Background: Choroidal melanoma is the most common intraocular malignant tumor in adults. It threatens not only the visual function but also the patient's life. Therefore, it is important to find a non-traumatic, quantitative and repetitive diagnostic method. This study investigated the value of quantitative analysis of contrast-enhanced ultrasound (CEUS) in the diagnosis of choroidal melanoma.
Methods: CEUS were performed in 51 cases of choroidal melanoma, which were diagnosed either pathologically or clinically and in 14 cases of choroidal hemangioma. The characteristics of the time-intensity curve of the contrast agent were analyzed. For the quantitative analysis, the following parameters of the contrast agent in the lesion were included: rising time (RT), time to peak (TTP), maximum intensity (MI) and the mean transit time (MTT).
Results: Choroidal melanoma had the following characteristics on CEUS: Choroidal lesions were completely filled with contrast agent. The typical filling pattern was centripetal, with the peripheral of the choroidal lesion filled with the contrast agent first and then the center of the lesion. In some cases, areas with contrast agent filling defect were observed in the lesions. The contrast agent filled the lesion slower than the normal eye and orbital tissue but faded faster in the lesion. Quantitative analysis showed that in choroidal melanoma, MI of contrast agent (191.31% ± 146.90%) was significantly more than that of the normal tissue (100.00% ± 0.00%) (P < 0.05) and MTT ((63.56 ± 26.04) seconds) was significantly less than that of the normal tissue ((149.87 ± 182.68) seconds) (P < 0.05). TTP (22.80 ± 9.85) was less than that of the normal tissue ((29.57 ± 24.76) seconds) and RT ((18.52 ± 7.09) seconds) was less than that of the normal tissue ((26.45 ± 21.83) seconds). Both the differences of TTP and RT were not statistically significant though. Logistic regression showed that to predict choroidal melanoma and choroidal hemangioma with MI and MTT, the sensitivity was 90.5% and the specific degrees was 85.7%.
Conclusions: CEUS is a new method to diagnose tumors in the eye. Choroidal melanoma may be diagnosed objectively and accurately by combining the graphic characteristics on CEUS and the time-intensity curve quantitative analysis.