MRI of healthy brain aging: A review

Abstract

We present a review of the characterization of healthy brain aging using MRI with an emphasis on morphology, lesions, and quantitative MR parameters. A scope review found 6612 articles encompassing the keywords “Brain Aging” and “Magnetic Resonance”; papers involving functional MRI or not involving imaging of healthy human brain aging were discarded, leaving 2246 articles. We first consider some of the biogerontological mechanisms of aging, and the consequences of aging in terms of cognition and onset of disease. Morphological changes with aging are reviewed for the whole brain, cerebral cortex, white matter, subcortical gray matter, and other individual structures. In general, volume and cortical thickness decline with age, beginning in mid‐life. Prevalent silent lesions such as white matter hyperintensities, microbleeds, and lacunar infarcts are also observed with increasing frequency. The literature regarding quantitative MR parameter changes includes T1, T2, T2*, magnetic susceptibility, spectroscopy, magnetization transfer, diffusion, and blood flow. We summarize the findings on how each of these parameters varies with aging. Finally, we examine how the aforementioned techniques have been used for age prediction. While relatively large in scope, we present a comprehensive review that should provide the reader with sound understanding of what MRI has been able to tell us about how the healthy brain ages.

Dissecting motor skill acquisition: Spatial coordinates take precedence

“…Previous research shows neurophysiological, structural, and functional changes occurring in the aging brain that lead to a decline in cognitive (17) and motor functions (18)(19)(20)(21)(22); for review, please refer to (23,24). Hence, motor skill acquisition is typically diminished in older adults (3,25,26).…”

Effects of a 5-Year Exercise Intervention on White Matter Microstructural Organization in Older Adults. A Generation 100 Substudy

“…After participating in the study for 1 year, FA values in more WM areas in the frontal lobe were associated with CRF compared to baseline. Previous studies report that the anterior WM regions are most vulnerable to the aging process ( MacDonald and Pike, 2021 ). The current results, therefore, suggest that a higher CRF could improve age-related WM microstructural organization in these anterior regions sensitive to aging.…”

Neurovascular unit dysfunction as a mechanism of seizures and epilepsy during aging

“…[127][128][129][130] These techniques can be applied to study structural and functional modifications of the NVU during aging and epileptogenesis, such as BBB permeability, cerebral blood flow (CBF) alterations, inflammation, neuronal and axonal changes, as well as gradual, pathological processes such as the presence of amyloid and tau-related markers. 6,99,[130][131][132][133][134][135] Recent developments include multi-photon laser scanning microscopy (MPLSM) and functional ultrasound imaging (fUSi). 128,136 MPLSM can be used for in vivo imaging of cellular dynamics and morphology, together with CBF.…”

“…Depending on the required spatial and temporal resolution, experimental imaging tools vary from two‐photon microscopy, laser speckle contrast imaging, to intrinsic optical imaging; translational and clinical modalities include positron emission tomographic (PET), single‐photon emission computed tomography (SPECT), and magnetic resonance imaging (MRI) 127–130 . These techniques can be applied to study structural and functional modifications of the NVU during aging and epileptogenesis, such as BBB permeability, cerebral blood flow (CBF) alterations, inflammation, neuronal and axonal changes, as well as gradual, pathological processes such as the presence of amyloid and tau‐related markers 6,99,130–135 . Recent developments include multi‐photon laser scanning microscopy (MPLSM) and functional ultrasound imaging (fUSi) 128,136 .…”