Advances in Electromagnetic and Acoustic-based Imaging Technologies and Their Applications in Brain Disease

Early and precise detection of brain diseases (e.g., stroke, brain tumors, and neurodegenerative diseases) is crucial for improving patient prognosis. Although traditional CT and MRI are widely used in clinical practice, they exhibit limitations in terms of portability, real-time capability, and safety. This paper systematically reviews emerging brain imaging technologies based on electromagnetic and acoustic waves, focusing on three core categories: electromagnetic-based imaging (microwave imaging, optical imaging), ultrasound-based imaging (transcranial Doppler ultrasound, transcranial Color Doppler ultrasound, contrast-enhanced transcranial ultrasound, 3D transcranial ultrasound localization microscopy), and electromagnetic-acoustic hybrid imaging (thermoacoustic, photoacoustic, magneto-acousto-electrical, and radiacoustic imaging). We provide an indepth analysis of the physical principles, imaging advantages, technical limitations, and latest application progress in detecting diseases such as brain tumors and stroke. Furthermore, a comparative evaluation of performance metrics across various technologies is conducted. Finally, we prospect the future directions of multimodal fusion and artificial intelligence-assisted imaging.