Ultrasound-CT registration of vertebrae without reconstruction

Area of Science:

• Medical imaging
• Surgical navigation
• Biomedical engineering

Background:

• Accurate intraoperative image guidance is crucial for spinal surgery.
• Previous ultrasound-CT registration methods required time-consuming 3D reconstruction of ultrasound data.
• This limitation hindered the real-time applicability of automated registration techniques.

Purpose of the Study:

• To develop and validate a faster ultrasound-CT registration technique for vertebrae.
• To eliminate the need for 3D ultrasound volume reconstruction.
• To enhance the intraoperative practicality of automated spinal image registration.

Main Methods:

• A novel slices-to-volume registration strategy was implemented.
• Individual ultrasound slices were registered directly to pre-operative CT data.
• Validation involved a lumbosacral phantom and porcine cadavers.

Main Results:

• The slices-to-volume method reduced registration time per vertebra from 8 to 4 minutes.
• Registration accuracy and robustness were maintained or improved compared to volume-to-volume methods.
• A speed-accuracy trade-off was observed based on the number of ultrasound slices used.

Conclusions:

• The slices-to-volume ultrasound-CT registration significantly decreases vertebral registration time.
• This automated technique offers improved intraoperative feasibility for spinal procedures.
• The method provides a practical solution for real-time surgical navigation.