眼色素膜黑色素瘤的CT与MRI研究

目的研究色素膜黑色素瘤的ＣＴ和ＭＲＩ表现，探讨最佳ＭＲＩ的扫描序列。材料与方法１５例患者用各种ＭＲＩ序列进行扫描，其中１１例行ＣＴ扫描，并与手术病理进行对照。结果ＣＴ示９例表现为与眼外肌等密度的肿块，２例肿瘤太小未能显示。ＭＲＩ示１４例具有典型的短Ｔ１、短Ｔ２信号，１例３ｍｍ高度的虹膜黑色素瘤在Ｔ１ＷＩ上未能显示；１１例伴有视网膜脱离，呈短Ｔ１及长Ｔ２信号，与肿瘤在Ｔ１ＷＩ上很难区分。使用脂肪抑制和增强扫描的Ｔ１ＷＩ能较好地显示较小肿瘤（高度＜５ｍｍ）能区分肿瘤及其伴发的视网膜脱离。结论ＭＲＩ显示黑色素瘤的准确率和特异性较ＣＴ和Ｂ超优越。

Computed tomography and magnetic resonance imaging study of uveal melanoma

Purpose To study CT and MRI findings of uveal melanoma and detect the most appropriate MRI scanning sequences. Materials and methods A series of MRI scanning sequences were performed in 15 cases, and CT was performed in 11 cases. MRI and CT findings were compared with pathologic, operative and clinical findings. Results Of 11 cases receiving CT scannings, 9 displayed iso density masses with respect to extraocular muscles. The other two tumors were too small to be demonstrated. Forteen cases of melanoma showed characteristic MR appearances with hyperintense signal with respect to the vitreous on T 1 weighted images and hypointense with respect to the vitreous on T 2 weighted images. One case of iris melanoma only 3 mm in height was not demonstrated on T 1 weighted images, but was displayed hypointense signal on T 2 weighted images. Eleven cases associated with retinal detachment showed high intensity signal on T 1 and T 2 weighted images and could not be distinguished from melanoma. Postcontrast T 1 weighted images with fat suppression technique were found to be the most helpful in detecting and delineating small melanomas less than 5 mm as well as distinguishing them from retinal detachment. Conclusion MRI was superior to ultrasound or CT. Collaborative diagnosis including clinical, ultrasonographic, CT and MRI examinations is the best for ocular melanoma.