Coded excitation ultrasonic needle tracking: An in vivo study

Area of Science:

• Medical Imaging
• Biomedical Engineering
• Ultrasound Technology

Background:

• Accurate medical device guidance is essential for interventional procedures.
• Ultrasound imaging is widely used for guidance, but tracking device tips can be challenging.
• Current ultrasonic tracking methods face limitations in signal-to-noise ratio (SNR), restricting depth penetration.

Purpose of the Study:

• To introduce a novel ultrasonic tracking system utilizing coded excitation.
• To enhance the signal-to-noise ratio (SNR) for improved medical device tip localization.
• To evaluate the system's performance in improving tracking depth and accuracy without spatial averaging.

Main Methods:

• Integrated a fiber optic hydrophone transducer into a 20-gauge needle.
• Employed Barker and Golay coded excitation for ultrasonic transmissions, comparing against conventional bipolar excitation.
• Assessed the system's performance in an in vivo ovine model for brachial plexus and uterine cavity insertions.

Main Results:

• Coded excitation significantly increased SNR compared to bipolar excitation (e.g., 7.1x with Golay coding in brachial plexus insertions).
• Golay coding achieved a maximum SNR of 670, with visually absent range sidelobe artifacts.
• Spatial tracking accuracy remained unaffected by the coded excitation methods.

Conclusions:

• Coded excitation is a viable technique to enhance SNR in ultrasonic tracking.
• The method improves medical device visibility at greater depths without compromising spatial accuracy.
• This advancement has direct clinical implications for a wide range of interventional procedures.