Detecting Early Ocular Choroidal Melanoma Using Ultrasound Localization Microscopy

Area of Science:

• Ophthalmology
• Medical Imaging
• Biomedical Engineering

Background:

• Ocular choroidal melanoma (OCM) is the most common primary malignant eye tumor in adults.
• Early detection of OCM is challenging due to its similar appearance to benign choroidal nevus.
• Accurate diagnostic tools are crucial for timely OCM treatment and improved patient prognosis.

Purpose of the Study:

• To develop and validate ultrasound localization microscopy (ULM) for early diagnosis of small ocular choroidal melanomas.
• To enhance microvascular imaging and flow velocity estimation in ocular tissues.
• To improve the accuracy of differentiating OCM from benign choroidal nevi.

Main Methods:

• Implementation of an image deconvolution algorithm for ultrasound localization microscopy (ULM).
• Development of ultrasound (US) plane wave imaging with a three-frame difference algorithm for probe guidance.
• In vitro experiments using custom modules and in vivo studies on a rat ocular choroidal melanoma model with a high-frequency linear array transducer.

Main Results:

• The proposed deconvolution method demonstrated robust microbubble localization and finer microvasculature network reconstruction.
• More precise estimation of blood flow velocity was achieved using the ULM technique.
• Ultrasound plane wave imaging effectively guided probe placement in both flow phantoms and the in vivo OCM model.

Conclusions:

• Super-resolution ULM shows significant potential as a complementary imaging modality for early OCM diagnosis.
• The developed ULM technique can provide clinicians with conclusive diagnostic suggestions.
• This advancement is critical for improving the treatment and prognosis of patients with ocular choroidal melanoma.