QUANTITATIVE ASSESSMENT OF BONE-MARROW HEMATOPOIESIS USING PARAMETRICMAGNETIC-RESONANCE-IMAGING

Spatial maps of the percentage cellularity in pelvic bone marrow were calculated at a resolution of 15.6 mm(3) from six volunteers and 10 pa tients treated for documented hematologic disease using a three-point Dixon MRI pulse sequence. The percentage cellularity calculation was a ided by analyzing a two-dimensional feature space consisting of the ap parent water fraction (W-a), and the T-2 relaxation time of water (T-2 w), An extracellular water fraction was assigned to each voxel on the basis of a two-component T-2w algorithm. In six cases, the method was compared to results obtained from core biopsies or aspirates of the po sterior iliac crest. The results indicate that segmentation schemes th at combine high-quality phase-contrast imaging with nuclear relaxation time measurements can potentially identify the true fractional marrow volume occupied by hematopoietic elements in a variety of clinical si tuations.