The brain in healthy aged individuals: MR imaging

Area of Science:

• Neuroimaging
• Gerontology
• Brain Anatomy

Background:

• Aging is associated with structural brain changes.
• Understanding normal aging in cognitively healthy individuals is crucial.
• Previous studies have varied in findings due to differing subject selection and methodologies.

Purpose of the Study:

• To investigate brain structural changes in healthy, intellectually high-functioning aged individuals.
• To quantify white matter lesions, ventricular size, and cerebrospinal fluid (CSF) spaces.
• To explore correlations between age and specific brain tissue parameters.

Main Methods:

• Magnetic Resonance Imaging (MRI) using a low-field-strength imager (0.02-T).
• Visual rating scales for assessing white matter lesions and ventricular size.
• Computer-assisted classification for estimating brain tissue and CSF areas.
• T1 and T2 relaxation times were estimated in various brain regions.

Main Results:

• White matter lesions were observed in less than 9% of subjects.
• Enlarged lateral ventricles occurred in 8% of individuals.
• Expanded cortical CSF spaces were present in over 40% of participants.
• A positive correlation was found between frontal white matter T1 values and age.
• Computer-assisted measurements strongly correlated with visual estimations of ventricular size.

Conclusions:

• Healthy aging in cognitively high-functioning individuals is characterized by a low prevalence of white matter lesions.
• Cerebrospinal fluid spaces, particularly cortical ones, tend to increase with age.
• MRI parameters like T1 relaxation time in white matter show age-related changes.
• These findings contribute to defining the neuroimaging characteristics of normal brain aging.