Abstract
Purpose :
We hypothesized that contrast-enhanced ultrasound (CEUS) using a microbubble technique to quantify microvascular changes and Nakagami imaging for tissue characterization would provide a new approach for diagnosing and differentiating benign and malignant choroidal lesions.
Methods :
One patient with choroidal hemangioma (CH) and choroidal melanoma (CM) was selected for CEUS study. Definity®, which contains perflutren microbubbles, was administered as a slow IV bolus (1 ml). CEUS was performed for 1 min post-injection of the dye with video recording. The mean intensity was calculated for each ROI, and the time-averaged difference in pixel intensities of post-injection frames relative to reference pre-injection frame was calculated. Based on the Nakagami statistical distribution model, two Nakagami parameters, m and Ω, where m (shape parameter), representing tissue heterogeneity, and Ω (scale parameter), representing the average energy of backscattered signals, were studied in six patients (CM, 4 patients; CH, 2 patients)
Results :
CEUS analysis showed that the time-averaged contrast increased by a percentage difference of 9.9% ± 5.2% for CH and decreased by 4.2% ± 4.7% for CM. Furthermore, the intensity within the normal choroidal region was higher than that within the choroidal tumor region for both CH and CM. Nakagami analysis showed that the m estimates were comparatively higher for hemangioma than for melanoma (7.10 vs 3.73), indicating that hemangioma is a more heterogeneous tumor than melanoma. There was no significant difference in Ω estimates between hemangioma and melanoma (0.65 vs 0.54).
Conclusions :
Quantitative intensity-based perfusion analysis using CEUS and backscattering tissue analysis using Nakagami imaging can provide valuable insights to differentiate benign and malignant choroidal lesions.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.