Bone marrow cellularity: quantification by chemical-shift misregistration in magnetic resonance imaging and comparison with histomorphometrical techniques.

The accuracy of a technique that uses chemical-shift misregistration in magnetic resonance (MR) imaging to quantify vertebral bone marrow cellularity was tested on cadaveric specimens. In order to estimate the cellularity of 11 unfixed vertebral bodies, mid-sagittal MR images were obtained using a 1.5T magnet with a proton-density-weighted spin-echo sequence (repetition time/echo time, 2500/22 ms) and a narrow bandwidth. These values were subsequently compared to the histomorphometrical values for cellularity, amount of trabecular bone and deposited iron. The image-derived values for cellularity (VI, %) correlated well with values determined by histomorphometry (VH, %) (VI = 21.2 + 0.72 VH, r = 0.92) regardless of the presence of trabecular bone and small amount of stored iron in the specimens. This simple technique may be applicable in the estimation of marrow cellularity.