Quantitative Evaluation of Vascular Microcirculation Using Contrast-Enhanced Ultrasound Imaging In Rabbit Models of Choroidal Melanoma

Purpose: We investigated the application of contrast-enhanced ultrasound (CEUS) to quantify vascular perfusion in two animal models of choroidal melanoma. Methods: B16F10 and choroidal melanoma cell line (OCM1) melanoma xenografts were implanted into the cyclodialysis cleft of rabbits' right eyes. Fundus photography, indocyanine green angiography (ICGA), B-mode ultrasound, and CEUS were used to examine the tumors. Standard vascular parameters of CEUS imaging were evaluated, including the area under the receiver operating characteristic curve (AUC), peak intensity (IMAX), mean transit time (mTT), rise time, and time to peak. Kruskal-Wallis tests followed by Nemenyi tests and Bonferroni corrections were used to analyze the findings. Results: OCM1 and B16F10 animal models of choroidal melanoma were established. Tumor size was larger in the animals receiving B16F10 xenografts compared with the OCM1. Choroidal melanoma received a more abundant blood supply and had higher blood flow velocities than normal eye tissue. The animals receiving B16F10 xenografts had larger blood volume but smaller blood flow velocity compared with the OCM1 models. Vascular mimicry was present in seven of eight OCM1 tumors (87.5%). Growth and blood circulation patterns differed between OCM1 and B16F10 melanomas. Conclusions: CEUS could be used to noninvasively dynamically, and safely detect the microcirculation patterns, quantify blood circulation volume, and velocity in ocular melanoma in animal models. The blood circulation patterns of two models were different in both qualitatively and quantitative analysis under CEUS and ICGA.