Rotational-invariant speckle-scanning ultrasonography through thick bones

Area of Science:

• Medical Imaging
• Acoustics
• Biomedical Engineering

Background:

• Ultrasonography is vital for disease diagnosis but faces limitations in transcranial imaging due to bone-induced aberration and scattering.
• Achieving high-resolution ultrasonic imaging through thick bone, such as the human skull, remains a significant challenge.

Purpose of the Study:

• To develop a high-resolution speckle-scanning ultrasonography technique for imaging through thick bones.
• To leverage the rotational-invariant property of ultrasonic speckle for improved image reconstruction.

Main Methods:

• Experimental validation of the rotational invariance of ultrasonic speckle.
• Development of speckle-scanning ultrasonography by scanning a random speckle pattern across an object between bones.
• Image reconstruction using an iterative phase retrieval algorithm.

Main Results:

• Successful imaging of sub-millimeter features (holes and tubes) through 0.5–1 cm thick bones.
• Achieved a spatial resolution of 352 µm using 2.5-MHz excitation and third-harmonic detection.
• Demonstrated the feasibility of imaging through significant bone thickness.

Conclusions:

• Rotational-invariant speckle-scanning ultrasonography provides a novel method for imaging through thick bones.
• This technique offers a promising pathway towards high-resolution ultrasonic imaging of the brain.
• The study overcomes key limitations in transcranial ultrasonic diagnostics.