Fusion of multi-frequency ultrasound imaging based on wavelet transform for guided screw insertion

The insertion of pedicle screw is the most important step to fuse the damaged spines in spinal fusion surgery. Intraosseous ultrasound imaging can be used to guide the insertion of pedicle screw. However, it is difficult for an intraosseous ultrasound image to obtain high resolution and deep penetration simultaneously. To address these issues, a micro dual-frequency single element transducer was designed based on thickness and contour modes in our previous work. For further image, we proposed a multi-frequency ultrasound imaging fusion method based on wavelet transform (WT) which combined the advantages of high-frequency imaging and low-frequency imaging. The fusion method realizes dynamic fusion of high and low-frequency imaging through extracting the detail and approximate coefficients by multi-layer wavelet transform.