ASSESSMENT OF BRAIN CHANGES WITH REGISTERED MR BEFORE AND AFTER BONE-MARROW TRANSPLANTATION FOR CHRONIC MYELOID-LEUKEMIA

PURPOSE: To determine the frequency and nature of changes to the brain resulting from chemotherapy, radiation therapy, and bone marrow trans plantation for chronic myeloid leukemia and to compare the sensitivity of conventional and registered MR scans for detecting these changes. METHODS: In 15 patients, conventional T1-weighted, T2-weighted, and fl uid-attenuated inversion recovery MR sequences, as well as T1-weighted radio frequency spoiled 3-D volume MR scans were performed before, 4 to 6 days after, and up to 339 days after transplantation (13 allograf ts, two autografts). A subvoxel registration program was used to match the volume images precisely so that small changes could be detected a fter subtraction of scans. Five healthy adult control subjects were al so studied on two occasions 1 month apart. RESULTS: Studies performed 4 to 339 days after transplantation showed ventricular enlargement and cortical atrophy in all 13 patients who had allografts. The changes w ere evident at 4 to 6 days after transplantation and became more obvio us during later follow-up examinations, Similar changes were seen in o ne patient with an autograft but no significant change was seen in the other patient with an autograft or in the five control subjects. Accu rately registered volume scans were more sensitive than unregistered c onventional scans in detecting early (9/10 versus 0/10), intermediate (12/13 versus 3/12), and late (10/10 versus 4/9) ventricular enlargeme nt on follow-up examinations. The same applied to cortical atrophy (9/ 10 versus 0/10, 12/13 versus 0/12, and 10/10 versus 0/9.) CONCLUSION: The specific cause and clinical significance of these changes are unce rtain. Subvoxel registration of serial MR images may reveal changes th at are poorly seen or not apparent on conventional scans.