Magnetic resonance imaging of choroidal melanoma with and without gadolinium contrast enhancement.

Choroidal melanoma is the most common intraocular tumor and is uniquely suited for evaluation by magnetic resonance imaging (MRI) because of the paramagnetic effect of the melanin molecule. The authors performed T1-, T2-, and proton-density-weighted MRI on 34 patients with choroidal melanoma. Nineteen patients received gadolinium contrast, T1-weighted images were superior in both detecting and delineating tumors, showing increased contrast-to-noise ratios over other images. Gadolinium contrast further increased this ratio. These images are presented as evidence that gadolinium-enhanced MRI is valuable in the evaluation of choroidal melanoma.