Magnetic resonance imaging of ultrasound-induced strain fields for discrimination of solid and liquid phases

Focused ultrasound (FUS) has gained clinical utility as a non-invasive treatment option, but applications to diseases affecting blood vessels in the brain are just now being investigated. MR acoustic radiation force imaging (MR-ARFI) of FUS-induced displacement and strain fields were evaluated along with diffusion imaging as a method of differentiating solid and liquid material inside a tissue-mimicking gelatin phantom. Apparent diffusion coefficient (ADC) performed best as a solid-liquid classifier, and axial displacement performed worst. Normal and shear strain components performed better than displacement measurements alone.