Characterization of an intra-cardiac melanoma metastasis by magnetic resonance T1 and T2 mapping

Excerpt

A 64 year-old male patient with a history of melanoma was referred to our department for cardiac magnetic resonance (CMR) evaluation of an intra-cardiac mass. The echocardiography showed an ovoid tumoral mass embedded in the right atrial floor, just behind the tricuspid annulus, suspected to be a cardiac location of melanoma metastasis. CMR 1.5T T1 and T2 mapping sequences revealed low native T1 value inside the mass (736 ms) (Fig. 1, panel A) in comparison to myocardium (normal range 1030 ± 34 ms) consistent with a melanin content whose paramagnetic effect is related to the presence of free radicals and non-apparied electrons, and slightly elevated T2 (58 ms, normal range 50 ± 2 ms) (Fig. 1, panel B). After gadolinium injection, post-contrast T1 mapping sequence showed a 59 % T1 drop in the tumor (Fig. 1, panel C) and late-enhancement was clearly identified with PSIR sequence disclosing heterogeneous uptake inside the mass (Fig. 1, panel D). The tumor was surgically removed and histopathology confirmed the diagnosis of melanoma metastasis. …