Transcranial photoacoustic computed tomography based on a layered back-projection method.

Area of Science:

• Biomedical Imaging
• Acoustic Physics

Background:

• Transcranial photoacoustic computed tomography (PACT) faces challenges due to acoustic aberrations caused by the skull.
• Accurate brain imaging requires effective correction of skull-induced signal distortions.

Purpose of the Study:

• To introduce a novel de-aberration method for transcranial PACT.
• To improve the image quality of transcranial PACT by accounting for skull heterogeneity.

Main Methods:

• A modified universal back-projection (UBP) algorithm, termed layered UBP (L-UBP), was developed.
• The acoustic medium was stratified into layers (fluid, skull, brain) with distinct acoustic properties.
• Transmission coefficients and wave conversion at interfaces were incorporated into the L-UBP model.

Main Results:

• Simulations validated the L-UBP method for transcranial PACT.
• Ex vivo experiments using a 3D PACT system demonstrated substantial image quality improvement with L-UBP.
• The L-UBP method effectively de-aberrates transcranial photoacoustic signals.

Conclusions:

• L-UBP offers a significant advancement in correcting acoustic aberrations for transcranial PACT.
• The method holds promise for enhanced non-invasive brain imaging using PACT.