonas Persson, IDA-Brain project)

International collaborations

MIND-China (Multimodal interventions to delay dementia and disability in rural China, PIs: Chengxuan Qiu and Yifeng Du), part of World-Wide FINGERS

Selected publications

Contributions of the Catechol-O-Methyltransferase Val158Met Polymorphism to Changes in Brain Iron Across Adulthood and Their Relationships to Working Memory .
Gustavsson J, Papenberg G, Falahati F, Laukka EJ, Kalpouzos G
Front Hum Neurosci 2022 ;16():838228

Contributions of HFE polymorphisms to brain and blood iron load, and their links to cognitive and motor function in healthy adults.
Kalpouzos G, Mangialasche F, Falahati F, Laukka EJ, Papenberg G
Neuropsychopharmacol Rep 2021 Sep;41(3):393-404

Elevated neuroinflammation contributes to the deleterious impact of iron overload on brain function in aging.
Salami A, Papenberg G, Sitnikov R, Laukka EJ, Persson J, Kalpouzos G
Neuroimage 2021 Apr;230():117792

A positive influence of basal ganglia iron concentration on implicit sequence learning.
Persson J, Garzón B, Sitnikov R, Bäckman L, Kalpouzos G
Brain Struct Funct 2020 Mar;225(2):735-749

Functional coherence of striatal resting-state networks is modulated by striatal iron content.
Salami A, Avelar-Pereira B, Garzón B, Sitnikov R, Kalpouzos G
Neuroimage 2018 Dec;183():495-503

Automated segmentation of midbrain structures with high iron content.
Garzón B, Sitnikov R, Bäckman L, Kalpouzos G
Neuroimage 2018 Apr;170():199-209

Can transverse relaxation rates in deep gray matter be approximated from functional and T2-weighted FLAIR scans for relative brain iron quantification?
Garzón B, Sitnikov R, Bäckman L, Kalpouzos G
Magn Reson Imaging 2017 Jul;40():75-82

Higher Striatal Iron Concentration is Linked to Frontostriatal Underactivation and Poorer Memory in Normal Aging.
Kalpouzos G, Garzón B, Sitnikov R, Heiland C, Salami A, Persson J, Bäckman L
Cereb Cortex 2017 Jun;27(6):3427-3436