Towards ultrasound probe positioning optimization during prostate needle biopsy using pressure feedback

Area of Science:

• Medical imaging
• Robotics
• Biomedical engineering

Background:

• Accurate Transrectal Ultrasound (TRUS)-guided prostate biopsies require registration of preoperative 3D or MR images with intraoperative 2D TRUS images.
• Current image registration methods are time-consuming and lack real-time implementation.
• Ensuring consistent prostate deformation is crucial for accurate image registration, but visual feedback alone is insufficient.

Purpose of the Study:

• To develop a robotic needle biopsy system that bypasses the time-consuming image registration step.
• To ensure similar prostate deformation between preoperative and intraoperative imaging using contact pressure feedback.
• To achieve consistent minimum contact between the ultrasound probe and the prostate.

Main Methods:

• A robotic system equipped with a TRUS probe and pressure sensor array was utilized.
• Contact pressure measurements provided feedback to an optimization algorithm for precise probe positioning.
• The system aimed to match pressure patterns during 2D and 3D image acquisition, accounting for patient movement.
• An in silico phantom with a prostate finite element model simulated contact pressure distribution.

Main Results:

• The robotic system successfully achieved probe positioning with maximum contact pressure pattern similarity.
• Systematic variation of probe position led to the desired alignment between 2D and 3D imaging pressure patterns.
• The method demonstrated the ability to ensure minimal relative prostate deformation.

Conclusions:

• The proposed technique effectively ensures minimal relative prostate deformation between preoperative and intraoperative imaging.
• This approach has the potential to significantly improve the speed and accuracy of image registration for prostate biopsies.
• The findings pave the way for faster and more accurate TRUS-guided prostate needle biopsies.