3D ultrasonic visualization of hip displacement: A phantom study

Area of Science:

• Medical Imaging
• Pediatric Orthopedics
• Biomedical Engineering

Background:

• Hip displacement is a common complication in children with cerebral palsy (CP).
• Reimer's migration percentage (MP) on radiographs is the standard for assessing hip displacement.
• Conventional radiography involves ionizing radiation exposure.

Purpose of the Study:

• To evaluate the accuracy of 3D reconstructed ultrasound (US) images for measuring MP in pediatric hip phantoms.
• To compare the accuracy of this novel 3D US method with standard radiography and 2D US measurements.

Main Methods:

• Two 3D printed pediatric hip phantoms with known MPs were scanned using a handheld ultrasound device.
• 2D US images were acquired and stacked to create 3D reconstructed images.
• Morphological operations and least-squares sphere fitting were used to calculate MP from 3D US data.

Main Results:

• The 3D US method achieved high accuracy, with a maximum error of 1.16% compared to phantom ground truth.
• Conventional radiography showed a larger error of 7.6%, and the 2D US method had an error of 16.82%.

Conclusions:

• 3D reconstructed ultrasound imaging provides a highly accurate and radiation-free method for measuring hip displacement.
• This technique shows significant potential to improve patient care for children with cerebral palsy compared to X-ray methods.