In Vivo Functional Ultrasound (fUS) Real-Time Imaging and Dosimetry of Mice Brain Under Radiofrequency Exposure

Abstract

Overview

This study meticulously evaluates real-time changes in brain activation of anesthetized mice due to low-level continuous-wave and Global System for Mobile Communications (GSM) radiofrequency exposure at 1.8 GHz.

Methodology

• A specialized in vivo experimental setup featuring a dipole antenna was tailored for local brain exposure.
• The visualization method incorporated a functional ultrasound (fUS) probe to capture brain activation areas during RF exposure alongside manual whisker stimulation.

Findings

The analytical focus was on the advanced performance of the fUS imaging technique, which showcased spatial and temporal resolutions of approximately 100 μm and 1ms, respectively. The study verified that the fUS probe could function effectively during RF exposure without interference from the dipole.

Numerical and experimental dosimetry were conducted, affirming that exposure to specific absorption rates of 2 and 6 W/kg did not significantly alter the evoked fUS response timing in the left barrel field cortex.

Conclusion

This investigative approach confirms the fUS as a valuable technology for exploring brain activation under RF exposure. Significantly, it establishes a foundation for subsequent studies involving awake mice and adaptation to newer RF technologies like 5G networks, enhancing our understanding of RF impact on biological systems.