Figure 3. (a) Pre-contrast T₁ weighted sagittal MR image shows the retroperitoneal mass which is slightly hyperintense to adjacent muscle (arrows). (b) Axial T₂ weighted MR image demonstrates slight hyperintensity of the mass (large open arrow) compared with muscle (small open arrow). (c) Post gadolinium T₁ weighted image shows homogeneous enhancement of the lesion (large open arrows) compared with psoas muscle adjacent to the mass (small open arrow).