MRI-diffusion imaging of XXXX : first results and correlation to histology.

@entity1 @entity11535 @entity5 @entity521
The purpose of this study was to evaluate diffusion-weighted MR imaging in @entity521 . We prospectively examined seven @entity1 (age range 1-3 years) with seven solid body @entity521 . Diagnosis was established histologically. Diffusion-weighted echo-planar imaging (EPI) sequence was performed in all @entity1 , with a repetition time of 5400 ms and an echo time of 103 ms, and with a b-value of 1000 s/mm(2). The contrast of @entity5 tissue depicted with T2-weighted images and diffusion-weighted images were evaluated by means of region-of-interest measurements and a calculation of the apparent diffusion coefficient (ADC) was done. The ADC calculation showed a mean ADC of 1.1x10(-3) (SD 0.14x10(-3), range 0.9-1.2x10(-3)) mm(2)/s of all @entity5 . Diffusion-weighted images showed an increased @entity5 signal. Water proton diffusion within the @entity5 matrix of @entity521 is especially restricted by the molecular and macromolecular barriers due to the very dense structure of this @entity5 tissue. We hypothesize that high nuclear-to-cytoplasm ratio of @entity521 cells limits intracellular motion. Furthermore, the very densely packed @entity5 cells inhibit effective motion of extracellular water protons. @entity11535 leads to a reduction in the rate of apparent diffusion and to a marked increase in signal on diffusion-weighted EPI MR images.
