Characterization of ultrasound elevation beamwidth artifacts for prostate brachytherapy needle insertion

Area of Science:

• Medical Imaging
• Ultrasound Technology
• Surgical Navigation

Background:

• Ultrasound elevation beamwidth causes artifacts and localization uncertainties in medical imaging.
• Accurate localization of surgical instruments, such as needles, is critical for effective interventions.

Purpose of the Study:

• To investigate the clinical significance of elevation beamwidth artifacts in needle insertion procedures.
• To analyze the impact of imaging parameters on localization errors during ultrasound-guided interventions.

Main Methods:

• Beveled prostate brachytherapy needles were inserted using real-time transrectal ultrasound (TRUS) guidance.
• Needle tip positions from TRUS images were compared to their actual physical locations.
• A novel device was employed to measure ultrasound elevation beamwidth.

Main Results:

• Localization errors, influenced by TRUS imaging parameters, ranged from 0.5 to 4 mm.
• Minimal errors occurred near the grid template's center and within the beam's focal zone.
• Maximal errors were observed at the grid template's periphery and in the beam's far field, varying with lateral and elevation offsets.

Conclusions:

• Optimizing TRUS imaging settings, specifically reducing ultrasound gain and power, significantly minimizes elevation beamwidth artifacts.
• Adjusting these parameters effectively reduces needle tip localization errors, enhancing procedural accuracy.