MRI aging changes of brain

Question 1

What MRI changes occur in juvenile animals during brain maturation?

Answer 1

Expansion of the lateral ventricles, changes in gray and white matter signal intensity due to myelination, maturation of cerebellum and brainstem, and maturation of corpus callosum

Maturation occurs from caudal to rostral in the brainstem and from central to peripheral in the cerebrum.

Question 2

At what age is the maturation of the cerebellum and brainstem reached on T1 images?

Answer 2

4 weeks

Maturation is reached at 6 weeks on T2 and STIR images, and at 12 weeks on FLAIR.

Question 3

When does the maturation of the corpus callosum occur on T1 and T2 images?

Answer 3

6 weeks on T1 and 8 weeks on T2

Maturation is reached at 12 weeks on FLAIR.

Question 4

When does the maturation of cerebral gyri and sulci complete after birth?

Answer 4

By 14 days

Question 5

What are some neurobiologic changes associated with aging in the brain?

Answer 5

Cognitive dysfunction, cerebral cortical atrophy, and accumulation of beta-amyloid

Beta-amyloid accumulates in the form of diffuse senile plaques.

Question 6

What happens to Tau protein in the aging brain?

Answer 6

Hyperphosphorylation occurs, making it insoluble and filamentous

Neurofibrillary tangles (NFTs) are not observed in dogs.

Question 7

What vascular changes are noted in the aging brain?

Answer 7

Thickening and fibrosis of small arteries, calcification of blood vessel tunica externa, and microhemorrhages

In cats, reduced blood flow and hypoxia are observed due to various cardiovascular issues.

Question 8

List some other neuropathologic changes in the aging brain.

Answer 8

• Diffuse white matter abnormalities
• Gliosis characterized by astrocytosis
• Meningeal calcification
• Mitochondrial dysfunction
• Caspase activation
• DNA fragmentation
• Inflammation
• Spheroid formation in white matter
• Accumulation of polyglucosan bodies

Question 9

What are the MRI changes associated with aging in the brain?

Answer 9

• Widening of cerebral sulci
• Cerebral atrophy
• Change in size of frontal lobes
• Gray matter atrophy
• Decreased total brain volume
• Small interthalamic adhesion

Question 10

What are the MRI findings in aging cats?

Answer 10

• Cerebral atrophy
• Increased ventricular size
• Widened sulci
• Small multifocal areas of decreased signal intensity on T1 in piriform lobes