MRI and in vivo proton spectroscopy of the lesions of the globe.

MRI proved very valuable in the diagnosis of intraocular lesions. In this report, uveal melanomas, the most common intraocular tumors in adults, were seen as hyperintense lesions on T1W and PW images and as hypointense lesions on T2W images. MRI is not accurate for diagnosis when the melanoma is smaller than 3 mm. Associated retinal detachment as well as necrotic or hemorrhagic changes within the uveal melanoma can be identified by MRI. Choroidal metastasis may be difficult to differentiate from uveal melanoma. Choroidal hemangioma and hematoma often can be differentiated from uveal melanoma. Early experience with in vivo proton MR spectroscopy has the potential for obtaining biochemical information, thus enhancing the diagnostic sensitivity of MR studies. Future work on combined MRI with MR in vivo spectroscopy is needed to characterize abnormal conditions according to their patterns and for identification of tumor markers. A differential diagnosis list for ocular (globe) lesions can be found in the introduction to this issue. A discussion of the majority of the ocular lesions listed can be found in either this article or the article on congenital/pediatric lesions (Hopper et al) of the orbit, also in this issue.