Model-guided customization of a contrast pulse sequence for polyvinyl alcohol microbubbles

• Simulations of microbubbles (MBs) suggest that the excitation threshold for sub-harmonic generation is frequency-dependent. The minimum threshold, dependent on models and assumptions, might appear near the resonance frequency. Given that, in the current study, attempts were made to optimize a novel contrast pulse sequence, CPS4, for the in-house ultrasound contrast agent, polyvinyl alcohol microbubbles (PVA MBs) by setting the transmitting frequency near their resonance frequency to boost the sub-harmonic response. An improved model for PVA MBs was proposed to predict the resonance frequency. An in-vitro experiment was performed to evaluate the performance of CPS4 at different transmitting frequencies. The experiment results suggest the optimal performance of CPS4 with PVA MBs aqueous suspension appeared at the transmitting frequency of 11.25 MHz, which agrees with the values of the damped resonance frequency determined from simulation. The influence of the liquid environment on the performance of the CPS4 was also studied. The replacement of water with artificial blood degrades the contrast-to tissue ratio of CPS4 and shifts the optimal performance to the higher transmitting frequency.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Radiologi och bildbehandling (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Radiology, Nuclear Medicine and Medical Imaging (hsv//eng)

Keyword

contrast pulse sequence

microbubble

ultrasound

Medical Technology

Medicinsk teknologi

Publication and Content Type

vet (subject category)

ovr (subject category)