Diffuse shear wave imaging: toward passive elastography using low-frame rate spectral-domain optical coherence...

Area of Science:

• Biomedical Optics
• Medical Imaging
• Biophysics

Background:

• Optical coherence tomography (OCT) is a valuable tool for imaging biological tissues.
• Shear wave elastography (SWE) techniques map tissue stiffness but typically require active shear sources and ultrafast imaging.
• A need exists for less invasive and more accessible elastography methods.

Purpose of the Study:

• To develop and validate a novel passive elastography method using spectral-domain OCT.
• To retrieve tissue stiffness information from naturally occurring displacements.
• To assess the feasibility of this technique for in vivo applications.

Main Methods:

• A noise-correlation approach was applied to spectral-domain OCT imaging of diffuse displacement fields.
• The method was demonstrated on tissue-mimicking phantoms and compared with conventional ultrafast SWE.
• In vivo feasibility was investigated on rat eyes using naturally occurring pulsatile motions.

Main Results:

• The noise-correlation method successfully retrieved stiffness information from phantoms.
• Results from phantom studies showed good agreement with established ultrafast SWE techniques.
• In vivo imaging demonstrated the potential of detecting natural displacements for elastography.

Conclusions:

• Passive elastography using noise correlation with spectral-domain OCT is feasible.
• This approach can map tissue stiffness without active shear wave generation.
• The technique holds promise for clinical translation, particularly in ophthalmology and dermatology.