PT  - JOURNAL ARTICLE
AU  - Gaviani, P.
AU  - Mullins, M.E.
AU  - Braga, T.A.
AU  - Hedley-Whyte, E.T.
AU  - Halpern, E.F.
AU  - Schaefer, P.S.
AU  - Henson, J.W.
TI  - Improved Detection of Metastatic Melanoma by T2*-Weighted Imaging
DP  - 2006 Mar 01
TA  - American Journal of Neuroradiology
PG  - 605--608
VI  - 27
IP  - 3
4099  - http://www.ajnr.org/content/27/3/605.short
4100  - http://www.ajnr.org/content/27/3/605.full
SO  - Am. J. Neuroradiol.2006 Mar 01; 27
AB  - BACKGROUND AND PURPOSE: The imaging features of metastatic melanomas are distinctive due to the presence of melanin and the propensity for hemorrhage. Both hemorrhage and melanin can produce T1-weighted hyperintensity and T2*-weighted signal intensity loss. We hypothesized that T2*-weighted images would improve detection of metastatic melanoma.METHODS: The T2* and T1 characteristics of 120 newly detected metastatic brain lesions from 31 patients with malignant melanoma were compared with those of 120 brain metastases from 23 patients with lung cancer.RESULTS: Melanoma metastases were 5 times more likely to demonstrate prominent T2*-related signal intensity loss (susceptibility effect) than were lung metastases (42% vs 8%; P < .01), and 4.5 times more likely to demonstrate T1 hyperintensity (55% vs 12%; P < .01). Patients with melanoma had lesions that were either hypointense on T2*-weighted images, hyperintense on T1 images, or both, in 71% (85/120), compared with 19% (23/120) of lung carcinoma metastases (P < .01). Melanoma lesions were 16 times more likely than lung cancer lesions to show combined T2* related signal intensity loss and T1 hyperintensity (P < .01). Remarkably, 8 melanoma lesions (7%) in 3 patients were detectable principally on the T2*-weighted sequences, whereas no lung cancer lesion was detected solely on susceptibility images. We found a direct correlation between melanin content and T1 hyperintensity but no correlation between T2* intensity and melanin.CONCLUSION: T2*-weighted images improve lesion detection in patients with melanoma metastases, and in conjunction with T1-weighted sequences, can suggest melanoma as the etiology of an intracranial mass. This sequence should be employed for evaluation of possible brain metastasis in patients without a known primary malignancy and in studies for melanoma staging.