Signal Normalization Reduces Image Appearance Disparity Among Multiple Optical Coherence Tomography Devices

Area of Science:

• Ophthalmology
• Medical Imaging
• Biomedical Engineering

Background:

• Spectral-domain optical coherence tomography (SD-OCT) is crucial for retinal imaging.
• Discrepancies in image appearance exist among different SD-OCT devices.
• Standardization is needed for reliable cross-device image comparison.

Purpose of the Study:

• To evaluate the effectiveness of a signal normalization method in reducing appearance differences between SD-OCT devices.
• To determine if normalization improves the consistency of OCT images from multiple manufacturers.

Main Methods:

• Healthy and diseased eyes were scanned using three SD-OCT devices (Cirrus, RTVue, Spectralis).
• Images were processed using a signal normalization technique.
• Researchers compared pre- and post-normalization image pairs from different devices in a survey.

Main Results:

• Image similarity significantly improved across all device combinations after signal normalization (P ≤ 0.009).
• The Cirrus and RTVue combination showed the highest similarity post-normalization.
• Normalization effectively minimized visual disparities between SD-OCT devices.

Conclusions:

• The signal normalization method successfully reduces appearance disparities among multiple SD-OCT devices.
• This technique enables reliable clinical interpretation and comparison of OCT images irrespective of device.
• Normalization facilitates broader OCT use, including long-term follow-ups and data sharing.