彩色多普勒超声和MRI诊断脉络膜黑色素瘤

Value of color Doppler flow imaging and MRI in diagnosing choroidal melanoma

目的探讨彩色多普勒超声和MRI在诊断脉络膜黑色素瘤的价值。方法对经病理证实的35例(35只眼)脉络膜黑色素瘤的彩色多普勒超声和MRI图像资料进行回顾性对比分析。结果脉络膜黑色素瘤可呈蘑菇形、半球形和梭形,眼球各象限均可累及。彩色多普勒超声声像图上有挖空现象和脉络膜凹陷等特征性表现。瘤体内血流丰富,呈树枝状和点状分布,频谱分析显示为低阻高流型动脉频谱。MRI特征性表现为T_1WI为高信号(与玻璃体相比),T_2WI为低信号(与玻璃体相比)。强化后的T_1WI能更清楚地区隔肿瘤和视网膜下积液。结论彩色多普勒超声和MRI均可对脉络膜黑色素瘤做出定位和定性诊断,联合应用可提高诊断的准确性。

Objective To evaluate the diagnostic value of color Doppler flow imaging （ CDFI ） in comparison with MRI for choroidal melanoma. Methods A comparative analysis was carried out retrospectively on images of CDFI and MRI of 35 choroidal melanoma cases confirmed pathologically. Results The main shapes of choroidal melanomas were mushroom-shaped, hemlsphere-shaped and spindle-shaped. The tumor may occur in any quadrant of the eyeball. The characteristics of choroidal melanoma on CDFI included higher sound absorption and choroidal excavation. There was plenty of arboresent blood flow and spot blood flow inside the tumor. Spectral analysis demonstrated low vascular resistance and high flow velocity. Choroidal melanomas characteristically demonstrated hyperintensity compared to vitreous on T1 weighted images and hypeintensity on T2 weighted images. Enhanced T1 weighted images could distinguish tumors from hydrops under retina. Conclusion Choroidal melanomas can be diagnosed localizedly and qualitatively either by CDFI or by MRI. Combined use of CDFI and MRI should improve the diagnosis accuracy.