Improving ultrasound-based brachytherapy needle conspicuity by applying an echogenic coating

Area of Science:

• Medical Imaging
• Oncology
• Biomedical Engineering

Background:

• Ultrasound-guided brachytherapy applicator conspicuity is often limited by imaging artifacts and geometry.
• These limitations can impede accurate needle placement and increase dose delivery uncertainty.

Purpose of the Study:

• To enhance the visibility of high-dose rate (HDR) brachytherapy needles in B-mode ultrasound using an echogenic surface coating.
• To test the hypothesis that an echogenic coating would decrease artifacts and improve needle visualization in signal-degraded areas.

Main Methods:

• Titanium HDR brachytherapy needles were coated with microspheres (27, 40, 64 μm) and compared to uncoated controls.
• Needle conspicuity was evaluated using B-mode ultrasound in phantoms and cadavers under various implant conditions (single, multiple, angled needles).
• Qualitative assessment of conspicuity and artifacts, alongside quantitative grey-scale intensity analysis, was performed.

Main Results:

• The 64 μm echogenic coating reduced reverberation artifacts by 31% and comet tail artifacts by 40-70%.
• Improved needle contrast and conspicuity were observed, especially for angled needles (up to 30°).
• The 64 μm coating demonstrated superior performance, providing clear signals even with acoustic shadowing from multiple needles.

Conclusions:

• Echogenic surface coatings effectively reduce imaging artifacts and enhance needle conspicuity in ultrasound-guided brachytherapy.
• Improved visualization can lead to more efficient needle placement and precise digitization, ultimately improving treatment accuracy.