Ultrasound B-Mode Visualization of Imperceptible Subwavelength Vibration in Magnetomotive Ultrasound Imaging

• Published in: Vibration Vol. 7; no. 3; pp. 764 - 775
• Main Authors: Shen, Wei-Hsiang, Yeh, Tzu-Min, Liao, Mei-Yi, Li, Meng-Lin
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.09.2024
• Subjects: Algorithms; Diagnosis, Ultrasonic; Imaging; In vivo methods and tests; Lymphatic system; Magnetic fields; magnetomotive ultrasound; motion magnification; Motion perception; Nanoparticles; Propagation modes; shear wave propagation; Tracking; Ultrasonic imaging; Ultrasonic testing; ultrasound imaging; Vibration; Vibration research; Visualization; Wave propagation; Taiwan
• ISSN: 2571-631X; 2571-631X
• DOI: 10.3390/vibration7030040

Magnetomotive ultrasound (MMUS) is a promising imaging modality for detecting magnetic nanoparticles. In MMUS, an external oscillating magnetic field induces the motion of the injected magnetic nanoparticles within tissue, and phase-based tracking algorithms are used to detect the motion. However, the subwavelength scale of these displacements (often a few micrometers) makes direct visualization on conventional ultrasound B-mode images impossible. In this work, we adapt the Eulerian motion magnification technique to create a novel ultrasound display mode for identifying the nanoparticle locations, eliminating the need for displacement tracking algorithms. Phantom and in vivo experiments demonstrate that our technique successfully magnifies magnetomotion and the associated shear wave propagation in ultrasound B-mode imaging and pinpoints the nanoparticle vibration source, even in low-concentration scenarios.