A nanoparticle enabled focused ultrasound-stimulated magnetic resonance imaging spotlight†
Abstract
Periodic high-intensity focused ultrasound modulation of a nanoparticle generates reversible MRI T1 relaxivity changes at the 1.5 mm3 focal point causing periodic T1-weighted signal changes. Fourier analysis extracts signal changes at the modulation frequency, and a modulation enhancement map spotlights the precise region of interest by increasing contrast almost 100-fold.