- Intratumoral hemorrhage (acute, subacute, or chronic) as seen on hemosiderin-sensitive (gradient-echo) MRI may preclude patient inclusion because of anticipated limited evaluation due to magnetic susceptibility artifact on the heavily T2-weighted DSC-MRI images; if the region of enhancing tumor not affected by blooming artifact on the hemosiderin-sensitive images does not meet the 10 x 10 x 10 mm ?measurable enhancement? threshold specified elsewhere, the patient is ineligible