Figure 11c. Venous malformation of the elbow. (a) Spin-echo T1-weighted MR image shows an isointense mass (arrowheads) infiltrating the periarticular fat and the triceps muscle. Subtle infiltration of the subcortical bone medulla is also seen (arrow). (b) Axial T2-weighted MR image clearly demonstrates the malformation with involvement of the distal humeral bone and infiltration of the olecranon fossa and the distal portion of the triceps muscle. (c) Gadolinium-enhanced T1-weighted MR image demonstrates perfusion of the entire malformation.