Fig. 2.

(Case 1) Mediastinal mature cystic teratoma in a 37-year-old man. MRI findings: (a) In-phase and (b) opposed-phase MRI scans demonstrate a decrease in signal intensity on the opposed-phase images comparing with the in-phase images. The hypointensities on opposed-phase imaging reveals areas of microscopic intracellular lipid within the lesion. (c) Axial T2 haste and (d) axial T2 blade FS show the large left anterior mediastinal mass lesion causing an impression on the superior vena cava with internal heterogeneous areas of signal intensity abnormality. (e) Axial contrast-enhanced fat-suppressed T1-weighted MR image and (f) axial T1 FS subtraction, obtained after administration of intravenous gadolinium-based contrast material, show a lack of solid enhancement within the mass lesion.