The quantitative study of lumbar vertebral bone marrow using T1 mapping and image analysis techniques: methodology and preliminary results.

A method of quantifying lumbar vertebral bone marrow using pixel by pixel T1 mapping of spin echo magnetic resonance images is described. The accuracy and precision of the relaxation time measurements is confirmed by studies with the EEC Concerted Research Project, test object no. 5. The T1 data from all the pixels sampled from lumbar vertebral marrow are displayed as a histogram. By "thresholding" relative to normal control data the spatial distribution of high or low T1 pixels can be demonstrated. The approach is superior to that of the conventional region of interest method for quantifying and analysing relaxation time data, and allows tissue heterogeneity to be studied. Studies in patients with aplastic anaemia and acute leukaemia have been performed.