Value of diffusion - Weighted magnetic resonance imaging in the assessmentof bone marrow in vertebral metastases

Aim of the study. The aim of the study was the evaluation of the diffusion coefficient (ADC) of vertebral metastasis and regular vertebral bodies with diffusion weighted MRI (DWI). DWI evaluates the tissue-specific molecular diffusion of protons. In tissues with high cell densities (neoplasm) a decr eased ADC can be expected due to restricted diffusion according to an exagg erated amount of intra- and intercellular membranes (i.e. diffusion barrier s). Methods. In 5 breast cancer patients the ADC of both known vertebral metast ases and of adjacent regular vertebral bodies were measured with DWI (1.0 T ; Phased-Array-Body-Coil; b: 880 and 440 s/mm(2)). Results. The ADC of regular vertebral bodies (1.3+/-0.23x10(-3)s/mm(2)) was significantly (p less than or equal to 0.0002) higher than in vertebral me tastases (0.39+/-0.11x10(-3)s/mm(2)). Conclusions. These data demonstrate that the ADC can be reliably measured i n vertebral bodies. The quantitative evaluation of the ADC in vertebral bod ies seems to he an objective and comparable parameter for differentiating m align from benign vertebral tissue.