葡萄膜黑色素瘤MRI及动态增强研究

The Study of Plane and Dynamic Contrast-enhanced MRI in Uveal Melanoma

目的探讨葡萄膜黑色素瘤的MRI和动态增强表现及其与肿瘤微血管密度的关系。方法回顾性分析经病理证实的20例葡萄膜黑色素瘤的MRI资料,主要研究动态增强扫描的表现,对其手术后标本行免疫组织化学染色计数微血管密度,绘制时间-信号曲线,计算峰值时间、上升斜率、强化率和流出率,分析动态增强参数与微血管密度的关系。结果20例黑色素瘤中,肿瘤位于眼球赤道后方占95%,呈半球形或蘑菇形者占75%,呈短T1信号者占65%,呈短T2信号者占55%,信号均匀者占80%,伴视网膜脱离者占75%;峰值时间为(52.9±13.7)秒,上升斜率为0.62±0.29,强化率0.32±0.13,流出率(42.64±23.16)%,不同病理类型之间上升斜率、强化率有显著性差异(P<0.05),峰值时间、流出率无显著性差异(P>0.05);微血管密度为43.56±19.89,与峰值时间、上升斜率、强化率和流出率无线性相关关系(P>0.05)。结论葡萄膜黑色素瘤在MRI上具有典型征象,动态增强能提供定性信息。

Objective To evaluate the correlation between the MVD and DCE-MRI findings of uveal melanoma. Methods The MRI data were retrospectively analyzed in 20 patients with uveal melanomas including DCE data, time to peak, slope, washout ratio, enhancement ratio.MVD were counted in the immunohistochemically stained microscopic section after operation. Results Uveal melanomas was found posterior to the equator of eyeball in 95%, 75% appeared hemispherical or mushroom-shaped mass, 65% appeared hyperintense signal on T1WI compared to the vitreous, 55% appeared hypointense signal on T2WI, 80% appeared homogeneous signal, accompanying retinal detachment was found in 75%. Time to peak was （52.9 ± 13.7） s, slope ratio was 0.62 ± 0.29 washout ratio was （42.6 ± 23.2）%, enhancement ratio was 0.32 ± 0.13. Twelve of 20 cases belonged to spindle cell type, epithelioid cell type 5 cases, mixed cell type 3 cases, and slope ratio and ER were significant difference （P〈0.05）, Tpeak and WR were not significant difference （P〉0.05） among different types. MVD was 43.56 ± 19.89, there were not linear correlation between MVD and Tpeak, slope ratio, WR and ER （P〉0.05）. Conclusion There are characteristic appearances of uveal melanoma in plane and DCE MRI which can offer some qualitative information.