Time-reversal acoustics and ultrasound-assisted convection-enhanced drug delivery to the brain

J Acoust Soc Am. 2013 Aug;134(2):1569-75. doi: 10.1121/1.4812879.


Time-reversal acoustics is an effective way of focusing ultrasound deep inside heterogeneous media such as biological tissues. Convection-enhanced delivery is a method of delivering drugs into the brain by infusing them directly into the brain interstitium. These two technologies are combined in a focusing system that uses a "smart needle" to simultaneously infuse fluid into the brain and provide the necessary feedback for focusing ultrasound using time-reversal acoustics. The effects of time-reversal acoustics-focused ultrasound on the spatial distribution of infused low- and high-molecular weight tracer molecules are examined in live, anesthetized rats. Results show that exposing the rat brain to focused ultrasound significantly increases the penetration of infused compounds into the brain. The addition of stabilized microbubbles enhances the effect of ultrasound exposure.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Albumins / administration & dosage
  • Albumins / metabolism
  • Animals
  • Brain / metabolism*
  • Catheters
  • Coloring Agents / administration & dosage
  • Coloring Agents / metabolism
  • Convection*
  • Drug Delivery Systems / instrumentation
  • Drug Delivery Systems / methods*
  • Equipment Design
  • Evans Blue / administration & dosage
  • Evans Blue / analogs & derivatives
  • Evans Blue / metabolism
  • Infusions, Parenteral
  • Male
  • Microbubbles
  • Motion
  • Needles
  • Permeability
  • Rats
  • Rats, Sprague-Dawley
  • Sound*
  • Time Factors
  • Ultrasonics / instrumentation
  • Ultrasonics / methods*


  • Albumins
  • Coloring Agents
  • Evans Blue