Magnetic Resonance Imaging in the Evaluation and Differentiation of Uveal Melanoma

Malignant Melanoma in Ten-Month-Old Patient Diagnosed by Magnetic Resonance Imaging

“…In these instances, it is very difficult to tell malignant melanoma, choroi dal detachment, choroidal hemangioma or choroidal metastatic cancer from each other. Both CT and MRI generate images of uveal melanomas and stimulating lesions [5,6], On MRI, the T| and T; parameters of uveal mela noma are considerably unique due to the mel anin-free radical (high signal intensity on Tr weighted image and low signal intensity on T;-weighted image) [7].…”

Imaging Techniques for Uveal Melanoma

“…30 However, these are also characteristic of a melanocytoma as a result of the presence of the melanin-free radical. 31,32 Although the use of the surface coils has greatly facilitated the evaluation of intraocular tumors, MRI is not specific for uveal melanoma. It is also expensive and not superior to ultrasound and therefore not used routinely for diagnostic evaluation.…”

False positive magnetic resonance imaging of a choroidal nevus simulating choroidal melanoma

“…Several reports have demonstrated the advantages of MRI over CT in tissue characterization, especially when used in differentiating uveal melanoma from other lesions [2,8,10,15]. The unique features of uveal melanoma on MRI were attributed to the paramagnetic properties of melanin.…”

“…The tumors are unique among the malignant tumors of the eye in that both T~ and T2 are relatively shortened in magnetic resonance imaging (MRI) study [1,3,9]. Until recently, this MRI characteristic has provided a reliable noninvasive method for differentiation of malignant melanoma from other mass lesions within the uveal tract [8,10,15]. Choroidal nevi are frequently seen congenital lesions with a prevalence as high as 30% [5].…”