Uveal melanoma: detection of extraocular growth with MR imaging and US.

To compare the sensitivity and specificity of magnetic resonance (MR) imaging with that of ultrasound (US) in the detection of extraocular extension of uveal melanoma.In 70 patients, the diagnosis of melanoma and absence or presence of extraocular growth were confirmed with histologic examination (13 patients) or with ophthalmoscopy and surgery (57 patients). Unenhanced and enhanced T1-weighted and T2-weighted MR imaging was performed with surface coils at 1.5 T. A- and B-mode US scans were obtained with 8- and 10-MHz probes, respectively.Extraocular growth was confirmed in seven patients: Five patients had retrobulbar tumor, and two had optic nerve infiltration. US enabled detection in three cases, whereas six cases were diagnosed with MR imaging including both cases of optic nerve infiltration. False-positive findings were more frequent with US (n = 5) than with MR imaging (n = 1).MR imaging proved to be more sensitive and more specific than US in the detection of extraocular extension of uveal melanoma.