Effects of tissue susceptibility on brain temperature mapping

Area of Science:

• Neuroscience
• Medical Imaging
• Biophysics

Background:

• Accurate brain temperature mapping is crucial for understanding neurological function and disease.
• Noninvasive methods are needed to overcome the limitations of invasive temperature measurements.
• Proton MR spectroscopic imaging offers a potential avenue for volumetric brain temperature assessment.

Purpose of the Study:

• To implement and validate a volumetric proton MR spectroscopic imaging method for brain temperature mapping.
• To investigate age- and sex-related differences in brain temperature.
• To explore the influence of magnetic susceptibility variations on temperature measurements.

Main Methods:

• Volumetric proton MR spectroscopic imaging was applied to 150 healthy subjects.
• Magnetic susceptibility-induced frequency shifts in gray and white matter were measured and used for correction.
• Metabolite-specific susceptibility effects, particularly N-Acetylaspartate, were analyzed.

Main Results:

• No significant change in apparent brain temperature was observed with age (18-84 years).
• Females exhibited a slight increase in cerebral temperature (approx. 0.1°C) compared to males.
• The cerebellum showed a lower temperature (0.3°C) than cerebral white matter; left hemisphere was slightly warmer than the right.

Conclusions:

• A novel, noninvasive method for brain temperature mapping using volumetric proton MR spectroscopic imaging was developed.
• The technique has potential for diagnostic purposes and treatment monitoring.
• Limitations include confounding effects from tissue magnetic susceptibility variations, particularly metabolite-specific effects.