Abstract #0607

Ames M, Lui Y, Law M, Babb J, Johnson G, George E

Are DTI metrics and tractography useful in distinguishing between infiltrating and well-circumscribed posterior fossa tumors? DTI was performed in subjects and controls. Of 36 patients, 16 had infiltrating tumors and 20 had well-circumscribed lesions. Subjects had elevated MD, decreased FA, elevated Elong, and elevated Etrans compared to controls in areas of T2 prolongation. Corticospinal tracts with T2 prolongation demonstrated higher MD, lower FA, and higher Etrans in infiltrating tumors compared with circumscribed tumors. Differences between patient groups were also seen in NAWM. Circumscribed lesions displaced fiber tracts, whereas gliomas disrupted them. DTI can help to characterize posterior fossa tumors.