Abstract
Purpose :
Point-of-care ultrasound has been shown to have high sensitivity and specificity when diagnosing ocular trauma. However, standard ocular ultrasonography provides 1D A-mode or 2D B-mode images only, visualizing finite anatomical details and making interpretation difficult. 3D ocular US imaging has been limited. We aim to develop a US image acquisition platform that can provide 3D visualization of the eye.
Methods :
An ultraportable and wireless ultrasound scanner Clarius L7 (Vancouver, Canada) is used to acquire ocular US images using its ophthalmology mode. The US scanner is attached to a linear precision positioning slide (McMaster-Carr) by a multi-axis camera clamp mount (ULANZI), which manipulates the orientation of the scanner at ease. Turning the handwheel of the slide moves the US scanner along the slide, performing a sequence of ocular scans at a controllable travel distance as fine as 0.0254 mm. During scanning, the subject is prompted to sit and stabilize the head on a chin rest, which also mounts the platform. The sterile ultrasonic gel is applied on the closed eyelid to provide coupling between the scanner and the eye. The distance from the probe to the eye can be adjusted by moving the 3D-printed base hosting the slider.
Results :
Sequences of sagittal ocular US images at fixed intervals were obtained from the system showing ocular structures at different anatomical locations in three dimensions. The system was easy to set up and use, and image acquisition caused minimal discomfort to the subjects. US images were displayed on a mobile device in real-time and can be downloaded from the server for processing. These 2D images were imported into Slicer3D to visualize the orbit in 3D. Ocular structures such as the lens, anterior chamber, and retina can be visualized from other perspectives such as the axial plane and coronal plane.
Conclusions :
The prototype system demonstrates the feasibility of obtaining 2D ocular US image stacks with desired slice thickness using a mechanical slide. These 2D images can then be used to provide 3D visualization of the ocular structures. The system addresses the limitations of traditional 2D freehand ultrasound imaging of the eye and has the potential to become a cost-efficient and practical platform for 3D ocular imaging.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.