Histotripsy Group
    Biomedical Engineering Department, University of Michigan

Prior to Treatment

Monitoring Treatment

After Treatment

Research -> Histotripsy Imaging Feedback

Real-time Imaging Feedback for Histotripsy Treatment
In vivo Canine Liver Ablation Experiment

Imaging Feedback for Targeting Prior to Treatment

Locate the therapy transducer focus
Launch in external player
Prior to the treatment, a bubble cloud was generated in an empty water bath and showed as hyperechoic zone on B-mode ultrasound image. This hyperechoic zone was marked as the therapy transducer focus.

Verification of the target localization in the in vivo liver tissue
Launch in external player
After the therapy focus marker with aligned with the targeted liver volume, a small number of histotripsy pulses were applied to create a bubble cloud in the liver tissue, which showed as a hyperechoic zone.

Imaging Feedback for Treatment Monitoring

Launch in external player
During the treatment, the actively cavitating bubble cloud were seen as temporally changing hyperechoic zone, which is an indication that the histotripsy process has been initiated and working properly. The treatment was gated with the respiration cycle, so that tissue outside the treatment zone was not damaged during breathing. Therefore, no pulses were seen during breathing.

Imaging Feedback to Visualize the Fractionated Liver Volume After Treatment

After treatment, the fractionated liver volume was seen clearly as a square-shaped hypoechoic zone (pointed by arrow) on B-mode ultrasound image. The "x" marked the therapy focus.