Diffusion-weighted imaging features of brain in obesity

Area of Science:

• Neuroimaging
• Obesity Research
• Medical Physics

Background:

• Obesity is associated with altered body fluid distribution.
• Brain tissue fluid distribution, specifically extracellular and intracellular components, remains understudied in obesity.
• Diffusion Weighted Imaging (DWI) offers a method to assess brain tissue microstructure.

Purpose of the Study:

• To investigate potential changes in brain diffusion patterns in obese subjects using DWI.
• To specifically examine diffusion changes in brain regions associated with hunger and satiety.
• To correlate body mass index (BMI) with observed diffusion changes.

Main Methods:

• Conventional MRI and DWI of the brain were performed on 81 obese and 29 nonobese individuals.
• Apparent Diffusion Coefficient (ADC) values were quantified in multiple brain regions, including the hypothalamus, amygdala, and various cortical areas.
• Statistical comparisons were made between obese and nonobese groups, and between morbidly obese and obese subgroups.

Main Results:

• Significantly increased ADC values were observed in the hypothalamus, amygdala, insula, cerebellum, and midbrain in obese subjects compared to controls.
• Morbidly obese individuals showed higher ADC values in several regions, including the thalamus, hippocampus, and frontal and temporal cortex, compared to nonobese subjects.
• Positive correlations were found between BMI and ADC values in the amygdala, insula, orbitofrontal, and middle temporal cortex.

Conclusions:

• Increased ADC values in satiety and hunger-related brain centers suggest altered fluid distribution or vasogenic edema in obese individuals.
• These neuroimaging findings highlight potential changes in brain tissue composition and function associated with obesity.
• Understanding these brain abnormalities may provide insights into the underlying mechanisms of obesity-related neurological alterations.