Sequential quantitative MR analysis of bone marrow: differences during treatment of lymphoid versus myeloid leukemia.

PURPOSE: To assess the use of bulk T1 measurements with magnetic resonance (MR) imaging for monitoring treatment response in leukemic patients, with separate analysis of patients with acute lymphoid (ALL) and those with acute myeloid leukemia (AML). MATERIALS AND METHODS: Bulk T1 values were determined repeatedly during the first 4 weeks of treatment in 16 patients with ALL (age range, 16-72 years) and the first 6 weeks of treatment in 51 patients with AML (age range, 17-75 years). Bulk T1 values were compared in all patients with AML or ALL and in those who did or did not respond to treatment. RESULTS: MR imaging of lumbar bone marrow demonstrated statistically significant differences in initial bulk T1 values and in changes in bulk T1 values during treatment between patients with ALL and those with AML. Changes in bulk T1 after the 2nd week of treatment were statistically significantly different between patients with and those without a response who had ALL but not in those with AML. CONCLUSION: Sequential quantitative MR imaging during treatment appears valuable for prediction of response in patients with ALL but not in those with AML. Further investigations are needed to determine what influence MR imaging can have on patient care, but patients with ALL should be analyzed separately from those with AML.